Introduction

Ustekinumab (UST) is a monoclonal antibody against the p40 subunit, common to IL-12 and IL-23 and was approved recently for the treatment of moderate to severe ulcerative colitis (UC).

Aims & Methods

The aim of this ongoing study is to report and analyze data from a large cohort of Greek patients with UC, who receive treatment with UST. We collected data from patients with UC from 14 Greek hospitals who commenced treatment with UST and evaluated their clinical response at week 16. Clinical response was defined as 50% reduction in the UC PRO2 values at week 16 compared to the values before treatment (baseline).

Results

Herein, we report the clinical outcomes at week 16, following the completion of induction regimen (i.v. loading 6mg/kg plus 1^st 90mg sc injection at week 8). The demographics and disease characteristics of the first 101 enrolled patients are shown in Table 1. The majority of patients (70, 70%) commenced treatment with UST due to active disease despite previous treatments. Seventy-six patients (76%) had been exposed to at least one biologic agent, most commonly anti-TNFs (54%). Thirty-eight (38%) and 29 (29%) patients were exposed to one and two biologics, respectively. Sixteen patients (16%) had previously received both infliximab (IFX) and vedolizumab (VDZ). Corticosteroids (50%) and mesalazine (5-ASA, 68%) were the most common concomitant treatments. UST was discontinued in 4 patients due to no response. A total of 79 patients have reached the 16^th week time-point, out of whom 61 have enough data to be analyzed. Analysis of the patients who had active disease at induction (total number with adequate data: 50) showed that clinical response was achieved in 36 (72%) and clinical steroid-free remission in 23 (46%) patients. In multiple logistic analysis concomitant use of 5-ASA was associated with a higher probability of clinical response at week 16 (P=0.009), while hemoglobin >13.1g/dL (P=0.047), and age >60 years (P=0.059) were associated with a lower probability of response. Seven patients were receiving concomitant corticosteroids at week 16.

Conclusion

In a real world clinical setting, UST was mostly used as a 2^nd or 3^rd line treatment for moderate to severe UC. At the end of induction treatment, the majority of patients showed clinical response and almost half were in steroid-free remission. Positive predictive factors of response to UST included the concomitant use of 5-ASA, while Hb >13.1 g/dl and age >60 years were associated with lack of response.
Funding: This study was funded through a research grant from the Greek IBD study group (EOMIFNE) to G.B. EOMIFNE grant: 2022EOMIFNEmp1

Disclosure

GB: Advisor/lecturer for Janssen, Pfizer, Takeda, Abbvie, MSD, Mylan, Genesis Pharma,
Adacyte Therapeutics, Amgen, Ferring, Cooper; Funding (Grants/Honoraria): Pfizer, Takeda,
Abbvie, Aenorasis; Research/Clinical Trials: Abbvie, Takeda.
EZ: Advisor/lecturer for Pfizer, Takeda, Abbvie, Amgen, Genesis Pharma, Aenorasis, Janssen
SM: Advisory/Lecturer for Pfizer, Takeda, Abbvie, Ferring, MSD, Janssen
GM: Advisor/lecturer for AbbVie, Celgene, Celtrion, Ferrirng, Genesis, Hospira, Janssen,
Millennium Pharmaceuticals, MSD, Mylan, Pharmacosmos, Pfizer, Takeda, VIANEX, Angelini,
Falk Pharma, Galenica, Omega Pharma; Consultancies for MSD and Takeda; Research support
from AbbVie, Galenica, Genesis, Menarini Group, MSD, Pharmathen.
KK: Advisor/lecturer for Abbvie, Aenorasis, Janssen, MSD, Pfizer and Takeda, Amgen, Ferring,
Galenica, Genesis Pharma.
MT: Advisor/lecturer for Janssen, Pfizer, Takeda, Abbvie, MSD, Mylan, Genesis Pharma,
Amgen, Research/Clinical Trials: AbbVie, Gilead, Takeda

Introduction

Mirikizumab [(miri), a p19-directed IL-23 antibody] has been shown to be effective in patients with moderately to severely active ulcerative colitis (UC) in Phase 3, randomised, double-blind, placebo-controlled trials (LUCENT-1 NCT03518086; LUCENT-2 NCT03524092).¹ Given the importance of understanding treat-to-target strategies, the relationship between improved histologic and endoscopic endpoints and improvement of the inflammatory biomarkers faecal calprotectin (fCal) and C-reactive protein (CRP) was studied within miri-treated patients enrolled in the programme.

