# Vacuolar myopathy with monoclonal gammapathy and stiffness: A new Monoclonal gammopathy of muscle significance

Yves Allenbach, Emmanuelle Salort-Campana, Edoardo Malfatti, Bruno

Eymard, Shahram Attarian, Andre Maues De Paula, Aude Rigolet, Sarah

Leonard-Louis, Olivier Benveniste, Tanya Stojkovic

► To cite this version:

Yves Allenbach, Emmanuelle Salort-Campana, Edoardo Malfatti, Bruno Eymard, Shahram Attarian, et al.. Vacuolar myopathy with monoclonal gammapathy and stiffness: A new Monoclonal gammopathy of muscle significance. GCOM 2019 - Global Conference on Myositis 2019, Mar 2019, Berlin, Germany.. BMC Rheumatology Poster presentation n° P133, 3 (S1), pp.31, 2019, 10.1186/s41927-019-0078-3. doi:10.1186/s41927-019-0078-3

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# Abstracts of scientific contributions to GCOM 2019

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Berlin, Germany. 27 - 30 March 2019

Published: 19 August 2019

## I1

### Selected highlights from the 3rd Global Conference of Myositis, Berlin

Hector Chinoy<sup>1,2,3</sup>, James B. Lilleker<sup>3,4</sup>

<sup>1</sup>National Institute for Health Research Manchester Biomedical Research Centre, Manchester University NHS Foundation Trust, The University of Manchester (Manchester, UK); <sup>2</sup>Department of Rheumatology, Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre (Salford, UK); <sup>3</sup>Centre for Musculoskeletal Research, Faculty of Biology, Medicine and Health, The University of Manchester (Manchester, UK); <sup>4</sup>Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust (Salford, UK)

**Correspondence:** Hector Chinoy (hector.chinoy@manchester.ac.uk)

BMC Rheumatology 2019, 3(Suppl 1):I1

March 2019 saw the 3rd Global Conference of Myositis at the historical European School of Management and Technology, Berlin, Germany, organized by Professors Werner Stenzel, Olivier Benveniste, Ichizo Nishino, and the Scientific and Organising Committee. The conference was well attended by 375 delegates from 30 different countries, including 20 invited speakers,

A opportunity arose to fund a series of fellowships to junior researchers, from funds left over from the previous GCOM meeting at Potomac. There was a series of wonderful and enlightening talks from all over the world and from neighbouring disciplines.

The conference started off with interesting pathology workshop detailing difficult cases. There then followed an introductory lecture by Voit on recent developments in the therapeutic approaches to neuromuscular diseases, including antisense therapy. Regulators are increasingly willing to accept 'contemporary controls' selected according to the same entry criteria to strengthen small placebo controls groups and improve power to detect change where short-term effect sizes are small. Discussion was also made about using myostatin, an activin 2b receptor binder, as a disease progression biomarker. Decreased levels of myostatin and downregulation of the myostatin-activin pathway are seen in neuromuscular disease, potentially also explaining the paucity of therapeutic benefits seen to date from myostatin receptor blockade.

Kjaer discussed how age impairs the performance of the skeletal muscle and cardiovascular system. Three to six months of training can result in a 10-15% increase in strength/function, akin to 3-5 years of rejuvenation. Ageing can affect the transcriptional regulation of human skeletal muscle disease atrophy, with the result that older people require four times as much time to recover from periods of immobility (1). This is associated with reduced anabolic signaling, and a decrease in number and responsiveness of satellite cells.

Inclusion body myositis (IBM) was the subject of a number of talks. Wiehl discussed pathogenic mechanisms connecting inherited and acquired IBM, including disruptions in protein homeostasis and autophagy which have recently been interrogated using a targeted proteomic approach. (2). Britson described a xenograft model of sporadic IBM which shows impaired regeneration and TDP43 mislocalization. Greenberg discussed a potential therapeutic strategy of

targeting highly differentiated T cells, particularly effector memory KLRG1+ cytotoxic T cells in IBM. There appears to be overlapping features between IBM and T cell large granular lymphocytic leukaemia, a malignancy of highly differentiated CD8 cytotoxic T cells which also exhibit upregulation of KLRG1. (3)

Immune checkpoint inhibitors are increasingly being used to activate the immune system against malignant cells, particularly melanoma, but they can have autoimmune adverse effects, including myositis. Moslehi discussed his report in the Lancet where they identified 101 cases of severe myocarditis following treatment with immune checkpoint inhibitors (4). Of relevance to myologists, a substantial increase in incidence over time was noted.

Klareskog gave an eloquent overview of the role of environmental factors, focusing on the lungs as a trigger of autoimmunity. He cited the analogy of rheumatoid arthritis, where a combination of genetics, epidemiological risk factors (including smoking, hormones, stress and the HPA axis), systemic immune dysregulation and disruption of musical biology create an at-risk population for development of autoimmunity (5). Smoking may predispose to antigenic peptide fragments being presented on the cell surface by HLA class II molecules (forming part of the common ancestral haplotype), and interact with autoaggressive CD4+ cells, for the subsequent development of anti-aminoacyl tRNA synthetase antibodies (6).

The association of cancer and dermatomyositis was also a theme. Dani described register data from 2002 to 2016 in Sweden. Cancer risk in IIM patients is increased before diagnosis, reaches a peak one year pre-diagnosis, and continues to be significant until 10 years post-diagnosis. Site-specific cancer risk is highest for respiratory before diagnosis and the buccal cavity after. Even patients with IIM diagnoses other than DM are at risk of developing cancer. Oldroyd also described a temporal relationship with cancer and DM (7). Specifically, anti-TIF1gamma-positive-associated malignancy occurs exclusively within the three year period on either side of DM onset, the risk being highest in those 39 years or younger. Within the anti-TIF1gamma-positive cohort, breast cancer was the most common malignancy (33%), followed by ovarian cancer (19%) and lymphoma (14%). Ovarian cancer constituted a significantly higher proportion of cancers in the anti-TIF1gamma-positive vs. -negative cases.

It appears that possession of a specific anti-TIF1gamma IgG subtype is necessary to incur risk of cancer. A poster from Aussy (8) examined 51 anti-TIF1gamma-positive patients, where 40 (78%) had cancer. Detection of anti-TIF1gamma IgG2 was significantly associated with mortality (p=0.0011) and occurrence of cancer during the follow-up period, with a 100% positive predictive value of cancer when then mean fluorescence intensity of anti-TIF1gamma IgG2 was >385.

Patients with anti-MDA5 antibody-associated disease represent a challenging group where disease is often resistant to treatment and mortality is high. Toquet described a cohort of 121 anti-MDA5 antibody-associated DM, where three subgroups with different outcomes were identified. Overall mortality was 27%. Cluster one had less arthralgia/arthritis, but all had interstitial lung disease and there was a high frequency of mechanics' hands. Cluster two, the "athro-cutaneo"-form, tended to have more arthralgia/arthritis, were less likely to be male and had a better prognosis. Cluster three, the "vasculo-cutaneo-muscular"-

<figure><img src="image_3.png" /></figure>
form, were more likely to be male, have skin vasculopathy (Raynaud's, skin ulcers, digital necrosis, calcinosis), myositis and had an intermediate prognosis. Gono discussed an intensive treatment combination used for anti-MDA5 antibody-associated interstitial lung disease (9). This included high dose prednisolone, cyclosporine and intravenous cyclophosphamide. Peng discussed neopterin as a marker of macrophage activation. Increased neopterin levels have been noted in DM and in patients with MDA5. There was a positive correlation of neopterin with ferritin and markers of disease severity, and negative correlation with pulmonary function.

Paik presented results of an open label study of the JAK inhibitor, Tofacitinib, in refractory DM, testing the hypothesis that the drug would inhibit the production or secretion of key pro-inflammatory chemokines e.g. CXCL9/10 to induce clinical remission (10). All 10 patients enrolled met the IMACS definition of improvement. Five of seven anti-TIF1gamma positive patients were moderate responders, and three of five were able to come off steroids.

Generous financial support by Myositis UK formed the basis for a novel "speed-funding" event, where 17 grant applications were initially considered. Six junior researchers were then put forward to present a 15 minute funding proposal to a set of judges and the audience. Amidst a high-pressure atmosphere, the following were successful in securing funding: Kyla Britson, USA: The pathogenesis and treatment of inclusion body myositis in a xenograft model; Saslia Lassche, Netherlands; Inclusion body myositis on a chip, Erin Wilfong, USA; CD27-CXCR4hiCD21lo cells in Jo1 positive IIM.

Other highlights included a workshop for young researchers, a patient-centred workshop and further discussion about the establishment of a World Myositis Society. We now look forward now to the 4th GCOM which will provisionally be held in Prague, Czech Republic, in 2021.

**Sources of Funding:**

HC is supported by a grant from the Medical Research Council (MR/N003322/1) and the NIHR Biomedical Research Centre Funding Scheme. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health.

**References**

1. Suetta C, Frandsen U, Jensen L, Jensen MM, Jespersen JG, Hvid LG, et al. Aging affects the transcriptional regulation of human skeletal muscle disuse atrophy. Calbet JAL, ed. PLoS One 2012;7:e51238.

2. Gütsches A-K, Brady S, Krause K, Maerkens A, Uszkoreit J, Eisenacher M, et al. Proteomics of rimmed vacuoles define new risk allele in inclusion body myositis. Ann Neurol 2016.

3. Greenberg SA, Pinkus JL, Amato AA, Kristensen T, Dorfman DM. Association of inclusion body myositis with T cell large granular lymphocytic leukaemia. Brain 2016;139:1348–60.

4. Moslehi JJ, Salem J-E, Sosman JA, Lebrun-Vignes B, Johnson DB. Increased reporting of fatal immune checkpoint inhibitor-associated myocarditis. Lancet (London, England) 2018;391:933.

5. Holers VM, Demoruelle MK, Kuhn KA, Buckner JH, Robinson WH, Okamoto Y, et al. Rheumatoid arthritis and the mucosal origins hypothesis: protection turns to destruction. Nat Rev Rheumatol 2018;14:542–557.

6. Chinoy H, Adimulam S, Marriage F, New P, Vincze M, Zilahi E, et al. Interaction of HLA-DRB1*03 and smoking for the development of anti-Jo-1 antibodies in adult idiopathic inflammatory myopathies: a European-wide case study. Ann Rheum Dis 2012;71:961–5.

7. Oldroyd A, Sergeant JC, New P, McHugh NJ, Betteridge Z, Lamb JA, et al. The temporal relationship between cancer and adult onset anti-transcriptional intermediary factor 1 antibody-positive dermatomyositis. Rheumatology 2018.

8. Aussy A, Fréret M, Gallay L, Bessis D, Vincent T, Jullien D, et al. The IgG2 isotype of anti-transcription intermediary factor 1-gamma autoantibodies is a biomarker of mortality in adult dermatomyositis. Arthritis Rheumatol (Hoboken, NJ) 2019;art.40895.

9. Nakashima R, Hosono Y, Mimori T. Clinical significance and new detection system of autoantibodies in myositis with interstitial lung disease. Lupus 2016;25:925–933.

10. Paik J, Albayda J, Tiniakou E, Koenig A, Christopher-Stine L. Study of Tofacitinib in Refractory Dermatomyositis (STIR): An Open Label Pilot Study in

Refractory Dermatomyositis - ACR Meeting Abstracts. Arthritis Rheum 2018;70:L02.

**Oral Presentation**

O1 Xenograft model of sporadic inclusion body myositis

K. Britson

O2 Targeting highly differentiated effector memory KLRG1+ cytotoxic T cells in inclusion body myositis

S. Greenberg

O3 CD8+T-bet+ cells as a predominant biomarker for inclusion body myositis

G. Dzangué-Tchoupou

O4 Overall and site-specific cancer risk before and after diagnosis of idiopathic inflammatory myopathies: Novel register data from 2002 to 2016 in Sweden

L. Dani

O5 Immunization of dermatomyositis-specific auto-antigen transcriptional intermediary factor (TIF1)-γ induces myositis in mice

N. Okiyama

O6 The temporal relationship between cancer and adult onset anti-transcriptional intermediary factor 1 antibody positive dermatomyositis

A. Oldroyd

O7 Pruritonegic mediators in skin samples of patients with dermatomyositis

A. Vincze

O8 High level of serum neopterin is associated with rapidly progressive interstitial lung disease and reduced survival indermatomyositis

Q. Peng

O9 Anti-MDA5 antibody-associated dermatomyositis: Three subgroups with different outcomes

S. Toquet

O10 Risk stratification in patients with anti-melanoma differentiation-associated gene 5 antibody-associated interstitial lung disease treated initially with intensive combination regimen

T. Gono

O11 Quantitative high throughput screening of small molecule libraries to inhibit interferon beta-stimulated major histocompatibility complex class I in myositismuscle

T. Kinder

O12 Study of Tofacitinib in refractory dermatomyositis

J. Paik

O13 A one-year study investigating the effect of specialised and intensive ADL training in patients with idiopathic inflammatory myopathies -preliminary results

M. Špiritović

O14 The use of metabolomics to develop novel biomarkers for juvenile dermatomyositis

J. Overgsten

O15 Endothelial biomarker profiles reflect heterogeneity of juvenile dermatomyositisand may predict disease course

J. Wienke

O16 The relationship of pain, fatigue and emotional distress with quality of life in juvenile myositis

K. Ardalan

O17 Juvenile dermatomyositis – data of a national pediatric rheumatology database

C. Sengler

O18 Mitochondrial dysfunction: A novel treatment focus in juvenile dermatomyositis

M. Wilkinson

O19 Differential peripheral IFN score expression in juvenile dermatomyositis vs. Mendelian interferonopathies

H. Kim

O20 Juvenile inflammatory myopathy with anti-MDA5 auto-antibodies: A specific subgroup demonstrating differentially enhanced upregulation of interferon-alpha signaling

I. Melki

O21 Identification of six dermatomyositis subgroups using principal component analysis-based cluster analysis

H. Zhu

O22 Overexpression of type 1 IFN in skeletal muscle affects muscle function

M. Morales
O23 The role of low-density granulocytes (LDGs) and neutrophil extracellular traps (NETs) in the clinical profile of patients with idiopathic inflammatory myopathies

J. Torres-Ruiz

O24 Auto-antibodies targeting components of sarcolemma membrane repair: A pathogenic mechanism in inflammatory myopathies

W. Jarjour

O25 Investigating chaperone-mediated selective autophagy in immune-mediated necrotizing myopathies

N. Fischer

O26 Severe axial and pelvifemoral muscle damage in immune-mediated necrotizing myopathy evaluated by whole-body MRI

O. Landon-Cardinal

O27 Role of MircoRNAs in immune-mediated necrotizing myopathy through regulation of myogenic differentiation-associated genes

Y. Zuo

O28 The interferon gene signature in dermatomyositis, the anti-synthetase syndrome, immune-mediated necrotizing myopathy, and inclusion body myositis: A comparative study

I. Pinal-Fernandez

O29 Evaluation of a novel particle-based assay for detection of myositis specific antibodies

K. Malyavantham

O30 Optimization of muscle NMR imaged segmentation to best discriminate disease progression in adult patients with inflammatory myopathies

H. Reynoudt

O31 Identification of novel auto-antibodies for idiopathic inflammatory myopathies using human proteome microarray

L. Li

O32 IFN level assessed by ultrasensitive detection technology in myositis patients: A promising biomarker of disease activity in dermatomyositis and anti-synthetase syndrome

L. Bolko

O33 Analysis of muscle transcriptomic features in idiopathic inflammatory myopathies

H. Chen

# Poster Presentation

## P1

### Autoantibody to transcriptional intermediary factor-1β as myositis-specific antibody: clinical correlation with CADM or DM with mild myopathy

Yasuhito Hamaguchi, Ikuko Ueda-Hayakawa, Kazuhiko Takehara, Manabu Fujimoto

Kanazawa University, Kanazawa, Japan

**Correspondence:** Yasuhito Hamaguchi

BMC Rheumatology 2019, **3**(Suppl 1):P1

**Background:** Myositis-specific autoantibodies (MSAs) are associated with unique clinical subsets in polymyositis/dermatomyositis (PM/DM). Autoantibodies (autoAbs) against transcriptional intermediary factor (TIF) 1α and T1F1γ are known to be MSAs. We reported that T1F1β Abs are also targeted in DM patients with or without concomitant anti-T1F1α/γ Abs. Objectives. We evaluated the clinical features of seven cases with anti-T1F1β Abs alone.

**Methods:** Anti-T1F1β Abs were identified by protein immunoprecipitation assay and western blotting was performed to confirm autoAbs reactivity against T1F1β. The clinical characteristics of patients with anti-T1F1β Abs alone were examined.

**Results:** Anti-T1F1β Abs were identified by immunoprecipitation assay in 24 cases. Among them, seven patients were positive for anti-T1F1β Abs alone. Six out of seven patients were classified as DM. Among the six DM cases, two patients had no muscle weakness and normal CK levels, and were classified as clinically amyopathic DM. Four patients had muscle weakness, but 3 of them had normal serum CK levels that responded well to systemic corticosteroids. Characteristic DM skin rashes, such as Gottron's sign, periungual erythema, punctate hemorrhage on the perionychium, and facial erythema including heliotrope were observed in 86%, 57%, 86%, 71% of our cases, respectively. One out of seven patients had appendiceal cancer. None of the patients had interstitial lung disease.

**Conclusion:** Seven patients were confirmed to have anti-T1F1β Abs without any other MSAs, including T1F1α/γ Abs, and six of them were diagnosed with DM. Anti-T1F1β Abs are one of the MSAs that is associated with clinically amyopathic DM or DM with mild myopathy.

## P2

### Laboratory diagnostics of autoantibodies in autoimmune myopathies

Miriam Mende, Wolfgang Meyer, Thomas Scheper

Euroimmun AG; Lübeck, Germany

**Correspondence:** Miriam Mende

BMC Rheumatology 2019, **3**(Suppl 1):P2

**Objectives:** Idiopathic inflammatory myopathies (IIM) are rare autoimmune diseases of skeletal muscle. The main forms are polymyositis (PM), dermatomyositis (DM), necrotizing myopathy (NM) and sporadic inclusion body myositis (sIBM). IIM are characterised by a diverse range of autoantibodies. Their specificities provide an indication of the disease sub-form. Antibodies against Jo-1, PL-7, PL-12, EJ, and OJ are characteristic of PM, antibodies against SRP and HMGCR are indicative for NM, while those against Mi-2alpha, Mi-2beta, SAE1, NXP2, MDA5 and T1F1gamma occur in DM. The only known serum marker for sIBM is anti-cN1A. Antibodies against PM-Scl75, PM-Scl100 and Ku indicate an overlap syndrome, in particular with the autoimmune connective tissue disease systemic sclerosis. Some antibodies, for example anti-MDA5, -PL7, -PL12, -OJ and -EJ, are associated with an increased risk of interstitial lung disease. Positivity for myositis autoantibodies can also be the first indicator of an underlying tumour (e.g. T1F1gamma). The combined frequency of all autoantibodies in myositis amounts to around 60%, whereby there is virtually no overlap in the occurrence of the different antibodies. Therefore, comprehensive multiparametric testing is essential to maximise the diagnostic information obtained from the analysis. In suspected cases of PM/DM, patient sera are serologically investigated using an indirect immunofluorescence test (IIFT) on a substrate combination of HEP-2 cells and primate liver, with confirmation of results by monospecific tests. Since antibodies against cytoplasmic antigens are sometimes not clearly detectable with IIFT, parallel performance of the screening and confirmatory test is recommended. Multiparametric immunoblots are an ideal confirmatory method, as they enable monospecific and simultaneous detection of many different antibodies.

**Methods:** A total of 804 sera from myositis patients and 786 control sera were investigated using a line immunoblot containing 16 antigens to detect the most relevant myositis-specific and -associated autoantibodies.

**Results:** The antibody prevalences obtained in the myositis patients ranged from 1% (anti-EJ, -OJ) to 21% (anti-Jo-1), while the specificities for the individual antigens amounted to 97-100%. In another study, a novel Anti-cN-1A ELISA provided a diagnostic sensitivity for sIBM of 35-39% at a specificity of 96%.

**Conclusion:** Diagnosis of IIM is challenging due to rarity of the diseases, the varying clinical presentation and the possibility of overlap syndromes. The determination of myositis-specific and myositis-associated autoantibodies can significantly reduce the time to diagnosis, with multiparametric testing ensuring the highest serological detection rate. Immunoblots are ideal for multiplex confirmatory testing as they offer broad antigen combinations, easy interpretation and full automatability.

## P3

### Comparison of autoantibody specificities tested by a line blot assay and immunoprecipitation-based algorithm in patients with idiopathic inflammatory myopathies

Hector Fabricio Espinosa-Ortega¹, Marie Holmqvist¹, Helene Alexanderson¹, Helena Storfors², Tsuneyo Mimori³, Ingrid E. Lundberg¹, Johan Rönnelid²

¹Karolinska Institute, Stockholm, Sweden; ²Uppsala University Hospital, Uppsala, Sweden; ³Kyoto University, Kyoto, Japan

**Correspondence:** Hector Fabricio Espinosa-Ortega

BMC Rheumatology 2019, **3**(Suppl 1):P3
To date, there is no standardized approach of myositis specific auto-
antibodies/Myositis associated autoantibodies (MSA/MAA) testing to
be used in clinical settings. Immunoprecipitation (IP) of RNA's with
silver staining and/or protein IP on cellular lysates is considered the
gold standard for most autoantibodies but is time-consuming, does
not differentiate antibodies targeting proteins with the same molecu-
lar weight, and does not measure levels of autoantibodies and is not
routinely available in clinical settings. Line blot assays (LB) represent
a faster and semi-quantitative option to detect autoantibodies.

Objectives: We aimed to compare the performance of a line blot (LB) and immunoprecipitation (IP) assays and to describe clinical associations to autoantibody specificities in a cohort of patients classified as idiopathic inflammatory myopathies (IIM). 119 patients were tested by a commercial LB (Euroline Myositis Antigen Profile 4, Euroimmun, Germany) and a combination of protein- and RNA-IP together with an anti-MDA5 ELISA. Agreement between assays was calculated by Cohen's kappa coefficient.

Results: The overall concordance was 76% with moderate agreement (k:0.49). Agreement was very good for anti-SRP (k: 0.85) and anti-Ku (k: 0.85), good for anti-Jo-1 (k: 0.69) and moderate for anti-PmScl (k:0.58), anti-MDA5 (k:0.49), anti-TIF1gamma (0.57). Jo-1 LB+ IIM had interstitial lung disease and arthritis compared to LB-negative (p < 0.001). Nineteen % of DM/PM patients were Jo-1+ compared to 0% of IBM (p < 0.001). Anti-TIF1gamma+ patients had higher frequency of DM skin rash than patients with other specificities (p = 0.003). LB-Mi-2+ was more common compared to IP+.

Conclusion: In conclusion, the concordance rate between the two as-
says for detection of myositis autoantibodies was moderate to very
good for SRP and most of prevalent specificities. The LB assay seems
to be valid and useful to identify subgroups of IIM with specific clin-
ical features.

P4

The RIG-I pathway is involved in lymphopenia in patients with
dermatomyositis

Lu Zhang, Qisheng Xia, Wenli Li, Qinglin Peng, Xin Lu, Guochun Wang
China-Japan Friendship Hospital, Beijing, China

Correspondence: Lu Zhang

BMC Rheumatology 2019, **3**(Suppl 1):P4

Objective: To determine retinoic acid-inducible gene I (RIG-I) expres-
sion levels in peripheral lymphocytes and to explore the mechanism
of RIG-I in the development of lymphopenia in patients with derm-
atomyositis (DM).

Methods: The mRNA and protein expression levels of the RIG-I were determined in peripheral T lymphocytes of 26 treatment-naive DM patients by q-PCR and Western blot, respectively. The associations between RIG-I expression levels and clinical characteristics were investigated. We examined the relationship between RIG-I expression and cell apoptosis by RIG-I overexpression or knockout in Jurkat cells. Cell apoptosis was assessed by flow cytometry. Fas and Caspase 3 were identified by Western blot. CCK8 colorimeter was performed to monitor cell proliferation.

