No abstract

Ulcerative colitis is a common chronic inflammatory disease of the colon and rectum, resulting from a dysregulated immune response towards intraluminal antigens in a genetically predisposed host. The disease has a varying extent and severity. Approximately 20% of patients with ulcerative colitis experience a severe flare during the course of their disease, requiring hospitalization. Acute severe ulcerative colitis (ASUC) is potentially a life-threatening condition that requires early recognition, hospitalization, correction of body fluids and electrolytes, and nutritional support if needed. Superimposed bacterial or viral infections need to be excluded and thromboprophylaxis should be started. Intravenous corticosteroids are the first-line treatment for this condition. Rescue treatment with ciclosporin or infliximab is indicated in patients who do not sufficiently respond to corticosteroids after 3-5 days, with close monitoring of the patients' symptoms, serum C-reactive protein and albumin levels. If medical therapy fails, timely colectomy should be performed to prevent critical complications. In this article, we review all relevant aspects of ASUC, from its pathophysiological background to modern management in clinical practice.

Tissue hypoxia occurs when local oxygen demand exceeds oxygen supply. In chronic inflammatory conditions such as IBD, the increased oxygen demand by resident and gut-infiltrating immune cells coupled with vascular dysfunction brings about a marked reduction in mucosal oxygen concentrations. To counter the hypoxic challenge and ensure their survival, mucosal cells induce adaptive responses, including the activation of hypoxia-inducible factors (HIFs) and modulation of nuclear factor-κB (NF-κB). Both pathways are tightly regulated by oxygen-sensitive prolyl hydroxylases (PHDs), which therefore represent promising therapeutic targets for IBD. In this Review, we discuss the involvement of mucosal hypoxia and hypoxia-induced signalling in the pathogenesis of IBD and elaborate in detail on the role of HIFs, NF-κB and PHDs in different cell types during intestinal inflammation. We also provide an update on the development of PHD inhibitors and discuss their therapeutic potential in IBD.

Local ROCK inhibition prevents and reverses intestinal fibrosis by diminishing MRTF and p38 MAPK activation and increasing autophagy in fibroblasts. Overall, our results show that local ROCK inhibition is promising for counteracting fibrosis as an add-on therapy for CD.

See editorial on page 925. BACKGROUND & AIMS:We evaluated the ability of vedolizumab to induce endoscopic and histologic remission in patients with Crohn's disease (CD). METHODS: We performed a prospective study of 110 patients with active CD, based on CD activity index (CDAI) scores >220 and mucosal ulcerations, who received open-label vedolizumab (300 mg) infusions at weeks 0, 2, and 6, and every 8 weeks thereafter through week 52 at tertiary centers in Europe. Patients received an additional infusion at week 10 if their CDAI score had not decreased by 70 points. Patients underwent ileocolonoscopy with collection of biopsies at baseline and weeks 26 and 52; a local and central reader determined simple endoscopic index for CD (SES-CD) scores. Histologic features were assessed by a blinded pathologist at week 26. Serum concentrations of vedolizumab were measured at serial time points. The primary outcome was endoscopic and histologic remission in patients with active CD treated with vedolizumab for 52 weeks. RESULTS: At weeks 26 and 52, 36 patients (29%) and 34 patients (31%), respectively, were in corticosteroid-free clinical remission (CDAI score <150), respectively. Based on intent-to-treat analysis, endoscopic remission (SES-CD score <4) was achieved by 36 patients (33%) and 40 patients (36%) at weeks 26 and 52. Endoscopic responses (decrease in SES-CD score 50%) occurred in 44 patients (40%) at week 26 and 5 patients (45%) at week 52. Serum concentrations of vedolizumab were higher at weeks 2, 10, and 22 in patients with lower SES-CD scores. Histologic remission at week 26 was observed in 43 (64%) of 67 patients based on Geboes Score and 37 (66%) of 56 patients based on Robarts Histopathology Index scores in analyses of paired biopsies with inflammation at baseline. Serum concentrations of vedolizumab above 10 mg/L at week 22 were associated with endoscopic remission at week 26. CONCLUSIONS: In a prospective trial, we found that approximately one-third of patients with CD achieve endoscopic remission after 52 weeks of treatment with vedolizumab and two-thirds achieve histologic remission at week 26. Higher serum concentrations of vedolizumab were associated with better outcomes. EUDRACT no: 2014-005376-29.