bluuebunny/crossref_metadata_2025 huggingface dataset:
OP36 Investigating the role of bioactives produced by gut bacteria to modulate immune response in inflammatory bowel disease
Authors: Giri R , Shamsunnahar K , Salim A , Capon R , Morrison M , O Cuiv P , Begun J
Published: January 2020

Background

inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract. Although the pathogenesis of IBD is not fully understood, it is believed to result from the interaction between various genetic and environmental factors, including the microbiome, resulting in inappropriate gut inflammation. Under homeostatic conditions, the gut immune system exists in a tolerogenic state with the microbiota. However, microbial dysbiosis and an imbalance of pro- and anti-inflammatory cytokines in the gut characterise IBD and recently faecal microbiota transplantation studies have demonstrated that manipulation of the microbiome can induce remission. In this study, the ability of bioactives produced from single species of anaerobic gut bacteria cultured from healthy human faecal samples to modulate NF-kB activity was investigated, their biochemical properties were assessed and their ability to alleviate colitis was also investigated.

Methods

The NF-κB suppressive effects of culture supernatants (CSs) from 23 different isolates were tested on colonic epithelial cell lines. Suppressive CSs were also tested on human-derived colonic organoids from IBD patients and healthy controls and IL-8 expression was measured. Furthermore, CS from AHG0001 strain was also tested in spontaneous colitis model Winnie in vivo. The supernatant was further characterised by extraction in multiple solvents and fractionated through reversed-phase analytic HPLC column to test for suppressive fractions and further investigate their chemical characteristics.

Results

LS174T and Caco-2 reporter cells stimulated with TNFα and IL-1β respectively, resulted in NF-κB activation. Of the 23 isolates screened, CS from five isolates significantly suppressed NF-κB activation. The selected CSs also suppressed IL-8 secretion in PBMCs and gut organoids from both UC and CD patients, as well as healthy controls, with notable individual variation. Rectal gavage of CS from AHG0001 also reduced disease activity, improved histologic inflammation and reduced the pro-inflammatory gene expression in Winnie mice. Furthermore, a potent small molecule (IC50 = 3 nM) produced by AHG0001 was also identified through bioassay-guided solvent extractions and filtrations, followed by UPLC-QTOF and comparative metabolomics.

Conclusion

Our anaerobic culturing and NF-κB reporter assay system allows for the rapid identification of bacteria producing immunomodulatory bioactives, which could lead to the future development of novel therapeutics. Our in vivo and ex vivo testing utilising spontaneous colitis model and patient-derived organoids demonstrates the potential of precision medicine-based approaches for bacterial based therapeutics.
DOP02 The dose-dependent effect of enteral nutrition on faecal microbial metabolites of healthy volunteers
Authors: Svolos V , Gkikas K , Rizou V , Christina E , Kapranos P , Kleingunnewiek J , Seenan J P , Macdonald J , Gaya D R , Hansen R , Russell R K , Gerasimidis K
Published: January 2020

Background

Treatment with exclusive enteral nutrition (EEN) offers a nutritional therapy paradigm in Crohn’s disease, with the extensive modulation of gut microbiome being its proposed mechanism of action (1). Recent studies propose variable clinical efficacy for 85% EN (Cheat EN/CEN), 50% EN (Partial EN/PEN) and 20% EN (maintenance EN/MEN), and a dose-dependent effect of EN use in CD (2–5). Therefore, this study aims to investigate the dose-dependent effect of 100%, 85%, 50%, and 20% EN on faecal microbial metabolites; and to investigate if this effect can be used as a compliance marker for EEN.

Methods

Healthy adults followed EEN, CEN, PEN or MEN diet for 7 days. Fresh faecal samples were collected before and after each dietary intervention Dietary assessment was performed throughout the intervention using estimated weight food diaries. Faecal pH, water content, Bristol Stool Chart Score, short-chain fatty acids and hydrogen sulphide were measured.

Results

A total of 122 faecal samples were collected from 61 subjects. The Mean(SEM) EN intake for the four groups was EEN: 100(0), CEN: 85.6(0.5), PEN: 50.1(0.4), MEN: 19.9(0.2) % of total energy intake. The baseline levels of all faecal sample measures were no different between the four groups. Faecal water content, propionic acid and Bristol Stool Chart Score significantly decreased only during EEN (all p≤0.03). Faecal pH significantly increased during EEN, CEN and PEN (all p < 0.001), but not during MEN (p = 0.728). Faecal pH post-intervention was highest for EEN, followed by CEN and PEN [Mean(SEM), EEN: 8.2(0.1); CEN: 7.8(0.2); PEN: 7.3(0.1), all pairwise p ≤ 0.002]. The faecal concentration of hydrogen sulphide, acetic and butyric acid significantly decreased following both EEN and CEN groups (all p ≤ 0.009). The concentration of acetic acid post-EEN was significantly lower than the concentration post CEN [Mean(SEM), EEN: 173(10); CEN: 261(24) μmol/g, p = 0.001]. Hydrogen sulphide and butyric acid concentrations post EEN and post CEN were unchanged (p = 0.337, p = 0.141).

Conclusion

EEN extensively modulates faecal microbial metabolites and CEN induces similar effects. PEN induces variable effects and further analysis should investigate if variation in responses reflects differences in the non-EN food intake of the participants (50%). MEN had no effect on faecal microbial metabolites. Further analysis including high-throughput deep sequencing techniques will provide additional information about the dose-dependent effect of EN regimen on gut microbiome composition.