Results: The average lymphocyte count decreased significantly in DM compared with that in the normal control group (1.03±0.58×10⁹ vs 2.14±0.43×10⁹, P=0.000). Lymphopenia (0.64±0.23×10⁹) was noted in 14 patients. The ratio of apoptosis cell from DM patients were increased significantly than healthy control (8.53±2.47 vs 5.61±1.44, P=0.002) and significantly correlated with peripheral lymphocyte count(r=-0.595, P=0.032). RIG-I expression gene and protein levels were significantly higher in peripheral T lymphocytes of DM patients than those in control subjects (0.091 ± 0.051 vs 0.052 ± 0.024; p=0.011, 0.30 ± 0.18 vs 0.18 ± 0.08; p=0.005, respectively). The gene and protein expression levels of RIG-I correlated negatively with the lymphocyte count(r=-0.478, p=0.014; r=-0.517, p=0.007, respectively). RIG-I protein expression decreased significantly and the number of lymphocytes increased when disease was improved. In Jurkat cells, increased apoptosis were observed following RIG-I overexpression (9.13 ± 1.63 vs 0.57 ± 0.31; p=0.001) or RIG-I specific ligand (pppRNA) 12 and 24 hours activation (4.07 ± 0.21 vs 0.53 ± 0.15; p=0.000, 11.03

± 1.70 vs 2.53 ± 0.59; p=0.001, respectively). The increased apoptosis also be confirmed by elevated expressions of Fas and cleaved Caspase-3 protein. Furthermore, the proliferation of Jurkat cells was markedly reduced by RIG-I overexpression (1.13 ± 0.44 vs 0.91 ± 0.45; p=0.000) or pppRNA 12 and 24 hours activation (1.43 ± 0.89 vs 1.17 ± 0.25; p=0.000, 1.17 ± 0.82 vs 1.05 ± 0.27; p=0.017). Whereas, neither the ratio of apoptotic population nor the cell viability of the RIG-I knockout clones exhibited significant changes following pppRNA activation.

Conclusion: The present study indicated that increased expression of RIG-I in peripheral T lymphocytes was significantly associated with lymphopenia in patients with DM. The RIG-I pathway played a critical role in the induction of lymphocyte apoptosis.

P5

Clinical symptoms indicative of a paraneoplastic etiology in adult
dermatomyositis patients: A retrospective case-control study

Géza Nagy, Sándor Husz, Lajos Kemény, Lászlo Kovács, Zsuzsanna Bata-
Csörgő

University of Szeged; Szeged, Hungary

Correspondence: Géza Nagy

BMC Rheumatology 2019, 3(Suppl 1):P5

Objective: While some clinical features are reported as risk factors for cancer-associated dermatomyositis (DM), most results are conflicting with paucity in the literature regarding paraneoplastic DM. The aim of our study was to determine clinical symptoms, which are characteristic for a paraneoplastic etiology by comparing our findings with those in the literature.

Methods: A retrospective analysis of adult patients who were diag-
nosed with dermatomyositis between January 1998 and January
2014 was performed. Demographic data, the presence or absence of
objective and subjective symptoms, initial and follow-up treatments,
and the times of relapses were examined.

Results: In all, 30 idiopathic and 11 paraneoplastic DM cases were reviewed and compared. Of the cutaneous symptoms, heliotrope rash with a profound periorbital oedema (43.3% vs 81.8% %; p=0.038), pruritus (16.7% vs 63.6%; p=0.007) and skin ulceration (0.0% vs 27.3%; p=0.015) were found to be associated with a paraneoplastic etiology. In addition, respiratory muscle involvement (3.3% vs 36.4%; p=0.014), lower creatine kinase increase (3355.9 ± 53116 vs 1009 ± 813.3; p=0.037), lack of ANAs or ENAs (40.0% vs 100%; p=0.002) and absence of immune complex deposits in the intramuscular vasculature of the skeletal muscles (16.7% vs 72.7%; p=0.001) also showed a positive association with paraneoplasia.

Conclusion: The clinical manifestations of paraneoplastic DM differ
from previously described risk factors for cancer-associated DM. This
indicates a need for etiological stratification when assessing
malignancy-associable features in future studies. Additionally, pres-
ence of these symptoms should warrant more extensive tumor
screenings following initial DM diagnosis.

P6

Pronounced focal muscle pathology in a patient with Anti-NXP2
autoantibody associated severe myositis

Leonie Rager¹, Marco Meyer¹, Mesut Yenigün¹, Corinna Preusse²,
Heidrun Krämer-Best¹, Stephanie Wolff¹, Werner Stenzel², Anne
Schänzer¹

¹Justus-Liebig-Universität Gießen, Gießen, Germany; ²Charité
Universitätsmedizin Berlin, Berlin, Germany

Correspondence: Anne Schänzer

BMC Rheumatology 2019, 3(Suppl 1):P6

Introduction: Classification of idiopathic inflammatory myopathies (IIM's) including dermatomyositis (DM), polymyositis (PM), immunemediated-necrotizing-myopathy (IMNM) and sporadic inclusion body myositis (sIBM) are based on the clinical presentation and muscle pathology. Myositis autoantibodies (MSAs) are useful tools for identifying subgroups and predicting the clinical progress and outcome
under therapy. Anti-NXP2 is a major MSA in juvenile DM and is associ-
ated with severe muscle pathology. In adults, anti-NXP2 is rather rare
and thorough descriptions of muscle pathology findings are sparse.

Case report: We describe a 59 years-old male patient who developed a proximal myopathy with increased CK levels up to 40.000 U/l. MRI images of the proximal tights showed muscle oedema and areas with high signal intensity suggestive for myositis and electromyography is compatible with a myopathy. The muscle biopsy showed a large regional oedema with pre-necrotic muscle fibres with decreased enzymatic staining. MHC1 was upregulated in these muscle fibres with deposits of complement (C5b9) without significant lymphocytic infiltrates. The pathology was similar as described for so called 'regional ischemic myopathy' (RIIM). RIIM is proposed as a separate entity by some authors but has not been included in the classification of IIMs. In the follow-up of this patient, highly elevated anti-NXP2 ABs and PM75 and ROS2 antibodies were detected. Additional electron microscope findings as endomysial capillaries with endothelial cells containing microtubular inclusions and immunohistochemistry with a sarocplasmatic expression of myxovirus resistance A (MxA) were consistent with the diagnosis of DM. Under immunosuppression the patient's muscle strength slowly increased and he was able to walk without help. The patient was former smoker but tumour screening was negative. The level of anti-NXP2 ABs decreased and PM75 was not detectable whereas ROS2 was still high.

Conclusion: We demonstrate a new morphological phenotype in a patient with severe myositis associated with anti-NXP2 ABs showing a strong focal pathology resembling a focal ischemic damage. Additional TEM findings and analysis of MxA expression supports the diagnosis of DM, hence placing this phenotype in the spectrum of Dermatomyositis pathology.

P7

Short-term changes after treatments in needle electromyography among patients with polymyositis and dermatomyositis: A retrospective study

Hidenaga Kawasumi¹, Yasuhiro Katsumata², Eiichi Ito³, Yasushi Kawaguchi²

¹Tokyo Metropolitan Ohtsuka Hospital, Tokyo, Japan; ²Tokyo Women's Medical University, Tokyo, Japan; ³Fukushima National Hospital, Fukushima, Japan

**Correspondence:** Hidenaga Kawasumi

BMC Rheumatology 2019, **3**(Suppl 1):P7

Objectives: Although needle electromyography (EMG) is useful for diagnosis of polymyositis (PM) and dermatomyositis (DM), the efficiency of EMG on estimating the response to any therapies remains to be elucidated. We aimed to examine short-term changes after treatments in needle EMG findings among patients with PM/DM.

Methods: This is a retrospective and observational study. Patients were included when they met all these criteria: (1) fulfill the Bohan and Peter classification criteria; (2) were administered to our University hospital from 2009 through 2014; (3) received needle EMG both before and after treatments. The data of manual muscle testing (MMT), serum creatine kinase (CK) levels, and needle EMG findings: fibrillation potential, positive sharp wave, low amplitude motor unit potential (MUP), and short duration MUP were retrospectively collected.

Results: Ultimately, 23 patients were included in the present study, and 23, 16, and 10 patients received needle EMG at 0, 4, and 8 weeks after start of initial treatments, respectively: fibrillation potential, positive sharp wave, low amplitude MUP, and short duration MUP improved in 56%, 63%, 31%, and 25% of the patients at 4 weeks, and in 90%, 90%, 100%, and 90% of the patients at 8 weeks, respectively. Fibrillation potential and positive sharp wave significantly improved at 4 weeks, and all of 4 findings improved at 8 weeks (p < 0.05 in each comparison). The improvements of MMT and CK levels did not significantly agree with those of needle EMG findings except for fibrillation potential/positive sharp wave and CK levels at 8 weeks.

Conclusion: The present study showed that electrical activities in muscles significantly improved at as early as 4 and 8 weeks after

start of initial treatments. Needle EMG findings can serve as an out-
come measure independent upon MMT and CK levels in PM/DM.

P8

Clinical characteristics of patients with clinically amyopathic
dermatomyositis positive for anti-TIF1r antibody

Yukie Yamaguchi, Miwa Kanaoka, Asami Akita, Yasushi Ototake, Tomoya Watanabe, Nobuaki Ikeda, Michiko Aihara
Yokohama City University Graduate School of Medicine, Yokohama, Japan

**Correspondence:** Yukie Yamaguchi

BMC Rheumatology 2019, 3(Suppl 1):P8

Objectives: It has been recognized that myositis-specific autoanti-
bodies are correlated with unique sets of clinical manifestations. For
instance, higher prevalence of malignancy is associated with derm-
atomyositis (DM) patients positive for anti-TIF1r antibody (Ab). Anti-
MDA5 Ab is highly found in patients with clinically amyopathic DM
(CAD) with rapidly progressive interstitial lung disease. In this study,
we analyzed clinical features of patients with anti-TIF1r Ab-positive
DM, especially in cases of CADM.

Methods: We enrolled 32 DM patients with anti-TIF1y Ab, who were treating in our department. CADM cases were extracted from anti-TIF1r Ab-positive DM and their clinical features, such as skin manifestations, prevalence of concomitant malignancy and interstitial lung disease, and the level of anti-TIF1r Ab, were evaluated.

Results: Within 32 cases of DM patients positive for anti-TIF1y Ab, there were 9 CADM cases (28.1%). In these cases, Gottron's papule, Gottoron's sign, and heliotrope rash tended to be highly observed compared to that in patients with non-CADM patients with this Ab. The prevalence of concomitant malignancy, which was defined by the diagnosis within 2 years before or after DM diagnosis, was 60.9% (14/23) in anti-TIF1r Ab-positive non-CADM patients, while that was 11.1% (1/9) in anti-TIF1r Ab-positive CAMD patients, which was significantly lower (P = 0.02). Meanwhile, interstitial lung disease was observed in 4 out of 9 patients with CADM (44.1%), which tended to be higher than that in anti-TIF1r Ab-positive non-CADM patients (3/23, 13%, P = 0.08). There was no rapidly progressive type in all cases. Finally, serum anti-TIF1r antibody level was significantly lower in CADM patients than that in non-CADM cases (71.6 ± 39.7, 106.8 ± 35.2, respectively, P = 0.03).

Conclusion: Anti-TIF1r Ab-positive CADM cases may have different clinical features from the normally recognized profile of this antibody. The population of this study is small and further study in a larger population will be required.

P9

Anti-calreticulin antibody – A Novel Autoantibody in Patients with Idiopathic Inflammatory Myopathies and Its Association with Malignancy

He Chen, Yong-Peng Ge, Guo-Chun Wang, Han-Bao Yang, Qing-Lin Peng, Ya-Mei Zhang, Xin Lu
China Japan Friendship Hospital, Beijing, China

**Correspondence:** He Chen

BMC Rheumatology 2019, 3(Suppl 1):P9

Objective: To investigate the occurrence of anti-calreticulin anti-
bodies (anti-CRT Abs) and evaluate its association with malignancy in
patients with idiopathic inflammatory myopathies (IIM).

Methods: In total, 211 patients with IIM were enrolled in our study and patients complicated with malignancy were separated into a single category. The levels of anti-CRT Abs were measured in serum samples from 106 with dermatomyositis (DM), 21 with polymyositis (PM), 34 with immune-mediated necrotizing myositis (IMNM), 50 IIM with malignancy and 40 healthy controls (HC) by an in-house enzyme-linked immunosorbent assay (ELISA) using recombinant full-length CALR. The clinical and laboratorial data were collected and compared between anti-CRT Abs positive and negative patients. Then 8 IIM patients were followed longitudinally whose changes in
concentrations of anti-CRT Ab were assessed and variations in disease activity were measured by myositis disease activity assessment visual analog scales (MYOACT) scores. Receiver operating characteristic (ROC) curve analysis was performed to determine the value of anti-CRT Abs in distinguishing IIM with malignancy from those without malignancy.

**Results:** Serum levels of anti-CRT Abs were significantly higher in IIM [median 5.3 AU (IQR 2.5-11.6)] than in HC [median 3.8 AU (IQR 1.8-6.4), P = 0.003] and anti-CRT Abs were judged to be positive in 48 of 211 IIM patients (22.7%). Among the IIM subgroups, 17/106 (16.1%) DM, 2/21 (9.5%) PM, 7/34 (20.6%) IMNM and 22/50 (44%) IIM with malignancy were seropositive for anti-CRT Abs. Higher frequency of malignancy, heliotrope rash and gottron papules as well as elevated concentrations of immunoglobulin G (IgG) and anti-nuclear Abs (ANA) were present in IIM patients with positive anti-CRT Abs than in those negative. A positive correlation between serum anti-CRT Abs concentrations and MYOACT scores was shown by longitudinal study. ROC curve analysis revealed that the anti-CRT Abs had diagnostic value in distinguishing IIM with malignancy from those without malignancy, with an area under curve (AUC) value of 0.65 (95% CI 0.56 – 0.74, P = 0.001).

**Conclusion:** This is the first report to discover that anti-CRT Abs could be a novel autoantibody detected in IIM. The levels of anti-CRT Abs increased significantly and markedly high anti-CRT Abs levels could be a possible serological marker of malignancies in IIM patients.

## P10

### Specific autoantibodies and clinical phenotypes correlate with the aberrant expression of immune-related microRNAs in Dermatomyositis

Lifang Ye, Xiaoming Shu, Guochun Wang
China-Japan Friendship Hospital, Beijing, China

**Correspondence:** Lifang Ye
BMC Rheumatology 2019, **3**(Suppl 1):P10

**Aims:** The serum concentrations of miRNAs, miR-23a-3p, miR-23b-3p, miR-146a-5p, miR-146b-5p, and miR-150-5p were shown to be associated with immune and inflammatory progression. We assessed the expressions of these five miRNAs in association with clinical p heno types and myositis-specific autoantibody-defined subgroups of Dermatomyositis (DM).

**Methods:** The present study included 49 patients with DM and 30 healthy controls. Serum conc entrations of miR-23a-3p, miR-23b-3p, miR-146a-5p, miR-146b-5p, and miR-150-5p were m easured by quantitative reverse transcription polymerase chain reaction (qRT- PCR). Associatio ns between serum concentrations of miRNAs and DM clinical immune-phenotypes were exa mined as well.

**Results:** Serum concentrations of miR-23b-3p, miR-146a-5p, and miR- 150-5p were significantly down-regulated in DM patients (P < 0.001, P < 0.001, P = 0.002, respect ively), while miR-146b-5p was remark ably up-regulated in DM patients compared with those in healthy controls (P = 0.039). Similarly, the expressions of miR-23b-3p, miR- 146a-5p, an d miR-150-5p were significantly down-regulated in peripher al blood mononuclear cells (PBM Cs) from DM patients. Further study indicated that serum level of miR-23b-3p was significa n tly cor related with creatine kinase (CK) (r = -0.286, P = 0.046), and serum level of miR -146a-5p was evidently correlated with C-reactive protein (CRP) (r = -0.358, P = 0.012). Significant correlations were also observed between serum level of miR-146b-5p and CRP (r = -0.347, P = 0.014) and erythrocyte sedimentation rate (ESR) (r = -0.287, P = 0.046). In addition, the expression level of miR-146b-5p was up- regulated in DM complicated with tumors compared with those with- out tumors (P = 0.001, P < 0.001, respectively). Espe cially, miR-150- 5p was significantly down-regulated in DM patients with anti-MDA5 antib odies and anti-NXP2 antibodies compared with those without (P = 0.017, P = 0.047, respecti vely). No significant differences were observed between four sera microRNAs in patients with and without interstitial lung diseases (all P > 0.05).

**Conclusion:** The results suggest an association between four immune- related microRNAs and different clinical immune-phenotypes and this

association may regulate the complexity of disease processes through multi-path ways in DM patients.

## P11

### Increased serum Galectin-9 (Gal-9) in patients with idiopathic inflammatory myopathies

Lin Liang, Qinglin Peng, He Chen, Yamei Zhang, Xin Lu, Guochun Wang
China-Japan Friendship Hospital; Beijing, China

**Correspondence:** Lin Liang
BMC Rheumatology 2019, **3**(Suppl 1):P11

**Objective:** To investigate the levels of serum galectin9 (Gal-9) in pa tients with idiopathic inflammatory myopathies (IIMs) and their rela tion to IIM-related features.

**Methods:** Serum levels of Gal-9 were detected in 107 Dermatomyo-sitis (DM)patients, 22 immune mediated necrotizing myositis (IMNM) patients ,22 anti-synthetic enzyme syndrome (ASS) patients and 30 healthy controls by using the ELISA method. Total RNA isolated from Peripheral blood mononuclear cells (PBMC)of 12 anti-MDA5 positive IIM patients ,7 IMNM patients and 6 healthy controls were used for analyzing the mRNA levels of Tim3, CD44, MIX1 and IFIH1 by quanti tative reverse transcription polymerase chain reaction (qRT-PCR).

**Results:** Serum levels of Gal-9 were significantly increased in IIM pa tients [median 19.8, interquartile range (IQR) 10.0-33.6] compared to those in healthy controls (median 4.9 ng/ml, IQR3.5-6.3, p< 0.001). The Gal-9 levels in cultured supernatant of PBMC from anti-MDA5 DM patients(mean 3.7 ±2.3ng/ml) was higher than those from healthy controls(mean 1.4±1.2ng/ml, p=0.049). A significantly high level of serum Gal-9 was found in patients with positive MDA5 anti-bodies, rapidly progressive interstitial lung disease (RPILD), dysphagia and arthritis. According to cross-sectional study and follow-up study, there was a positive correlation between serum Gal-9 levels and disease activity. Interestingly, serum Gal-9 levels were found to be asso ciated with the expression of type I interferon-inducible genes MX1 and IFIH1, which were observed to be elevated in the PBMC of IIM patients and it was consistent with the trend of serum Gal-9. In addition, CD44, a receptor of Gal9, was found increased in the PBMC of anti-MDA5 positive DM patients than IMNM patients(p< 0.001), while there was no significant difference in Tim3 mRNA expression between anti-MDA5 positive IIM patients and IMNM patients.

**Conclusions:** The serum Gal-9 levels were significantly increased and associated with disease activity in DM patients. The dysregulated Gal-9 and its receptor CD44 may play a role in DM pathogenesis.

## P12

### Myogenesis impairment in Dermatomyositis

Laure Gallay, Nathalie Streichenberger, Guy Mouchiroud, Bénédicte Chazaud

Institut NeuroMyoGène, Universite Claude Bernard, Lyon, France

**Correspondence:** Laure Gallay
BMC Rheumatology 2019, **3**(Suppl 1):P12

**Objectives:** Dermatomyositis (DM) is a rare acquired myopathy, oc curring during child and adulthood, and potentially life-threatening. Diagnosis is based on the association of muscle weakness, inflamma tory infiltrates on histological muscle sections and auto-antibodies in the serum. Etiopathogenesis, that has mainly focused on adaptive immunity, remains largely unknown. In DM, the necrosis/regener ation balance appears to be negative, with a chronic course and al leged clinical outcome. Nevertheless, the capacity of muscle regeneration has been barely studied. In normal muscle, lesion is followed by regenerative process, achieved by adult myogenesis of myogenic precursor cells (MPCs) that build new myofibers. The aim of our project is to evaluate DM-derived MPC capacity to undertake myogenesis.

**Methods:** DM (severe [n=5] and mild [n=3]), and healthy controls (HC [n=5]) selection (sex and age paired) was performed in the Hospices Civils de Lyon hospital database and samples were obtained from the hospital biobank. Myogenesis was explored in vitro by the culture of
MPCs for the evaluation of their proliferation, differentiation as well as fu-
sion, and were analyzed by immunofluorescence. Proliferation was evalu-
ated as the incorporation of a thymidine analog into DNA during
proliferation. Terminal myogenic differentiation was evaluated by myo-
genin expression, an essential transcription factor of myogenic differenti-
ation. Cell fusion was quantified as the number of nuclei incorporated
into myotubes. Quantitative analysis was performed using Image J soft-
ware, and statistical analysis was performed by mean comparison (t test
or ANOVA).

Results: Analysis of MPC proliferation indicates that DM-derived MPCs exhibited a significant lower proliferation than HC-derived MPCs, and this alteration was more pronounced in severe DM than in mild (p=0.02 and p=0.001, respectively). Terminal myogenic differentiation was also strongly impaired in severe DM-derived MPCs while less al- tered in mild-DM-derived cells (p=0.002 and p=0.004, respectively). MPC fusion was significantly altered in DM-derived MPCs with a dra- matic decreased observed in severe DM and to a lesser degree in mild DM (p= 0.0005 and p=0.003, respectively).

Conclusion: These results show that skeletal muscle regeneration is impaired in DM due to altered capacities of MPCs to proliferate, to differentiate and to fuse. This may explain in part the muscle alter- ations and muscle weakness that are observed in patients. Further in- vestigations will include the seek for molecular mechanisms underlying myogenesis alteration in DM. These results support the hypothesis of intrinsic alterations of MPC properties in DM, participat- ing to the pathogenesis of the disease.

P13

The IgG2 isotype of anti-transcription intermediary factor 1-
gamma autoantibodies is a biomarker of mortality and cancer in
adult dermatomyositis

Audrey Aussy¹, Manuel Fréret¹, Laure Gallay², Laurent Drouot¹, Fabienne Jouen¹, Yves Allenbach³, Olivier Benveniste⁴, Nadège Cordel², Olivier Boyer¹

¹Rouen University Hospital, Rouen, France; ²Edouard Herriot University Hospital, Lyon, France; ³Centre de Recherche en Myologie, Paris, France;

⁴Pitié-Salpêtrière University Hospital, Paris, France; ⁵French West Indies University, Pointe-à-Pitre, Guadeloupe

Correspondence: Audrey Aussy

BMC Rheumatology 2019, **3**(Suppl 1):P13

Objective: Anti-TIF1gamma antibodies (aAb) are the main predictors of cancer in dermatomyositis (DM). Yet, a substantial proportion of anti-TIF1gamma positive DM patients remain without cancer. Our ob- jective was to identify biomarkers to better evaluate the risk of can- cer and mortality.

Methods: Anti-TIF1gamma aAb levels and IgG subclasses were identified using a home-developed quantitative immunoassay. Adult anti-TIF1gamma+ DM patients detected with this assay were enrolled be-tween August 2013 and August 2017 in numerous French university hos-pitals. Age, gender, DM signs and activity, malignancy, and creatine kinase (CK) level were recorded. anti-TIF1gamma level and IgG subclasses were also recorded. Risk factors were determined by univariate and multi-variate analysis according to a Cox regression model.

