Ulcerative colitis is a chronic inflammatory disease affecting the colon, and its incidence is rising worldwide. The pathogenesis is multifactorial, involving genetic predisposition, epithelial barrier defects, dysregulated immune responses, and environmental factors. Patients with ulcerative colitis have mucosal inflammation starting in the rectum that can extend continuously to proximal segments of the colon. Ulcerative colitis usually presents with bloody diarrhoea and is diagnosed by colonoscopy and histological findings. The aim of management is to induce and then maintain remission, defined as resolution of symptoms and endoscopic healing. Treatments for ulcerative colitis include 5-aminosalicylic acid drugs, steroids, and immunosuppressants. Some patients can require colectomy for medically refractory disease or to treat colonic neoplasia. The therapeutic armamentarium for ulcerative colitis is expanding, and the number of drugs with new targets will rapidly increase in coming years.

This article has an accompanying continuing medical education activity, also eligible for MOC credit, on page e12. Learning Objective: Upon completion of this CME activity, successful learners will be able to discuss how steroids are associated with severe outcomes from COVID-19 among patients with inflammatory bowel disease (IBD). See Covering the Cover synopsis on page 407. BACKGROUND AND AIMS: The impact of Coronavirus disease 2019 (COVID-19) on patients with inflammatory bowel disease (IBD) is unknown. We sought to characterize the clinical course of COVID-19 among patients with IBD and evaluate the association among demographics, clinical characteristics, and immunosuppressant treatments on COVID-19 outcomes. METHODS: Surveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease (SECURE-IBD) is a large, international registry created to monitor outcomes of patients with IBD with confirmed COVID-19. We calculated age-standardized mortality ratios and used multivariable logistic regression to identify factors associated with severe COVID-19, defined as intensive care unit admission, ventilator use, and/or death. RESULTS: 525 cases from 33 countries were reported (median age 43 years, 53% men). Thirty-seven patients (7%) had severe COVID-19, 161 (31%) were hospitalized, and 16 patients died (3% case fatality rate). Standardized mortality ratios for patients with IBD were 1.8 (95% confidence interval [CI], 0.9-2.6), 1.5 (95% CI, 0.7-2.2), and 1.7 (95% CI, 0.9-2.5) relative to data from China, Italy, and the United States, respectively. Risk factors for severe COVID-19 among patients with IBD included increasing age (adjusted odds ratio [aOR], 1.04; 95% CI, 1.01-1.02), 2 comorbidities (aOR, 2.9; 95% CI, 1.1-7.8), systemic corticosteroids (aOR, 6.9; 95% CI, 2.3-20.5), and sulfasalazine or 5-aminosalicylate use (aOR, 3.1; 95% CI, 1.3-7.7). Tumor necrosis factor antagonist treatment was not associated with severe COVID-19 (aOR, 0.9; 95% CI, 0.4-2.2). CONCLUSIONS: Increasing age, comorbidities, and corticosteroids are associated with severe COVID-19 among patients with IBD, although a causal relationship cannot be definitively established. Notably, tumor necrosis factor antagonists do not appear to be associated with severe COVID-19.

Clinical benefits of cytokine blockade in ileal Crohn's disease (iCD) are limited to a subset of patients. Here, we applied single-cell technologies to iCD lesions to address whether cellular heterogeneity contributes to treatment resistance. We found that a subset of patients expressed a unique cellular module in inflamed tissues that consisted of IgG plasma cells, inflammatory mononuclear phagocytes, activated T cells, and stromal cells, which we named the GIMATS module. Analysis of ligand-receptor interaction pairs identified a distinct network connectivity that likely drives the GIMATS module. Strikingly, the GIMATS module was also present in a subset of patients in four independent iCD cohorts (n = 441), and its presence at diagnosis correlated with failure to achieve durable corticosteroid-free remission upon anti-TNF therapy. These results emphasize the limitations of current diagnostic assays and the potential for single-cell mapping tools to identify novel bio-markers of treatment response and tailored therapeutic opportunities.

