What do we know about the renin angiotensin system and inflammatory bowel disease?

INTRODUCTION: The renin-angiotensin system (RAS) is an important homeostatic pathway, with emerging evidence for the impact of its components on inflammation and fibrosis in gastrointestinal tissues. This review aims to review current knowledge of the physiological mechanism of RAS in inflammatory bowel disease (IBD), and potential therapeutic implications. AREAS COVERED: An extensive online literature review including Pubmed, Medline, and Google Scholar was undertaken. Discussion on the components of the RAS, localization, and physiological functions in the gastrointestinal tract, preclinical, and clinical data in IBD, and the relation with SARS-Cov-2 are covered in this review. EXPERT OPINION: RAS inhibition may have a role as anti-fibrotic adjunct therapy. Targeting the local gastrointestinal RAS with novel modes of delivery may be a target for future therapeutics for IBD, given the widespread availability and safety of current options as utilized in other diseases. Further insight into the mechanism and downstream effects of gastrointestinal ACE2 may lead to a better understanding of the pathogenesis of IBD.

Treatment adaptations and outcomes of patients experiencing inflammatory bowel disease flares during the early COVID-19 pandemic: the PREPARE-IBD multicentre cohort study.

BACKGROUND: The COVID-19 pandemic offered a unique opportunity to understand inflammatory bowel disease (IBD) management during unexpected disruption. This could help to guide practice overall. AIMS: To compare prescribing behaviour for IBD flares and outcomes during the early pandemic with pre-pandemic findings METHODS: We performed an observational cohort study comprising patients who contacted IBD teams for symptomatic flares between March and June 2020 in 60 National Health Service trusts in the United Kingdom. Data were compared with a pre-pandemic cohort after propensity-matching for age and physician global assessment of disease activity. RESULTS: We included 1864 patients in each of the pandemic and pre-pandemic cohorts. The principal findings were reduced systemic corticosteroid prescription during the pandemic in Crohn's disease (prednisolone: pandemic 26.5% vs. 37.1%; p < 0.001) and ulcerative colitis (UC) (prednisolone: pandemic 33.5% vs. 40.7%, p < 0.001), with increases in poorly bioavailable oral corticosteroids in Crohn's (pandemic 15.6% vs. 6.8%; p < 0.001) and UC (pandemic 11.8% vs. 5.2%; p < 0.001). Ustekinumab (Crohn's and UC) and vedolizumab (UC) treatment also significantly increased. Three-month steroid-free remission in each period was similar in Crohn's (pandemic 28.4% vs. 32.1%; p = 0.17) and UC (pandemic 36.4% vs. 40.2%; p = 0.095). Patients experiencing a flare and suspected COVID-19 were more likely to have moderately-to-severely active disease at 3 months than those with a flare alone. CONCLUSIONS: Despite treatment adaptations during the pandemic, steroid-free outcomes were comparable with pre-pandemic levels, although concurrent flare and suspected COVID-19 caused worse outcomes. These findings have implications for IBD management during future pandemics and for standard practice.

Ambulatory care management of 69 patients with acute severe ulcerative colitis in comparison to 695 inpatients: insights from a multicentre UK cohort study.

INTRODUCTION: Acute severe ulcerative colitis (ASUC) traditionally requires inpatient hospital management for intravenous therapies and/or colectomy. Ambulatory ASUC care has not yet been evaluated in large cohorts. AIMS: We used data from PROTECT, a UK multicentre observational COVID-19 inflammatory bowel disease study, to report the extent, safety and effectiveness of ASUC ambulatory pathways. METHODS: Adults (≥18 years old) meeting Truelove and Witts criteria between 1 January 2019-1 June 2019 and 1 March 2020-30 June 2020 were recruited to PROTECT. We used demographic, disease phenotype, treatment outcomes and 3-month follow-up data. Primary outcome was rate of colectomy during the index ASUC episode. Secondary outcomes included corticosteroid response, time to and rate of rescue or primary induction therapy, response to rescue or primary induction therapy, time to colectomy, mortality, duration of inpatient treatment and hospital readmission and colectomy within 3 months of index flare. We compared outcomes in three cohorts: (1) patients treated entirely in inpatient setting; ambulatory patients subdivided into; (2) patients managed as ambulatory from diagnosis and (3) patients hospitalised and subsequently discharged to ambulatory care for continued intravenous steroids. RESULTS: 37% (22/60) participating hospitals used ambulatory pathways. Of 764 eligible patients, 695 (91%) patients received entirely inpatient care, 15 (2%) patients were managed as ambulatory from diagnosis and 54 (7%) patients were discharged to ambulatory pathways. Aside from younger age in patients treated as ambulatory from diagnosis, no significant differences in disease or patient phenotype were observed. The rate of colectomy (15.0% (104/695) vs 13.3% (2/15) vs 13.0% (7/54), respectively, p=0.96) and secondary outcomes were similar among all three cohorts. Stool culture and flexible sigmoidoscopy were less frequently performed in ambulatory cohorts. Forty per cent of patients treated as ambulatory from diagnosis required subsequent hospital admission. CONCLUSIONS: In a post hoc analysis of one of the largest ASUC cohorts collected to date, we report an emerging UK ambulatory practice which challenges treatment paradigms. However, our analysis remains underpowered to detect key outcome measures and further studies exploring clinical and cost-effectiveness as well as patient and physician acceptability are needed. TRIAL REGISTRATION NUMBER: NCT04411784.