Results: Among the 51 adult patients enrolled (mean age 61+/- 17 years, sex-ratio m/f: 0.65), 40 (78 %) had cancer and 21 (41%) died, with 10+/-6 months mean survival. Detection of anti-TIF1gamma-IgG2 was significantly associated with mortality (p=0.0011) and oc-currence of cancer during follow-up (p < 0.0001), with a 100% posi-tive predictive value of cancer when mean fluorescence intensity of anti-TIF1gamma IgG2 was > 385. No cancer developed after 24 months of follow-up. Univariate survival analyses also showed that mortality was associated with age > 60 years (p=0.0003), active DM (p=0.0042), cancer (p=0.0031), male gender (p=0.011), and CK level > 1084 U/L (p=0.005). Multivariate analysis confirmed that age > 60 years (p=0.015) and presence of anti-TIF1gamma IgG2 (p=0.048) were independently associated with mortality. Concerning the evolu-tion of the disease, 8/11 (73%) patients without cancer had persist-ence of DM signs. Among patients with cancer, 18/19 (95%) living patients had cancer in remission, among whom 13/18 (72%) had

concomitantly complete remission of DM. Within the deceased group, 13/15 (87%) patients had active cancer and active DM at last follow-up.

Conclusion: This study has evidenced anti-TIF1gamma IgG2 as a po-
tential new biomarker of cancer which should be helpful to identify
the risk of mortality among anti-TIF1gamma+ DM patients with can-
cer. The absence of cancer occurrence after 24 months could lead to
alleviate the screening examinations. The severity of this form of DM
is here highlighted and suggest the importance of an early and
strong treatment.

P14

Association of IL-17RC rs708567 polymorphism with
dermatomyositis: a pilot study

Joana Pozharashka, Lyubomir Dourmishev, Zornitsa Kamenarska, Maria Hristova, Gyulnas Dzhebir, Svetla Nikolova, Anton Vinkov, Radka Kaneva, Lyubka Miteva

Medical University Sofia, Sofia, Bulgaria

Correspondence: Joana Pozharashka

BMC Rheumatology 2019, 3(Suppl 1):P14

Objectives: Polymorphisms in the cytokine genes and their receptors are thought to influence the predisposition to dermatomyositis (DM). Evidence suggests that both the dysfunction of IL-17RC and the IL-17/IL-17R signalling axis could be implicated in the development of DM. The aim of this case-control study is to investigate the association between the IL-17RC rs708567 polymorphism and the susceptibility to DM in Bulgarian patients.

Methods: Altogether 33 patients with DM as well as 93 unrelated healthy controls were included in this study. The analysis of IL-17RC rs708567 was performed by using TaqMan genotyping assay. Allele and genotype frequencies were compared between DM cases and controls, using Fisher's exact test to calculate p values for 2x2 tables. Where significant, data were expressed as p-value, odds ratios (OR) with exact 95% confidence intervals (CI). Test for Hardy-Weinberg equilibrium was done by χ2 statistics.

Results: The distribution of the genotypes was in Hardy-Weinberg equi-
librium (HWE). The IL-17RC rs708567 CC+CT types were found associ-
ated with the development of DM (p=0.035, OR 2.8, 1-8). No
association was found concerning the allele distribution, although the
C allele was prevalent among the patients compared to controls, lead-
ing to increased OR (53.0% vs. 44.1%, p=0.13, OR 1.4, 95% CI 0.8-2.5).

Conclusion: Our results indicate that the IL-17RC rs708567 polymorphism might play a role in the development of DM.

P15

Dermatomyositis associated with antibodies to small ubiquitin like
modifier activating enzyme: a retrospective series of 41 cases

Mathieu Vautier¹, Pierre Duffau², Olivier Chosidow³, Alice Berezne⁴,
Nadege Cordel⁵, Jean Schmidt⁶, Marie Jachiet⁷, Julie Graveleau⁸, Nicolas
Champtiaux⁹, Perrine Guillaume-Jugnot¹, Baptiste Hervier¹, Judith Victor²,
Aude Rigolet¹, Oceane Landon-Cardinal¹, Olivier Benveniste¹, Yves
Allenbach¹

¹Pitié-Salpêtrière University Hospital, Paris, France; ²Bordeaux University Hospital, Bordeaux, France, ³Hôpital Henri Mondor, Créteil, France; ⁴CH Annecy Genevois, Metz-Tessy, France; ⁵Guadeloupe University Hospital, Les Abymes, Guadeloupe; ⁶Amiens University Hospital, Salouël, France; ⁷Hôpital Saint-Louis, Paris, France; ⁸St Nazaire Hospital, Saint-Nazaire, France

Correspondence: Mathieu Vautier; Yves Allenbach

BMC Rheumatology 2019, **3**(Suppl 1):P15

Myositis-specific antibodies detection is a crucial diagnostic tool since they are specific and delimit homogenous groups of patients. Anti-SAE antibody positive (anti-SAE+) DM represent less than 10% of DM, and the number of reported cases remains limited. Muscular and extra-muscular feature remains to be characterized in anti-SAE+ DM. This multicentric national study (n = 37 centers) included DM patients according to the ENMC criteria, with anti-SAE antibodies detected with
immuno-DOT test, according to local practice. Demographic, clinical, paraclinical data and treatment were analyzed retrospectively. Patients (n = 41) were predominantly women (85.4%) with a median age at diagnosis of 53 years [5 - 90]. All patients had a classical DM skin rash in photo-exposed areas (erythema of the neckline (56%), shawl sign (56%), and hands, peri-inguinal erythema (77%), a sign of gottron (79%)). Nine patients (23%) presented cutaneous ulcerations and 4 patients (10%) had subcutaneous calcifications. Muscular involvement was observed in 82% of patients. Two-thirds (62.5%) of the patients had proximal muscle weakness, but the muscular deficit was mild (median Medical research Council (MRC) Score 4 [2 - 5]). Creatine kinase (CK) level was moderately elevated (median = 216 IU / l [63 - 10511]) and 62.5% had an increased level. In contrast, almost half of the patients (40%) had swallowing disorders. Six out of 41 (14.6%) patients had parenchymal computed tomography CT lesions: organized pneumonia (OP) (n=3/6) and/or NSIP (n = 3/6). The respiratory functional explorations were normal in half of the cases (n = 3/6). Five patients (12%), with a median age of 68 years [39 - 81], had synchronous neoplastic pathology (rectal cancer, gynecologic cancer, and pulmonary cancer). The majority of patients received first-line treatment with systemic corticosteroids (84%) and 73% received concomitant immunosuppressive therapy (methotrexate in n =17/37). Thirty-eight percent of patients received intravenous immunoglobulin, in most cases, due to swallowing disorders (78.6%). The median duration of follow-up was 21 months [1 - 302]. Majority (55%), of patients received only one line of treatment. The others received several lines of treatment because of relapse or persistence of cutaneous and/or muscular symptoms (2 lines, n = 6, 3 lines, n = 7 and 4 lines, n = 3). Only one patient died during follow-up, from complications of disseminated tuberculosis. DM SAE is a rare subgroup of DM characterized by a classical DM skin rash with a mild muscle weakness but frequently swallowing disorders. Non-serious pulmonary

P16

Dermatomyositis with anti-MDA5 auto-antibodies: is there a seasonal pattern of disease onset?

Kubéraka Mariampillai<fnref n="1" />, Ségolène Toquet<fnref n="1" />, Yurdagul Uzunhan², Gaelle Leroux<fnref n="1" />, Laure Gallay<fnref n="3" />, Alain Meyer⁴, Hilario Nunes², Benjamin Granger<fnref n="1" />, Olivier Benveniste<fnref n="1" />, Yves Allenbach<fnref n="1" />

**Correspondence:** Kubéraka Mariampillai

BMC Rheumatology 2019, **3**(Suppl 1):P16

**Objectives:** Melanoma differentiation-associated gene 5 (MDA5) is a protein involves in anti-viral defense. Anti-MDA5 autoantibodies are associated with dermatomyositis (DM) characterized by a very high frequency of interstitial lung disease (ILD) with life-threatening complications. We hypothesize that viral infections may trigger the disease, thus we test if there is evidence for seasonal variation in MDA5 DM.

**Methods:** An observational, retrospective multicentric (n=37) cohort study was performed. Anti-MDA5 antibody positive (Euroimmun® or D-Tek®) patients were included. Myositis onset periodicity and associated predictive factors were assessed by goodness of fit chi squared test and non-linear model.

**Results:** Anti-MDA5+ patients (n=122) were 49 years [34-58] at diagnosis. Skin lesions were highly frequent (87.5%) as well as ILD (76.47%) and the mortality was high (27.27%). The first symptoms appeared in spring for 36% (n=37; p=0.05). There was no evidence for seasonality regarding the first respiratory symptoms (p=0.16) and deaths (p=0.34). Next we compared MDA5 DM patients with a spring onset to the others. ILD occurred in 70.3% in patients with a spring onset and in 87.9% for the others (p=0.05). No significant differences were highlighted regarding the gender (p=0.4), age at diagnosis (p=0.4), ethnicity (p=0.3), skin lesions (p=0.6), proximal deficit (p=0.2), or rheumatologic signs (p=0.3). In addition the frequency in admission in intensive care unit was similar 37% for the spring onset patients and 40% for the others (p=0.9) as well the mortality rate 27% in spring onset patients and 34% in others (p=0.5).

**Conclusion:** These exploratory results may suggest a seasonal distribution in the onset of the disease without showing a clear different phenotype for patients with a spring onset. Harmonic analyses are ongoing to explore and identify factors associated with seasonality.

P17

Polymyositis (PM) and Dermatomyositis (DM) Symptom Flares and Associated Impact from the Patient Perspective

Lisa Christopher-Stine<fnref n="1" />, Winn Nelson², William Kelly<fnref n="1" />, Linda Kobert<fnref n="3" />,

Barima Opong-Owusu², Michael Reed⁴

**Correspondence:** Lisa Christopher-Stine

BMC Rheumatology 2019, **3**(Suppl 1):P17

**Objectives:** Flare activity or worsening symptoms are not well defined for myositis. This analysis characterizes PM and DM flares from the patient perspective and reports the corresponding disability and rate of unplanned medical encounters.

**Methods:** Online surveys were collected from volunteer patients from The Myositis Association and Johns Hopkins Myositis Center. Data collection included sociodemographics, flare symptoms, Health Assessment Questionnaire Disability Index (HAQ-DI) and HAQ-Pain index, Work Productivity and Activity Impairment (WPAI), emergency department and urgent care (ER/UC) visits during the past year. Flare frequency was assessed asking, "Have you ever had a flare or worsening myositis symptoms?" if yes, "How many times in the past 12 months?"

**Results:** 564 individuals with self-reported diagnoses of PM (n=243) and DM (n=321) completed the survey between December 2017 and May 2018. Recall of symptom flares was reported by 524 (86.6% Caucasian, 78.1% female, 43.1% employed, mean age 55.4 years). Among the 524 respondents, 33 (6.3%) reported never experiencing a flare, 113 (21.6%) reported 0 flares in the past year, 244 (46.6%) reported 1-3 flares, and 134 (25.6%) reported 3 flares in the past year. The pattern of flare frequency was similar for PM and DM respondents. Among the 378 respondents with self-reported flares in the past year, the most common worsened symptoms were muscle weakness (84%), extreme fatigue (79%), muscle pain/discomfort (64%), trouble climbing stairs (62%), trouble standing from a seated position (50%), and skin rash (45%). Dysphagia occurred for 27%. Increasing flare frequency was associated with greater mean HAQ-DI (F=17.653, P < .001), HAQ-Pain (F=28.291, P < .001), WPAI activity impairment (F=20.109, P < .001) and, for the employed, lost productive work time (F=9.933, P < .001). Rates for one or more past year ER/UC visits were also related (χ²=11.634, P < .009) to flare frequency (never 9.1%, 0 flares 8.8%, 1-3 flares 20.5%, 3 flares 23.1%).

**Conclusion:** PM/DM-related flares or worsening symptoms are common, with 72% of respondents reporting one or more flares in the past year. Exacerbations of muscle weakness and fatigue were the most common flare symptoms, and flare frequency was associated with greater disability, more pain, more absenteeism and presenteeism, and activity impairment. ER/UC utilization was also more common as flare frequency increased. Higher frequency of patient-reported flares may serve as a marker of worsening physical functioning and intensifying health care needs, and therefore suggests their importance in the clinical assessment of patients with PM/DM.

P18

murin model of anti-TIF1gamma dermatomyositis: preliminary results

Audrey Aussy<fnref n="1" />, Maire Chilles<fnref n="1" />, Laurent Drouot<fnref n="1" />, Fabienne Jouen<fnref n="1" />, Christophe Arnoult², Olivier Benveniste<fnref n="3" />, Olivier Boyer<fnref n="1" />

**Correspondence:** Audrey Aussy

BMC Rheumatology 2019, **3**(Suppl 1):P18

<footnote n="1">¹Pitié Salpêtrière Hospital, Paris, France; ²Avicenne Hospital, Paris, France;</footnote>

<footnote n="3">³Lyon Sud University, Lyon, France; ⁴Strasbourg University, Strasbourg, France</footnote>

<footnote n="1">¹Johns Hopkins University, Baltimore, USA; ²Mallinckrodt</footnote>

<footnote>Pharmaceuticals, California, USA, ³The Myositis Association, Alexandria, USA; ⁴Vedanta Research, Chapel Hill, USA</footnote>

<footnote n="1">¹Rouen University Hospital, Rouen, France; ²Normandie Université, Rouen, France; ³Pitié Salpêtrière Hospital, Paris, France</footnote>
**Introduction:** Pathophysiology of dermatomyositis involve type 1 interferon pathway, complement system, vasculopathy and antibodies but remain elusive. The absence of murin model is limiting the capacity to establish the exact role of these different actors. Among the specific autoantibodies (aAb) associated with DM, anti-TIF1gamma aAb are associated with poor prognosis in juvenile and adult DM, with an higher risk of cancer in adults. The objective is to evaluate the role of anti-TIF1gamma aAb in murin model.

**Methods:** The first approach consisted of daily injection of 400µg of purified IgG from patient with anti-TIF1gamma+ DM or from healthy donors. The second approach consisted of immunization of mice with human recombinant TIF1gamma protein diluted in adjuvant containing ODN-CpG. The level of anti-TIF1gamma antibodies were evaluated with home-made assay in ALBIA (Adressable Laser Beads Immunoassay). Muscular strength was analyzed using grip-test. Muscles were analyzed after staining with Eosin-hematoxylin, indirect immunofluorescence or immunohistochemistry.

**Results:** Passive transfer of purified IgG containing anti-TIF1gamma antibodies provokes moderate muscle weakness but no histological abnormalities. Immunization with recombinant TIF1gamma protein leads to muscle weakness and moderate histological lesions such as edema, necrosis and IgG deposits.

**Conclusion and perspectives:** IgG containing anti-TIF1gamma antibodies from patients are not sufficient to induce DM lesions. The anti-TIF1gamma immune response lead to muscular weakness and moderate inflammatory lesion in muscle, suggesting the associated role of antigen-presnetating cells, T and B cells in the occurrence of disease. These results encouraged us to reproduce the experiments using other adjuvants which activate the type 1 interferon pathways.

## P19

### Novel Nailfold Video Capillaroscopy Parameters for Monitoring Juvenile and Adult Dermatomyositis

Nathan Arnett, Hans Prakash, Alexander Gorbach, Frederick Miller, Lisa

Rider, Adma Schiffenbauer

National Institutes of Health, Bethesda, USA

**Correspondence:** Nathan Arnett; Adma Schiffenbauer

BMC Rheumatology 2019, **3**(Suppl 1):P19

**Objectives:** Nailfold capillaroscopy has previously been used to assess nailfold capillary density in patients with dermatomyositis (DM). Additional attributes of nailfold capillary architecture, such as tortuosity and interlimb distance, as well as nailfold capillary blood velocity, have not yet been fully described in a quantifiable manner. In this study, quantification methods were developed to evaluate three attributes of nailfold capillary architecture (capillary density, interlimb distance, and tortuosity) and two attributes of nailfold capillary blood velocity [arterial blood velocity (BVA) and venous blood velocity (BVV)]. These attributes were then evaluated in DM patients and healthy control subjects.

**Methods:** Eighteen patients with DM, twenty-eight patients with Juvenile Dermatomyositis (JDM), and fifteen healthy control subjects were enrolled in a myositis natural history study from July 2013 to March 2017. These subjects underwent Nailfold Video Capillaroscopy (NFVC) and Nailfold Capillaroscopy (NFC) evaluation. During the study, participants sat in a comfortable upright position, and NFC photography was obtained and NFVC was conducted on the left ring finger of each patient. Imaging was performed using a Leica M205C stereomicroscope and six to ten images were taken with the recording of videos up to fifteen seconds long. Measurements of the five capillary parameters were performed on five to ten capillaries and averaged. The Spearman's rank correlation coefficient was used to identify significant correlations among the five capillaroscopy parameters.

**Results:** Significant differences were found between JDM/DM patients and healthy control subjects for capillary density (medians of 5.0 capillaries/mm vs. 6.3 capillaries/mm, p < 0.001), interlimb distance (medians of 13.7 um vs. 11.0 um, p < 0.001), tortuosity (medians of 5.0 radians vs. 4.0 radians, p < 0.05), arterial blood velocity (medians of 552.5 um/s vs. 1068.0 um/s, p < 0.05), and venous blood velocity (medians of 360.2 um/s vs. 720.4 um/s, p < 0.05). Significant correlations were found

between capillary density and interlimb distance in DM patients (p = -0.51, p < 0.001), and between BVA and BVV in DM patients (p = 0.96, p < 0.001) and controls (p = 0.85, p < 0.001).

**Conclusions:** This study presents new analytical techniques for NFVC that offer significant promise as tools in diagnosing patients with JDM/DM due to their quantifiable objective nature and the significant differences detected between patients and controls.

## P20

### Distinct clinical profiles of Chinese and Swedish idiopathic inflammatory myopathy patients with anti-melanoma differentiation associated gene 5 (MDA5) antibody

Ho So¹, Ingrid Lundberg², Maryam Dastmalchi², Valérie Leclair², Tommy Lam, Roy Ho, Victor Wong

¹Kwong Wah Hospital, Hong Kong, Hong Kong; ²Karolinska Institutet, Solna, Sweden

**Correspondence:** Ho So

BMC Rheumatology 2019, **3**(Suppl 1):P20

**Objective:** The objectives of the study was to compare the prevalence of the anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) and various clinical features between a Chinese and a Swedish IIM cohort.

**Methods:** This multicenter retrospective cohort study was conducted on IIM patients with available anti-MDA5 Ab results seen in the rheumatology clinic or admitted to the rheumatology wards of the participating hospitals in Hong Kong and Karolinska University Hospital, Sweden from September 2015 until August 2018. The diagnosis of IIM was based on the 2017 European League Against Rheumatism/American College of Rheumatology Classification Criteria with definite or probable cases being included. Patients with juvenile onset myositis were excluded. Demographics and clinical features were collected by reviewing medical records. A commercial line blot immunoassay kit (EUROIMMUN) was used to detect the anti-MDA5 autoantibodies.

**Results:** Altogether, 402 patients with IIM (Sweden: 206, Hong Kong: 196) were recruited. The Swedish patients were older (mean age 58.1 vs 51.3 years, p < 0.001), and the frequency of male was higher (41.4% vs 23.5%, p < 0.001). Subgroups of patients were: dermatomyositis 39.5%, polymyositis 39%, inclusion body myositis 15% and clinically amyopathic dermatomyositis 2% in the Swedish cohort, and 39.8%, 38.8%, 0% and 21.4% respectively in the Chinese cohort. Anti-MDA5 Ab was found in 11.7% of the Chinese and 5.83% of the Swedish patients (p=0.036). The Hong Kong Chinese patients were found to have significantly more ILD (53.6% vs 35.4%) and RPILD (9.23% v 3.95%), while the Swedish patients had more dysphagia (50% vs 28.7%) and cardiac involvement (13.5% vs 5.5%). Anti-MDA5 Ab was associated with male gender, younger age at diagnosis, amyopathy, ILD and RPILD in the Swedish patients. The same associations were found in the Chinese patients except the young age at diagnosis. Besides, in the Chinese cohort, the antibody was also positively associated with skin ulceration and vasculitis, and negatively associated with cancer and dysphagia. When grouping all the anti-MDA5 Ab positive patients together, Chinese patients had significantly more vasculitic skin changes (68% vs 0%, p < 0.001) than the Swedish. They also had a tendency towards developing more skin ulcers (47.8% vs 9.09%, p=0.053). No other significant difference was identified.

**Conclusion:** The distinct clinical profiles identified in both groups could enhance our knowledge about the clinical utility of the antibody and the deciphering of the pathogenesis of this complex disease.

## P21

### The clinical significance of progranulin in DM patients

Shan-Shan Li, Yamei Zhang, Xin Lu, Guochun Wang

China-Japan Friendship Hospital, Beijing, China

**Correspondence:** Shan-Shan Li

BMC Rheumatology 2019, **3**(Suppl 1):P21
**Objective:** To investigate the clinical significance of progranulin (PGRN) in patients with dermatomyositis (DM).

**Methods:** The levels of PGRN and IL-6 in 15 patients with DM (untreated before and 3 months after treatment) and 8 healthy controls were detected by ELISA in serum. The relationship between PGRN and clinical data was analyzed. T-test and Spearman correlation analysis were used.

**Results:** The level of PGRN in untreated DM patients (109.25 + 74.01 ng/ml) was much higher than those in healthy controls (27.04 + 15.07 ng/ml) (t = 3.076, P = 0.006). There was no difference in PGRN between patients with and without ILD. The expression of PGRN in patients, whose muscle strength was less than or equal to grade 3, was higher than those with muscle strength over grade 3 (150.16+75.17 ng/ml vs 62.51+37.52 ng/ml, t=2.787, P = 0.015). In laboratory data, PGRN was correlated with the levels of AST (r = 0.806, P = 0.000), LDH (r = 0.595, P = 0.019) and HBDH (r = 0.668, P = 0.007), but not with ALT or CK (p > 0.05). There was no significant difference in PGRN levels between MSA positive group and negative one (t = 0.808, P = 0.434). PGRN in serum was correlated with the expression of IL-6 (r = 0.824, P = 0.000). After 3 months of treatment, PGRN (62.41 + 48.49 ng/ml) decreased significantly (t=3.956, p=0.001) in these patients, and there was no difference compared with healthy controls (t=1.993, p=0.059).

**Conclusions:** PGRN levels of DM patients increased significantly in disease onset, and decreased after effective treatment, which may be related to the degree of muscle injury and inflammation.

## P22

### Performance of the 2017 European League Against Rheumatism / American College of Rheumatology (EULAR/ACR) Classification Criteria for adult idiopathic inflammatory myopathies in a Hong Kong cohort

Ho So, Roy Ho, Tommy Lam, Victor Wong
Kwong Wah Hospital, Hong Kong, Hong Kong

**Correspondence:** Ho So
BMC Rheumatology 2019, **3**(Suppl 1):P22

**Objectives:** The objective of the study was to evaluate the performance of the 2017 EULAR/ACR classification criteria in a cohort of Hong Kong adult idiopathic inflammatory myopathy (IIM) patients. The secondary objectives included examining the level of agreement between the new criteria and the traditional criteria and assessing the effect of including other myositis specific autoantibodies (MSAs) into the criteria.

**Methods:** This was a multi-centre retrospective cross-sectional study. Consecutive patients with a clinical diagnosis of IIMs and MSA tested seen in the rheumatology clinic or admitted to the rheumatology wards of the participating hospitals in Hong Kong up till April 2018 were recruited. Patients with juvenile onset myositis were excluded. Clinical parameters required by the two criteria will be collected by reviewing the medical records. A commercial line blot immunoassay kit (EUROIMMUN) was used to detect the MSAs.