Aims & Methods

This analysis focused on miri-treated patients (n=868) from the induction study receiving intravenous (IV) every 4 weeks (Q4W) until week (W)12 and miri induction responders at week W12, who were rerandomised for the maintenance period, receiving subcutaneous miri (n=365) Q4W up to W52. The relationship between achieving histologic-endoscopic mucosal improvement (HEMI), histologic-endoscopic mucosal remission (HEMR) (definitions in Tables) and improvement of fCal (≤250µg/g) and CRP (≤6mg/L) levels at W12 and W52 was explored using Fisher’s exact tests.

Results

At W12, a significantly higher percentage of miri-treated patients achieving HEMI (n=235/868) had normalised fCal and CRP values (76.2% and 88.5%), compared to miri-treated patients who did not achieve HEMI (n=633/868) (21.8% and 72.7%, both p<0.001; Table). Similarly, a higher proportion of patients achieving HEMR (n=193/868) had normalised fCal and CRP values (79.3% and 89.6%), compared to those who did not achieve HEMR (n=675/868) (24.3% and 73.3%, both p<0.001; Table). At W52, a significantly higher percentage of the miri induction responder patients rerandomised to miri achieving HEMI (174/365) had normalised fCal and CRP values (74.1% and 87.9%), compared to patients not achieving HEMI (191/365) (32.5% and 61.3%; both p<0.001). Similarly, at W52, a higher proportion of patients achieving HEMR (n=158/365) had normalised fCal and CRP values (76.6% and 88.0%), versus patients not achieving HEMR (n=207/365) (33.8% and 63.3%; both p<0.001, Table).

Conclusion

At both W12 and W52, patients treated with miri who achieved HEMI or HEMR showed statistically significant improvements in fCal and CRP levels. This suggests that CRP and fCal may be useful markers of histology and endoscopy outcomes after induction and maintenance with miri.

References

1. Magro et al., MP245 Efficacy of mirikizumab in resolving active histologic inflammation in Ulcerative Colitis in Lucent-1 induction and Lucent-2 maintenance trials (2022), UEG Week Moderated Posters. United European Gastroenterol J, 10: 185-472.