References

1. Quince et al., Am J Gastroenterol, 110:1718–1729.

2. Logan et al., Aliment Pharmacol Ther, 2019;50:664–674.

3. Gupta et al., IBD, 2013;19:1374–1378.

4. Duncan et al., BMC Gastroenterol, 2014;14:50.

5. Lee et al., IBD, 2015;21:1786–1793.
DOP14 Modelling of the relationship between infliximab exposure, faecal calprotectin, and endoscopic remission in patients with Crohn’s disease
Authors: Dreesen E , Berends S , Laharie D , D’Haens G , Vermeire S , Gils A , Mathôt R
Published: January 2020

Background

Less than 50% of patients with Crohn’s disease (CD) starting infliximab (IFX) therapy achieve endoscopic remission (ER). Evidence for the benefits of pharmacokinetic (PK) and pharmacodynamic (PD) monitoring remains scarce. We aimed to develop a population (pop)PK/PD model to characterise the IFX dose-exposure-biomarker-response (faecal calprotectin [fCal] and ER) relationship in patients with CD.

Methods

Analyses were performed using data of a phase 4 dose-escalation study (TAILORIX). Patients started standard 5 mg/kg IFX induction therapy at weeks [w]0, 2 and 6. From w14 through w54, the IFX dose could be irreversibly doubled based on one of the three monitoring algorithms.1 Endoscopies were performed at w0, 12 and 54. Three sequential models were developed: A 2-compartment popPK model linking IFX dose to exposure, an indirect response popPK-PD model describing the inhibitory effect of IFX exposure on fCal, and a first-order Markov popPD model linking fCal to transitions between states of ER (CD endoscopic index of severity <3), no ER and dropout (Figure 1). All modelling and simulation were performed using NONMEM 7.4.

Results

The study included 116/122 (95%) patients with CD enrolled in TAILORIX who had ≥1 detectable IFX serum concentration. In the developed models, it was shown that IFX clearance increased with increasing fCal, decreasing albumin, increasing CD activity index and presence of antibodies to IFX (transiently). Baseline fCal increased with increasing CRP and decreasing platelet count. Lower fCal increased probability of attaining ER and decreased probability of losing ER. Probability of dropping out given an earlier state of absence of ER increased with elapsing time. Simulations of 150 000 patients receiving 5, 7.5 or 10 mg/kg IFX (1:1:1) resulted in a flat dose–response curve due to large interindividual variability in PK and PD (Figure 2, top panels). The predicted fraction of patients achieving ER at w12 was 45.1% [30.3–60.5] (median [IQR]) when on 5 mg/kg IFX (~46.4% observed in data). However, simulations of 10 mg/kg IFX induction doses predicted only a slight increase in the fraction of patients achieving ER at w12 to 47.5% [32.0–62.6]. This minor benefit at the population level argues against systematic 10 mg/kg induction dosing in all patients. A similar observation was done during maintenance therapy, where 70.8% [62.6–75.5] of all simulated patients maintained ER at w54 (~72.2% observed in data) (Figure 2, right panels).

Conclusion

Model-informed infliximab dose optimisation towards a predefined fCal concentration—while accounting for PK and PD variability—may improve the effectiveness of infliximab therapy (eg. 64% chance of ER at w12 ~100 μg/g fCal at w6).

Reference
DOP16 An evaluation of the exposure–efficacy relationship for subcutaneous vedolizumab maintenance treatment of Crohn’s disease: Pharmacokinetic findings from VISIBLE 2
Authors: Chen C , Rosario M , Polhamus D , Dirks N , Zhang W , Sun W , Kisfalvi K , Feagan B , Sandborn W , Vermeire S , D’Haens G
Published: January 2020

Background

The exposure–efficacy relationship and immunogenicity rates of the new vedolizumab subcutaneous (SC) formulation have been established for maintenance treatment of ulcerative colitis (UC).1 Here, we report vedolizumab SC exposure–efficacy and immunogenicity in Crohn’s disease (CD).

Methods

VISIBLE 2 (NCT02611817; EudraCT 2015-000481-58) was a pivotal, phase 3, randomised, double-blind, placebo-controlled trial evaluating the efficacy and safety of vedolizumab SC (108 mg every 2 weeks) as maintenance treatment in patients with moderately to severely active CD. Following intravenous (IV) vedolizumab (300 mg Week 0 and 2) induction, patients with a clinical response at Week 6 (≥70-point decrease in CD activity index [CDAI] from Week 0) were randomised to blinded maintenance treatment and included in the analyses. Vedolizumab serum concentrations were measured prior to dosing using an enzyme-linked immunosorbent assay. Immunogenicity was assessed with a drug-tolerant electrochemiluminescence assay. Predicted vedolizumab trough concentrations at Week 52 were grouped by quartiles (Q), and Week 52 efficacy outcome rates calculated for each Q. Missing efficacy outcome data were imputed as failures. Efficacy outcomes were clinical remission (CDAI ≤150) and enhanced clinical response (≥100-point decrease in CDAI from Week 0 at Week 52).

Results

Following vedolizumab IV induction (N = 644), patients with a clinical response were randomised and received vedolizumab SC (N = 275) or placebo (N = 134) as maintenance treatment. At Week 52, patients on vedolizumab SC maintenance had a positive exposure–efficacy relationship for clinical remission (Q1: 37.7%; Q4: 50.7%) and enhanced clinical response (Q1: 37.7%; Q4: 53.6%; Figures 1 and 2). Overall, 7/275 (2.5%) patients on vedolizumab SC (following vedolizumab IV induction) developed anti-vedolizumab antibodies (AVAs): 3/7 patients were persistently AVA positive and 4/7 had neutralising antibodies. Five of 7 AVA-positive patients on vedolizumab SC did not achieve clinical remission and enhanced clinical response at Week 52; 2 of those patients were persistently AVA-positive. Immunogenicity was not associated with injection-site reactions or hypersensitivity reactions.