**Results:** Two hundred and four patients with IIM were recruited. The mean age was 59.3 years. There was a female predominance of 76.5%. The subgroups of the patients were: polymyositis 40.7%, dermatomyositis 38.2%, clinically amyopathic dermatomyositis patients 21.1%. MSAs were detected in 59.3% of the patients with anti-Jo-1 antibody being the commonest (13.2%). The new 2017 EULAR/ACR Criteria could classify 96.1% of the patients as having definite or probable IIM. The Bohan and Peter criteria could only classify 76.0% of the patients. When combining with the Sontheimer's criteria for CADM, 93.1% of the patients could be classified. The percentage agreement of the new and the Bohan and Peter criteria also increased from 77.0% to 93.1% when the latter was supplemented by the Sontheimer's criteria. If the presence of any MSAs is considered one of the criteria, the performance of the 2017 criteria improved to 97.5% while the combined Bohan and Peter/Sontheimer's criteria to 96.1%. However, the new criteria still failed to highlight the important subtype of IIM associated with anti-MDA5 autoantibody.

**Conclusion:** In a population with a significant proportion of CADM patients, the new 2017 EULAR/ACR classification criteria outperformed the old criteria. Finally, a clinico-serological criteria for "anti-MDA5 syndrome" is proposed in which a patient must have positive serologic testing for an anti-MDA5 autoantibody, plus one of the following conditions: myositis by the new EULAR/ACR criteria, interstitial lung disease or typical rash (skin ulceration, palmer papules).

## P23

### Anti-NXP2 Dermatomyositis: a severe muscle and skin disease

Camille Rasmussen, Laure Gallay, Alain Meyer, Delphine Larivière, Sarah Leonard-Louis, Perrine Guillaume-Jugnot, Mathieu Vauthier, Kuberaka Mariampillai, Olivier Benveniste, Yves Allenbach Hôpital Pitié Salpêtrière; Paris, France

**Correspondence:** Camille Rasmussen

BMC Rheumatology 2019, **3**(Suppl 1):P23

**Objectives:** Myositis specific antibodies (MSA) delineates homogeneous groups of myositis patients with characteristic muscular and extra-muscular phenotypes. Anti-nuclear matrix protein 2 (NXP2) occurs only in juvenile and adult dermatomyositis (DM) patients (1-30%). Anti-NXP2 DM have been associated with (i) calcinosis and edema, (ii) a severe muscle vasculopathy at least for juvenile DM and (iii) an increased risk of malignancy in adults. The number of reported cases is limited and studies sometimes showed conflicting results (e.g on the risk of malignancy). We aimed to characterize the muscular and extra-muscular phenotype in an independent cohort.

**Methods:** This multicentric (n=9) retrospective study included adults and juvenile DM based on Bohan and Peter's and/or the Sontheimer's criteria, with anti-NXP2 antibody (Immunodot DTEK® or Euroimmun®). Clinical and paraclinical data were collected retrospectively using medical charts and an electronic database. Muscle biopsies were analyzed by two independent experts.

**Results:** Thirty nine patients were included (n=8 juvenile, n=31 adults DM). They were 29 years [IQR;19-49] (jDM 6.5 y [IQR;3-14.7] and aDM 38 y [IQR;22-52]) and mainly female (69 %). Nearly all patients presented myalgia (84.2%) and a proximal muscle weakness (89.7%), rather severe (57% had a MRC score ≤ 3); and half of them also showed a distal weakness (54.5%). The CK was 1983 U/L [IQR;744.3-6900]. The majority of patients (92.1%) presented a classical DM skin rash (heliotropic rash, gottron papules, manicure sign). Otherwise, edema was frequently observed (67.5%) and nearly a quarter (23%) had severe cutaneous manifestation, defined by the presence of either superficial ulceration or necrosis). Calcinosis was also reported in a third of the cases. 60% had dysphagia, and among them a quarter (25.9%) needed enteric nutrition. A quarter of patients presented a gastro-intestinal involvement (colitis, n=7). Cardiac involvement was reported in 5.4% and interstitial lung disease was identified in 14.8% of patients (with a chest CT). Cancer associated myositis was observed in 7.8% of people (n=3/38). Furthermore, comparison between adult and juvenile DM, showed that dysphagia and skin ulceration occurred more frequently in adult DM. All but one patient received corticosteroids and 92% were also treated with an immunosuppressant. Patients received 1.5 line of treatment [IQR;1-2.250]. Median number of relapses per patient was 0 [range 0-4]. Follow-up was 21 months [IQR;7-35].

**Conclusion:** Anti-NXP2 DM is associated with a severe vasculopathy attested by important skin lesions and frequent GI involvement as well as a severe muscle disease (major weakness and dysphagia).

## P24

### NVC (nailfold videocapilaroscopy) in MDA5 positive patients with and without skin ulcers

Florentina Berianu
Mayo Clinic, Ponte Vedra Beach, USA
BMC Rheumatology 2019, **3**(Suppl 1):P24

**Background/Purpose:** The MDA5 was classified as a myositis-specific antibody and has been associated with rapidly progressive interstitial
lung disease (ILD), amyopathic dermatomyositis (aDM), mechanic's hands, ulcerations, inflammatory arthritis, and increased mortality. Nailfold videocapilaroscopy (NVC) represents the best method to assess the microvascular abnormalities. A defined pattern on NVC has been reported in patients with dermatomyositis. This study sought to distinguish the NVC characteristics of MDA5-positive with skin ulcers versus non skin ulcers to see if NVC findings will correlate with the severity of skin lesion.

Methods: The NVC was performed in all 7 MDA5 positive patients; mean age 59.6, 3 male, 4 female. The capillary parameters were scored as reported in literature. 3 patients MDA5 positive with skin ulcers were compared to 4 patients MDA5 positive without skin ulcers. Baseline clinical characteristics and serology were recorded in all patients.

Results: A scleroderma like pattern was noted in 5 out of 7 patients but no significant differences were noted between the 2 groups. In our sample only 2 patients MDA5 positive presented with Raynaud's. 5 out of 7 patients MDA5 positive had periungual erythema, 2 had mechanics hands. 1 patient with cutaneous ulceration died soon after diagnosis and his NVC was normal.

Conclusion: No statistical significant differences were reported between the 2 groups. The comparison was done at different stages of the disease and response to therapy. Further studies on larger cohort of patients may find differences between the 2 groups.

## P25
Infections are leading cause of in-hospital mortality in Indian patients with inflammatory myositis

Hafis Muhammed, Latika Gupta, Abhishek Arvind Zanwar, Durga Misra, Able Lawrence, Vikas Agarwal, Amita Aggarwal, Ramnath Misra
Sanjay Gandhi Post Graduate Institute of Medical Science, Uttar Pradesh, India

**Correspondence:** Hafis Muhammed
*BMC Rheumatology* 2019, **3**(Suppl 1):P25

Background: Idiopathic inflammatory myositis (IIM) are debilitating and often lead to mortality. We explored causes of in-hospital mortality and predictors of early mortality at a tertiary care center in northern India.

Methods: Records of adults and children with dermatomyositis (DM), polymyositis (PM), or anti-synthetase syndrome (ASS) who died between 2000 and 2018 were reviewed and cause of death determined. Early mortality was defined as death with 6 months of diagnosis. For comparison patients with IIM surviving more than 6 months after diagnosis and having registration number before and after the index case were included. Severe weakness was defined as MRC less than 3 in any group of muscles.

Results: Of the 38 (32 women) deaths, 20 were DM including 2 clinically amyopathic DM, 4 JDM, 12 PM and 2 ASS. Median age at death was 42.2 years. At time of death 18 had active disease, while 14 and 6 had grumbling and inactive disease respectively. Thirty-two (84.2%) had infection (11 bacteriologically proven), of which 19 died of septic shock. Other causes of death included: myocarditis (n=3), respiratory failure (n=4), cerebral bleed (n=1) and pulmonary embolism (n=1). One patient of ASS succumbed to rapidly progressive ILD, while another one died following RTX induced ARDS. 25 (65.7%) patients had died within 6 months of disease. In comparison to controls (n=50) they were older, had higher frequency of severe weakness (OR: 5.73, 95% CI: 1.62-20.26; p0.007), neck muscle weakness (OR:3.55, 95% CI: 1.26-10.01; p:0.015), respiratory involvement (OR: 12.25, 95% CI: 1.35-111.5; p:0.014) and thrombocytopenia (OR: 9.04, 95% CI: 2.48-32.87; p:0.001). Conditional logistic regression was conducted using statistically significant variables (severe weakness, neck muscle weakness, thrombocytopenia and age at presentation) with death with in 6 months of presentation as outcome. In the final model only severe muscle weakness at onset remained as independent risk factor (OR: 10.83, 95% CI: 1.17-100.55; p:0.04).

Conclusions: Infections are the most common cause of in-hospital mortality in IIM patients. Severe muscle weakness if the single most important predictor of early mortality.

## P26
The Predictive Risk Factors for Opportunistic Infection during treatment for Polymyositis/dermatomyositis

Yumiko Sugiyama¹, Ryusuke Yoshimi¹, Mitsuhiro Takeno², Yohei Kirino¹, Shigeru Ohno¹, Hideaki Nakajima¹
¹Yokohama City University Medical Center, Yokohama, Japan; ²Nippon Medical School Graduate School of Medicine, Tokyo, Japan

**Correspondence:** Yumiko Sugiyama
*BMC Rheumatology* 2019, **3**(Suppl 1):P26

Background/Purpose: Although concomitant infectious diseases are the predominant causes of death in patients with polymyositis (PM)/dermatomyositis (DM), intensive immunosuppressive treatment are necessary for severe cases. We have already reported that high initial dose of glucocorticoid and combination immunosuppressive therapy for induction therapy, and KL-6 levels at the baseline were independent risk factors for infection. Here we investigated the predictive risk factors for opportunistic infection during immunosuppressive treatment for PM/DM by assessing cytomegalovirus (CMV) antigen test as a barometer for immunocompromised status.

Methods: We retrospectively analyzed clinical features, laboratory data at baseline in the patients with PM/DM who had received initial treatment at six hospitals affiliated to Yokohama City University from 2003 to 2016. We also investigated initial therapeutic regimens and clinical outcomes including CMV antigenemia as a complication. We conducted univariate and multivariate analyses to extract risk factors for CMV antigenemia.

Results: One hundred sixty-eight (PM 42, DM 82, and clinically amyopathic DM (CADM) 44) were recruited. As initial therapies, oral prednisolone (PSL) was prescribed in all patients. Methylprednisolone (mPSL) pulse, intravenous cyclophosphamide (IVCY), and oral calcineurin inhibitor therapies were performed in 93 (56%), 50 (30%) and 86 (51%), respectively. Forty patients (24%) received combination therapy with IVCY and a calcineurin inhibitor. Fifty-two patients (31%) had CMV antigenemia within 6 months from initiation of immunosuppressant. A multivariate logistic regression analyses revealed that low PaCO2 (p = 0.023, OR 0.78) and old age (p = 0.040, OR 1.07) were independent risk factors for CMV antigenemia. As we focused on PM/DM-ILD patients, a multivariate logistic regression analyses revealed that low PaCO2 (p = 0.044, OR 4.96), above 0.6 mg/kg/day of initial PSL dose (p = 0.027, OR 3.56) and the treatment with oral calcineurin inhibitor (p = 0.007, OR 21.23) were independent risk factors for CMV antigenemia. Moreover, the patients with positive CMV antigenemia tended to infected which were needed antibiotic therapy with significant differences (OR 4.52, p < 0.001). There were no patients with organ dysfunction as CMV infection.

Conclusion: Although rapid and intensive therapies are required for PM/DM, appropriate monitoring, prophylaxis and early treatment for opportunistic infection are important, especially in patients who receive strong immunosuppressive therapy and who show low PaCO2 level and old age at baseline.

## P27
Pneumocystis jirovecii pneumonia (PCP) in Patients with Idiopathic inflammatory myopathy

Yong-Peng Ge, Xin Lu, Guochun. Wang, Si-Zhao Li
China Japan Friendship Hospital, Beijing, China

**Correspondence:** Yong-Peng Ge
*BMC Rheumatology* 2019, **3**(Suppl 1):P27

Objective: Immunosuppressant medications increase the occurrence of Pneumocystis jirovecii pneumonia (PCP) in patients with idiopathic inflammatory myopathy (IIM). The objective of this study was to describe clinical features, risk factors and prognosis of PCP in IIM.

Methods: This retrospective cohort study analyzed data from 830 patients (2008-2018) diagnosed as having IIM. Clinical and laboratory data of these patients with PCP were compared to those of matched patients suffering from IIM but no PCP.

Results: A total of 28 (3.4%) cases of IIM with PCP including 27 DM (96.4) and 1 PM (3.6%), and 24 (85.7%) patients were diagnosed by
bronchoalveolar lavage (BAL) fluid. Twenty two (78.6%) patients developed PCP within 6 months after onset, 27 (96.4%) patients were receiving average >30 mg of prednisone equivalent daily therapy and/or cytotoxic drugs for at least one month before developed to PCP. Most of patients (77.8%) had acute/subacute intestinal lung disease (ILD). The average CD4 lymphocyte counts of DM patients with PCP was 314.8 cells/mm3, which were significantly lower than those in DM patients without PCP (608.2 cells/mm3). Among myositis special antibodies (MSAs), anti-MDA5 antibodies occurred more frequent in DM patients with PCP than those without PCP (40.7% vs 17.5%, p=0.008). Multivariate analysis revealed that CD4 lymphocyte count < 200 cells/mm3 were the most important risk factors for PCP (OR 24.9, P < 0.001). Comparison with DM patients without PCP, those with PCP had higher mortality rate (44.4% vs 7.1%, p< 0.001). Conclusions: PCP is not a rare disease in patients with IIM; especially in anti-MDA5 related DM. BAL is major tool for the diagnosis of PCP. Low CD4 lymphocyte count shows the risk factors for PCP.

## P28

### Alterations of Body Composition in Myositis Patients Are Associated with Disease Activity, Duration and Muscle Involvement

Sabina Oreska, Maja Spiritovic, Hana Storkanova, Barbora Hermankova, Karel Pavelka, Ladislav Senolt, Herman Mann, Jiri Vencovsky, Michal Tomcik

Charles University, Prague, Czech Republic

**Correspondence:** Sabina Oreska

BMC Rheumatology 2019, **3**(Suppl 1):P28

**Objectives:** Skeletal muscle, pulmonary and articular involvement in idiopathic inflammatory myopathies (IIM) limit the mobility/self-sufficiency of patients, and can have a negative impact on body composition. The aim was to assess body composition and physical activity of IIM patients and healthy controls (HC).

**Methods:** 54 patients with IIM (45 females; mean age 57.7; disease duration 5.8 years; PM, 22 / DM, 25 / IMNM, 7) and 54 age-/sex-matched HC (45 females, mean age 57.7) without rheumatic/tumor diseases were included. PM/DM patients fulfilled Bohan/Peter criteria for PM/DM. Anthropometric parameters and body composition were assessed (by densitometry: iDXA Lunar, and by bioelectric impedance: BIA2000-M), and physical activity was evaluated using Human Activity Profile (HAP) questionnaire. Disease activity was evaluated by MITAX and MYOACT activity score and muscle involvement by manual muscle test (MMT-8) and functional index 2 (FI2). Data are presented as mean±SD.

**Results:** Compared to HC, patients with IIM had a trend towards increased body fat % (BF%) (iDXA: 39.9±7.1 vs. 42.4±7.1 %, p=0.077), but significantly decreased lean body mass (LBM) (iDXA: 45.6±8.1 vs. 40.6±7.2 kg, p=0.001; BIA: 52.6±8.8 vs. 48.7±9.0 kg, p=0.023), and increased extracellular mass/body cell mass (ECM/BCM) ratio (1.06±0.15 vs. 1.44±0.42, p < 0.001). Higher ECM/BCM ratio reflects worse muscle predispositions for physical exercise, and deteriorated nutritional status. Compared to HC, IIM patients had significantly lower bone mineral density (BMD: 1.2±0.1 vs. 1.1±0.1 g/cm2, "p < 0.001"). Disease duration negatively correlated with BMD (r=-0.392, p=0.004) and LBM-BIA (r=-0.272, p=0.047). Disease activity assessed by both MITAX and MYOACT positively correlated with LBM-BIA (MITAX: r=0.294, p=0.031; MYOACT: r=0.335, p=0.013) and LBM-DXA (MITAX: r=0.341, p=0.012; MYOACT: r=0.368, p=0.007), as well as with basal metabolic rate (BMR; MITAX: r=0.336, p=0.014; MYOACT: r=0.351, p=0.010), and fat free mass (FFM; MITAX: r=0.338, p=0.014; MYOACT: r=0.356, p=0.009). CRP was positively associated with BF% assessed both by DEXA (r=0.276, p=0.035) and BIA (r=0.306, p=0.025). Higher BF%-DEXA was associated with worse physical endurance (FI2: r=-0.311, p=0.026) and worse ability to perform physical activity (HAP: r=-0.292, p=0.032). MMT-8 scores negatively correlated with ECM/BCM ratio (r=-0.385, p=0.006).

**Conclusions:** Compared to healthy age-/sex-matched individuals we found significant negative changes in body composition of our IIM patients, which are associated with their disease activity and duration, inflammatory status, skeletal muscle involvement, and physical activity.

These data could reflect their impaired nutritional status and predispositions for physical exercise, aerobic fitness and performance.

**Acknowledgements:** Supported by AZV NV18-01-0016116-33574A, MHCR 023728 and GAUK 312218.

## P29

### Prevalent Vertebral Fractures incur high risk of future fractures in inflammatory myositis

Sujata Ganguly, Able Lawrence, Ramnath Misra, Latika Gupta, Saroj Sahoo

Sanjay Gandhi Post Graduate Institute of Medical Science, Uttar Pradesh, India

**Correspondence:** Sujata Ganguly

BMC Rheumatology 2019, **3**(Suppl 1):P29

**Objective:** To assess accrual of new vertebral fractures (VF) in patients with inflammatory myositis over a period of time.

**Methods:** Hundred patients who were previously enrolled for a cross-sectional study on prevalence of asymptomatic VF were telephonically requested to review with repeat dorsal and lumbar Spinal radiographs and dual-energy X-ray absorptiometry (DEXA) and Bone mineral Density (BMD) evaluation 3 years after the initial assessment. Radiographs were scored using Genant's semi-quantitative technique by two independent observers. Involvement of new vertebra, worsening of fracture grade of a previously fractured one or new site of fracture within a fractured vertebra were recorded as a fracture event. Demographics, previous fractures, menopausal status and disease related variables were recorded. All results are expressed in median and interquartile range. Statistical analysis was done using Prism Graph Pad 8.0 (trial version for windows 8.0).

**Results:** Radiographs from 21 patients (5 men and 16 women) of median age 42 years were reviewed. Of these, 7 patients had Polymyositis, 9 dermatomyositis and 5 overlap myositis. Fifteen of the 21 (71.4%) had VF at baseline. At 61.9 patient years of follow-up, twelve of 15 (75%) patients with previous VF had new events (p=0.009), while none of those without previous fractures had new fractures. There was an increase in total number of fractures (25 to 43, p: 0.01). Accounting for worsening of previous fractures as well, there were 25 new fractures events. Most patients had more than 1 fracture (11 of 15,73.3 %) although most of these (31 of 43, 72.09%) were grade 1 VF. The increase in lumbar fractures was greater than thoracic. (p=0.04, RR:2.2). Patients with previous VF have 5 times higher risk of developing a new VF. Patients with old VF accrue fractures at a rate of 8.5/year. Of the 13 patients who underwent DEXA scans, 3 had osteoporosis and 5 were osteopenic. T scores at the middle (r=-0.7, p=0.015) and lower third (r= -0.7, p= 0.0094) of radius correlated with fracture number. Conventional risk factors such as age, weight, and gender did not differ between fracture progressors and non-progressors. Change in disease activity had no bearing on progression of fractures (p=ns).

**Conclusion:** Patients with inflammatory myositis with a prior asymptomatic vertebral fracture have a very high risk of subsequent vertebral fractures irrespective of disease activity.

## P30

### Poor muscle endurance of swallowing muscles in myositis patients with dysphagia

Alba Azola, Tae Chung, Lisa Christopher-Stein
Johns Hopkins University School of Medicine, Lutherville, USA

**Correspondence:** Alba Azola

BMC Rheumatology 2019, **3**(Suppl 1):P30

**Introduction:** The prevalence of dysphagia in patients with immunemediated inflammatory myopathies (myositis) has been reported to be as high as 60%. Aspiration pneumonia is one of the main causes of mortality in patients affected by myositis, especially in those with chronic deterioration. However, the pathophysiology of myositis-related dysphagia has not been well characterized.
**Objectives:** The goal of this study was to characterize the pathophysiologic changes in swallowing of myositis patients by examining videofluoroscopic swallow studies (VFSS) for kinematic, temporal, and functional measures of swallowing. **Methods:** VFSS of 23 myositis patients (IBM = 7, Necrotizing = 2, DM = 13, PM = 1, age range = 21 - 81) complaining of dysphagia were collected, and frame by frame analysis of temporal and kinematic measures were performed. The swallows of each subjects were rated by MBSImPª© and Penetration-Aspiration Scale. Swallowing measures from patients were compared to those from 64 healthy subjects (ages range = 18 - 90) by Wilcoxon rank-sum tests.

**Results:** In patients with myositis, food entered the pharynx earlier relative to the initiation of swallowing than in healthy participants (p < 0.0001). Myositis patients had a significantly shorter duration of upper esophageal sphincter (UES) opening and laryngeal vestibule closure than healthy subjects (p < 0.0001). There were no statistically significant differences in AP diameter of the UES between healthy subjects and myositis patients (p = 0.9). In myositis patients, several MBSImPª© component scores indicated impairment, particularly those related to residue after swallowing, base of tongue movement, and posterior pharyngeal wall movement. Aspiration was observed in 26% of the patients.

**Conclusion:** Poor endurance of swallowing muscles, which causes short UES opening and other changes in swallowing pattern, appears to be an underlying mechanism of dysphagia in patients with myositis. Our findings suggest that endurance exercises of the tongue and submental muscles are potential therapeutic targets for preservation of swallowing function in myositis patients.

## P31
miR-1 Is a Novel Biomarker for Polymyositis/dermatomyositis-associated Interstitial Lung Disease

Yumiko Sugiyama, Ryusuke Yoshimi, Mitsuhiro Takeno, Yohei Kirino, Shigeru Ohno, Hideaki Nakajima
Yokohama City University Medical Center, Yokohama, Japan; ²Nippon Medical School Graduate School of Medicine, Toyko, Japan

**Correspondence:** Yumiko Sugiyama¹

BMC Rheumatology 2019, **3**(Suppl 1):P31

**Background/Purpose:** Although intensive immunosuppressive treatment are necessary for the severe cases with polymyositis (PM)/dermatomyositis (DM), the prognostic factors or disease activity indices for PM/DM have not established yet. On the other hand, microRNAs are small non-coding RNAs, some of which have a certain function such as a transcriptional regulation. MicroRNA-1 (miR-1) has been shown to be associated with myocyte differentiation, decreased in muscle biopsy sample from patients with inflammatory myopathies. Here we investigated the association between serum miR-1 level and clinical course of PM/DM patients.

**Methods:** We retrospectively analyzed clinical features, laboratory data at baseline in patients with PM/DM patients who had received initial treatment at Yokohama City University Hospital from 2008 to 2017. We also investigated initial therapeutic regimens, clinical outcomes, and episodes of serious infection. The serum samples from PM/DM were collected before and after starting treatment and those from healthy controls were recruited from the biobank institution in the hospital. The serum miR-1 levels were measured by quantitative real-time PCR.

**Results:** Twenty-two patients (PM 4, DM 11, clinically amyopathic DM (CADM) 7) were recruited. The mean age was 63.5 ± 8.5 years, 13 (59%) were female, and 14 patients (64%) had interstitial lung disease. The serum miR-1 level was significantly elevated in PM/DM patients as compared to healthy control (p = 0.008). In PM/DM patients, the serum miR-1 level was significantly decreased by treatment (p = 0.03). There was a correlation between serum CK and miR-1 levels in PM/DM patients (p = 0.005, r = 0.58), although there was no correlation between serum CK and miR-1 levels in PM/DM-ILD patients. We identified the cutoff value of serum miR-1 level from the two standard deviations in healthy controls, and divided the PM/DM-ILD into two groups, high miR-1 group, and normal miR-1 group, by serum miR-1 level at baseline. Although there were no significant differences in the clinical data

and the initial prednisolone (PSL) dose between the two groups, PSL dose at 16 weeks and cumulative PSL dose until 16 weeks were significantly higher in the high miR-1 group (p = 0.025 and p = 0.036, respectively). We also found that serious infections were significantly more frequent in the high miR-1 group (p = 0.026).