Disclosure

R. Panaccione has received speaker fees and/or served as a consultant and/or advisory board member for: Abbott, AbbVie, Alimentiv, Amgen, Arena Pharmaceuticals, AstraZeneca, Biogen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Celltrion, Cosmo Pharmaceuticals, Eisai, Elan Pharma, Eli Lilly and Company, Ferring Pharmaceuticals, Galapagos NV, Genentech, Gilead Sciences, GlaxoSmithKline, Janssen, Merck, Mylan, Oppilan Pharma, Pandion Therapeutics, Pfizer, Progenity, Protagonist Therapeutics, Roche, Sandoz, Satisfai Health, Shire, Sublimity Therapeutics, Takeda, Theravance Biopharma and UCB Pharma; and has received research and/or educational support from: AbbVie, Ferring Pharmaceuticals, Janssen, Pfizer and Takeda; C. Sapin, F. Chan-Diehl and R. Moses are employees and shareholders of: Eli Lilly and Company;
B. Siegmund has served as a consultant and/or speaker for: AbbVie, Arena Pharmaceuticals, Bristol Myers Squibb, Boehringer Ingelheim, CED Service GmbH, Celgene, Dr Falk Pharma, Eli Lilly and Company, Ferring Pharmaceuticals, Galapagos NV, Janssen, Novartis, Pfizer, Prometheus Therapeutics and Takeda;
A. Walsh has received grant and/or research support from: AbbVie and Pfizer; and has received consultancy fees from: AbbVie, Eli Lilly and Company, Novartis and UCB Pharma;
T. Kobayashi has served as a speaker, consultant and advisory board member for: AbbVie, Ajinomoto Bio-Pharma, Alfresa Pharma, Asahi Kasei Pharma, Astellas, Bristol Myers Squibb, Celltrion, Covidien, EA Pharma, Eisai, Eli Lilly and Company, Ferring Pharmaceuticals, Galapagos NV, Gilead Sciences, Janssen, JIMRO, Kyorin, Mitsubishi Tanabe Pharma, Mochida Pharmaceutical, Nippon Kayaku, Pfizer, Takeda, Thermo Fisher Scientific and Zeria Pharmaceutical; and has received research funding from: AbbVie, ActivAid, Alfresa Pharma, Asahi Kasei Pharma, EA Pharma, Google, JMDC, Kyorin, Mochida Pharmaceutical, Nippon Kayaku, Otsuka, Sekisui Medical, Thermo Fisher Scientific and Zeria Pharmaceutical;
P. S. Dulai has served as a consultant for: AbbVie, Abivax, Addiso, Bristol Myers Squibb, Eli Lilly and Company, Janssen, Pfizer, Precidiag, Prometheus and Takeda;
S. Travis has received grants from: AbbVie, BUHLMANN Diagnostics, ECCO, Eli Lilly and Company, Ferring Pharmaceuticals, International Organization for the Study of Inflammatory Bowel Disease, Janssen, Merck Sharp & Dohme, Norman Collision Foundation, Pfizer, Procter & Gamble, Schering-Plough, Takeda, UCB Pharma, Vifor Pharma and Warner Chilcott; and reports other disclosures from: Abacus Pharma, AbbVie, Actial Farmaceutica, ai4gi, Alcimed, Allergan, Amgen, Aptel, Arena Pharmaceuticals, Asahi Kasei Pharma, Aspen Pharmacare, Astellas, AstraZeneca, Atlantic Pharmaceuticals, Barco, Biocare Medical, Biogen, BL Pharma, Boehringer Ingelheim, Bristol Myers Squibb, BUHLMANN Diagnostics, Calcico Therapeutics, Celgene, Cellerix, Cerimon Pharmaceuticals, ChemoCentryx, Chiesi, Cisbio, Comcast, Coronado Biosciences, Cosmo Pharmaceuticals, Dr Falk Pharma, Ducentis BioTherapeutics, Dynavax Technologies, Elan, Eli Lilly and Company, Enterome, Equillium, Ferring Pharmaceuticals, Galapagos NV, Genentech/Roche, Genzyme, Gilead Sciences, GlaxoSmithKline, Glenmark Pharmaceuticals, Grünenthal, GW Pharmaceuticals, Immunocore, Indigo Biosciences, Janssen, Lexicon Pharmaceuticals, Medarex, MedTrix, Merck, Merrimack Pharmaceuticals, Mestag Therapeutics, Millennium Pharmaceuticals, Neovacs, Novartis, Novo Nordisk, NPS Pharmaceuticals/Nycomed, Ocera Therapeutics, OPTIMA Pharma, Origin Pharma, Otsuka, Procter & Gamble, Palau Pharma, Pentax Medical, Pfizer, PharmaVentures, Phesi, Phillips Pharma Group, Pronota, Proximagen, Resolute, Robarts Clinical Trials, Sandoz, Santarus, Satisfai Health, Sensyne Health, Shire, Sigmoid Pharma, Sorriso Pharmaceuticals, Souffinez, SynDermix, Synthon, Takeda, Theravance Biopharma, TiGenix, Tillotts Pharma AG, Topivert, Trino Therapeutics with Wellcome Trust, TxCell, UCB Pharma, Vertex Pharma, VHsquared, Vifor Pharma, Warner Chilcott and Zeria Pharmaceutical

Introduction

Filgotinib (FIL) is a once-daily, oral, Janus kinase 1 preferential inhibitor approved for the treatment of ulcerative colitis (UC). Previous analyses of data from the phase 2b/3 SELECTION trial (NCT02914522) demonstrated that FIL 200 mg (FIL200) improved health-related quality of life (HRQoL) and led to comprehensive disease control (comprising clinical, biomarker, HRQoL and endoscopic improvements) in patients with UC.¹