Conclusion

These preliminary results suggest a trend for higher vedolizumab SC serum concentrations with greater efficacy in CD, but the association was less pronounced than was reported in UC. (1) The AVA rate was similar to what was observed in prior vedolizumab IV studies. (2) In this study, vedolizumab immunogenicity appeared to be associated with clinical outcome.

References
DOP18 Impact of adherence to anti-tumour necrosis factor therapy on clinical outcomes in Crohn’s disease: A nationwide population-based study
Authors: Park J J , Koo H , Park Y , Park S J , Kim T I , Kim W H , Cheon J H , Han E H
Published: January 2020

Background

The impact of compliance with anti-tumour necrosis factor (TNF) on the clinical outcomes of Crohn’s disease (CD) is not well unknown. We performed a nationwide population-based study to investigate the impact of adherence to anti-TNF therapy on clinical outcomes in CD patients.

Methods

Using the National Health Insurance claims data, we collected data on newly diagnosed patients with CD between 2004 and 2015. Given that infliximab was listed in the National Health Insurance Service in 2006 and adalimumab in 2010, data only after the listing date were extracted. A total of 2784 patients were included according to inclusion criteria. Medication adherence was measured based on the following three criteria, including the ratio of delayed visit, the ratio of the number of visits, and the ratio of actual administration, and was assessed at four-point in time from the initial administration: 14, 22, 39, and 48 weeks.

Results

A total of 2179 patients received infliximab, and 605 patients received adalimumab. The mean cumulative actual to predetermined prescription ratio (CAPPR) at 14 and 48 weeks was 1.07 and 1.17, respectively. CAPPRs of infliximab users were higher than those of adalimumab users (1.06 and 1.21 vs. 1.02 and 1.04 at 14 and 48 weeks, respectively). As hospital visits were delayed one more day, risk of perianal surgery (odds ratio [OR] 1.21, 95% confidence interval [CI] 1.089–1.333), corticosteroid use (OR = 1.008, 95% CI 1–1.016), and hospitalisation (OR = 1.05,95% CI 1.002–1.108) at 48 weeks were significantly increased. Moreover, as CAPPR decreased by 1 percent point, risk of bowel resection (OR = 1.589, 95% CI 0.713–3.542), perianal surgery (OR = 1.246, 95% CI 0.868–1.79), and hospitalisation (OR = 1.128, 95% CI 0.998–1.276) at 14 weeks were significantly increased.

Conclusion

Our data indicate that adherence to anti-TNF therapy affects major clinical outcomes of CD in the short- and mid-term period. Intervention to improving adherence to anti-TNF therapy is highly needed for better clinical outcomes in CD.
DOP21 Time to first treatment with biologic agents for ulcerative colitis and Crohn’s disease across four Nordic countries: Results from the TRINordic study
Authors: Høivik M , Lördal M , Burisch J , Langholz E , Knudsen T , Voutilainen M , Moum B , Anisdahl K , Saebo B , Haiko P , Malmgren C , Coskun M , Melberg H O
Published: January 2020

Background

Real-world data on time from diagnosis to first biologic treatment is limited for ulcerative colitis (UC) and Crohn’s disease (CD) patient populations.

Methods

This retrospective observational study collected data from the National Patient Registries and National Prescription Registries in Sweden (data on biologic use was only available for Stockholm [STK], Norway [NOR], Denmark [DEN]) and one university hospital database (Turku, Finland [FIN]) during 2010–2017 to investigate time from diagnosis to first biologic treatment for UC and CD. Patients with ≥2 ICD-10 diagnosis codes for UC (K51) or CD (K50) from 2010 or later were included; patients were classified according to their last code. The look-back period for SWE was until 2000, for NOR until 2008, for DEN until 1995, and for FIN until 2004. Time to first biologic was defined as the period from the first UC or CD code to first biologic record. In FIN, it was only possible to investigate infliximab (IFX).

Results

A total of 47,568 patients were included (STK n = 5594, NOR n = 20,761, FIN n = 2118, DEN n = 19,095). Of them, 30 397 patients had UC and 17 171 CD diagnosed during 2010–2017. Time to first biologic following diagnosis of UC or CD was decreased over time. For patients diagnosed with CD in 2015, in STK, NOR, FIN, and DEN, 30%, 35%, 25%, and 26%, respectively, received a biologic within 2 years; in 2010, the proportions were less than 10%, 20%, 5%, and 22%, respectively. FIN results may be attributed to only IFX use captured in the data sources. NOR had in most cohorts the shortest time between diagnosis and first treatment with a biologic agent, e.g. 33%, 35%, 36%, 34% and 33% of patients diagnosed with CD in 2011, 2012, 2013, 2014 and 2015, respectively, received a biologic already one month after diagnosis compared with 2%, 1%, 3%, 4% and 6%, respectively, in STK, 7%, 5%, 9%, 4% and 5%, respectively, in FIN and 3%, 10%, 28%, 12% and 23%, respectively, in DEN. Fewer UC than CD patients received biologics, but the time to first biologic was shortened to the same extent (Figure 1 and 2, respectively). In NOR, FIN and DEN, the most common biologic used was IFX for UC and CD, e.g. 18%, 14% and 15%, respectively, of UC and 35%, 17% and 35%, respectively, of CD patients diagnosed in 2015 had received IFX; in STK it was IFX for UC (8% of patients diagnosed in 2015) and adalimumab for CD (20% of patients diagnosed in 2015).