**Conclusion:** We propose serum miR-1 as a promising novel biomarker for predicting therapeutic response in PM/DM-ILD.

## P32
Clinical significance of radiological pattern of HRCT and macrophage activation for polymyositis and dermatomyositis patients with different MSAs

Yu Zuo, Lifang Ye, Min Liu, Fang Chen, Xin Lu, Guochun Wang, Xiaoming Shu
China-Japan Friendship Hospital, Beijing, China

**Correspondence:** Yu Zuo

BMC Rheumatology 2019, **3**(Suppl 1):P32

**Objectives:** Polymyositis and dermatomyositis-associated interstitial lung disease (PM/DM-ILD) have variable courses with different myositis specific autoantibodies (MSAs) and different histopathological and radiological types. The aim of this study was to examine the different distributions of radiological types of different MSAs group, to identify the prognostic value of high-resolution computed tomography (HRCT) in PM/DM-ILD and to explore the possible mechanism.
**Methods:** The present study included 165 patients with PM/DM-ILD. The distribution of HRCT radiological type with different MSAs was analysed as well as the relationship between radiological features with the ILD course and prognosis, especially consolidation in the posterobasal portions in HRCT of patients with anti-MDA5 and aminoacyl-tRNA synthetase antibodies (ARS). In addition, immunohistochemistry analysis using anti-human CD163 antibody was performed on the lung sections of 15 patients with PM/DM-ILD to assess the macrophage activation.

**Results:** Organizing pneumonia (OP) pattern was dominant in HRCT of 165 PM/DM-ILD patients, especially in patients with anti-SAE (6/6, 100%) and patients with anti-MDA5 (46/62, 74.2%). The ratio of OP pattern and nonspecific interstitial pneumonia (NSIP) pattern was almost equal in patients with anti-ARS and NSIP pattern was associated with mild clinical course and favorable prognosis. Among patients with anti-MDA5, consolidation with a gravitationally dependent gradient in HRCT was related to rapidly progressive ILD (RP-ILD) and overall mortality. Ferritin levels >1000 ng/mL, elevated LDH and several tumor markers including CEA, CA125, CA19-9, SCC, and the presence of anti-Ro52 were significantly associated with the lower consolidation pattern in patients with anti-MDA5. Multivariate analysis revealed that ferritin levels >1000 ng/mL (odds ratio, 12.3; P=0.009), elevated CEA (odds ratio, 5.8; P=0.046) and CA19-9 (odds ratio, 7.8; P=0.018) were independent predictors of lower consolidation pattern. Meanwhile, immunohistochemical analysis of lung specimens obtained from 15 patients with DM-related ILD showed that compared with patients with anti-ARS, accumulation of CD163-positive macrophages at alveolar spaces seemed to be more evident in the lungs of patients with anti-MDA5 or only with anti-Ro52. The macrophage infiltration in the lung of cases with RP-ILD was apparently severe.

**Conclusion:** HRCT patterns at diagnosis can help predict the prognosis of patients with PM/DM-ILD. Our results also suggest the importance of macrophage activation in the disease.

## P33
Reliability of PET/TC cancer screening in a large cohort of patients diagnosed with idiopathic inflammatory myopathy

Albert Gil-Vila, Ernesto Trallero-Araguás, Marcelo Alvarado-Cardenas, Iago Pinal-Fernandez, Xavier. Martínez-Gómez, Joan Castells-Conesa, Albert Selva-O'Callaghan

Vall d'Hebron General Hospital, Barcelona, Spain

**Correspondence:** Albert Gil-Vila

BMC Rheumatology 2019, **3**(Suppl 1):P33
**Objectives:** Cancer associated myositis develops in a third of patients with idiopathic inflammatory myopathy (IIM), mainly dermatomyositis (DM). Previous data suggest that PET/CT seems to be a useful approach for cancer screening in those patients. Our aim was to ascertain the reliability of PET/CT for cancer screening in patients diagnosed with myositis from 2010 to 2018.

**Methods:** A total of 115 adult patients (74 female) were diagnosed with IIM (59 DM -20 of which amyopathic-, 14 IMNM, 36 overlap -28 ASS, 10 of them without myositis, and 8 scleromyositis-, and 6 PM). PET/CT was performed at disease onset, other confirmatory tests were carried out when data obtained with PET/CT was inconsistent in terms of cancer or not. Occult cancer was defined when cancer was diagnosed by means of PET/CT in a patient without cancer-concerning symptoms.

**Results:** PET/CT was performed mostly in patients with DM [30 out of 39 classical DM (77%), and 9 out of 20 amyopathic form (45%)]. The two main causes because some DM patients do not receive a PET/CT were MDA5 positive rapidly progressive ILD (8 cases) and a previous diagnosis of cancer (7). PET/CT was also performed in 10 out of 14 IMNM patients, 12 out of 36 overlap myositis (9 anti-synthetase positive), and 2 out of 6 PM. PET/CT raised the suspicion of cancer in 14 patients with DM/ADM. Complementary studies confirmed cancer diagnosis in 8 cases, all of them occult. Among the other myositis phenotypes only 5 out 24 patients had PET/CT findings that prompted to further evaluation, being all of them negative for cancer. Only 2 DM patients, with a normal PET/CT at disease onset developed a cancer during follow-up, one and five years respectively after DM diagnosis. None of the 104 patients in whom PET/CT was not performed, was normal or had suspicious features that were not confirmed as cancer, developed any type of malignancy at follow up (median 3 years, IQR 0.9-5.2 years). PET/CT in patients with cancer-associated DM/ADM yields a PPV of 57%, NPV of 92%, with a sensitivity of 80% and specificity of 79%, and an AUC ROC of 0.79 that means a good test for screening purposes.

**Conclusions:** PET/CT screening in real clinical practice is a good option for cancer screening in patients with DM/ADM, allowing diagnosis of occult cancer. Clinical judgement is of paramount relevance to perform this test in cases of myositis phenotypes different than DM.

## P34
### Tumour Infiltrating Lymphocytes quantification in Cancer-Associated Dermatomyositis

Javi Ros¹, Julia Lostes¹, Paolo Nuciforo², Cristina Viaplana¹, Jóse Milisenda³, Ernesto Trallero-Araguás¹, Iago Pinal-Fernandez¹, Albert Gil-Vila¹, Josep Maria Grau-Junyent³, Rodrigo Dienstmann¹, Albert Selva-O'Callaghan¹

¹Vall d'Hebron General Hospital, Barcelona, Spain; ²Instituto de Salud Carlos III, Madrid, Spain; ³dibaps-Cellex-Hospital Clinic of Barcelona, Barcelona, Spain

**Correspondence:** Javi Ros

BMC Rheumatology 2019, **3**(Suppl 1):P34

**Objectives:** Tumour infiltrating-lymphocytes (TILs) are a validated prognostic marker in different neoplasms and have been linked to anti-tumour immune response. Dermatomyositis (DM) is an autoimmune disorder frequently associated with cancer. Our aim was to quantify the intensity of TILs in a series of patients diagnosed with cancer-associated dermatomyositis (CADM).

**Method:** A total of 16 adult patients (12 female, 4 amyopathic), with mean (SD) age 55.3 (4.8) diagnosed with CADM (cancer occurring within 3 years of the DM diagnosis), were proposed for the study of the presence and density of TILs. Immunological profile and DM outcome in regard with cancer evolution and chemotherapy were also analysed. Histopathologic analysis of the proportion of TILs was done in whole sections of tumour tissue stained with hematoxylin and eosin. TILs were quantified according to the 2014 Guidelines developed by the International TILs Working Group. Briefly, TILs are reported as an overall percentage of the stromal area within the borders of the invasive tumour that is covered by mononuclear immune cells.

**Results:** Nine out of 16 patients had remaining tissue available for TILs quantification. Ten patients, 7 anti-TIF1g (+), 2 anti-NXP2 (+), and 1 anti-MDA5 (+) presented as paraneoplastic (DM runs in parallel with the activity of cancer), and the other 6, 4 anti-TIF1g (+), 1 anti-MDA5 (+), and 1 without antibodies, flared after chemotherapy treatment. The types of neoplasms studied for TILs quantification were as follows: small cell lung cancer (SCLC, 3 patients), breast cancer (2 patients), cervical cancer (2 patients), colorectal, and ovarian cancer (one patient each). Only the 2 SCLC cases had low percentage of TILs (1%) and 6 patients had "hot" tumours (> 20% TILs), with the all gynaecological cancers displaying unusually high levels (30%, 50%, 60%).

**Conclusions:** Microenvironment TILs density is a potential predictor of response to immune checkpoint inhibitors (ICIs). Until now, patients with autoimmune disorders have been consistently excluded from clinical trials with these agents. CADM may be a surrogate of an active immune response, also in the tumor microenvironment with high infiltration with TILs. Our preliminary findings open the door for careful evaluation of ICIs in patients with CADM. We will expand our cohort and perform more in-depth biomarker research (tumour mutation burden and PDL1 expression).

## P35
### Traditional and disease-related risk factors for arterial and venous thrombotic events (TE) in idiopathic inflammatory myopathies (IIM)

Antonella Notarnicola, Simone Barsotti, Linnea Näsman, Quan Tang, Marie Holmqvist, Ingrid E. Lundberg, Aleksandra Antovic
Karolinska Institute and Karolinska University Hospital, Stockholm, Sweden

**Correspondence:** Antonella Notarnicola

BMC Rheumatology 2019, **3**(Suppl 1):P35

**Objectives:** To assess the prevalence of traditional and disease-related risk factors for arterial and venous TE in patients with IIM by comparing those reporting TE (cases) with those without history of TE (comparators). To compare clinical characteristics, autoantibody profile inclusive antiphospholipid antibodies (aPL) and serum levels of adhesion molecules (VCAM, ICAM and e-selectin) between cases and comparators as well as between cases reporting arterial versus venous TE.

**Methods:** Using national and international registries, and medical charts, we identified 58 cases and 158 comparators with IIM followed at Karolinska University Hospital between 1993 and 2014. Information on gender, age at the time of diagnosis, IIM subgroup, presence of interstitial lung disease (ILD), myositis specific antibodies (MSAs), was retrospectively collected. Information on traditional risk factors for arterial and venous TE (essential hypertension, diabetes mellitus, dyslipidemia, smoking, malignancy) was retrieved for both groups. Serum levels of aPL and adhesion molecules were analyzed in stored sera from the time of diagnosis in both groups, before TE in cases and in 40 age and gender matched heathy controls (HC).

**Results:** One out of 5 IIM patients (22,92%) had suffered from at least one TE, which was observed especially during the first 5 years after diagnosis. Myocardial infarction was the most frequent TE, followed by pulmonary embolism and deep venous thrombosis. In the multivariate analysis, male gender and older age were independent risk factors for TE. Essential hypertension had statistically significant higher prevalence in cases than comparators. Arterial TE was more common in polymyositis, while venous TE occurred more frequently in patients with dermatomyositis, history of malignancy and in those with MSAs. At time of IIM diagnosis, the prevalence of aPL was 6% with no difference between cases and comparators. Significantly higher levels of VCAM and ICAM were obtained in IIM patients compared to HC but without difference between cases and comparators. Lower levels of e-selectin were associated with higher odds of developing TE, especially in males and older patients, with no difference between arterial and venous TE.

**Conclusions:** A high risk of arterial and venous TE should be taken into account in patients with IIM, particularly close to time of diagnosis, with extra attention in male patients and older individuals.
Preventive measures should be considered especially in patients with concomitant essential hypertension and malignancy. Lower serum levels of e-selectin might predict TE in IIM patients but the mechanism for this risk factor is not known.

## P36

**The potassium channel KCNK2 is a regulator of immune cell trafficking and inflammatory responses in idiopathic inflammatory myopathies**

Thomas Müntefering
University Clinic Münster, Münster, Germany
BMC Rheumatology 2019, **3**(Suppl 1):P36

**Objectives:** KCNK2, a two-pore domain potassium channel, has been implicated as important regulator of leukocyte transmigration into the central nervous system (CNS). In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, Kcnk2-/- mice demonstrated an increased disease severity with facilitated immune-cell migration into the CNS. An upregulation of cellular adhesion molecules on brain endothelial cells in Kcnk2-/- mice were found as potential underlying mechanisms. Of note, immune-cell infiltration into the muscle is also a pathogenic hallmark of idiopathic-inflammatory-myopathies (IIM), however the underlying mechanisms remain to be elucidated. Following our previous results, we therefore investigated if KCNK2 might also be involved in the peripheral autoimmune responses of IIMs.

**Methods:** Murine muscle tissue was dissociated and primary murine microvascular endothelial cells (PMMEC) and primary murine muscle cells (PMMC) were isolated by magnetic-activated cell sorting technique. Purified primary cells were cultured and KCNK2 gene expression was measured by qPCR whereas protein expression was detected by western blot. Pro-inflammatory and adhesion molecule expression in stimulated primary cells were investigated via flow cytometry. To test the functional role of KCNK2 for the interaction of T cells and PMMEC in vitro, we used a flow assay. Further, the regulatory role of KCNK2 for the migratory behavior of T cells in vivo was characterized by intravital microscopy of cremaster muscle microvessels.

**Results:** In accordance to our previous results, we found KCNK2 expression in primary murine microvascular endothelial cells (PMMEC) and in primary murine muscle cells (PMMC) on gene and protein level. Stimulation with pro-inflammatory cytokines led to a downregulation of KCNK2 expression on differentiated PMMC and PMMEC. KCNK2 knockout or pharmacological blockade with spadin increased pro-inflammatory and adhesion molecule expression in muscle and endothelial cells. Correspondingly, we found significantly more adhered T cells on KCNK2-/- PMMEC in vitro under low shear flow and in vivo in cremaster muscle microvessels.

**Conclusion:** In summary, KCNK2 might be critically involved in the regulation of immunological processes in the skeletal muscle, especially immune cell trafficking. These regulatory mechanisms might be impaired in IIMs and therefore represent targets for new therapeutic strategies.

## P37

**Infection in patients with Idiopathic Inflammatory Myopathies**

Yong-Peng Ge, Guo-Chun Wang, Xin Lu, Si-Zhao Li, Lin-Rong He
China Japan Friendship Hospital, Beijing, China

**Correspondence:** Yong-Peng Ge
BMC Rheumatology 2019, **3**(Suppl 1):P37

**Objectives:** To assess the incidence and characteristics of infections in idiopathic inflammatory myopathies (IIM) patients and to analyze the risk factors for infections on clinical presentation and biochemical findings of IIM.

**Methods:** The medical records of IIM patients followed up in a single medical center from January 2008 to December 2017 were retrospectively reviewed.

**Results:** In the 779 IIM patients, 215 (27.6%) suffered from infections. The incidence of infection in dermatomyositis (DM) (29.8%) was more than polymyositis (PM) (18.5%). Pulmonary infection was the most common infection site (66.5%). Opportunistic infections comprised 37.7% of all infectious episodes. Multivariate analysis showed that pulsed methylprednisolone (OR 3.22; 95% CI 1.60-6.48; P = 0.001), age of onset >50 years (OR 1.02; 95% CI 1.00-1.03; P = 0.011), anti-melanoma differentiation-associated gene 5 (MDA5) antibody (OR 1.93; 95% CI 1.20-3.11; P = 0.007), lymphocyte count < 1200/mm3 (OR 2.85; 95% CI 1.89-4.30; P < 0.001) and interstitial lung diseases (ILD) (OR 2.03; 95% CI 1.30-3.71; P = 0.002) are risk factors for infections. Survival analysis showed that survival rate in infection group was lower than no-infection group (69.8% vs 92.9%, P < 0.001).

**Conclusion:** Among hospitalized individuals with IIM, infection is frequency and the leading cause of mortality. Anti-MDA5 antibody, lymphopenia, ILD, old age of onset and treatment with methylprednisolone pulse are contributing factors for the development of infections in IIM patients. Strategies to lower infection risk in IIM patients should be evaluated to improve disease outcomes.

## P38

**Frequency, Risk factor, Outcome and Prognostic factor in Calcinosis of Adult Idiopathic Inflammatory Myopathy: Single Center Cohort Study**

Wei Jiang, Kanbo Yang, Sizhao Li, Xiaolan Tian, Lu Zhang, Xin Lu, Guochun Wang
China-Japan Friendship Hospital, Beijing, China

**Correspondence:** Wei Jiang
BMC Rheumatology 2019, **3**(Suppl 1):P38

**Objective:** To determine the prevalence of calcinosis and to analyze clinical features and risk factors for calcinosis in adult idiopathic inflammatory myopathy(IIM). To assess outcomes in adult patients with calcinosis, with emphasis on survival probability and prognostic factors.

**Methods:** A total of 480 patients with clinical data were collected. Multiple factors logistic regression model analysis was performed to assess the risk factors for calcinosis in adult IIM. Survival probability at 1, 5 and 10 years was estimated according to the Kaplan-Meier method. Cox regression was used to analyze the prognostic factors for calcinosis.

**Results:** The frequency of calcinosis in adult IIM was 4.6% in our cohort. Patients with calcinosis had a longer disease duration(P=0.000)and more myothenia(P=0.038), panniculitis(P=0.011), perlungual erythematosus(P=0.011), skin ulcer(P=0.000), raynaund's phenomenon(P=0.035). The anti-NXP2 antibody(P=0.000)and anti-MDA5 antibody(P=0.021)were more frequently found in patients with calcinosis. Multiple factors logistic regression showed that anti-NXP2 antibody(OR=10.899, 95%CI 2.593, 45.816), long diseases duration(OR=1.105, 95%CI 1.008, 1.021) and skin ulcer(OR=31.585, 95%CI 10.683, 93.387) were the risk factors of calcinosis in adult patients. The survival probability at 1, 5 and 10 years respectively were 95.8%, 91.3%, 91.3%. Patients with calcinosis improvement had lower baseline calcification VAS score(P=0.035), higher rate of V sign(P=0.033) and clinical remission within 3 months(P=0.04). Clinical remission within 3 months(HR=0.236) was the protective factor for calcinosis.
**Conclusion:** Calcinosis was uncommon clinical feature in our cohort. Long disease duration, skin ulcer and anti-NXP2 positive were independent risk factors for calcinosis. Adult patients with calcinosis were lower mortality. Clinical remission within 3 months was the protective factor for calcinosis, which indicated that aggressive treatment for patients with calcinosis at very early stage of disease may improve the outcome of calcinosis.

P39

**A single center experience using a clustering approach to identify
clinico-serological phenotypes in Idiopathic Inflammatory**

**Myopathies**

Valérie Leclair, Angeles Shunashy Galindo Feria, Ingrid E. Lundberg, Leonid Padyukov, Lina Marcella Diaz-Gallo Karolinska Institutet, Stockholm, Sweden

**Correspondence:** Valérie Leclair

BMC Rheumatology 2019, 3(Suppl 1):P39

**Background:** A large number of idiopathic inflammatory myopathy (IIM) patients are presenting extramuscular features. Novel approaches to identify more homogenous IIM subgroups are explored to improve the classification of these patients for research and clinical purposes. The aim of this project is to use a clustering approach to identify subgroups of IIM patients based on serological and clinical features.

**Methods:** We included 319 Swedish IIM subjects followed in the EuroMyositis registry, regardless of their specific subset. The occurrence of 18 autoantibodies was determined: anti-Jo1, -PL7, -PL12, -EJ, -OJ, -SRP, -RNP, -Ro, -Mi2, -TIF1g, -MDA5, -Ku, -PmScl, -PmScl75, -PmScl100, -SAE1, -NXP2 and -HMGCR. A cluster analysis was done using Gower distance matrix followed by partition around medoids cluster calculation. The number of clusters was validated using Silhouette metric. Logistic regression was applied to estimate the p-value, odds ratios (OR) and 95% confidence intervals (CI) of having a clinical manifestation depending on the cluster assigned.

**Results:** Figure 1 presents six (1-6) clusters based on the occurrence of 18 autoantibodies, while Table 1 shows the relations between specific clinical manifestations and each cluster. Each cluster is grouped around a medoid representing the predominant antibody profile of that group: 1) antibody negative (49%), 2) Jo1+Ro+ (11%), 3) Jo1-Ro+ (19%), 4) Jo1+Ro- (9%), 5) PmScl+ (6%), and 6) TIF1g+ (7%). Compared to the other clusters, muscle weakness was significantly more prevalent in cluster 1. In cluster 2, ILD was strongly overrepresented, and arthritis and mechanic's hand were common. Heliotrope rash and ulcerations were more frequent in cluster 3 compared to the other clusters. Subjects in cluster 4 had significantly more ILD, arthritis and mechanic's hand, but to a lesser extent than cluster 2. For cluster 5, Raynaud, calcinosis and ulceration were more frequent than in other clusters. Heliotrope rash and Gottron's papules or sign were more frequent in cluster 6.

**Conclusion:** These preliminary results indicate that IIM individuals can be grouped in six clinico-serological phenotypes. Further studies are needed to validate these results in other cohorts.

P40

**Creatinin- and cystatin C-estimated glomerular filtration rate for
estimating renal function during inclusion body myositis**

Olivier Mangin¹, Jean Philippe Bertocchio², Yves Allenbach¹, Gerard Maruani², Pascal Houillier², Olivier Benveniste¹

¹Hôpital Pitié Salpêtrière, Paris, France; ²Hôpital Européen Georges-Pompidou, Paris, France

**Correspondence:** Olivier Mangin

BMC Rheumatology 2019, 3(Suppl 1):P40

Creatinin is creatin metabolite. The main glomerular filtration rate (GFR) estimation formulas use creatininemia and thus rely upon muscular mass. Inclusion body myositis (IBM) is an acquired myopathy leading to amyotrophia. It only concerns senior patients, a population with a high incidence of chronic kidney disease (CKD). Our objective was to find out whether GFR estimations based on creatininemia are reliable in

IBM patients. 20 patients from the internal medicine service of the Pitié Salpêtrière hospital in Paris had their GFR simultenously measured with 51Cr-EDTA (GFRm) and estimated (GFRe) with MDRD, CKD-EPI creatinin and CKD-EPI C cystatin. Creatininemia and 24h urines were sampled the day before. The body composition (lean appendicular mass) was measured by X ray biphotonic absorptiometry (DXA). Height men and twelve women, aged 65±9 years were included. Their mean lean appendicular mass and creatininemia were in the lower values of normal, respectively -1.85 [-2.50;-1.18] and 43.5µM [35,3-56,8]. GFRm was 78±18 mL/min/1.73m2, height patients (40%) had a CKD according to KDIGO 2012 criteria, and four of them had a GFRm < 60mL/min/1.73m2 ; GFRm were 157±64, 109±18, 54±17 mL/min/1.73m2, respectively with MDRD, CKD-EPI creatinin and CKD-EPI C cystatine formulas. The average measurement bias were 80±55, 32±17 and -24±17mL/min/1.73m2, respectively. There was no statistically significant correlation between the lean appendicular mass and GFRm measurement bias. Only the patients without CKD were correctly classified, whatever the formula. Amongst these patients with low muscular mass, GFR estimation based on creatininemia or C cystatine is biased, especially with MDRD formula. This measurement bias prevents the diagnostic and classification of CKD in these patients. Using those formulas may lead to a delay in the care of CKD and also overdoses of drugs eliminated by the kidneys. In our population, using a CKD-EPI creatinin eGFR threshold of 100mL/min/1.73m2, the sensitivity to screen stage ≥ 3 CKD is 100% and specificity 87.5% (χ2=11.67). Surprisingly the bias between eGFR and mGFR were not correlated with lean appendicular mass. This may be explained by the small size of our population, but also by the muscle quality which isn't assessed by DXA. During IBM, GFR is surestimated by usual estimation formulas in spite of a moderately lower muscular mass. GFR estimation formulas don't allow to screen CKD in this population. We propose that each IBM patient with a CKD-EPI creatinin eGFR < 100mL/min/1.73m2 has a measure of GFR with

P41

**Design of Phase 3 Study of Lenabasum for the Treatment of
Dermatomyositis**

Victoria P. Werth¹, Chester V. Oddis², Ingrid E. Lundberg³, David Fiorentino⁴, Caitlin Cornwall⁵, Nancy Dgetluck⁵, Scott Constantine⁵, Barbara White²

¹University of Pennsylvania, Philadelphia, USA; ²University of Pittsburgh, Pittsburgh, USA; ³Karolinska Institutet, Stockholm, Sweden; ⁴Stanford University, Stanford, USA; ⁵Corbus Pharmaceuticals, Massachusetts, USA

**Correspondence:** Victoria P. Werth

BMC Rheumatology 2019, 3(Suppl 1):P41

**Objectives:** To provide Phase 3 efficacy and safety data on lenaba-sum for the treatment of DM.

**Methods:** Lenabasum is a synthetic, non-immunosuppressive, selective cannabinoid receptor type 2 agonist that activates resolution of innate immune responses. Lenabasum had acceptable safety and tolerability and improved efficacy outcomes in the double-blinded, randomized, placebo-controlled Phase 2 trial in dermatomyositis (DM) subjects with refractory, skin-predominant involvement. Phase 3 trial design was based on Phase 2 data, input from a steering committee of experts in DM clinical trials, and recommendations made by FDA at an End-of-Phase 2 meeting. Input from EMA and PMDA is pending.