Aims & Methods

We evaluated individual Inflammatory Bowel Disease Questionnaire (IBDQ) item data from SELECTION to assess which items drive the benefits of FIL treatment. In SELECTION, adults with moderately to severely active UC were randomized 2:2:1 to receive FIL200, FIL 100 mg or PBO once daily for 11 weeks in Induction Studies A and B (biologic-naive and -experienced patients, respectively). Patients who responded to FIL were rerandomized 2:1 to continue their induction FIL dose in the 47-week Maintenance Study. In this post hoc analysis, standardized effect sizes (SES) were calculated to evaluate the relative magnitude of the difference in mean scores of individual IBDQ items at week 10 (W10) between FIL200 versus PBO-treated patients, and at week 58 (W58) between patients who continued FIL200 treatment (FIL200→FIL200) versus those who were rerandomized to PBO (FIL200→PBO). SES were also calculated for the mean change in score of individual IBDQ items from baseline to W10, and from maintenance baseline to W58. SES were categorized by Cohen’s thresholds (‘trivial’ [<0.2]; ‘small’ [≥0.2–<0.5]; ‘moderate’ [≥0.5–<0.8]; and ‘large’ [≥0.8]). A last observation carried forward imputation approach was used for missing data.

Results

At W10, patients treated with FIL200 overall (n=506) had improvements in all individual IBDQ items versus those treated with PBO (n=277) and had moderate to large increases from baseline (SES ≥0.5) in all individual IBDQ items. The IBDQ items with the five largest SES for FIL200 versus PBO at W10 (analysed by induction study), and for FIL200→FIL200 (n=199) versus FIL200→PBO (n=98) at W58 are summarized in the Table. FIL200 treatment consistently resulted in the largest benefits in items related to pain (‘abdominal pain’ and ‘abdominal cramps’), ability to engage socially (‘satisfied with life’, ‘depressed or discouraged’, ‘social engagement’ and ‘problems with activities’) and bowel urgency (‘loose bowel movements’ and ‘finding a washroom’) versus PBO at W10, and versus FIL200→PBO at W58

Table. Top five individual IBDQ item scores ranked by SES for FIL200 versus PBO groups at W10 and FIL200→FIL200 versus FIL200→PBO groups at W58.

Conclusion

FIL200 treatment provides improvements in HRQoL versus PBO, with large SES seen for most IBDQ items, and the greatest improvements in items related to pain, social engagement and bowel urgency over 58 weeks. This analysis reveals the specific IBDQ items that drive the benefits to HRQoL of FIL and adds further evidence to that showing that FIL contributes to restoration of health through comprehensive disease control for patients with UC.¹

