Introduction

Enzymatic modification of gliadin peptides by human transglutaminase 2 (TG2) is pivotal in celiac disease (CeD) pathogenesis. ZED1227, an oral TG2 inhibitor, shows promise in preventing gluten-induced mucosal damage and symptoms. This study aims to further elucidate the molecular mechanisms underlying the therapeutic efficacy of ZED1227 in CeD.

Aims & Methods

Duodenal biopsy samples were collected from 125 patients with CeD in a phase 2a clinical trial with ZED1227 (CEC-3/CEL; EudraCT-2017-002241-30). Samples were obtained before and after a 6-week gluten challenge (3g/day). Participants received ZED1227 (10mg/day, 50 mg/day, or 100 mg/day) or placebo. RNA extracted from the biopsies underwent next-generation RNA sequencing (RNA-seq) analysis.

Results

Our analysis revealed that after a 6-week gluten challenge, 377 genes exhibited differential expression in the placebo group. Under low-dose ZED1227 (10 mg) treatment, 150 genes remained differentially expressed, primarily affecting metabolism-related pathways but not the interferon-γ (IFN-γ) response. However, higher doses of ZED1227 (50 mg and 100 mg) completely eliminated gluten-induced gene expression changes, including those associated with the IFN-γ response, showing a dose-dependent effect on gene regulation. Notably, almost half of the gluten induced genes that were suppressed by ZED1227 were related to the IFN-γ response. Initial analysis of human leukocyte antigen (HLA) genotypes suggested that the impact of ZED1227 on mucosal architecture and the IFN-γ response may be modulated by an individual's HLA-DQ2 or -DQ8 genetic background, providing valuable insights into its therapeutic potential in CeD.

Conclusion

ZED1227 effectively prevents gluten-induced mucosal damage in patients with CeD and beneficially modulates gene expression associated with mucosal integrity and the immune response, particularly of the IFN-γ pathway that is central to CD4 T cell mediated CeD pathogenesis. These data corroborate and further elucidate key pathways of intestinal damage in CeD and may suggest new biomarkers of mucosal injury.

Disclosure

SY, JZ, JT and DAL are employees and shareholders of Takeda. DS received study related management/advisory fees from Dr. Falk Pharma. VD has nothing to disclose. TZ, RM and BT are employees of Dr Falk Pharma GmbH. MH is an employee and shareholder of Zedira GmbH. JI is the founder and owner of Jilab, Inc.; is a Full Professor at Tampere University, Medical Faculty; and has a consulting agreement with Takeda. MM is the Founder and Chair of Board at Maki HealthTech Ltd (MHT). MHT receives Management/Advisory Affiliation fees from Dr. Falk Pharma, ImmunogenX, Immunic Therapeutics, Topas Therapeutics, and Calypso Biotech; holds patent licensed to Labsystems Diagnostics from where MHT receives royalties via Tampere University Hospital. KV has nothing to disclose.

Introduction

Inflammatory bowel disease (IBD) is a chronic systemic condition of unknown etiology. Dysregulated T-cell responses play a fundamental role in perpetuating intestinal inflammation in IBD. Unconventional T cells are a diverse subset of T cells with innate and adaptive characteristics including: Gamma Delta T cells (GDT), mucosa-associated invariant T (MAIT) cells, and invariant natural killer T (iNKT) cells. As new studies emerge, unconventional T cells’ role in IBD pathogenesis has been increasingly recognized, but their role in the pathogenesis and possible clinical application remains to be elucidated.

Aims & Methods

The aim of the study is to characterize the immune profile of IBD patients and controls in a large well-characterized cohort with focus on Unconventional T cells. We performed an in-depth, multidimensional flow cytometry analysis of unconventional T cells and plasma proteins from patinets´samples collected from the IBD biobank in Norway.
We used immunophenotyping from isolated PBMC to study both conventional T cells and unconventional T cells and evaluated their gut-homing -a4 and b7 expression-, activation and senescence markers. A 65-plex Luminex assay was used to quantify soluble plasma proteins. We studied the variations of T cell profiles within the different disease phenotypes and their correlation with disease activity. A subset of patients was followed-up clinically for 6 (+/-2) years to evaluate the association with disease outcomes.
Statistical analysis was performed using GraphPad Prism (San Diego, CA). Two-tailed Mann-Whitney U test was used to compare two independent groups and ROC analysis was used for diagnostic accuracy; p≤ 0.05 was considered statistically significant. Ethical approvals were obtained and all patients gave written informed consent.