**Results:** A global, double-blind, randomized, interventional design was chosen to provide an unbiased assessment of the efficacy, safety and tolerability of lenabasum 20 mg bid and 5 mg bid compared to placebo in the treatment of DM. A 52-week treatment duration was selected to provide safety and efficacy data adequate to support chronic treatment of DM patients. Eligibility criteria include DM patients with active disease, allowing for a range of muscle, skin, and other disease manifestations. Subjects must be on stable doses of current DM treatments with any background immunosuppressive medications allowed except prednisone ≥ 20 mg per day or equivalent. This inclusivity allows testing of efficacy and safety of lenaba-sum in the setting of current treatment practice and reduces risk of disease flare early in the study. The primary efficacy outcome is change from Baseline in 2016 ACR/EULAR Total Improvement Score
(TIS). This composite outcome has six domains that broadly capture improvement in disease activity, is relevant to the range of manifestations in DM, and is applicable to the assessment of efficacy in the target patient population. Secondary efficacy outcomes were chosen to reflect how the subject functions (Short Form – 36 physical functioning domain), assess major organ involvement (MMT-8, CDASI activity score, and a new Investigator Global Assessment scale of skin activity designed specifically for this study), and measure lung function (FVC). Change in oral corticosteroid dose also will be captured.
Conclusions: To our knowledge, this is the first Phase 3 study in DM with a new molecular entity and primarily sponsored by industry. As such, agreement with experts and regulatory authorities on design represents a step forward in the development pathway of new treatments for DM.

## P42

### Patient reported outcome core set for adult idiopathic inflammatory myopathies

Christopher Mecoli¹, Malin Regardt, Jin Kyun Park, Ingrid de Groot, Catherine Sarver, Merrilee Needham, Marianne de Visser, Clifton Bingham III, Ingrid Lundberg, Yeong Wook Song, Helene Alexanderson, Lisa Christopher-Stine
Johns Hopkins University School of Medicine, Baltimore, USA

**Correspondence:** Christopher Mecoli

BMC Rheumatology 2019, **3**(Suppl 1):P42

**Objective:** Currently, the patient-reported outcome measures (PROMs) included in the IMACS Core Set (HAQ-DI, Patient Global Activity Visual Analog Scale) fall short in encapsulating the myositis life experience of adult IIM patients. Our goal is to develop a patient-reported outcome core domain set specific to idiopathic inflammatory myopathies (IIM) following methodology outlined by Outcome Measures in Rheumatology (OMERACT).

**Methods:** The OMERACT Myositis Working Group consists of IIM experts and qualitative methodologists from Sweden, The USA, The Netherlands, Australia, and South Korea, as well as IIM patient research partners. Over a 6-year period, 11 international focus groups and three modified Delphis were performed with multiple stakeholder groups including patients, healthcare providers, and primary caregivers. From these results, we developed a preliminary PRO core domain set in agreement with OMERACT methodology.

**Results:** Four domains - muscle symptoms, fatigue, levels of physical activity and pain, achieved widespread consensus to be assessed in all clinical research studies. Three additional domains - lung, joint, and skin symptoms were considered mandatory only in specific circumstances. Additional domains (including cognitive effects, emotional distress, sleep quality, and GI symptoms) were deemed important for further research. This core set was strongly endorsed in OMERACT 2018 by patients, healthcare providers, and qualitative researchers.

**Conclusion:** We propose a PRO core set for patients with adult IIM. The next steps of the Myositis OMERACT Working Group are to develop and validate instruments to measure these domains.

## P43

### Preliminary Response to Janus Kinase (JAK) Inhibition with Baricitinib in Refractory Juvenile Dermatomyositis

Hanna Kim, Samantha Dill, Michelle O'Brien, April Brundidge, Lisa G. Rider, Robert A. Colbert
National Institute of Arthritis and Musculoskeletal and Skin; Bethesda, USA

**Correspondence:** Hanna Kim

BMC Rheumatology 2019, **3**(Suppl 1):P43

**Objectives:** Juvenile dermatomyositis (JDM) is a systemic autoimmune disease with a prominent interferon (IFN) signature. Treatment is generally empiric, requiring prolonged high-dose steroids and often ≥2 other immunosuppressive medications. In a compassionate use program, we assessed efficacy and safety of baricitinib (JAK 1/2 inhibitor) in active refractory JDM.

**Methods:** Active (based on ≥3 core set measures (CSM)) and refractory (active after high dose steroids and ≥2 other medications, including ≥1 biologic therapy) JDM subjects were enrolled after washing out biologic agents other than IVIG. Baricitinib was dosed based on weight and renal function. Primary outcome was reduction in symptom daily diary score (DDS) of weakness, fatigue, musculoskeletal pain, and rash. Other assessments included International Myositis Assessment and Clinical Studies (IMACS) disease activity CSMs, including manual muscle testing (MMT8), as well as Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). Paired t-test was used to compare baseline to 12 weeks. Safety and tolerability were also assessed.

**Results:** Four JDM patients (5.8-20.7 years old) who had failed high dose steroids, IVIG, and at least 1 other medication were enrolled (NCT01724580). Patients received baricitinib 4-8 mg/day PO divided BID. After 12 weeks, DDS reduced from a mean of 2.0 (range 1.1-2.3) to 1.0 (0.8-1.3; mean decrease 46%, p=0.02). Physician global activity visual analog scale (VAS) decreased from a mean of 5.2 (3.5-7.7) to 3.9 (3.0-6.0; 24% decrease, p=0.04). In the 2/4 with baseline weakness, MMT8 increased from 108 to 134 and 116 to 141 (mean improvement 23%). Extramuscular global VAS decreased from mean 5.2 (3.0-7.7) to 3.6 (1.0-4.9; mean 34% decrease, p=0.047). CDASI activity score reduced from mean 42 (26-53) to 27 (18-46; mean improvement 35%, p=0.04). One individual reduced prednisone dose from 21 to 16.5 mg/day; 3 patients' doses remained unchanged. Baricitinib was generally well tolerated. One patient had an increase in plasma BK viral titer; the other 3 patients were negative for BK virus in blood and urine. No adverse events required holding/discontinuing baricitinib.

**Conclusions:** Preliminary data on the use of baricitinib (JAK 1/2 inhibitor) in refractory JDM patients are encouraging, showing improvement in symptom DDS as well as in validated measures of rash (4/4) and strength (2/2 with baseline weakness), and other CSMs. Baricitinib was generally well tolerated and further evaluation in this population should be considered. Disclosures: Baricitinib provided by Eli Lilly and Company, expanded access program sponsor.

**Other support:** Intramural Research Program of NIH, NIAMS, NIEHS, CC.

## P44

### Intravenous iMMunoglobulins as early treatment in newly DIagnosed idiopathic inflammaTory myopathiEs (IMMEDIATE): a phase-2 open-label pilot study.

Johan Lim, Myrthe Jaring, Amin Amin, Yigal Pinto, Nils Planken, Matthijs Boekholdt, Anneke van der Kooi
University of Amsterdam; Amsterdam, Netherlands

**Correspondence:** Johan Lim

BMC Rheumatology 2019, **3**(Suppl 1):P44

**Background:** Cardiac involvement in patients with myositis - a group of rare auto-immune disorders - causes myositis-related mortality in approximately 5%, yet standardized and evidence-based screening strategies lack. Therefore, we explored different diagnostic modalities to screen for cardiac involvement in new-onset myositis, and potentially reversible peri/myocarditis in particular.

**Methods:** Adult patients with biopsy-proven myositis from April 2017 to April 2018 were consecutively included at three neuromuscular referral centers in The Netherlands. All patients were referred to a cardiologist for standardized clinical evaluation and cardiac investigations at diagnosis which consisted of: cardiac enzymes (cardiac troponin T, cardiac troponin I, and N-terminal pro b-type natriuretic peptide, electrocardiography (ECG), cardiac ultrasound (US; consisting of standard and strain investigations), and cardiac Magnetic Resonance Imaging (MRI; amongst others consisting of late gadolinium enhancement, T1 mapping, and extracellular volume investigations). Peri/myocarditis and/or other cardiac abnormalities were defined as cardiac involvement at the discretion of the treating physician.

**Results:** We included 25 patients: 11 with dermatomyositis, seven with immune-mediated necrotizing myopathy, four with non-specific myositis/overlap myositis, and three with anti-synthetase syndrome. Median age at onset was 56 years (range: 25-80 years). There was a female predominance of patients (F:M ratio of 2:1). The median
disease duration at diagnosis was five months (range: 1-25 months). Three of 25 (12%), three of 23 (14%), six of 23 (26%), and 11 of 13 (85%) patients were already treated with immunosuppressants during evaluation of cardiac enzymes, ECG, US and MRI, respectively. Eleven patients (44%) had complaints (dyspnea, palpitations, peripheral edema, atypical chest pain) of possible cardiac origin at time of diagnosis. One of six patients (17%) with clinical relevant abnormalities on ancillary investigations had none of the abovementioned complaints. We found four cases (16%) of peri/myocarditis confirmed by cardiac MRI and one suspected case of peri/myocarditis as assessed by the treating cardiologist. Other signs of cardiac involvement were arrhythmias in two patients; no cases of cardiac failure or pulmonary hypertension were found. We found that peri/myocarditis was reversible on cardiac MRI after 9 weeks of intravenous immunoglobulin (IVIg) monotherapy in at least one patient.

**Conclusion:** Early multimodality screening for potentially reversible cardiac involvement in myositis has added value as illustrated by the number of patients with (suspected) peri/myocarditis (16%) and the patient whose peri/myocarditis improved IVIg therapy. A subsequent RCT on an alternative treatment regimen for cardiac involvement in myositis on clinical outcome is needed.

P45

Preliminary prospective validation of the juvenile dermatomyositis activity index (JDMAI)

Silvia Rosina¹, Giulia Camilla Varnier², Alessandro Consolaro¹, Pieter van Dijkhuizen¹, Kiran Nistala², Nicola Ruperto¹, Angela Pistorio¹, Clarissa Pilkington¹, Angelo Ravelli¹

¹Istituto Giannina Gaslini, Genova, Italy; ²Great Ormond Street Hospital, London, UK

**Correspondence:** Silvia Rosina

BMC Rheumatology 2019, **3**(Suppl 1):P45

**Objectives:** To test prospectively the validity of the first composite disease activity score for juvenile dermatomyositis (JDM), named JDMAI, in a sample of patients seen in daily practice. The 6 preliminary versions of the tool performed similarly in previous validation analyses.

**Methods:** 57 JDM patients seen consecutively at 2 tertiary-care paediatric rheumatology centers, either at disease onset or at a follow-up visit, a median of 2 years after disease onset, were enrolled. Each patient received a retrospective assessment and a cross-sectional evaluation at study entry. 30 patients also underwent a second assessment after a median of 3.6 months. Physician-centered evaluations included assessment of muscle, skin and overall disease activity on a visual analogue scale (VAS) or through the Disease Activity Score (DAS), rating of disease state and course and measurement of disease damage with the Myositis Damage Index (MDI). Laboratory data comprised muscle enzymes and ESR. Parent-reported outcomes were collected through the administration of the Juvenile Dermatomyositis Multidimensional Assessment Report (JDMAR). Validation analyses included assessment of construct validity, internal consistency (with Cronbach's α), discriminant ability, and responsiveness to change in disease state over time (with standardized response mean, SRM).

**Results:** All JDMAI versions showed strong ($r > 0.7$) correlations with muscle disease activity VAS (0.83-0.84), muscle section of DAS (0.78-0.80), total DAS (0.86-0.89), pain VAS (0.71-0.74), and fatigue VAS (0.88-0.89). The correlations of the different JDMAI versions with the skin index not contained in the specific version (skin disease activity VAS or skin section of DAS) were strong (0.72-0.76). As expected, JDMAI correlations were moderate ($r=0.4-0.7$) or low ($r < 0.4$) with laboratory parameters and with the MDI (0.04-0.52). The SRM was greater in patients judged as improved by the physician or the parent (0.83-1.15) than in those judged as not improved (0.02-0.51). Cronbach's α was very high (0.884-0.900) for all JDMAI versions. All JDMAI versions discriminated strongly between patients classified in different disease activity states by the physician ($p < 0.0001$) or by the parent ($p=0.011-0.031$), and between patients whose parents were satisfied or not with their children's disease status ($p \le 0.0001$).

**Conclusion:** Validation analyses in this prospective patient sample confirmed that the JDMAI possesses good measurement properties and is a suitable and reliable tool for the assessment of disease

activity in children with JDM both in clinical practice and research. Importantly, the new tool revealed a strong capacity to capture the improvement of disease activity over time.

P46

Nodular Regenerative Hyperplasia of the Liver in Juvenile Dermatomyositis

Rita Volochayev, David E. Kleiner, Prateek Gowda, Anusha Vittal, Theo Heller, Lisa G. Rider

National Institutes of Health, Bethesda, USA

**Correspondence:** Rita Volochayev

BMC Rheumatology 2019, **3**(Suppl 1):P46

**Objectives:** To present two cases of Nodular Regenerative Hyperplasia (NRH) of the liver associated with Juvenile Dermatomyositis (JDM).

**Methods:** We reviewed liver biopsies of four JDM patients from a cohort of 159 patients, and two had changes consistent with NRH. A PubMed search revealed 2 patients with NRH in adult Polymyositis and Dermatomyositis, but no previously reported cases in JDM.

**Results:** Case 1. Nine-year-old male with anti-MJ autoantibodies, diagnosed with JDM at two years of age, with chronically active disease with severe weakness and rashes, severe calcinosis and dysphagia, dysphonia, colitis with diarrhea and weight loss, hepatosplenomegaly, and portal hypertension. Prior immunosuppressive medications, often used in combination, included prednisone, mycophenolate mofetil, azathioprine, methotrexate, cyclophosphamide, hydroxychloroquine, etanercept, infliximab, abatacept, and tocilizumab. Blood laboratories were notable for development of elevated liver enzymes (ALT 84 U/L (5-30), AST 83 U/L (0-40), GGT 72 U/L (3-22), Aldolase 11.6 U/L (1.0-8.0); normal alkaline phosphatase and total bilirubin; and decreased Platelet Count 127K (206-369K). Hepatitis, HIV and Epstein Barr testing was negative for active infection. Abdominal ultrasound showed splenomegaly and portal hypertension. Liver biopsy showed vaguely nodular architecture that on reticulin stain revealed regenerative nodules bounded by atrophic liver plates, with mild sinusoidal fibrosis and congestion, diagnostic of NRH. Case 2. 18-year-old Asian female with anti-MDA5 autoantibodies, diagnosed with JDM at age 16, who had ulcerative skin lesions, Raynaud's, arthritis, and interstitial lung disease with pulmonary hypertension, moderate to severe weakness, calcinosis and chronically active disease. Medications included prednisone, methotrexate, abatacept, cyclophosphamide, tofacitinib, and sildenafil. Laboratories were remarkable for elevated alkaline phosphatase of 133 U/L (35-105), ALT 34 U/L (0-33), AST 43 U/L (0-32), GGT 89 U/L (0-39), and progressively decreasing platelet count of 154K (173-369K), but normal Aldolase at 4.9 U/L (1.0-8.0). Hepatitis, HIV and Epstein Barr testing was negative for active infection. Ultrasound of liver, abdomen and spleen was normal. Elastography was 1.63 m/s and FibroScan 11 kPa, in a range indicative of fibrosis. Liver biopsy showed nodular parenchyma without fibrosis, that on reticulin stain also demonstrated characteristic regenerative nodules bounded by atrophic liver plates.

**Conclusion:** We have identified 2 cases of NRH in patients with severe JDM via liver biopsy, which is currently the only way to diagnose NRH. Both patients received Azathioprine, which has been associated with NRH, and had severe, chronically active disease. These patients need to be monitored for complications of NRH, including development of portal hypertension and varices.

P47

Preliminary Validation of Rectus Femoris Muscle Ultrasound in Juvenile Dermatomyositis

Erica McBride¹, Gulnara Mamyrova¹, Michael Harris-Love², Ahalya Premkumar², Deloris Koziol², Jianhua Yao², Lawrence Yao², Joseph Shrader², Rodolfo Curiel¹, Lisa Rider²

¹George Washington University, Alexandria, USA; ²National Institutes of Health, Bethesda, USA

**Correspondence:** Erica McBride

BMC Rheumatology 2019, **3**(Suppl 1):P47
Objectives: The goal of this study was to examine muscle ultrasound (MUS) parameters in Juvenile Dermatomyositis (JDM), to assess correlation with disease activity and damage, and to compare the sensitivity and specificity of MUS to magnetic resonance imaging (MRI).

Methods: MUS of the right mid-rectus femoris (RF) using the Acuson Sequoia was performed in 21 JDM patients (PTS) meeting probable or definite Bohan and Peter criteria and 28 age-, gender- and race-matched healthy controls (CON). Quantitative MUS parameters of patients were correlated (Spearman rank) with JDM disease activity and damage assessments and semi-quantitative thigh MRI short tau inversion recovery (STIR) and T1 scores. Echogenicity and Doppler was quantified using imaging processing software. The area under the receiver operating characteristic (ROC) was used to compare sensitivity and specificity of MUS to MRI.

Results: The median age at diagnosis of JDM PTS was 12 years, 67% were female, 81% were Caucasian. The median age of CON was 14.1 years, with similar gender and races as PTS. Median MD Global Disease Activity was 3.1 cm and MD Global Disease Damage was 1.9 cm (10 cm VAS). There was a significant increase in RF echogenicity [median 47.8 in PTS vs. 38.5 CON, p=0.002], in JDM PTS compared with CON. Mean echogenicity correlated with MD Global Activity (rs=0.46, p=0.04) and inversely with MMT (rs -0.54, p ≤ 0.01). Resting and contracted RF area inversely correlated with MD Global Activity (rs -0.46-; -0.56, p=0.04) and positively with proximal MMT (rs=0.47 -0.79, p ≤ 0.03). Contracted RF area also correlated with CMAS (rs=0.80, p < 0.0001) and serum creatinine kinase (CK) (rs=0.47, p=0.03). Several MUS parameters also correlated with isometric dynamometry: notably, QMT Knee Extension correlated with RF area (rs=0.76, p < 0.0001) and RF contracted area (rs=0.86, p < 0.0001). MUS echogenicity moderately correlated with both STIR (rs=0.43 p=0.058) and T1 MRI sequences (rs=0.55, p=0.01). T1 MRI correlated with the difference in RF area between the contracted and resting states (rs=0.62, p=0.004). The area under the curve by ROC analysis of MUS echogenicity vs. STIR MRI was 0.75, and using an average of STIR and T1 MRI, improved to 0.87.

Conclusions: Several MUS parameters of RF differed between JDM vs. CON. MUS also had moderate to strong construct validity with JDM disease activity, strength and MRI measures. MUS echogenicity has strong sensitivity and specificity compared to MRI, and is a promising imaging modality for JDM patients.

## P48
### Circulating microparticles as potential markers of disease progression and vascular dysfunction in Juvenile Dermatomyositis

Charalampia Papadopoulou¹, Ying Hong¹, Petra Krol¹, Yiannis Ioannou², Clarissa Pilkington¹, Marietta Charakida³, Lucy R. Wedderburn¹, Paul Brogan¹, Despina Eleftheriou¹

¹Great Ormond Street Institute of Child Health, London, UK; ²Arthritis Research UK, Chesterfield, UK; ³University College London, London, UL

Correspondence: Charalampia Papadopoulou

BMC Rheumatology 2019, **3**(Suppl 1):P48

Background: JDM is an autoimmune disease characterised by proximal muscle weakness and pathognomonic skin rashes. Vasculopathy plays a central role into disease pathogenesis. There is, however, a lack of appropriate biomarkers to detect and monitor endothelial injury and persistently high disease activity relating to the vasculopathy of JDM. Microparticles (MP) are membrane vesicles released during cell activation or apoptosis that can allow tracking of endothelial injury and cellular activation. MP also have important pro-coagulant properties.

Objectives: To investigate the MP profiles associated with endothelial activation and cellular activation in children with JDM, and to examine whether this approach could serve as a biomarker for monitoring disease activity relating to the vasculopathy of JDM. Methods: 90 patients recruited to the UK JDM Cohort & Biomarker Study were included; median age 10.21 (range 6.68-13.40) years with median disease duration of 1.63 (0.28-4.66) years. Inactive disease was defined as per modified PRINTO criteria: no skin rashes, CK ≤ 150, CMAS ≥ 48, MMT8 ≥ 78, Physician's global assessment (PhyGLOVAS) ≤ 0.2 on a visual analogue scale. MPs were

identified with multicolour flow cytometry, respectively. Plasma thrombin generation was determined using a fluorogenic assay. Results are expressed as median and range.

Results: Total circulating MP counts differed significantly between those with active JDM, 301 (186-584) x103/ml and those with inactive disease, 81 (34-191) x103/ml, p < 0.0001; and controls 44 (15-249) x103/ml, p < 0.0001. These circulating MPs were predominantly of platelet and endothelial origin. Enhanced plasma mediated thrombin generation likely due to MP presence was demonstrated in active compared to inactive JDM and controls (p=0.001) while TF+CD14+MP counts strongly associated with the endogenous thrombin potential (r=0.21, p=0.01) suggesting for the first time that MP could have an important prothrombotic role in the pathogenesis of JDM vasculopathy. Total Annexin V+ MP counts were strongly correlated with circulating endothelial cells (r=0.42, p < 0.0001) and strongly correlated with the PhyGLOVAS (r=0.43, p=0.0002).

Conclusion: Circulating MP profiles may reflect distinct disease activity status in patients with JDM. These novel biomarkers of vascular pathology, platelet activation and thrombotic propensity can track disease trajectories in JDM and predict high risk groups for poorer disease outcomes.

## P49
### Efficacy of Adrenocorticotropic Hormone Gel (Acthar) in Refractory Juvenile Dermatomyositis

Aarat Patel¹, Thomas Michael Pender², Margalit Rosenkranz³

¹University of Virginia, Charlottesville, USA; ²Eastern Virginia Medical School, Norfolk, USA; ³Children's Hospital of Pittsburgh, Pittsburgh, USA

Correspondence: Aarat Patel

BMC Rheumatology 2019, **3**(Suppl 1):P49

Patient 1: 12 year old obese male presented with proximal muscle weakness, characteristic skin rash, elevated muscle enzymes (Aldolase 57.2U/L, LDH 917U/L, CK 12,480U/L). Prednisone caused anxiety. Keeping obesity in mind, acthar 80U twice weekly was used (3 months) with IVIG (6 months) and methotrexate. After 1 month of acthar, all enzymes had normalized. No weight gain or other steroidogenic AE's occurred. Methotrexate (18 months) was weaned with remission maintained.