Conclusion

This retrospective observational study of >45 000 patients with inflammatory bowel disease in four Nordic countries showed reduced time between diagnosis and first biologic from 2010 to 2017, with the shortest time between diagnosis and first biologic in Norway. IFX was most commonly used.
DOP26 Real-life dosing patterns and concomitant drug use among ustekinumab-treated patients with Crohn’s disease
Authors: af Björkesten C G , Ilus T , Hallinen T , Soini E , Eberl A , Hakala K , Heikura M , Hirsi E , Jussila A , Kellokumpu M , Koskela R , Koskinen I , Moilanen V , Nielsen C , Nieminen U , Nuutinen H , Heikkinen M , Suhonen U M , Tillonen J , Utriainen K , Vihriälä I , Wennerström C , Borsi A , Nissinen R , Koivunen M , Sipponen T
Published: January 2020

Background

Real-life long-term evidence on ustekinumab treatment in patients with Crohn’s disease (CD) is limited. We performed a retrospective non-interventional nation-wide chart review study of dosing and long-term clinical outcomes in Finnish CD patients treated with ustekinumab (FINUSTE2, EUPAS30920).

Methods

FINUSTE2 was carried out in 17 Finnish centres. Eligible patients were adults with CD, receiving an intravenous (IV) first dose of ustekinumab during 2017 or 2018. Data on disease activity, dosage, and concomitant medications were collected at baseline, 16 weeks, and 1 year from treatment initiation. All measurements on ustekinumab trough concentrations (TC) were recorded.

Results

The study included 155 patients (48% female) with a mean age of 44 and disease duration of 14 years. The disease was stricturing or penetrating in 69% of patients, 59% had prior CD-related surgeries, and 96% had a treatment history of at least one biologic agent. After one IV dose and one to two subcutaneous (SC) doses at 8 to 16 weeks, 140 patients (93%) continued to maintenance treatment with SC ustekinumab, of which nearly three-quarters with a dosage interval of 8 weeks (Figure 1). Of 93 patients with a follow-up of at least 1 year, 77 were still on ustekinumab. During follow-up, 55 patients (39%) had their ustekinumab dose adjusted, mostly (n = 44, 31.4%) as a shortening of the dosage interval. Forty-nine patients had in total 65 ustekinumab TC measurements performed, with a mean of 2.2 µg/ml at 16 weeks (n = 23) and 2.7 µg/ml at 1 year (n = 25). In 67% of cases, the reason for measuring TC was lack of or insufficient response. No anti-drug antibodies appeared at any time point. The proportion of patients on ustekinumab monotherapy increased significantly, from 34% (n = 52) at baseline to 54% (n = 79/146; p < 0.001) at 16 weeks and 64% (n = 49/77; p < 0.01) at 1 year. Correspondingly, corticosteroid use decreased significantly, and a trend towards reduced use of immunomodulators was observed (Figure 2).

Conclusion

In this nationwide real-life study, treatment with ustekinumab in patients with longstanding and complicated CD was persistent and allowed for significant corticosteroid tapering. A vast majority started the maintenance treatment with an 8-week dosage interval and nearly one-third of all patients required a dose increase, suggesting a highly refractory disease phenotype. The lack of detected antidrug antibodies during follow-up indicates low immunogenicity for ustekinumab.
DOP32 Clinical and molecular characterisation of patients with durable response to ustekinumab induction therapy: Results from the UNIFI phase 3 studies in moderate-to-severe ulcerative colitis
Authors: Li K , Yang F , Hayden K , Strawn D , Wadman E , Bhagat S , Marano C , Friednman J R
Published: January 2020

Background

Ustekinumab (UST) is an effective therapy for moderate-to-severe ulcerative colitis (UC).1 A subset of patients responded to the induction dose of UST and achieved clinical remission at maintenance Week 44 (M-Week 44) following placebo (PBO) maintenance. The clinical and molecular characteristics of this group are unknown.

Methods

Three subsets of patients in the UNIFI phase 3 studies were compared: (1) UST induction Week 8 (I-Week 8) responders who achieved clinical remission at M-Week 44 following PBO maintenance (n = 32; referred to as 1UST-R); (2) UST I-Week 8 responders who did not achieve clinical remission at M-Week 44 following PBO maintenance (n = 87; 1UST-NR); (3) patients who had no clinical response following two doses of UST induction (n = 93; 2UST-NR). Clinical characteristics, histologic activity, inflammation burden, and genetic risk were compared among the three groups at induction baseline. Serum biomarkers related to the IL-12 and IL-23 pathways and/or UC in general (IFNg, IL-17A, IL-22, MMPs, SAA, and NGAL) were analysed in ~60% of patients within the three groups and compared with patients who achieved M-Week 44 clinical remission following UST maintenance and normal controls.

Results

1UST-R had lower disease activity and inflammation burden (CRP, faecal calprotectin, and faecal lactoferrin) at induction baseline than 1UST-NR and 2UST-NR. They had shorter disease duration, a lower frequency of biologic therapy failure, and a trend of lower polygenic genetic risk scores. Disease (MMPs and NGAL) and pathway-related biomarkers (IL17A and IL22) for this group were comparatively less elevated at induction baseline. Histologic measures of architectural change and chronic inflammation were higher in 2UST-NR than in 1UST-R or 1UST-NR at induction baseline. IFNg, IL17A, IL22, MMPs, and SAA in UC were partially normalised by UST induction and further improved with UST maintenance therapy. In contrast, there was no further improvement in these serum markers among the 1UST-R patients during the maintenance phase.

Conclusion

Patients with a durable response to UST induction had lower disease activity, serum biomarkers indicative of inflammation, and IL-12 and IL-23 pathway activity. Although the molecular effects of UST induction were retained through M-Week 44 in this group, the lack of further improvement suggests a molecular benefit of UST maintenance therapy.