Risk of severe COVID-19 outcomes associated with inflammatory bowel disease medications: Reassuring insights from PREPARE-IBD

ATU-3 Frigure 1ConclusionsOur data provide reassurance for the continued evidence-based use of corticosteroids, immunomodulators and biologic therapies in IBD during the ongoing COVID-19 pandemic, and is consistent with an as yet unexplained association between mesalazine use and severe COVID-19 outcomes.

Implications of recurrent SARS-CoV-2 outbreaks for IBD management.

The initial phases of the global SARS-CoV2 pandemic had significant implications for the management of patients with inflammatory bowel disease (IBD). This impact is likely to be sustained and far-reaching across all models of care. Initial questions about the risk of SARS-CoV2 infection, and COVID-19 complications, in patients taking maintenance anti-TNFs, JAK inhibitors and other immune modulators have preliminary data. Current models for SARS-CoV-2 transmission predict intermittent outbreaks until 2022, which could disrupt clinical care and negatively affect outcomes for many patients across the globe. This review summarises changes in IBD clinical practice that will be required during the 'post-peak' phase of viral pandemics.

An Unusual Cause of Gastrointestinal Perforation in an Adolescent Patient With Beta-Thalassemia on Deferasirox and SARS-CoV-2 Infection.

Chelation therapy is recognized as a safe and effective treatment option in patients with beta-thalassemia with iron overload. We report an 18-year-old male with acute abdomen and gastrointestinal bleeding with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection secondary to gastric perforation due to chelation therapy. This patient had a prolonged intensive care stay with complications of SARS-CoV-2 and a small bowel obstruction post-surgery that resolved after conservative management. Given the acute presentation, chelation therapy use and concomitant SARS-CoV-2 infection, clinicians should keep an open mind on the differential diagnosis of acute abdomen in patients with beta-thalassemia.

SARS-CoV-2 vaccination for patients with inflammatory bowel disease: a British Society of Gastroenterology Inflammatory Bowel Disease section and IBD Clinical Research Group position statement.

SARS-CoV-2 has caused a global health crisis and mass vaccination programmes provide the best opportunity for controlling transmission and protecting populations. Despite the impressive clinical trial results of the BNT162b2 (Pfizer/BioNTech), ChAdOx1 nCoV-19 (Oxford/AstraZeneca), and mRNA-1273 (Moderna) vaccines, important unanswered questions remain, especially in patients with pre-existing conditions. In this position statement endorsed by the British Society of Gastroenterology Inflammatory Bowel Disease (IBD) section and IBD Clinical Research Group, we consider SARS-CoV-2 vaccination strategy in patients with IBD. The risks of SARS-CoV-2 vaccination are anticipated to be very low, and we strongly support SARS-CoV-2 vaccination in patients with IBD. Based on data from previous studies with other vaccines, there are conceptual concerns that protective immune responses to SARS-CoV-2 vaccination may be diminished in some patients with IBD, such as those taking anti-TNF drugs. However, the benefits of vaccination, even in patients treated with anti-TNF drugs, are likely to outweigh these theoretical concerns. Key areas for further research are discussed, including vaccine hesitancy and its effect in the IBD community, the effect of immunosuppression on vaccine efficacy, and the search for predictive biomarkers of vaccine success.

Assessment, endoscopy, and treatment in patients with acute severe ulcerative colitis during the COVID-19 pandemic (PROTECT-ASUC): a multicentre, observational, case-control study.