Patient 2: 15 year old female presented with proximal muscle weakness, characteristic skin rash, elevated muscle enzymes and inflammatory arthritis. MRI was positive for myositis. Patient started prednisone, methotrexate and plaquenil and flared when prednisone was weaned. IVIG (6 months) was initiated and restarting prednisone caused acne, cushingoid appearance and striae. Acthar 80units q5days (6 months) was used as a steroid-sparing agent. Methotrexate and plaquenil have kept the patient in remission.

Patient 3: 5-year-old female presented with proximal muscle weakness, characteristic skin rash, elevated muscle enzymes, lymphadenopathy and skin ulcerations. There was minimal response to methotrexate and plaquenil; no response to azathioprine; good response to IVIG however severe headaches. Chronic prednisone use caused gastritis, cushingoid appearance and striae. Acthar 80U twice weekly (4 months) with methotrexate did not help wean off of IVIG and prednisone. Finally she responded to rituximab every 6 months with methotrexate. Acthar was not effective.

Patient 4: 20 year female presented with proximal muscle weakness, characteristic skin rash, elevated muscle enzymes, calcinosis, inflammatory arthritis, Raynaud's, mechanics hands, difficulty swallowing, SOB. CT scan showed ILD changes. Labs revealed elevated muscle enzymes (Aldolase 54U/L, and CK 2,309U/L). She was initially treated with prednisone, IVIG and azathioprine. Azathioprine was not effective. Prednisone caused anxiety and worsening depression. Acthar 80U twice weekly (11 months) was used while IVIG was tapered and methotrexate was started; she achieved remission in all disease manifestations. Discussion: Acthar is thought to play an immunomodulatory role through engagement of the melanocortin receptors in the immune system.

All patients in this case series were refractory to first and second line treatments and/or had AE's to corticosteroids. Acthar was used as a bridge therapy and steroid sparing agent while patients were experiencing ongoing disease. Improvement was noted in three of four
patients. AE's that were seen with steroids were absent with acthar. Our results are similar to other retrospective case series of patients with refractory myositis however this would be the first reported data in JDM.

## P50

### Long-term Outcome of Children with Juvenile Dermatomyositis: a single-centre study from North India

Avinash Sharma¹, Anju Gupta², Amit Rawat², Deepti Suri², Surjit Singh²
¹Dr. Rajendra Prasad Government Medical College, Himachal Pradesh, India; ²Post Graduate Institute of Medical Education & Research, Chandigarh, India

**Correspondence:** Avinash Sharma

BMC Rheumatology 2019, 3(Suppl 1):P50

**Background:** Juvenile dermatomyositis (JDM) is a rare inflammatory myopathy seen in children. There have been few studies on long-term outcome in children with JDM using validated outcome measures. We undertook this study to assess the long-term outcome of JDM using validated measures of outcome.

**Methods:** Cross-sectional observational study. All children diagnosed to have JDM for more than 2 years and registered in Pediatric Rheumatology Clinic at Post Graduate Institute of Medical Education and Research, Chandigarh, India, were deemed eligible for recruitment. Study was conducted from January 1, 2015 to June 30, 2016. Those who were not on regular follow-up were called for assessment. Assessment was done by a single observer using CMAS, MMT8, MDAAT, aCAT, MDI and CHAQ.

**Results:** Thirty-five children were enrolled in this study. Twenty-two (62.9%) were on regular follow-up. Mean age was 13.9 years (range 4-29). Mean age at diagnosis was 7.51 ± 3.56 years with median time interval between onset of symptoms and diagnosis being 5 months. Mean duration of disease at the time of enrolment was 7.18 years. Disease course was monocyclic in 24 (68.6%). Muscle strength was normal in 71.4% with MMT8 score of 80 and normal CMAS. Severe involvement defined as MMT8 score below 64 was seen in 8.6%. Cutaneous activity was determined by aCAT with 14 (40%) children having a score of ≥ 1 suggesting some form of cutaneous activity. Based on MYOACT, 31.4% children in our study had evidence of disease activity at the time of assessment with skin being the commonest organ system involved in 28.6% followed by muscles in 22.9%. Twenty-one (60%) children had some form of cutaneous damage. Calcinosis was seen in 12 (34.3%) and lipodystrophy in 8 (22.9%). Twenty-four (68.6%) subjects had an MDI score of ≥ 1 at the time of evaluation suggesting damage in at least one organ system. Most commonly affected organs were cutaneous, endocrine and muscles in 20 (57.1%), 12 (34.3%) and 9 (25.7%) subjects respectively. Nine (25.7%) subjects in our study had some form of a physical dysfunction suggested by a CHAQ score above 0 at the time of cross-sectional assessment.

**Conclusion:** The highlight of this study is use of validated outcome measures for evaluation of long-term outcomes. After mean disease duration of 7.18 years, one-third subjects had evidence of disease activity with almost one-tenth having moderate to severe activity. About 2/3rd had damage in at least one organ system.

## P51

### Presentation Features and Misdiagnosis in anti-MDA5 Autoantibody (Ab) Associated Juvenile Dermatomyositis (JDM)

Gulnara Mamyrova¹, Lan Wu², Adam M. Huber³, Ira N. Targoff⁴, Rodolfo V. Curiel¹, Frederick W. Miller², Lisa G. Rider²

¹George Washington University, Washington, USA; ²National Institute of Environmental Health Sciences, Bethesda, USA; ³IKW Health Centre and Dalhousie University, Halifax, Canada; ⁴University of Oklahoma Health Sciences, Oklahoma City, USA

**Correspondence:** Gulnara Mamyrova

BMC Rheumatology 2019, 3(Suppl 1):P51

**Background/Purpose:** To assess presentation features of anti-MDA5 (melanoma-differentiation associated gene 5) Ab associated JDM.

**Methods:** Physician completed questionnaire about presentation features for 35 MDA5 Ab+ JDM patients meeting probable or definite Bohan and Peter criteria and compared to those of 132 patients with anti-TIF1, 84 anti-NXP2, 15 anti-ARS (aminoacyl-tRNA synthetase), 12 anti-Mi2 Abs, and 144 MSA/MAA negative patients. Myositis Abs were tested by validated immunoprecipitation (IP) and IP-immunoblotting. **Results:** Median delay to diagnosis in MDA5 (4 [1-8] months) was shorter compared to anti-ARS (7.5 [3-13.2] months, p=0.033). The most frequent first symptoms in anti-MDA5 Ab+ were cutaneous (37%), constitutional (14%), muscular and skeletal (8.6% each). Rash as a first symptom was less frequent in anti-MDA5 Ab+ compared to anti-TIF1 (75%, p=0.0001). Weakness as a first symptom was less frequent in anti-MDA5 (8.6%) compared to anti-NXP2 (48%, p=0.0001), ARS (32%, p=0.05), Mi2 Ab+ (25%, p=0.018), and Ab negative (35%, p=0.0012). Skeletal symptoms were less frequently first compared to anti-ARS (8.6% vs. 32%, p=0.05). 28% of anti-MDA5 had a combination of cutaneous, constitutional, and skeletal symptoms initially; 26% of anti-MDA5 Ab+ presented with rash and weakness simultaneously. Rash before weakness was less frequent in anti-MDA5 Ab+ compared to anti-TIF1 (49% vs. 72%, p=0.014). Gottron's papules (31%) were most often first rash followed by both Gottron's and heliotrope (14%), and heliotrope alone (11%). In 11.6% of anti-MDA5 patients, first rash was a combination of both Gottron's and heliotrope with other rashes (malar, V-sign, skin ulcerations). Gottron's combined with ulceration, malar, or periungual erythema were first rashes in 8.7%. Other initial rashes included malar and/or other erythema (5.7% each), or mucus membrane lesions, maculopapular and vasculopathic rashes (2.9% each). Heliotrope was less frequent first rash in anti-MDA5 Ab compared to anti-NXP2 (11% vs. 34%, p=0.013) and anti-ARS (47%, p=0.01). First weakness was proximal in 80% of anti-MDA5 patients, both proximal and distal in 8.6%, and distal in 11%. Early distal weakness was more frequent in anti-MDA5 compared to anti-TIF1 Ab+ (11% vs. 0.8%, p=0.007), anti-NXP2 (0%, p=0.006), and MSA negative patients (1.8%, p=0.019). 23.5% of anti-MDA5 Ab patients had one and 14.7% two misdiagnoses, including infections (17.6%), skin diseases (14.7%), other autoimmune (5.9%), cardiac and psychologic disorders (2.9% each).

**Conclusion:** In anti-MDA5 Ab+ JDM, cutaneous, constitutional and skeletal symptoms are observed most frequently at illness onset, and patients present most often with rash before weakness. Illness presentations of anti-MDA5 Abs differ from other MSAs.

## P52

### Autoantibody Profile of Children with Juvenile Dermatomyositis from a single-centre in North India

Avinash Sharma¹, Anju Gupta, Amit Rawat, Deepti Suri, Surjit Singh

¹Dr. Rajendra Prasad Government Medical College, Himachal Pradesh, India; ²Post Graduate Institute of Medical Education & Research, Chandigarh, India

**Correspondence:** Avinash Sharma

BMC Rheumatology 2019, 3(Suppl 1):P52

**Background:** Children with JDM can have autoantibodies in their sera like other autoimmune diseases. Over the last few years, few novel Myositis Specific Antibodies (MSA) have been identified, like anti-p155/140 (Anti-TIF1y), anti-p140 (anti NXP2), CADM-140 (anti-MDA5), anti-SAE and anti 200/100 (anti HMG-CoA reductase). Some phenotypical associations have been described with these autoantibodies. Few of these autoantibodies have not been studied in children. We undertook this study to look for autoantibodies including anti p200/100 (anti HMG CoA reductase) which has not been evaluated in children and anti p-140 (anti NXP2) which has been shown to have correlation with calcinosis in children with JDM.

**Methods:** Cross-sectional study. All children diagnosed to have JDM for more than 2 years and registered in Pediatric Rheumatology Clinic at PGMER, Chandigarh, India, were deemed eligible for recruitment. Study
period: January 1, 2015 to June 30, 2016. Autoantibody testing for MSA and MAA was done for enrolled children. Immunodot was done to detect IgG antibodies against Jo1, threonyl-tRNA synthetase (PL7), alanyl-tRNA synthetase (PL12), glycyl-tRNA synthetase (EJ), Signal Recognition Particle (SRP), Mi-2, MDA-5, TIF-1γ, Ku, PMScl 100, Schl 70 and SSA/Ro52. Evaluation for anti-p-140 or NXP2 and anti-200/100 or 3HMG CoA reductase was done using ELISA.

Results: Antinuclear antibody (ANA) testing was done in 34 patients. Fourteen (40%) tested positive. Anti-SRP antibodies were present in 4 (11.4%) children, anti-MDA5 in 3 (8.6%), anti-Mi2 in 1 (2.9%) and 1 patient tested positive for anti-SSA/Ro52 antibodies. All 4 children with anti-SRP were girls, had polycyclic course and 2 of them had calcinosis and signs of disease activity at the time of evaluation. Patients with anti-MDA5 had predominant skin involvement, less severe muscle disease and followed monocyclic course. Two of them had arthritis/arthralgia at the time of presentation. The only patient in our study with anti-Mi2 had normal muscle strength/endurance at the time of assessment. None had anti-synthetase antibodies (anti-Jo1, anti-PL-7, anti-PL-12, anti-EJ), anti-ku or anti-Scl70. None of the subjects tested positive for anti-NXP2 or anti-HMG CoA.

Conclusion: Prevalence of autoantibodies in children with JDM in our study is similar to what has been described previously. Type of autoantibodies, though, is not similar. This may be due to ethnic differences of the population. Autoantibodies were tested in children while they were on treatment. This may have resulted in lower positivity. Evaluation of autoantibody profile at the time of diagnosis may assist in predicting the course of disease and response to treatment.

## P53
Myositis-specific antibodies in juvenile dermatomyositis and their associated clinical phenotypes in a German cohort

Svea Horn¹, Claudia Sengler¹, Nadine Grösch¹, Jens Klotsche¹, Johannes-Peter Haas², Claas Hinze³, Gerd Horneff¹, Tilmann Kallinich², Frank Weller-Heinemann⁶, Kirsten Minden¹

¹German Rheumatism Research Center, Berlin, Germany; ²German Center for Pediatric and Adolescent Rheumatology Garmisch-Partenkirchen, Garmisch-Partenkirchen, Germany; ³Universität Münster, Münster, Germany; ⁴Asklepios Klinik St. Augustin, Sankt Augustin, Germany;

⁵Charité - Universitätsmedizin Berlin, Berlin, Germany; ⁶Prof.-Hess-Kinderklinik Bremen, Bremen, Germany

Correspondence: Svea Horn

BMC Rheumatology 2019, 3(Suppl 1):P53

Objectives: Juvenile dermatomyositis (JDM) is a heterogenous disease – next to weakness of the proximal muscles and typical skin lesions as leading symptoms there can be involvement of the joints, lungs, heart, gastrointestinal tract or mucosa. Myositis-specific antibodies (MSA) may help to distinguish clinically distinct phenotypes of JDM with possibly different treatment response and outcome.

Methods: Cross-sectional data of patients with JDM documented in the national pediatric rheumatology database (NPRD) between 2014 and 2016 were analyzed. In addition, a retrospective chart review was conducted for all patients with MSA determination to further specify the phenotype and patient's outcome. MSA were determined centrally by a commercial multiplex array (EUROLINE AutoImmune Inflammatory Myopathies).

Results: MSA testing was performed on 88 patients with JDM (73% female). Mean age at disease onset was 7.6 years (SD 3.6) with a mean age at documentation of 12.2 years (SD 3.8). MSA could be detected in 42% of patients with the following frequencies: anti-NXP2 16%, anti-TIF1γ 14%, anti-MDA5 6%, anti-Mi2 3%, anti-synthetase-antibodies 3% (anti-Jo1, anti-PL-12, anti-OJ, anti-EJ). Anti-SAE and anti-SRP that are also part of the test assay were not found in our patients. The most common clinical feature was dysphagia in patients with anti-NXP2, calcinosis in patients with anti-TIF1γ, lung involvement in patients with anti-synthetase antibodies, and muscle weakness in patients with anti-Mi2. Patients with anti-MDA5 detection were characterized by frequent interstitial lung involvement, mucosal

ulcers, fever and polyarticular arthritis of small joints. The extent of muscle weakness based on the Childhood Myositis Assessment Score (CMAS) was significantly associated with increased levels of creatine kinase. At last consultation (mean disease duration 4.7 years), 32% and 14% received oral glucocorticoids < 0.2 mg/kg or ≥ 0.2 mg/kg body weight, respectively, 52% were treated with methotrexate (MTX), 27% had received intravenous immunoglobulins within the past 12 months. Only 6 patients received biologics, 5 rituximab and 1 etanercept. Physician's global assessment of disease activity (PGA) was equal or less than one in 65% of patients at last consultation, 22% of those were off therapy.

Conclusion: Myositis-specific antibodies could be found in almost half of the patients examined by a commercial multiplex array. Clinical phenotypes were associated with specific MSA. Outcome after 5 years was good in 2/3 of patients, with still about half of the patients receiving MTX and/or glucocorticoid therapy.

## P54
Genetic Differences in the HLA Region Between Adult- and Juvenile-Onset IIM Patients with Anti-TIF1 Autoantibodies

Simon Rothwell¹, Ingrid E. Lundberg², Frederick W. Miller³, Lisa G. Rider³, Lucy R. Wedderburn⁴, Neil J. McHugh⁵, Hector Chinoy¹, Janine A. Lamb¹

¹University of Manchester, Manchester, UK; ²Karolinska Institute and Karolinska University Hospital, Stockholm, Sweden; ³National Institutes of Health, Bethesda, USA; ⁴Great Ormond Street Institute of Child Health, London, UK; ⁵University of Bath, Bath, UK

Correspondence: Simon Rothwell

BMC Rheumatology 2019, 3(Suppl 1):P54

Objectives: Idiopathic inflammatory myopathies (IIM) are a spectrum of rare autoimmune diseases characterised clinically by muscle weakness and heterogeneous systemic organ involvement. The strongest genetic risk is thought to be within the major histocompatibility complex (MHC) in autoantibody defined subgroups. Clinical features of disease may differ between adult- and juvenile-onset disease with the same autoantibody. For example, there is association of anti-TIF1 autoantibodies and cancer in adult-onset disease that is not present in juvenile-onset disease. We investigated potential differences in HLA associations between adult- and juvenile-onset myositis in autoantibody subgroups.

Methods: We used SNP2HLA to impute classical HLA alleles and amino acids from Immunochip genotyping data generated through the Myositis Genetics Consortium (MYOGEN). Genotypes from an additional 19 UK juvenile-onset patients were included from the Juvenile Dermatomyositis Cohort Biomarker Study and Repository. Autoantibodies were detected using immunoprecipitation (IP), IP-immunoblot, lineblot and/or ELISA. We stratified the autoantibody defined subgroup by age and compared the frequency of HLA variants against healthy controls.

Results: We report a strong association between HLA-DQB1*02 and anti-TIF1 (n=197) autoantibodies, and identify genetic differences at this locus between adult-(n=91) and juvenile-onset (n=106) patients with this autoantibody. In adult-onset IIM, the strongest HLA association was with HLA-DQB1*02:02 (p=2.63x10-5). This allele was not significantly associated in juvenile patients, whereas a strong association was found with HLA-DRB1*03:01 (p=3.51x10-6), which is present on the 8.1 ancestral haplotype. An additional analysis was restricted to UK anti-TIF1 patients serotyped using IP in the same centre at the University of Bath, including adult- (n=40) and juvenile-onset patients (n=48) with anti-TIF1 autoantibodies. We replicated observations from the combined cohort showing this difference in association was not due to batch effects or method of autoantibody detection. For anti-Jo-1, anti-PM/Scl, anti-Mi-2 and anti-cN1A the trends for HLA association were in the same direction in juvenile-onset IIM as in the combined cohort, but did not reach statistical significance due to small sample numbers.

Conclusions: We show for the first time that there are genetic differences between adult and juvenile-onset patients with anti-TIF1 autoantibodies.
These genetic differences may suggest a different aetiology, and may
provide insight into specific mechanisms of disease.

P55

Using the internationally agreed-upon Consensus Dataset for
Juvenile Dermatomyositis (JDM) in clinical practice and research

Liza McCann¹; Michael W. Beresford²; Clarissa A. Pilkington³; Adam Huber⁴; Angelo Ravelli⁵; Claire T. Deakin⁶; Hector Chinoy⁷; Lucy R. Wedderburn⁶

¹Alder Hey Children's NHS Foundation Trust, Liverpool, UK; ²University of Liverpool, Liverpool, UK; ³Great Ormond Street Hospital for Children, London, UK; ⁴IWK Health Centre and Dalhousie University, Halifax, Canada; ⁵Università degli Studi di Genova and Istituto Giannina Gaslini Pediatria Ilm, Genova, Italy; ⁶University College London, London, UK; ⁷University of Manchester, Manchester, UK

**Correspondence:** Liza McCann

BMC Rheumatology 2019, 3(Suppl 1):P55

Objectives: Through a robust international process, using the infra-
structure of paediatric rheumatology and myositis organisations and
patient/parent groups (including IMACS, CARRA, PReS, JDRG, PRINTO,
Euromyositis, COMET, OMERACT, Myositis UK, Cure JM), to develop a
JDM Consensus Dataset that can capture disease activity and dam-
age over time, be used in clinical practice and research, and that is
freely available.

Methods: Exploiting Delphi methodology, two web-based questionnaires were distributed to healthcare professionals caring for JDM identified through e-mail distribution lists of international paediatric rheumatology and myositis research groups (181 replies). A separate questionnaire was sent to parents of children with JDM and patients with JDM identified through established research networks and patient/parent support groups (301 replies). Results informed a face-to-face consensus meeting of 18 voting experts from paediatric and adult healthcare with representation from rheumatology, neurology, dermatology and physiotherapy, tasked with defining contents of the dataset.

Results: A JDM Consensus Dataset (123 items) has been formulated into 3 sections, with accompanying glossaries of definitions. Form A, collected at baseline only, contains demographic and diagnostic data. Form B includes disease activity measures, collected at every visit. Damage items, contained within form C, are collected at baseline and annually. After testing in practice, the dataset has been incorporated into two large research registries: the JDM component of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) and JDM Euromyositis. Work has started to migrate the dataset into the UK Juvenile Dermatomyositis Cohort and Biomarker Study (JDCBS), which currently holds data on >580 subjects, with collaboration allowing the greatest number of children and young people with JDM to be analysed. Data captured from patient/parent questionnaires can be used to help inform the development of Patient Reported Outcome Measures relevant and specific to children and young people.

Conclusions: International collaboration for JDM is essential to in-
crease patient numbers to help understand how risk factors interplay
with age or environment and influence long-term outcome. Use of
the JDM Consensus Dataset allows standardisation of data collection
to aid data sharing and comparison between groups. Current barriers
to data sharing between registries include legal and ethical regula-
tions and the fact that data collection on juvenile-onset myositis
within paediatric registries often stops when young people transfer
to adult services. Our group is working to resolve these issues and
test the dataset within hypothesis driven research projects. We wel-
come collaboration with other groups and use of the JDM Consensus
Dataset.

P56

Physical Function Trajectories in Children with Juvenile Myositis

Kaveh Ardalan¹, Elizabeth Gray¹, Julia Lee¹, Madison Wolfe², Gabrielle
Morgan³, Lauren Pachman¹

¹Northwestern University, St. Evanston, USA; ²Creighton University, Omaha, USA; ³Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, USA

**Correspondence:** Kaveh Ardalan

BMC Rheumatology 2019, 3(Suppl 1):P56

Objectives: Juvenile myositis (JM) is an inflammatory disease that causes muscle weakness, skin rashes, and significant deconditioning. Little is known about long-term resolution of physical disability. We examined trajectories of physical function in JM.

Methods: JM registry data were collected at routine visits (January 2000 to June 2014) to Ann & Robert H. Lurie Children's Hospital of Chicago and analyzed in this study. Only patients whose baseline visit was < 3 months after initiation of treatment were included. The following variables were extracted: parent-proxy reported Childhood Health Assessment Questionnaire (CHAQ), gender, race, duration of untreated disease, Disease Activity Score (DAS) - muscle/skin domains, Childhood Myositis Assessment Scale (CMAS), muscle enzymes, nailfold capillary end row loops (NFC-ERL), von Willebrand factor antigen (vWFAg), calcinosis (ever experienced), lipodystrophy (ever experienced), TNFalpha-308A allele, and treatments. Descriptive statistics were calculated. Latent trajectory analysis was performed assessing probability of CHAQ > 0 (binary outcome 0 vs > 0). Baseline values for demographic/clinical variables above were compared across identified trajectories (Fisher's exact; Kruskal-Wallis).

Results: Baseline descriptive statistics for n = 104 included patients with median 13.5 study visits and median follow-up 54 months are similar to published JM cohorts. Three trajectories corresponding to mild (n = 46 [44%]), moderate (n = 32 [31%]), and severe disability (n = 26 [25%]) were identified. Statistically significant differences in baseline variables for mild vs moderate vs severe groups were noted for: CHAQ (0.13 vs 0.88 vs 1.35, p < 0.001), DAS-Muscle (4 vs 6 vs 6, p = 0.001), and CMAS (40 vs 31 vs 34, p = 0.01). Median baseline NFC-ERL differed, with higher counts in the mild group (= 5) vs moderate and severe groups (= 3.83 and 4.14), p = 0.047. Race trended toward significance (p = 0.08), with fewer white patients in the severe group (n = 13 white patients vs n = 26 total patients in severe group).