Reference
DOP33 Stratification of patients for treatment with adalimumab by a combination of immune-profiling and in vivo efficacy studies in a novel mouse model of ulcerative colitis
Authors: Gropp R , Jodeleit H , Caesar J , Villarroel Aguilera C , Sterz S , Holdt L , Beigel F , Breiteneicher S , Stallhofer J , Siebeck M
Published: January 2020

Background

The Holy Grail in chronic inflammatory diseases is the identification of biological markers which might explain the heterogeneity of disease manifestations and predict responses to treatment. The aim of this study was to identify immunological subgroups of patients with UC and to test responsiveness to adalimumab in these subgroups in the mouse model of ulcerative colitis (UC), which is based on NOD/scid IL-2Rγ null (NSG) mice reconstituted with peripheral blood mononuclear cells (PBMCs; NSG-UC).

Methods

The immunological profiles of 40 UC patients and 16 non-UC donors were determined by flow cytometric analysis of PBMCs in a snapshot and longitudinal study and analysed by principal component (PCA), orthogonal partial least square discrimination (oPLS-DA)- and hierarchical clustering analysis. NSG mice were reconstituted five times at consecutive time points with PBMCs from a single donor and were analysed for frequencies of human leukocytes, histological phenotype and levels of calprotectin (CRP) and transforming growth factor (TGF)-β. The response to adalimumab was tested in the NSG-UC model reconstituted with PBMC from patients clustering in group I (n = 2) or II (n = 2). Readout were the clinical, colon and histological scores, serum levels of glutamic and aspartic acid and interleukin (IL)-6 and IL-1β. The response was analysed by PCA.

Results

Hierarchical clustering identified two major subgroups in UC patients. Group I was characterised by TH17 and M1 monocytes, group II by TH2/TH1 and switched B cells. O-PLS-DA revealed significant discrimination between the two groups.

Patients analysed in longitudinal studies switched from one group to the other. Thus, these subgroups reflected the dynamics of inflammation in patients. Mice reconstituted five times at consecutive time points with PBMC from one donor achieved an immunological phenotype reflecting the one of the Patient at that time point. Like the patient, mice switched from a pro-inflammatory phenotype (group II) to an M1 monocyte driven inflammation (group I).

In mice, group II was characterised by a severe influx of inflammatory cells and oedema whereas group I was signified by extensive fibrosis. This observation was corroborated by colonic CRP and TGFß levels. CRP levels were significantly higher in group II, whereas TGFβ levels were increased in group I. PCA analysis revealed that mice reconstituted with PBMC from group II responded better to treatment with adalimumab than mice from group I.

Conclusion

The combination of profiling and testing of therapeutics in the NSG-UC model may ultimately lead to individualised and phase-dependent therapies.
DOP48 Gene expression landscape of epithelial monolayer in inflammatory bowel disease
Authors: Sæterstad S , Østvik A E , Sandvik A K , Granlund Van Beelen A
Published: January 2020

Background

Gene expression analyses on IBD tissue are dominated by analyses of biopsy homogenates that are highly heterogeneous due to a difference in cell populations when contrasting inflamed vs. healthy mucosa. We wished to characterise the inflammatory activity of the isolated epithelial monolayer (EM), avoiding the infiltrating inflammatory cells, thereby form a comprehensive understanding of the epithelium’s role in IBD pathobiology.

Methods

Total RNA was isolated from laser capture microdissected (LCM) colon EM, and sequencing libraries were prepared using TruSeq RNA access kit (Illumina, CA, USA). Gene cluster analysis (WGCNA) was used to stratify the expression data in genetic modules. Following this, we characterised the modules correlated to IBD status, using Metacore pathway analysis, in order to suggest what underlying biological processes contribute to the observed correlation of expression data. Finally, we used immunohistochemistry to verify the protein expression pattern of key players in the suggested pathways, thereby confirming EM involvement in these processes during inflammation.

Results

Biopsies from active (a) IBD (7 UCa, 5 CDa) and from un-inflamed (u) IBD and healthy control (7 UCu, 5 CDu and 6 HC) were included in the analysis. 6386 genes were differentially expressed (adjusted p-value (pval.) <0.05) in EM from active inflamed colon vs. un-inflamed (Figure 1). Six gene modules showed a significant correlation between inflammatory status and gene expression (Figure 2). Of note was a broad, significant up-regulation of MHC class II presentation machinery, e.g. STAT1 (log2 fold change (lfc) 0.93, p < 0.001), CIITA (lfc 2.57, p < 0.001) and HLA-DRB1 (lfc 3.69, p < 0.001), and a down-regulation unique to epithelial cells of the retinoic acid receptors RARA (lfc −0.79, p < 0.001) and RXRA (log fc −0.56, p < 0.001). The most significantly up-regulated pathway was ‘Immune Response’, induction of antigen presentation machinery by IFN-γ (FDR 2.5 × 10–18), while ‘RXR-dependent regulation of lipid metabolism’ (FDR 2.6 × 10–8) was the most significantly down-regulated pathway.

Conclusion

Our analyses suggest that the involvement of the EM in IBD inflammation goes far beyond acting as a barrier. The largest genetic modules are dominated by genes important for inflammatory regulation, suggesting that the EM is much more involved in these processes than what is commonly understood. This study lends support to further analyses of interplay between epithelial cells and immune cells, particularly in a pro-inflammatory environment.
N19 Understanding the emotional impact of inflammatory bowel disease: looking after nurses looking after patients
Authors: Younge L , Medcalf L , Hall A , Shaw C
Published: January 2020

Background

The emotional impact of inflammatory bowel disease (IBD) is well documented. Patients describe distress, anxiety, depression and relationship difficulties, (including with healthcare staff). Nurses working with IBD patients report being emotionally affected, with fears of ‘burnout’, feeling unable to respond helpfully to patients and feelings of guilt, frustration, sadness and anger. Understanding and managing the emotional impact of the work for IBD nurses is an area underrepresented in either research or nursing literature.

