Summary Background Accelerated induction regimens of infliximab have been proposed to improve response rates in patients with steroid‐refractory acute severe colitis. Aim To determine the differences in outcome for acute severe ulcerative colitis between accelerated and standard‐dose infliximab Methods We collected data on hospitalised patients receiving differing regimens of rescue therapy for steroid‐refractory acute severe ulcerative colitis. Our primary outcome was 30‐day colectomy rate. Secondary outcomes were colectomy within index admission, and at 90 days and 12 months. We used propensity score analysis with optimal calliper matching using high risk covariates defined a priori to reduce potential provider selection bias. Results We included 131 patients receiving infliximab rescue therapy; 102 received standard induction and 29 received accelerated induction. In the unmatched cohort, there was no difference by type of induction in the 30‐day colectomy rates (18% vs 20%, P = .45), colectomy during index admission (13% vs 20%, P = .26) or overall colectomy (20% vs 24%, P = .38). In the propensity score‐matched cohort of 52 patients, 30‐day colectomy (57% vs 27%, P = .048) and index admission colectomy (53% vs 23%, P = .045) rates were higher in those receiving standard induction compared to accelerated induction but there was no difference in overall colectomy rates (57% vs 31%, P = .09). There was no significant difference in length of stay or in complication and infection rates. Conclusion In a propensity score‐matched cohort, steroid‐refractory acute severe ulcerative colitis patients, short‐term, but not long‐term, colectomy rates appear to be lower in those receiving an accelerated induction regimen.

IntroductionLack of comparative trial data on dosing regimens of infliximab in patients with acute severe ulcerative colitis (ASUC) failing intravenous corticosteroids has resulted in variability of rescue regimes in ASUC with potential impact on clinical outcomes. We aimed to evaluate practice variability and physician perspectives in decision-making with rescue therapy.MethodologyAn internet-based survey of members of the inflammatory bowel disease (IBD) section of the British Society of Gastroenterology was conducted. The survey evaluated provider characteristics and general practice in the setting of ASUC, followed by a vignette with linked questions.ResultsThe response rate of the survey was 31% (209/682 IBD section members). 134 (78%) reported they would use standard infliximab dose (5 mg/kg) while 37 (22%) favoured a higher front-loading dose of 10 mg/kg citing low albumin, high C-reactive protein as their reason for their preference. IBD specialists chose the higher front-loading dose more often compared with other gastroenterologists (p=0.01) In the specific case vignette, accelerated induction (AI) was favoured by 51% of the respondents while 25% used the standard induction regime and 19% favoured colectomy. IBD specialists more often favoured AI compared with other gastroenterologists (p=0.03) with the main reason being presence of predictors of low infliximab levels (74%). The reasons cited for favouring standard induction (n=57) included lack of evidence for AI (18), their usual practice (11), unlicensed regime (7), and safety concerns (4).ConclusionsThere are significant variations in practice in the use of infliximab rescue therapies with an urgent need for development of care pathways to standardise practice.

Zinc Finger MIZ-Type Containing 1 (Zmiz1), also known as ZIMP10 or RAI17, is a transcription cofactor and member of the Protein Inhibitor of Activated STAT (PIAS) family of proteins. Zmiz1 is critical for a variety of biological processes including vascular development. However, its role in the lymphatic vasculature is unknown. In this study, we utilized human dermal lymphatic endothelial cells (HDLECs) and an inducible, lymphatic endothelial cell (LEC)-specific Zmiz1 knockout mouse model to investigate the role of Zmiz1 in LECs. Transcriptional profiling of Zmiz1-deficient HDLECs revealed downregulation of genes crucial for lymphatic vessel development. Additionally, our findings demonstrated that loss of Zmiz1 results in reduced expression of proliferation and migration genes in HDLECs and reduced proliferation and migration in vitro. We also presented evidence that Zmiz1 regulates Prox1 expression in vitro and in vivo by modulating chromatin accessibility at Prox1 regulatory regions. Furthermore, we observed that loss of Zmiz1 in mesenteric lymphatic vessels significantly reduced valve density. Collectively, our results highlight a novel role of Zmiz1 in LECs and as a transcriptional regulator of Prox1, shedding light on a previously unknown regulatory factor in lymphatic vascular biology.

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