Conclusion: To our knowledge, this is the first study describing longi-
tudinal trajectories of physical function (distinct from disease activity
or fitness) in JM. Baseline physical function (i.e. CHAQ) and muscle
weakness (i.e. DAS-Muscle, CMAS) predict long-term physical function
trajectory. Baseline vasculopathy (i.e. NFC-ERL) may be less promin-
ent in JM patients following the mild physical function trajectory.
There may also be racial disparities in physical function trajectories
among youth with JM, though this requires further study.

P57

Myositis Autoantibodies in Paediatric Idiopathic Inflammatory
Myopathies - a Case Series from Singapore

Santosi Buvaneswarran, Pei Ling Ooi, Pauline Chan Ng, Kean Lim Lee, Elizabeth Y. Ang

Khoo Teck Puat - National University Children's Medical Institute,
Singapore, Singapore

**Correspondence:** Santosi Buvaneswarran

BMC Rheumatology 2019, 3(Suppl 1):P57

Objectives: Distinct clinical-serological profiles in patients with Idio-
pathic Inflammatory Myopathies (IIMs) have been described, with dif-
ferences even among patients of varying ethnicities. Much less is
known about the associations of myositis autoantibodies in children.
We describe a series of children with IIMs and aim to correlate their serological profiles with their clinical course.

**Methods:** Retrospective review of medical records of patients with IIMs attending the Paediatric Rheumatology Clinic. All patients were tested for myositis-specific and myositis-associated antibodies (MSAs, MAAs), together with anti-nuclear antibodies (ANAs).

**Results:** Ten patients were identified: nine were female; age at diagnosis 3-15 years. Nine had juvenile dermatomyositis (JDMS) and one had necrotizing autoimmune myositis (NAM). Median time to diagnosis was 6 months (1-36 months). At diagnosis, MMT8 testing scores were 90 to 145/150, serum CK 50-9598 IU/ml, LDH 555-2292 IU/ml. Six patients (60%) had positive MSAs and all of these patients had JDMS: two with anti-TIF-1-gamma and one each with anti-Mi2, anti MDA5, anti-EJ and anti Ro52. The two patients with anti-TIF-1-gamma had significant cutaneous involvement, one with ulceration and the other with lipoatrophy. The patient with anti-MDA5 had mild proximal myopathy, marked cutaneous features of JDMS, scleroderma-like changes, oligoarthritis and restrictive lung disease on pulmonary function (PFT) testing with a normal HRCT of the lungs. The patient with anti-Mi2 had minimal skin involvement but marked proximal myopathy and arthritis, with restrictive lung disease on PFT only. The patient with anti-EJ presented with weight loss and had lipoatrophy, calcinosis and polyarthritis with minimal myopathy. The patient with anti-Ro52 had proximal myopathy and characteristic skin manifestations including calcinosis. Three patients were positive for ANA (>1:320): two with JDMS and one with NAM. All patients received steroids and methotrexate, 70% IVIG, 70% hydroxychloroquine, 40% mycophenolate mofetil, 20% tacrolimus, and 20% cyclosporine A. Five patients are in remission at the time of writing, with only one off medication.

**Conclusion:** Similar to previous paediatric series, approximately two-thirds of patients tested positive for myositis autoantibodies, with anti-TIF-1-gamma being the most prevalent MSA and associated with significant cutaneous disease. Different to other cohorts, anti-NXP2 was not found in our patients; none of them had clinically significant interstitial lung disease, even with a positive anti-MDA5. We postulate that South East Asian patients have a distinct autoantibody profile from their Caucasian or Japanese counterparts. A regional database would be useful in studying this hypothesis before these antibodies can definitively contribute to clinically significant decision-making.

P58

MYOSITIS DAMAGE INDEX IN A COHORT OF CHILDREN WITH JUVENILE DERMATOMYOSITIS (JDM) FROM A SINGLE CENTRE IN MUMBAI, INDIA

Santan Godad, Pallavi Pimpale Chavan, Raju P. Khubchandani
Jaslok Hospital and Research Centre, Mumbai, India

**Correspondence:** Pallavi Pimpale Chavan

BMC Rheumatology 2019, **3**(Suppl 1):P58

**Introduction:** IMACS developed Myositis Damage Index (MDI) separately for pediatrics and adults to document persistent changes in 11 organ systems thought to be related to damage. There is a dearth of studies on damage caused by JDM from less resourced countries.

**Objectives:**

**Primary:** Assessing MDI in our cohort of children with JDM

**Secondary:** Study associations of factors leading to long term damage in these children

**Methods:** After ethics approval/consents, 23 patients with JDM under regular treatment and at least a 2 year follow up, at first study visit were identified. Children with overlap syndrome were excluded. MDI was assessed as severity of damage and extent of damage at the first study visit and reassessed at second visit at least six months later. Damage present at both visits were scored to give a final severity and extent of damage score. Results: 23 children with age range at disease onset 1y-17.9 y (mean 6.9 y, median 6.8 y, IQR 3.5-8.8) were diagnosed as JDM after a duration of symptoms ranging 1m-30 m (mean 6.8 m, median 5 m, IQR 3-8.5). Age at the study visit ranged from 5.5 y-24.8 y (mean 13.4 y, median 12.9 y, IQR 10.4-15.3) after a follow up duration ranging from 2y-20.1y (mean 5.9 y, median 4.2 y, IQR 2.6-8.5). Total 136.5

patient yrs). Disease course was monocyclic in 14, continuous in 6, poly-cyclic in 3. Total MDI extent of damage score ranged from 0-8/35 (children) or 37 (adolescents) (mean 2.0, median 2.0, IQR 0.5-2.5) and severity of damage score ranged from 0-24.7/110 (mean 4.7, median 3.5, IQR 1.3-6.4). 17/23 children had damage in 1 or more organ systems, with 9 showing damage in one organ system, 4 in two organ systems, 3 in three organ systems and 1 child showed damage in six systems. Cutaneous (16/23), endocrine (ie growth retardation (6/23) and muscle (5/23) were the most commonly damaged organ systems. Two children showed skeletal damage while ocular, gastrointestinal and cardiac domains were involved in one each. Importantly, over this duration of follow up there were no children with infection, pulmonary, peripheral vascular disease or malignancy. Correlation between age at onset, gender, time to diagnosis, course of disease and duration of follow up did not yield statistically conclusive results.

**Conclusion:** This is amongst the earliest studies to report damage due to JDM from less resourced countries. Over the median follow up period of 4.2 yrs about 75% of the children suffer damage in one or more domains, cutaneous damage being the commonest. Uniquely despite high infection rates in the community, this domain was unaffected in our cohort. Continued enrolment with longer duration of follow up are needed to shed light on factors influencing damage.

P59

PROFILE OF MYOSITIS ANTIBODIES IN A COHORT OF CHILDREN WITH JUVENILE DERMATOMYOSITIS (JDM) FROM A SINGLE CENTRE IN MUMBAI, INDIA

Pallavi Pimpale Chavan, Rajesh Bendre, Raju P. Khubchandani
Jaslok Hospital and Research Centre, Mumbai, India

**Correspondence:** Raju P. Khubchandani

BMC Rheumatology 2019, **3**(Suppl 1):P59

**Introduction:** The study of myositis specific and myositis associated autoantibodies (MSA and MAA) in JDM is helping us gain insight into clinical and laboratory features of the disease and even its course and prognosis. Besides few large studies there is limited data from Asian geographies.

**Objective:** Profiling autoantibodies in a cohort of patients with JDM at our centre seen between 2003-2018.

**Methods:** We were able to contact 36 patients with conclusive JDM who we have seen at our centre since 2003. After ethics approval/consents blood samples were drawn for qualitative assessment of MSA viz Mi-2 (Mi-2α, Mi-2β), TIF1γ, MDA5, NXP2, SAE1, SRP, anti synthetase (Jo-1, PL-7, PL-12, EJ, OJ) and MAA viz Ku, Ro-52, PmScl (100 &75) using the Immunoblot technique with a kit manufactured by Euroimmune. All testing was performed by a single technician, supervised by the pathologist. Only tests reported as positive/strongly positive were recorded.

**Results:** Our cohort consisted of 15 males and 21 females in the age range 4 y -23 y (mean 10.4 yrs). 10/36 samples were drawn at diagnosis before starting therapy while 22/36 patients were on therapy and 4/36 were in remission and off therapy. The duration of follow up in the last 2 categories ranged from 0.5 y -14 y (mean 3.12y, median 3y). 25/36 (69.4%) were positive for at least one of the autoantibodies studied, with 24/36 demonstrating at least one MSA (MSA alone - 18, MSA + MAA - 6, MAA alone - 1). 13/36 demonstrated only one MSA while 3 showed two MSA and 2 had three MSA. The MSA which tested positive were MDA5 (19.4%), NXP2 (19.4%), Mi-2 (16.6%), TIF1γ (13.8%) and anti synthetase (11.1%) respectively. Of the 7/36 with MAA, 6 had these in combination with one MSA while one child had MAA alone. The MAA detected were Ro52 (11.1%) and PmScl (8.3%). 9/10 treatment naïve patients were positive for at least one autoantibody while 13/22 on treatment were positive. 3/4 who had stopped treatment remained positive for at least one autoantibody.

**Conclusions:** 66.6% of our cohort test positive for MSA with 50% having just one MSA. The commonest MSA in our series are MDA5 and NXP2 and the commonest MAA is Ro52. We will be glad to share available clinical and laboratory data with multicentre studies on myositis autoantibodies.
P60

Correlation of type I interferon score and interferon induced
mediators CXCL10 and neopterin with disease activity in Juvenile
Dermatomyositis

Rebecca Nicolai¹, Ivan Caiello¹, Lucilla Rava¹, Silvia Rosina², Luisa Bracci
Laudiero¹, Angelo Ravelli³, Fabrizio De Benedetti¹, Gian Marco Moneta¹
¹Ospedale Pediatrico Bambino Gesù, Rome, Italy; ²University of Genova,
Genoa, Italy; ³Giannina Gaslini Institute, Genoa, Italy

**Correspondence:** Rebecca Nicolai

BMC Rheumatology 2019, **3**(Suppl 1):P60

Objectives: The aim of this study was to investigate expression of interferon regulated genes (IRGs), serum levels of two type I and type II IFN induced chemokines (CXCL9, CXCL10) and neopterin in peripheral blood of JDM patients, and to assess their correlations with clinical and laboratory findings.

Methods: We collected 189 blood samples from 39 JDM patients at different time points during follow-up. In 11 patients the first blood sample was obtained at time of muscle biopsy. We measured expression of type I IRGs (IFI27, IFI44L, IFIT1, ISG15, RSAD2, SIGLEC1), IFNgamma and type II IRGs (CXCL9, CIITA, IDO1) by quantitative PCR (qPCR) and calculated a type I and type II IFN score for muscle and blood samples; serum levels of CXCL9, CXCL10 and neopterin were analyzed by ELISA. Ten healthy subjects were used as controls (HC). At each visit, the following clinical data were recorded: physician's global assessment (PGA) of disease activity VAS (Visual Analogue Scale), cutaneous VAS, Cutaneous Assessment Tool (CAT) activity score, Childhood Myositis Assessment Score (CMAS), serum levels of creatine phosphokinase (CK, IU/l), presence of myositis specific or myositis associated antibodies (MSA/MAA), prednisone (or equivalent) dose (mg/kg/daily), ongoing immunosuppressive medications.

Results: Serum levels of CXCL9 where significantly correlated with muscle expression of IFNgamma and type II IFN score. The correlation of CXCL10 levels with muscle type I and type II IFN score was weaker. Muscle expression of CXCL9 and CXCL10 correlated with serum levels of these chemokines. Type I IFN score in blood of JDM patients was increased compared to HC and significantly correlated with PGA, cutaneous VAS, CAT activity score. Serum levels of CXCL9 and CXCL10 were significantly higher in JDM patients compared to HC. MSA positive JDM patients showed higher levels of CXCL9 and CXCL10 compared to MSA negative patients. CXCL10 levels were correlated with PGA and CMAS, but not with cutaneous disease activity. CXCL9 showed no significant association with the evaluated clinical features. Neopterin levels were significantly correlated with PGA, cutaneous VAS, CAT activity score and CMAS. During the study period two patients experienced a disease flare. A progressive increase of type I IFN score preceeded any clinical or laboratory abnormality, suggesting that type I IFN score might predict flare in JDM patients.
Conclusion: Our findings indicate that type I IFN score, serum levels of CXCL10 and neopterin reflect specific features of disease activity in JDM, supporting their role as valuable disease biomarkers.

P61

Identifying and predicting novel classes of long-term disease trajectories for patients with juvenile dermatomyositis using growth mixture models

Claire T. Deakin, Charalampia Papadopoulou, Muthana Al-Obaidi, Clarissa A. Pilkington, Lucy R. Wedderburn, Bianca L. De Stavola
Great Ormond Street Institute of Child Health, London, UK

**Correspondence:** Claire T. Deakin

BMC Rheumatology 2019, **3**(Suppl 1):P61

Objectives: Uncertainty around medium- to long-term outcomes for patients with juvenile dermatomyositis (JDM) represents a major burden of disease for patients and their parents, as well as posing a challenge for clinical management. To address this problem, we sought to identify: 1. Novel classes of patients with JDM having similar temporal patterns in global assessment of disease activity; and 2. Clinical features at baseline that predict class membership.

Methods: Data were obtained for n=508 patients recruited to the UK-wide JDM Cohort & Biomarker Study (JDCBS), a registry with predominantly inception patients. Patients had a median and interquartile range of 5.1 [2.6-8.6] years of follow-up. The physician's global assessment of disease (PGA) was the main long-term outcome of interest which was analysed using growth mixture models (GMM), a probabilistic model-based method for deriving classes of patients with similar trajectories in PGA over time. Baseline predictors included diagnosis, demographic features, autoantibodies, abnormal respiration, ulceration, lipodystrophy, calcinosis, and skin and muscle disease activities as measured by the modified disease activity score for skin (modDAS) and childhood myositis assessment scale (CMAS), respectively. Clinical features and medications that characterised the classes over time were also described. Baseline predictors of class membership were identified in a second step using lasso regression, a method involving automatic selection of predictors and regularisation of coefficients. R packages "lcmm" and "glmnet" were used for the GMM and lasso regression analyses, respectively.

Results: GMM identified two classes of patients. Patients in Class 1 (88.6%) tended to improve their PGA over time, while patients in Class 2 (11.6%) tended to have more ongoing disease. Higher proportions of patients in Class 2 had arthritis, ulceration, lipodystrophy, calcinosis and abnormal respiration ever during their disease course. Lasso regression analysis identified modDAS, abnormal respiration and lipodystrophy as baseline predictors of Class 2 membership, with estimated odds ratios of 0.96, 1.48 and 1.68 respectively. Interestingly, demographic features and myositis-specific or -associated autoantibodies had similar prevalence across the two classes.

Conclusions: We have identified two classes of patients with different trajectories of global disease activity, using a large number of patients and a data-driven approach to defining long-term outcomes in JDM. Baseline predictors of being in the class with more ongoing disease include modDAS and having abnormal respiration or lipodystrophy. Ongoing work will use GMM to model skin disease activity, and identify genetic and other biological predictors of class membership.

P62

Myositis-Specific Antibodies and Acquired Lipodystrophy in
Juvenile Dermatomyositis: Evaluation of Fat Distribution using
Dual-Energy X-ray Absorptiometry (DXA)

Amer Khojah¹, Victoria Liu, Gabrielle Morgan², Chiang-Chiang Huang³,
Kaveh Ardalan¹, Richard Shore¹, Jackie Bellm¹, Lauren Pachman¹

¹Ann & Robert H. Lurie Children's Hospital, Chicago, USA; ²Stanley
Manne Research Center, Chicago, USA; ³University of Wisconsin-
Milwaukee, Milwaukee, USA

**Correspondence:** Amer Khojah, Kaveh Ardalan

BMC Rheumatology 2019, **3**(Suppl 1):P62

Objectives: Juvenile dermatomyositis (JDM) is the most common idiopathic inflammatory myopathy in childhood. Myositis-specific antibodies (MAS) have been utilized to categorize JDM into multiple distinct phenotypes. Of these MSA, p155/140 (aka anti-TIF-γ) antibody is the most common and has been associated with generalized lipodystrophy in small retrospective studies. The aim of this study to investigate the relationship between lipodystrophy and p155/140 antibody using DXA scan, which is a more objective tool to measure fat distributions.

Methods: An IRB approved chart review study (IRB# 2012-14858) was conducted at Ann & Robert H. Lurie Children's Hospital of Chicago on patient records spanning 2000 to 2017. We included all subjects with JDM who had at least 5 years of follow up data and DXA scan done during the study period. DXA was performed using GE-LUNAR iDXA bone densitometer and data were analyzed by Encore 16 software. Subjects with overlap syndrome were excluded from the analysis. We divided the study population into three groups based on their MSA (p155/140 antibody, other MSA, and MSA negative). We used One-way ANOVA and chi-square to compare the baseline characteristics and fat distribution (Trunk:Legs fat ratio) among the 3 groups.
Results: 96 subjects (78% female, 70% white, 44% p155/140 antibody, 23% other MSA, 33% MSA negative) were included. There were no significant difference in the initial total and skin disease activity scores (DAS) between the 3 groups, though DAS muscle domain did differ (4.3 in P155/140 group vs 5.8 and 5.9 in other MSA and MSA negative group respectively and p = 0.049). Interestingly, p155/140 group had decreased nailfold capillary end row loop (NFC-ERL) counts compared with the other groups (p = 0.006). Percentage of total body fat and trunk: legs fat ratio were similar among the 3 groups at different time points. Percentages of subjects with lipodystrophy by physician assessment were the same in all three groups (p = 0.69)

Conclusion: P155/140 antibody group have lower baseline NFC-ERL counts than the other two groups. Generalized lipodystrophy did not differ by MSA groups based on DXA and physician assessment.

P63

Investigating the role of complement activation in
driving the Th1/17 imbalance observed in Juvenile

Dermatomyositis

Lucy Marshall, Elizabeth Rosser, Claire Deakin, Cerise Johnson-Moore,
Despina Eleftheriou, Lucy Wedderburn
Great Ormond Street Institute of Child Health, London, UK

**Correspondence:** Lucy Marshall

BMC Rheumatology 2019, **3**(Suppl 1):P63

Objectives: A skewed Th17 phenotype in CD4+ T cells resulting in a Th1/17 imbalance has been observed in both child and adult-onset immune-mediated diseases including rheumatoid arthritis, SLE (systemic lupus erythematosus), and multiple sclerosis. This project aimed to investigate whether a Th1/17 imbalance can also be observed in patients with Juvenile Dermatomyositis (JDM) compared to age/sex-matched healthy controls.

Methods: PBMC from JDM (n=15) and age/sex-matched controls (CHC, n=6) were stimulated with PMA/lonomycin in the presence of Brefeldin A for 4 hours with the Th1/17 phenotypes measured by intracellular staining for IFN-γ and IL-17 respectively. Using previously generated RNAseq data within the Wedderburn lab, immune pathways defined by hallmark gene sets, were analysed within peripheral blood CD4+ T cells from treatment-naïve patients and patients after approx. 12 months of standard treatment (n=10). To further investigate Th1 response and the role of complement an in vitro CD46-activation, assay was performed on JDM (n=6) and CHC (n=3). Read outs of the assay included IFN-γ and IL-10 secretion via cytokine bead array.

Results: Analysis of the ratio of CD4+IFN-γ+ to CD4+IL-17+ cells within peripheral blood demonstrated that the CD4+ T cell phenotype is significantly skewed towards Th17 cells in JDM (p=0.04) compared to CHC. Isolated CD4+ T cells included in RNAseq analysis revealed that the complement pathway was over-represented in pretreatment JDM versus on-treatment JDM CD4+ T cells. Using an in vitro modelling assay to mimic intracellular complement activation in CD4+ T cells via anti-CD46 activation, a complement receptor known to induce Th1 responses, our preliminary analysis revealed that there is also low IFN-γ production in JDM compared to CHC under these conditions.

Conclusions: IFN-γ is reduced in CD4+ T cells from JDM patients compared to CHC leading to a Th17-skewed immunophenotype. Consistent with this observation, RNAseq analysis highlighted the complement pathway in CD4+ T cells from treatment naïve JDM patients compared to patients on treatment. Importantly, intracellular complement activation within CD4+ T cells has been shown to be critical for Th1 induction in healthy adults. To summarise, our initial results display a lack of Th1 response, via IFN-γ, in JDM patients compared to CHC. Future work aims to confirm these findings and investigate possible mechanisms involved.

P64

A single centre experience of immune-mediated necrotising
myopathies: a comparison of anti-3-hydroxy-3-methylglutaryl-
coenzyme A reductase and anti-signal recognition particle
myopathies

Su-Ann Yeoh¹, Rhys Thomas¹, Hasan Tahir¹, Aleksander Radunovic²

¹Whipps Cross University Hospital, London, UK; ²Royal London Hospital, London, UK

**Correspondence:** Su-Ann Yeoh

BMC Rheumatology 2019, **3**(Suppl 1):P64

Objectives: Immune-mediated necrotising myopathy (IMNM) is a rare condition characterised by muscle fibre necrosis with minimal inflammation. IMNM is associated with anti-signal recognition particle (SRP) and anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies. IMNM patients have been reported to be more resistant to conventional immunosuppression with anti-SRP myopathy following a more severe disease course.

We analysed our IMNM cohort, comparing disease characteristics and treatment outcomes of anti-SRP and anti-HMGCR patients.

Methods: Subjects diagnosed with IMNM from 2008 to 2018 were included in this study. Electronic patient records were reviewed. Patient characteristics and treatment outcomes were compared.

Results: 31 subjects were included, with 20 anti-HMGCR and 11 anti-SRP subjects. There was a female predominance in the anti-HMGCR group, with 15 (75%) versus 6 anti-SRP subjects (55%). Median age of anti-HMGCR subjects was 65 vs 52 in the anti-SRP group. There was a Caucasian predominance in the anti-HMGCR group (75%, 15/20 subjects) with an African/African-Caribbean predominance in the anti-SRP group (91%, 10/11 subjects). Statin exposure was prevalent in the anti-HMGCR group (90%, 18/20 subjects). Cardiac involvement was present in 2 anti-SRP subjects. Malignancy was present in 3 anti-HMGCR subjects vs 1 anti-SRP subject. 11 anti-HMGCR and 7 anti-SRP subjects were treated with 'triple therapy' – IV methylprednisolone followed by oral prednisolone, intravenous immunoglobulin (IVIg) and methotrexate (MTX)/azathioprine. 6 of the 11 anti-HMGCR subjects treated with triple therapy had complete response, not requiring further treatment. The remaining 5 responded initially but relapsed, treated with IVIg to good effect. 2 of the 7 anti-SRP subjects responded to triple therapy not requiring further treatment. 5 (46%) anti-SRP subjects were treated with rituximab compared to 3 (15%) anti-HMGCR subjects. 3 out of 5 anti-SRP subjects responded to rituximab clinically and biochemically (with 2 patients being followed up by local hospitals). One anti-HMGCR subject responded clinically but not biochemically, one failed to respond requiring plasma exchange and another anti-HMGCR subject has only recently been treated with rituximab.

Conclusions: IMNM is a rare condition often described to follow a severe disease course, refractory to standard therapy. We demonstrate that in our cohort, anti-SRP myopathy was more common in African/African-Caribbean patients and associated with cardiac involvement. Anti-HMGCR subjects responded more frequently to conventional immunosuppression compared to anti-SRP subjects. Anti-SRP subjects were treated with rituximab more frequently. Our study illustrates the heterogeneity in treatment choice given the paucity of data, highlighting the need for prospective studies and standardised protocols.

P65

Muscular dystrophy masquerading as inflammatory myositis

Char Loo Tan, Kong Bing Tan, Stacey Tay, Pei Ling Ooi, Elizabeth Y. Ang
National University of Singapore, Singapore, Singapore

**Correspondence:** Elizabeth Y. Ang

BMC Rheumatology 2019, **3**(Suppl 1):P65