AB0734 The Shades of Anti-JO1 Positive Antisynthetase Syndrome in a Hungarian Cohort
Authors: Z. Griger, K. Szabό, M. Nagy-Vincze, L. Bodoki, K. Hodosi, E. Zilahi, K. Dankό
Journal: Annals of the Rheumatic Diseases (2015)

<h3>Background</h3> The most frequent myositis specific antibody (MSA) in the serum of patients with idiopathic inflammatory myopathies is anti-Jo-1. The presence of anti-Jo-1 define a distinct clinical phenotype, antisynthetase syndrome (ASS), which is characterized by poor prognosis and multiple organ involvement, such as myositis, interstitial lung disease (ILD), non-erosive arthritis, Raynaud9s phenomen, mechanic9s hand, skin rashes, and fever. <h3>Objectives</h3> The aim of this study was to determine the clinical, serological, laboratory and genetic features of anti-Jo1 positive patients followed by our department. <h3>Methods</h3> Retrospective analysis of medical records of 49 patients (42 female, 7 male) were reviewed. Anti-Jo-1 titer was detected with enzyme-linked immunosorbent assay. HLA DRB1, DQA1 and DQB1 genotype was determined using commercial sequence-specific oligonucleotide kit. Statistical analysis was performed using Pearson Chi<sup>2</sup>, Fisher exact test, or Spearman correlation. <h3>Results</h3> The median age at diagnosis was 43±13,28 years (range: 18-70), 48 patients exhibited myositis (98%), 35 ILD (73%), 43 arthritis (88%), 32 Raynaud9s phenomen (65%), 21 fever (43%), 16 mechanic9s hand (33%), 27 skin rash (55%) and 6 dysphagia (12%). We could detect significant correlation between the initial anti-Jo-1 titer and the first CK (R=0,328; p=0,003) and CRP (R=0,374; p=0,016) level. Furthermore anti-Jo1 levels during disease course had significant correlation to the corresponding CK (R=0,497; p&lt;0.001), and CRP (R=0,325; p&lt;0.001) level. The most frequent antibody besides anti-Jo-1 was anti-SSA (28/49; 57%). The anti-Jo-1+/SSA+ population had younger age at the diagnosis (36,12±11,08 vs. 47,22±12,87; p=0,004), lower rate of ILD (53% vs. 81%; p=0,039), but higher maintaining steroid (methylprednisolone) dose (9,53 mg vs. 3,7 mg; p=0,031) compared to the Jo-1+/SSA- group. Higher (≥8 mg) maintaining steroid therapy was associated with higher initiating CRP (36,34 vs. 17,84 mg/l; p=0,014) ESR (33,87 vs. 19,81 mm/h; p=0,032) level and higher presence of fever (67% vs. 37%; p=0,038) at diagnosis but not with initiating CK (p=0,374), LDH (p=0,224) level or ILD presence (p=1). 68,96% of the patients were HLA DRB1*03 positive, where the CK level at diagnosis was significantly lower compared to the HLA DRB1*03 negative patients (2816,30 vs. 5969,44 U/l; p=0.04). 58.62% of the patients were positive for HLA DQA1*0501-DQB1*0201 haplotype, but no significant correlation was found regarding to any clinical or laboratory features. <h3>Conclusions</h3> Our results confirm previously reported data from other centers considering the clinical features of anti-Jo1 positive patients. HLA DRB1*03 positivity was associated with lower CK level but has no influence on clinical or serological features. It seems that anti-Jo1 level might reflect disease activity; ESR, CRP levels, associated fever and anti-SSA positivity at the diagnosis could be considered as prognostic markers. <h3>Disclosure of Interest</h3> None declared