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.

Review article: prevention, diagnosis and management of COVID-19 in the IBD patient.

BACKGROUND: The current COVID-19 pandemic, caused by SARS-CoV-2, has emerged as a public health emergency. All nations are seriously challenged as the virus spreads rapidly across the globe with no regard for borders. The primary management of IBD involves treating uncontrolled inflammation with most patients requiring immune-based therapies. However, these therapies may weaken the immune system and potentially place IBD patients at increased risk of infections and infectious complications including those from COVID-19. AIM: To summarise the scale of the COVID-19 pandemic, review unique concerns regarding IBD management and infection risk during the pandemic and assess COVID-19 management options and drug interactions in the IBD population. METHODS: A literature review on IBD, SARS-CoV-2 and COVID-19 was undertaken and relevant literature was summarised and critically examined. RESULTS: IBD patients do not appear to be more susceptible to SARS-CoV-2 infection and there is no evidence of an association between IBD therapies and increased risk of COVID-19. IBD medication adherence should be encouraged to prevent disease flare but where possible high-dose systemic corticosteroids should be avoided. Patients should exercise social distancing, optimise co-morbidities and be up to date with influenza and pneumococcal vaccines. If a patient develops COVID-19, immune suppressing medications should be withheld until infection resolution and if trial medications for COVID-19 are being considered, potential drug interactions should be checked. CONCLUSIONS: IBD patient management presents a challenge in the current COVID-19 pandemic. The primary focus should remain on keeping bowel inflammation controlled and encouraging medication adherence.