BACKGROUND: There is a paucity of evidence to support safe and effective management of patients with acute severe ulcerative colitis during the COVID-19 pandemic. We sought to identify alterations to established conventional evidence-based management of acute severe ulcerative colitis during the early COVID-19 pandemic, the effect on outcomes, and any associations with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe COVID-19 outcomes. METHODS: The PROTECT-ASUC study was a multicentre, observational, case-control study in 60 acute secondary care hospitals throughout the UK. We included adults (≥18 years) with either ulcerative colitis or inflammatory bowel disease unclassified, who presented with acute severe ulcerative colitis and fulfilled the Truelove and Witts criteria. Cases and controls were identified as either admitted or managed in emergency ambulatory care settings between March 1, 2020, and June 30, 2020 (COVID-19 pandemic period cohort), or between Jan 1, 2019, and June 30, 2019 (historical control cohort), respectively. The primary outcome was the proportion of patients with acute severe ulcerative colitis receiving rescue therapy (including primary induction) or colectomy. The study is registered with ClinicalTrials.gov, NCT04411784. FINDINGS: We included 782 patients (398 in the pandemic period cohort and 384 in the historical control cohort) who met the Truelove and Witts criteria for acute severe ulcerative colitis. The proportion of patients receiving rescue therapy (including primary induction) or surgery was higher during the pandemic period than in the historical period (217 [55%] of 393 patients vs 159 [42%] of 380 patients; p=0·00024) and the time to rescue therapy was shorter in the pandemic cohort than in the historical cohort (p=0·0026). This difference was driven by a greater use of rescue and primary induction therapies with biologicals, ciclosporin, or tofacitinib in the COVID-19 pandemic period cohort than in the historical control period cohort (177 [46%] of 387 patients in the COVID-19 cohort vs 134 [36%] of 373 patients in the historical cohort; p=0·0064). During the pandemic, more patients received ambulatory (outpatient) intravenous steroids (51 [13%] of 385 patients vs 19 [5%] of 360 patients; p=0·00023). Fewer patients received thiopurines (29 [7%] of 398 patients vs 46 [12%] of 384; p=0·029) and 5-aminosalicylic acids (67 [17%] of 398 patients vs 98 [26%] of 384; p=0·0037) during the pandemic than in the historical control period. Colectomy rates were similar between the pandemic and historical control groups (64 [16%] of 389 vs 50 [13%] of 375; p=0·26); however, laparoscopic surgery was less frequently performed during the pandemic period (34 [53%] of 64] vs 38 [76%] of 50; p=0·018). Five (2%) of 253 patients tested positive for SARS-CoV-2 during hospital treatment. Two (2%) of 103 patients re-tested for SARS-CoV-2 during the 3-month follow-up were positive 5 days and 12 days, respectively, after discharge from index admission. Both recovered without serious outcomes. INTERPRETATION: The COVID-19 pandemic altered practice patterns of gastroenterologists and colorectal surgeons in the management of acute severe ulcerative colitis but was associated with similar outcomes to a historical cohort. Despite continued use of high-dose corticosteroids and biologicals, the incidence of COVID-19 within 3 months was low and not associated with adverse COVID-19 outcomes. FUNDING: None.

The gut microbiome: an under-recognised contributor to the COVID-19 pandemic?

The novel coronavirus infection (COVID-19) caused by the SARS-CoV-2 virus has spread rapidly across the globe, culminating in major global morbidity and mortality. As such, there has been a rapid escalation in scientific and clinical activity aimed at increasing our comprehension of this virus. This volume of work has led to early insights into risk factors associated with severity of disease, and mechanisms that underpin the virulence and dynamics involved in viral transmission. These insights ultimately may help guide potential therapeutics to reduce the human, economic and social impact of this pandemic. Importantly, the gastrointestinal (GI) tract has emerged as an important organ influencing propensity to, and potentially severity of, COVID-19 infection. Furthermore, the gut microbiome has been linked to a variety of risk factors for COVID-19 infection, and manipulation of the gut microbiome is an attractive potential therapeutic target for a number of diseases. While data profiling the gut microbiome in COVID-19 infection to date are limited, they support the possibility of several routes of interaction between COVID-19, the gut microbiome, angiotensin converting enzyme 2 (ACE-2) expression in the small bowel and colon and gut inflammation. This article will explore the evidence that implicates the gut microbiome as a contributing factor to the pathogenesis, severity and disease course of COVID-19, and speculate about the gut microbiome's capability as a therapeutic avenue against COVID-19. LAY SUMMARY: It has been noted that certain baseline gut profiles of COVID-19 patients are associated with a more severe disease course, and the gut microbiome impacts the disease course of several contributory risk factors to the severity of COVID-19. A protein called ACE-2, which is found in the small intestine among other sites, is a key receptor for COVID-19 virus entry; there is evidence that the gut microbiome influences ACE-2 receptor expression, and hence may play a role in influencing COVID-19 infectivity and disease severity. Furthermore, the gut microbiome plays a significant role in immune regulation, and hence may be pivotal in influencing the immune response to COVID-19. In terms of understanding COVID-19 treatments, the gut microbiome is known to interact with several drug classes being used to target COVID-19 and should be factored into our understanding of how patients respond to treatment. Importantly, our understanding of the role of the gut microbiome in COVID-19 infection remains in its infancy, but future research may potentially aid our mechanistic understanding of viral infection, and new ways in which we might approach treating it.