References

1. Schreiber S et al. J Crohns Colitis 2023; https://doi.org/10.1093/ecco-jcc/jjad018

Disclosure

BF reports grants and personal fees from AbbVie, Amgen, AstraZeneca, Bristol Myers Squibb, Janssen Biotech/Centocor, Johnson & Johnson/Janssen, Pfizer, Receptos and Takeda; and personal fees from Ablynx, ActoGeniX, AdMIRx, Inc., Akebia Therapeutics, Inc., Allergan, Atlantic Pharmaceuticals, Avaxia Biologics, Inc., Avir Pharma, Baxter Healthcare Corporation, Biogen Idec, BiomX Israel, Boehringer Ingelheim, Boston Pharmaceuticals, Calypso Biotech, Celgene, Elan/Biogen, Eli Lilly, enGene, Ferring Pharmaceuticals, Galapagos, Genentech/Roche, gIcare Pharma, Gilead, Given Imaging, Gossamer Bio, GSK, Inception IBD, Inc., Ironwood Pharmaceuticals, Japan Tobacco Company, Kyowa Hakko Kirin Co. Ltd, Lexicon Pharmaceuticals, Lycera, Mesoblast, Millennium Pharmaceuticals, MSD, Nestlé, Nextbiotix, Novartis, Novo Nordisk, Par’Immune, Progenity, Prometheus Therapeutics and Diagnostics, Protagonist, Qu Biologics, Salix Pharmaceuticals, Shire, Sienna Biopharmaceuticals, Sigmoid Pharma, Synergy Pharma, Teva Pharmaceuticals, TiGenix, Tillotts Pharma, UCB, Vertex Pharmaceuticals, VHsquared, Vivelix Pharmaceuticals, Wyeth, Zealand Pharma and Zyngenia.
SV reports grants from AbbVie, Galapagos, J&J, Pfizer and Takeda; consulting and/or speaker fees from AbbVie, AbolerIS Pharma, AgomAb, Alimentiv, Arena Pharmaceuticals, AstraZeneca, Avaxia Biologics, Bristol Myers Squibb, Boehringer Ingelheim, Celgene, CVasThera, Cytoki Pharma, Dr Falk Pharma, Ferring Pharmaceuticals, Galapagos, Genentech/Roche, Gilead, GSK, Hospira, Imidomics, Janssen, J&J, Lilly, Materia Prima, MiroBio, Morphic, MrMHealth, Mundipharma, MSD, Pfizer, Prodigest, Progenity, Prometheus, Robarts Clinical Trials, Second Genome, Shire, Surrozen, Takeda, Theravance Biopharma, Tillotts Pharma and Zealand Pharma.
LP-B reports speaking fees from AbbVie, Amgen, Arena Pharmaceuticals, Biogen, Celltrion, Eli Lilly, Ferring Pharmaceuticals, Galapagos, Genentech, Gilead, Janssen Pharmaceuticals, Medac Pharma, MSD, Pfizer, Sandoz, Takeda, Tillotts Pharma, Viatris and Vifor Pharma;grants from Celltrion, Fresenius Kabi and Takeda; and consulting fees from AbbVie, Abivax, Alimentiv, Alma Bio Therapeutics, Amgen, Applied Molecular Transport, Arena Pharmaceuticals, Biogen, Bristol Myers Squibb, Celltrion, CONNECT Biopharma, Cytoki Pharma, Eli Lilly, Enthera, Ferring Pharmaceuticals, Fresenius Kabi, Galapagos, Genentech, Gilead, Gossamer Bio, GSK, H.A.C. Pharma, IAG Image Analysis, Index Pharmaceuticals, Inotrem, Janssen Pharmaceuticals, medac Pharma, Mopac, Morphic, MSD, Norgine, Novartis, OM Pharma, ONO Pharmaceutical, OSE

Introduction

Ulcerative colitis (UC) is a refractory inflammatory bowel disease of the colon with repeated relapses and remissions that requires lifelong treatment. Previous studies indicated that proinflammatory cytokines involved the onsets and developments of UC. New treatments for targeting these cytokines, such as TNF-α, IL-12 and IL-23 have been developed in a recent decade, underlying that immune abnormalities are the core for the etiology of UC.
Platelets play a role not only in hemostatic coagulation but in inflammatory mediator by interacting with various cells in the innate and adaptive immunity. Chronic inflammatory response confers platelets activation leading to elevated platelet count and hypercoagulability. Moreover, platelets aggregates with leukocyte in active inflammatory milieu. In fact, thrombocytosis, thromboembolism and upregulation of platelet-monocyte complex (PMC) in UC patients have been reported, implying that platelets could be novel biomarker, therapeutic target and clues for elucidating the pathology of UC. However, the clinical significance of platelet activation and PMC formation in UC is not fully elucidated and few studies were conducted to assess how platelet activation contributes to disease aggravations of UC. Therefore, we comprehensively analyzed platelet activation and platelet-monocyte complex by focusing on a correlation with clinical severity of UC.

Aims & Methods

Patients with UC (n=70) including MES0-2 group (n=34) and MES3 group (n=27), diagnosed according to a combination of symptoms, endoscopic findings, histologic findings, and the absence of alternative diagnoses, and age and sex-matched healthy controls (HCs) (n =19) were enrolled for this study. We analyzed the surface markers such as CD62P, CD40L, CD63, PAC-1 and Annexin V on CD61+ platelets by flowcytometry (FCM) in patients with UC in comparison with those in healthy adults. We also analyzed the proportion of CD61+CD14+ platelet-monocyte complexes and quantified the activation of PMCs by FCM. Moreover, we also investigated the correlation among surface markers, proportion of platelet-monocyte aggregates and Mayo endoscopic score (MES) in UC patients.