Results

A total of 184 individuals (106 F) were included: 149 IBD (84 UC and 65 CD) and 25 healthy controls. We found important quantitative and phenotypical differences in unconventional T cells and plasma protein in IBD and between UC and CD patients. Patients with IBD had a significant reduction in MAIT cells, and increase in GDT VD3+ and CD8+ cells (p< 0.05). MAIT cells from IBD patients had lower a4+ and b7+ expression than controls. (p<0.05, p<0.001). Interestingly, Macrophage Migration Inhibitor Factor (MIF) was significantly reduced in patients with UC but not in CD (p<0.0001).
Patients with total colitis presented a significant increase in platelet count, MIG, IL-2R, and CD30 (p<0.001,p<0.01 and p<0.05,respectively). CD patients with colonic affection (L2) had a significant increase in TNF-b, FGF-2, G-CSF compared with patients with ileal (L1) or ileocolonic (L3) CD (p<0.01). Interestingly, MAIT cells were the only immune cells significantly reduced in patients with extraintestinal manifestations. The combination of 6 parameters: IL-4, IL-5, IL-8, MIG, CD30 and Eotaxin-3 showed a good diagnostic accuracy in ROC curves (CI:0.759-1.000; p=0.0005) to distinguish patients with mucosal healing vs those with biochemical and clinical remission alone. A decrease in GDT VD2 cells was found in UC patients with worse outcomes (p<0.01). CD patients with bad prognosis showed a significant increase in platelet counts and a decrease in: FABP2, CXCL10 and APRIL (p<0.05).

Conclusion

These results demonstrate the potential of the characterization of Unconventional T cells and soluble plasma proteins as biomarkers in IBD and as markers of disease progression. Further investigation is warranted to elucidate the use of Unconventional T cells in precision medicine and as potential therapeutic targets in IBD.

References

1. Catalan-Serra I, Sandvik AK, Bruland T et al. Gammadelta T Cells in Crohn's Disease: A New Player in the Disease Pathogenesis? J Crohns Colitis. 2017;11:1135-1145.
2. Hinks TSC, Zhang XW. MAIT Cell Activation and Functions. Front Immunol. 2020 May 27;11:1014. doi: 10.3389/fimmu.2020.01014.

Disclosure

No

Introduction

Some patients with inflammatory bowel disease require subtotal colectomy with ileostomy electively or in emergency as the first step of surgical treatment. Secondary proctectomy with ileal pouch anal anastomosis or ileorectal anastomosis can be considered for bowel continuity restoration. However, recent literature reports a significant number of patients who do not undergo subsequent surgery and are resigned to live with a definitive end ileostomy.

Aims & Methods

Assess the rate and cumulative incidence of secondary reconstructive surgery after subtotal colectomy for inflammatory bowel disease and identify the risk factors associated with the absence of a completion procedure in a large national cohort study.
A national retrospective study from 2013 and 2021 was conducted on prospective collected data from the French Medical Information System Database (PMSI). All patients undergoing subtotal colectomy in France for inflammatory bowel disease were included. Cumulative incidence of reconstruction surgery either with proctectomy and ileal pouch anal anastomosis or with ileorectal anastomosis was calculated by means of a Kaplan-Meier survival curve. The association between the absence of a subsequent intervention and potential risk factors was studied using univariate and multivariate analyses.

Results

1860 patients were included (45 +/-19 years old), with a median follow-up of 30­ months. 77% (n=1442) presented an ulcerative colitis and 23% (n=418) a Crohn’s disease. Mortality and morbidity at 90 days after subtotal colectomy were 5% (n=100) and 47% (n=868). Reconstructive surgery was identified in 1255 patients (67%) with a mean time of 7 months. 74% (n=932) underwent a completion proctectomy with ileal pouch anal anastomosis and 26% (n=323) an ileorectal anastomosis. Among patients with a permanent ileostomy who did not have bowel continuity restorative surgery (33%, n=605), 19% (n=114) had an abdominoperineal resection and 81% (n=491) did not had any further surgical procedure after subtotal colectomy. Independent risk factors for definitive end ileostomy identified in multivariate analysis were older age, Crohn’s disease, colic neoplasia, postoperative complication after subtotal colectomy, laparotomy, and low volume centre.

Conclusion

In this large national cohort study, 67% of patients undergoing subtotal colectomy with ileostomy for inflammatory bowel disease were treated with reconstructive surgery. This rate is higher than previously reported in other population-based studies. Absence of reconstructive surgery is associated with age, Crohn’s disease, colic neoplasia, post-operative morbidity, laparotomy, and low volume centre.