Assessment of Risk for SARS-CoV-2 Infection in Inflammatory Bowel Disease

In a newly released viewpoint that was published in the Journal of Crohn’s and Colitis, the authors report that patients with inflammatory bowel disease (IBD) do not appear to be at increased risk for SARS-CoV-2 infection and discuss how IBD treatments might inform treatment options for severe cases of COVID-19.

It has been established that comorbidities are associated with poorer clinical outcomes in patients with SARS-CoV-2 infection, explain Dr Giovanni Monteleone of the University of Rome Tor Vergata and Dr Sandro Ardizzone of the University of Milan, Italy. Therefore, the team set out to assess whether patients with IBD are at higher risk for infection by the virus.

They highlight 2 key reasons why patients with IBD might be more susceptible to SARS-CoV-2:

• Coronaviruses, including SARS-CoV-2, bind cells using angiotensin-converting enzyme 2 (ACE2), a membrane-bound protein that is constitutively expressed by epithelial cells of the lungs, intestines, kidneys, and blood vessels. Furthermore, ACE2 is highly expressed in cells of the terminal ileum and colon, and individuals with IBD have elevated levels of ACE2 in their guts relative to individuals without IBD.

• To induce and maintain remission of IBD, many patients with IBD take immunosuppressants, such as azathioprine and methotrexate, which are associated with increased risk for infections.

According to the report, the authors have not identified any evidence to suggest that patients with IBD are at higher risk for infection by SARS-CoV-2. As a result of a PubMed search conducted through March 17, 2020, the team found no evidence to suggest that COVID-19 occurs more frequently in people with IBD than in the general population.  They also report that no patients with IBD and SARS-CoV-2 infection have been reported from tertiary IBD centers in Wuhan, China, where the first outbreak of the novel coronavirus was reported.

The authors highlight potential therapeutic strategies targeting the virus and to ease COVID-19 symptoms, including an isoform of ACE2. A non-membrane-bound form of ACE2 is present in the blood and might act as a competitive inhibitor of SARS-CoV-2 by preventing binding of the virus to the membrane-bound form of ACE2 on host cells.

Additionally, the authors discuss the potential use of cytokine blockers — which are often used to treat patients with IBD — to dampen severe COVID-19, especially cases with onset of the potentially lethal cytokine storm syndrome, and to prevent COVID-19-induced pneumonia in patients with SARS-CoV-2 infection. Indeed, patients with severe COVID-19 and cytokine storm syndrome appear to have cytokine profiles, including elevated levels of interleukin [IL]-2, IL-6, tumor necrosis factor, and interferon-γ, that are similar to those of the inflamed guts of patients with IBD. Thus, the authors posit that IL-6 receptor agonists, which have been used previously to treat cytokine storm syndrome, may be effective as treatment of COVID-19-driven pneumonia.

The authors concluded, “The overall available evidence suggests that IBD patients do not have an increased risk of developing COVID-19 and should stay on IBD medications. Patients receiving immunesuppressors should be carefully monitored for the occurrence of symptoms and/or signs suggesting COVID-19.”

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Reference

Monteleone G, Ardizzone S. Are patients with inflammatory bowel disease at increased risk for Covid-19 infection [published online March 26, 2020]? J Crohn’s Colitis. doi:10.1093/ecco-jcc/jjaa061