Results

The expression of CD62P but not other surface markers on platelets was significantly upregulated in UC when compared to HCs (p<0.01), and was significantly upregulated in in MES3 group when compared to the MES0-2 group (P<0.001). The proportion of PMC was also higher in MES3 groups when compared to MES0-2 group (P<0.05), and was markedly reduced by treatment (P<0.05). In addition, CD16+ monocytes, phenotypically mature and pro-inflammatory cell population, were increased in patients with UC when compared to HCs (P<0.01). The expression of CD16 on monocytes aggregated with platelets was significantly higher when compered to that without platelet (P<0.001).

Conclusion

Our study suggests that platelet activation accelerates mucosal inflammation via adhesion with monocytes in UC and contributes to the aggravation of disease.

References

Semple JW, et al. Platelets and the immune continuum.
Nat Rev Immunol. 2011 Apr;11(4):264-74.
Collins CE, et al. Platelets circulate in an activated state in inflammatory bowel disease.
Gastroenterology. 1994 Apr;106(4):840-5.

Introduction

Inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD), are non-infectious chronic inflammatory disorders of the gastro-intestinal tract. The continuous presence of inflammatory stimuli, such as increased circulation of cytokines and danger-associated molecular patterns (DAMPs), leads to an enhanced immune response in these patients that could explain some types of disease relapse. An important receptor for DAMPS and pathogen-associated molecular patterns (PAMPs) is NLRP3, a cytosolic pattern recognition receptor. The NLRP3 inflammasome is exclusively activated by inflammatory stimuli, like DAMPs and PAMPs, and therefore not expressed without inflammation. It is thought that NLRP3 associates with ASC to recruit pro-Caspase 1 to the NLRP3 inflammasome and cleave it to its active form. In turn, Caspase 1 cleaves pro-interleukin 1 beta (IL-1β) and pro-interleukin 18 (IL-18) to their mature forms. IL-1β is a known elevated pro-inflammatory cytokine in IBD, promoting intestinal inflammation and immune cell recruitment. We hypothesized that the NLRP3 inflammasome pathway is therefore upregulated in IBD patients.

Aims & Methods

We first set out to systematically analyze gene expression of NLRP3 and IL1B in IBD patients by performing a systematic literature review and subsequent meta-analysis according to the PRISMA guidelines and Cochrane Collaboration methods. Subsequently, an observational cohort of 70 active and quiescent patients with CD or UC was sampled for whole blood, to study NLRP3 inflammasome gene regulation, protein production, assembly and secretion. We performed ex vivo LPS and ATP challenges of whole blood, with and without NLRP3 inflammasome formation inhibitor MCC950.

Results

Across thirty studies with publicly available mRNA expression data, we found NLRP3 and IL1B expression to be significantly higher in IBD patients than in non-IBD controls. In fresh IBD patient-derived whole blood, LPS and ATP stimulation activated the NLRP3-related genes, protein production and subsequent cytokine secretion. No IL-1β and IL-18 were secreted upon incubation with MCC950, suggesting a crucial role for NLRP3 inflammasome assembly in IL-1β and IL-18 production in immune cells. In patients with active IBD, the inflammasome was transcribed at a higher level than in patients in remission. However, this effect was lost on the protein level. We found a large spread in IL-1β and IL-18 production, suggesting a variation in activation of the NLRP3 inflammasome between individuals which was not related to disease activity.

Conclusion

NLRP3 and IL1B mRNA transcription is significantly increased in IBD patients compared to non-IBD controls, and significantly higher in patients with active disease than in patients in remission. While this fits the inflammatory state of active IBD, we found that the level of IL-1β and IL-18 production by the NLRP3 inflammasome is not significantly different between disease states. This suggests a variance in individual immune response to challenges, that could help identify a subset of IBD patients that would benefit from additional therapies directed at NLRP3 and IL-1β.