Methods

A collaborative project with IBD nurses and nursing and psychotherapy colleagues from the Tavistock and Portman NHS Foundation Trust developed a one-day event for IBD nurses in the UK. Attendees were self-selecting and the event was supported by Pharma. The conference had three aims: To provide an opportunity to recognise and understand the emotional impact on nurses working with IBD patients, to provide a networking opportunity, and to use information gathered before, during and after the conference to develop a clearer understanding of nurses’ experiences and needs. A pre-conference questionnaire was sent to attendees, observations were made during the conference (noting themes and dilemmas) and an evaluation form was provided.

Results

89% agreed/strongly agreed the event provided understanding of how IBD can have an emotional and psychological impact on patients. 89% agreed/strongly agreed the event provided understanding of the emotional impact on nurses working with IBD patients. Eighty-nine per cent agreed/strongly agreed the event provided understanding of ways in which the emotional impact can influence provision of care and decision making in patients with IBD. Ninety-three per cent agreed/strongly agreed the event provided them with ideas for establishing and managing reflective learning opportunities. Seventy-five per cent agreed/strongly agreed the event enabled them to identify different ways of responding to patients they work with.

Conclusion

Feedback from attendees identified a need and an expressed wish by IBD nurses to understand and explore how they are affected by their work, in relation to maintaining therapeutic and safe relationships with patients and maintaining their own well-being and job satisfaction. Learning needs relating to training in supervision, developing skills in responding to patients’ emotional states, tools for looking after one’s self and opportunities for group discussions and learning were identified. There is an opportunity to develop further learning and training events in relation to these identified needs. Further exploration of accessibility, funding and evaluation would be beneficial in identifying the impact, if any, of further training.
N26 Experiences of patients with inflammatory bowel disease (IBD) regarding faecal incontinence and the guidance received
Authors: Toivonen T T I , Helin K , Nikkola R
Published: January 2020

Background

Patients with inflammatory bowel disease (IBD) suffer more often than the rest of the population from faecal incontinence, which decreases their quality of life. The purpose of this study was to describe the experiences of Finnish IBD patients regarding faecal incontinence and the guidance they need and have received for faecal incontinence.

Methods

The data were collected by executing focused interviews of eleven IBD patients, who at the time of the interview were in remission. The interviewees participated in the study via the Finnish patient association Crohn ja Colitis ry. The data were analysed using an inductive content analysis.

Results

Seven participants were men and four were women. They had had IBD for an average of 2 to 40 years. Five interviewees had Crohn’s disease and six had ulcerative colitis. The extent of the faecal incontinence and its impact on quality of life were assessed by Jorge–Wexner score, which examines the frequency of solid and loose stools and intestinal gas, use of diapers or protective pads, and the patients’ perception of the impact on the quality of life. Zero points stands for complete continence and 20 points for complete incontinence. The average Wexner score among participants was 9.8 (Figure 1). The participants felt that faecal incontinence was constantly disturbing their life. They especially wished for support and information regarding diet. Fear of faecal incontinence made participants skip planned activities and isolate themselves at home. Participants tried to anticipate bowel movements and find out toilet locations in advance in order to venture out of their homes. Participants had discussed faecal incontinence with an IBD nurse and a doctor, but none had met a continence nurse. Furthermore, none of the participants had been told about potential faecal incontinence or ways to manage it. Some participants felt that diet had improved their bowel function, although health care personnel had said in their guidance that diet has no effect on faecal incontinence. Participants also felt that they would have needed information regarding the risk of faecal incontinence and wished that they had been heard regarding problems caused by faecal incontinence.

Conclusion

IBD patients need guidance from health care personnel and information regarding faecal incontinence to balance their bowel function. Health care personnel taking care of IBD patients in Finland needs more training on faecal incontinence, and in addition, more guidance and criteria on when to direct a patient to a continence nurse is needed.
DOP85 The role of fibroblasts in the pathogenesis of Crohn’s disease-associated fistulas and in mesenchymal stem cell therapy
Authors: Bruckner R S , Barnhoorn M C , Mei H , Kiełbasa S M , Harrijvan T J , Hakuno S K , van der Reijden J J , van der Meulen-de Jong A E , Hawinkels L J A C
Published: January 2020

Background

Perianal fistulas are a severe and frequent complication in Crohn’s disease (CD) patients, significantly affecting their quality of life. High recurrence rates, incomplete fistula healing and non-responding patients make the treatment challenging. Despite some novel insights, current knowledge about the pathogenesis of fistula formation is still limited. Fibroblasts are abundantly present in CD fistulas and were recently reported to regulate Th1 cell activity in inflammatory bowel disease (IBD) (Beswick EJ et al. 2018). We hypothesised that fibroblasts act as the key drivers of fistula pathogenesis by regulating inflammatory cell recruitment.

Methods

Fibroblasts were isolated from curettage material of perianal CD fistulas, non-CD-associated fistulas, and the normal colon (obtained at surgery for colorectal cancer at least 10 cm away from the primary tumour). For all experiments, fibroblast populations were identified by qPCR and flow cytometry analysis first. Then gene expression profiling via mRNA sequencing of cultured fistula- and colon-derived fibroblasts was performed. The characterisation was complemented by flow cytometry analysis. Furthermore, the interaction of fistula-derived fibroblasts with regulatory T cells (Tregs) was studied in co-culture experiments.