ObjectiveWe sought to evaluate COVID-19 clinical course in patients with IBD treated with different medication classes and combinations.DesignSurveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease (SECURE-IBD) is a large, international registry created to monitor outcomes of IBD patients with confirmed COVID-19. We used multivariable regression with a generalised estimating equation accounting for country as a random effect to analyse the association of different medication classes with severe COVID-19, defined as intensive care unit admission, ventilator use and/or death.Results1439 cases from 47 countries were included (mean age 44.1 years, 51.4% men) of whom 112 patients (7.8%) had severe COVID-19. Compared with tumour necrosis factor (TNF) antagonist monotherapy, thiopurine monotherapy (adjusted OR (aOR) 4.08, 95% CI 1.73 to 9.61) and combination therapy with TNF antagonist and thiopurine (aOR 4.01, 95% CI 1.65 to 9.78) were associated with an increased risk of severe COVID-19. Any mesalamine/sulfasalazine compared with no mesalamine/sulfasalazine use was associated with an increased risk (aOR 1.70, 95% CI 1.26 to 2.29). This risk estimate increased when using TNF antagonist monotherapy as a reference group (aOR 3.52, 95% CI 1.93 to 6.45). Interleukin-12/23 and integrin antagonists were not associated with significantly different risk than TNF antagonist monotherapy (aOR 0.98, 95% CI 0.12 to 8.06 and aOR 2.42, 95% CI 0.59 to 9.96, respectively).ConclusionCombination therapy and thiopurines may be associated with an increased risk of severe COVID-19. No significant differences were observed when comparing classes of biologicals. These findings warrant confirmation in large population-based cohorts.MKH should be changed to MDK for co-last author line

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Clinical benefits to cytokine blockade in ileal Crohn's disease (iCD) have been limited to a subset of patients. Whether cellular and molecular heterogeneity contributes to variability in treatment responses has been unclear. Using single cell technologies combining scRNAseq, CyTOF and multiplex tissue imaging, we mapped the cellular landscape of inflamed ileum lesions, adjacent non-inflamed ileum and matched circulating blood cells of iCD patients.In inflamed tissues, we identified a pathogenic module characterized by an inflammatory mononuclear phagocyte (Inf.MNP)-associated cellular response organized around inflammatory macrophages and mature dendritic cells in a subset of iCD patients. We confirmed the Inf.MNPassociated cellular response in 4 independent iCD cohorts (n=441) and showed that presence of this pathogenic module at diagnosis correlated with primary resistance to anti-TNF therapy.Single cell mapping of iCD tissues identifies a complex cellular signature of anti-TNF resistance thereby revealing novel biomarkers of treatment response and tailored therapeutic opportunities.

Exposure to antibiotics appears to increase the odds of being newly diagnosed with CD but not UC. This risk is most marked in children diagnosed with CD.

OBJECTIVES: In 2015, the Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) program proposed shifting the therapeutic focus on ulcerative colitis (UC) toward altering the natural history of the disease course by regularly monitoring objective measurements of disease activity and tailoring treatment accordingly. The therapeutic paradigm shift was well received in the research community and is often cited. However, new evidence on optimal UC treatment targets continues to accumulate since the time of the STRIDE guidelines. This systematic review summarizes the evidence accrued since the STRIDE UC recommendations, discusses the barriers for adoption of treat-to-target approaches in clinical practice in UC, and suggests directions for future research. METHODS: We systematically reviewed MEDLINE for studies from the time of the STRIDE systematic review up to March 31, 2018, that assessed the potential treatment targets identified by the STRIDE recommendations. RESULTS: Each potential treatment target literature search returned > 200 articles, which were then reviewed by 2 independent investigators for relevant studies. Selected studies of clinical factors, patient-reported outcomes, endoscopy, histology, imaging, and biomarkers and implications on treatment targets are summarized. CONCLUSIONS: It appears that the relative weight given to different therapeutic targets in the development and improvement of UC treatments could be optimized, with an increased emphasis on endoscopic and histological targets over clinical or symptomatic targets. For this evolution to occur, however, new research has to demonstrate that the treat-to-target approach will deliver on the promise of better long-term outcomes compared with current approaches.