Introduction

Inflammatory bowel diseases are chronic disabling conditions with a complex and multifactorial aetiology, which is still not completely understood. OCTN1, an organic cation transporter could have a role in modulating the inflammatory response, whose genetic polymorphisms were associated to increased risk of inflammatory bowel diseases. Up to now, limited information exists on its role in predicting/modulating response to therapies.

Aims & Methods

The aim of this study was to evaluate the role of OCTN1 in modifying gut microbiota and immune composition to Infliximab therapy in murine colitis. Dextran sodium sulphate model of colitis on C57BL/6 mice and ocnt1 gene knockout mice was used to assess clinical efficacy of infliximab administered intravenously. Stool, colon and mesenteric lymph node samples were collected to assess differences in gut microbiota composition, histology for Rachmilewitz score and T cell populations respectively.

Results

Octn1^-/-influences microbiota profile and is associated with a worse dysbiosis in colitis mice. Infliximab treatment attenuates colitis-associated dysbiosis with increase of bacterial richness and evenness in both strains. In comparison with wild type, octn1^-/- mice have a higher baseline percentage of Treg, Tmemory, Th2 and Th17.

Conclusion

Our data support murine model to study OCTN1 genetic asset in inflammatory bowel diseases. This could be the first step to consider this membrane transporter as a biomarker in inflammatory conditions and as a predictor of response to therapies.

Introduction

Inflammatory bowel disease (IBD) is characterized by chronic inflammation due to an uncontrolled immune response orchestrated through, i.e. neutrophils. The basement membrane acts as a front-line defense promoting tissue integrity, where the α-3 chain of type IV collagen is solely expressed on the outermost layer of the mucosa. Detection of subclinical ulceration is crucial since early-stage IBD presents a unique window of opportunity for intervention, as the disease might become a self-sustaining process once deep inflammation becomes established. We therefore, wanted to develop a biomarker reflecting early tissue injury, aiding in the implementation of prompt treatment.

Aims & Methods

A competitive enzyme-linked immunosorbent assay quantifying a human neutrophil elastase (HNE) degraded fragment of type IV collagen α-3 chain was developed (C4A3-HNE). Dilution- and spiking recovery, inter- and intra-variability, and interference were evaluated. Acceptance criteria for technical validation were a recovery of 100% ±25 and an inter-intra variability of <15%. Commercial serum samples were purchased from ProteoGenex. Biological relevance was validated in an observational study from Odense University Hospital (OUH) and healthy controls. Groups were compared using Kruskal Wallis (Dunn‘s corrected).

Results

The technical validation of the C4A3-HNE assay demonstrated acceptable results for recovery, variation, and interference. Biological relevance was assessed in commercial IBD samples and healthy donors. C4A3-HNE was elevated in both CD and UC compared to healthy (p=0.001 and <0.0001)(AUC [95% CI]: 0.820 [0.669-0.971]; 0.875 [0.775-1.000]). The results were validated in an independent cohort of IBD patients (both p<0.0001). For UC, analysis showed that compared to patients in endoscopic remission, C4A3-HNE is elevated in patients with mild endoscopic activity, decreasing dose-dependently for moderate and severe disease (T1). Fecal calprotectin and CRP levels were also lower in IBD patients with high levels of C4A3-HNE (T1). With a cut-off value of 54.1 ng/ml, C4A3-HNE could significantly discriminate between mild and severe endoscopic disease (T1).

Conclusion

Our study demonstrates the biological and possible clinical relevance of the novel C4A3-HNE biomarker. The biomarker is elevated in patients with IBD compared with healthy, and high levels may reflect early mucosal damage in patients with UC. Furthermore, inflammatory markers were lower in IBD patients with high levels of C4A3-HNE, pointing towards high levels being indicative of early disease. C4A3-HNE may provide early detection of mucosal damage or prediction of relapse; however, further studies are required to assess the clinical validity of this biomarker.

Disclosure

MA, MP, MK, and JM are employees of Nordic Bioscience A/S. MK owns stocks in Nordic Bioscience A/S.