Results

mRNA sequencing analysis revealed no significant differences in gene expression between perianal CD fistulas and non-CD-associated fistulas. However, comparing fistula-derived samples to fibroblasts derived from the normal colon, we found over 6000 significantly differentially expressed genes. Among the 20 most significant differentially expressed genes between CD fistulas and colon fibroblasts were genes related to epithelial-mesenchymal transition, cell migration or the NF-κB signalling pathway. Furthermore, co-culture experiments with CD fistula-derived fibroblasts, revealed increased proliferation rates of CD25+FoxP3+ Treg cells. In addition, more CD4+ T cells differentiated into Treg cells after exposure to CD fistula fibroblasts.

Conclusion

Our data indicate a pathogenic role of fibroblasts located in the fistula tract. Their gene expression profile markedly differed from fibroblasts derived from the normal part of the colon. Based on our data, there is no difference between CD-associated and non-CD-associated fistula fibroblasts. CD fistula-derived fibroblasts seem to increase both the proliferation of Treg cells, and the differentiation of CD4+ T cells into Treg cells, indicating an important immunoregulatory role of fibroblasts. Ongoing experiments should reveal which cytokines and chemokines are involved in this process.
DOP87 SUCNR1 a novel key protagonist in fistula development
Authors: Bauset C , Gisbert-Ferrandiz L , Ortiz-Masia D , Coll S , Mamie C , Scharl M , Calatayud S , Barrachina M D , Cosín-Roger J
Published: January 2020

Background

Intestinal fistula is a common complication in CD patients whose aetiology is still not well-characterised. It is associated with an exacerbated inflammation and epithelial-to-mesenchymal transition (EMT), a process which allows a switch from epithelial towards a fibrotic behaviour. We have recently reported that SUCNR1 mediates intestinal inflammation and fibrosis1 but its role in fistula has not yet been analysed. Therefore, we aim to analyse the role of SUCNR1 in EMT and in fistula formation.

Methods

Intestinal resections were obtained from CD and non-IBD patients. Fistula specimens were identified by the surgeons and collected from B3-CD patients. The expression of SUCNR1 and EMT markers was analysed by qPCR and the protein expression of SUCNR1 by immunohistochemistry. HT-29 cells were treated with succinate (0,0.1,0.5,1,5 mM) or TGF-β (5 ng/ml) during 48 h and transfected with SUCNR1 siRNA. Expression of EMT markers was analysed by qPCR and western blot. Intestinal fibrosis was induced in vivo using the heterotopic transplant model in WT and Sucnr1−/− mice and expression of EMT markers was analysed by qPCR and by confocal microscopy. Statistical analysis was performed with one-way ANOVA followed by Newman–Keuls test. Correlations were analysed with the Spearman’s coefficient.

Results

In intestinal resections from B3-CD patients, SUCNR1 mRNA expression was significantly increased when compared with B2-CD or non-IBD controls and it correlates positively with the mRNA expression of Snail1 and Snail2 and negatively with that of E-Cadherin. In the fistula tract, SUCNR1 is expressed in intestinal epithelial cells and lamina propria cells of the submucosa with a higher intensity in cells close to the fistula tract than in more distant areas. Succinate induced, in a dose–response manner, a significant increase in Vimentin, Snail1 and Snail2 expression and a reduction in E-cadherin expression. This effect was completely abolished when SUCNR1 was transiently knocked-down. WT-grafts 7 days after surgery exhibited: (a) an increase in gene and protein expression of SUCNR1, (b) an increase in the expression of Vimentin, Snail1 and Snail2 and a significant reduction in E-Cadherin compared with WT-grafts at day 0. Of interest, KO-grafts at day 7 failed to exhibited changes in the expression of Vimentin, Snail1, Snail2 or E-Cadherin.

Conclusion

SUCNR1 is increased specifically in the fistula tract of B3-CD patients. It mediates EMT in intestinal epithelial cells and in a murine model of fibrosis. Hence, SUCNR1 might be a potential pharmacological target for fistula treatment.

Reference
P003 Metabolomics for improved patient stratification in inflammatory bowel disease: Characterisation of the ulcerative colitis metabolome
Authors: Diab J , Hansen T , Goll R , Stenlund H , Jensen E , Moritz T , Florholmen J , Forsdahl G
Published: January 2020

Background

The onset of ulcerative colitis (UC) is characterised by a dysregulated mucosal immune response triggered by several genetic and environmental factors in the context of host-microbe interaction. This complexity makes UC ideal for metabolomic studies to unravel the disease pathobiology and to improve the patient stratification strategies toward personalised medicine. This study aims to explore the mucosal metabolomic profile in treatment-naïve and deep remission UC patients, and to define the metabolic signature of UC.

Methods

Treatment-naive UC patients (n = 18), UC patients in deep remission (n = 10), and healthy volunteers (n = 14) were recruited. Mucosa biopsies were collected during colonoscopy. The UC activity and the state of deep remission were assessed by endoscopy, histology, and by measuring TNF gene expression.

Metabolomic analysis was performed by combined gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF-MS) and ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS). In total, 177 metabolites from 50 metabolic pathways were identified.

Results

Multivariate data analysis revealed a distinct metabolomic profile in inflamed mucosa taken from treatment- naïve UC patients compared with non-inflamed mucosa taken from UC remission patients and healthy controls. The mucosal metabolome in UC remission patients differed to a lesser extent from the healthy controls. The most prominent metabolome changes among the study groups were in lysophosphatidylcholine, acylcarnitine, and amino acid profiles. Several metabolic pathways were perturbed, ranging from amino acid metabolism (such as tryptophan metabolism, and alanine, aspartate and glutamate metabolism) to antioxidant defence pathway (glutathione pathway). Furthermore, the pathway analysis revealed a disruption in the long-and short-chain fatty acid (LCFA and SCFA) metabolism, namely linoleic metabolism and butyrate metabolism.

Conclusion

The mucosal metabolomic profiling revealed a metabolic signature during the onset of UC, and reflected the homeostatic disturbance in the gut. The altered metabolic pathways highlight the importance of system biology approaches to identify key drivers of IBD pathogenesis which prerequisite personalised treatment.
P015 Tricellulin overexpression protects against elevated macromolecule uptake in DSS colitis mice
Authors: WEIß F , Lee I F M , Fromm A , Hu J C E , Breiderhoff T , Fromm M , Schulzke J D , Krug S M
Published: January 2020

Background

In Inflammatory bowel disease, intestinal homeostasis cannot be sustained due to an overreaction of the immune system and a disturbed epithelial barrier due to an impaired tight junction (TJ). At tricellular TJs (tTJs), which are formed where three cells meet, the TJ network is basolaterally expanded and forms a central tube which would be potentially large enough to allow for a paracellular passage of macromolecules. Under normal conditions, the tTJ protein tricellulin (Tric) seals the central tube against luminal uptake. However, in ulcerative colitis (UC), Tric is downregulated, resulting in increased uptake of macromolecules including antigens which may further support the inflammatory processes. Thus, we aimed to identify whether or not overexpression of Tric has a protective effect against inflammation.

Methods

We generated intestinal epithelial cell-specific overexpression of Tric in mice (B6.C-Tg(Vil-cre) Rosa26tgGFP-Tric). In Tric-overexpressing (Tric-OE) and in wild-type (wt) mice experimental colitis was induced by 3% dextran sodium sulphate (DSS) for 6 days. The effect was assessed by determining the disease activity index (DAI: weight loss, stool consistency, and stool bleeding) and the colon dimensions. Using chamber experiments were performed to determine permeabilities for ions and macromolecules of different sizes (4 and 10 kDa).

Results

No difference in weight loss was observed between wt and Tric-OE mice upon DSS treatment. However, Tric-OE mice suffered less from diarrhoea and had less bloody stools compared with wt mice resulting in a lower DAI. In addition, DSS caused a reduced colon length which was less prominent in Tric-OE mice than in wt mice. Functional analysis revealed higher permeabilities for Na+ and Cl− after DSS treatment with no significant differences between Tric-OE and wt mice. In contrast, permeabilities for macromolecules of both sizes were unchanged after DSS treatment in Tric-OE mice but elevated in wt-mice.

Conclusion

Tric-overexpression prevents the epithelial barrier from elevated paracellular uptake of macromolecules during DSS colitis without affecting ion permeability. This protects against DSS colitis as indicated by less affected clinical and structural outcome parameters, most likely via a reduction in a load of immunologically active macromolecules in the subepithelium.
P023 Identification of regulated mechanistic pathways and genes to protect intestinal barrier injury by larazotide acetate in an IBD microenvironment
Authors: Jin Y , Madan J , Radha B K , Anthony B
Published: January 2020

Background

Inflammatory bowel disease (IBD) is due to a combination of factors, including genetics, mucosal barrier dysfunction and dysregulated immune responses. Recently, it has been appreciated that IBD is associated with profound tissue anoxia. Tight junctions (TJs) located at the apical lateral region of adjacent intestinal epithelial cells are largely responsible for regulating the intestinal mucosal barrier. Larazotide acetate (LA, Innovate Biopharmaceuticals, Inc., Raleigh, NC) is a synthetic, eight amino acid peptide that is known to act as a TJ regulator capable of closing ‘leaky’ interepithelial junctions. Presently, LA is being studied in Phase 3 clinical trials for the treatment of celiac disease. Based on prior work in our lab, we hypothesised that LA would protect the TJ barrier in an anoxic injury IBD model associated with upregulation of TJ-associated signalling pathways.

Methods

C2BBe1 (Caco-2 brush border expressing) monolayers were treated apically with LA and were subjected to anoxia for 2 h followed by reoxygenation with 21% O2. Barrier function was assessed by measuring transepithelial electrical resistance (TEER) during anoxic injury and recovery. TJ proteins and cytoskeleton protein F-actin were assessed by western blotting and immunofluorescence microscopy. Then, next-generation RNA sequencing was employed to assess cellular regulatory pathways.

Results

Pre-treatment of anoxic injured C2BBe1cells with 10 mM LA significantly increased TEER as compared with untreated anoxic injured cells. The TJ protein occludin and ZO-1 were disrupted in anoxia-injured monolayer. Alternatively, treatment with 10 mM LA prevented disruption of TJ proteins during anoxic injury. Gene ontology annotation revealed a number of critical signalling pathways that were differentially expressed in cells treated with LA, including biological processes involved in establishment of cell polarity, molecular functions that regulate junctional structures, and cellular components associated with epithelial repair (cell leading edge, ruffle and apical junctional complex). Furthermore, Ras/Rho GTPase binding and protein serine/threonine kinase activity were differentially expressed in cells treated with LA. Additionally, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed enrichment of target genes for ‘cell cycle,’ ‘adherens junction’ and ‘Wnt signalling pathways’.

Conclusion

The results of the present study provide novel insights into the molecular mechanism of action of LA on the protection of TJ integrity in anoxic injury, an IBD microenvironment and the potential for a more broad use in important digestive diseases such as IBD.