Viral screening before initiation of biologics in patients with inflammatory bowel disease during the COVID-19 outbreak.

We read with interest the Comment by Ren Mao and colleagues on the implications of coronavirus disease 2019 (COVID-19) in patients with pre-existing digestive diseases, and the strategies implemented in China to restrict the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with inflammatory bowel disease.

We agree with the current evidence that does not support drug suspension and also with the European Crohn's and Colitis Organisation COVID-19 Task Force's suggestion that, whenever possible during the COVID-19 pandemic, initiation of treatment with immunosuppressive drugs and biologics should be postponed based on an individual risk assessment. However, for patients with substantial clinical activity, delaying the initiation of treatment might not always be possible.

A meta-analysis of clinical trial data including 4135 patients given anti-tumor necrosis factor (TNF) therapy found that the relative risk of developing an opportunistic infection was 2·05 (95% CI 1·10–3·85) with anti-TNF therapy compared with placebo; opportunistic infections included tuberculosis, herpes simplex infection, oral or oesophageal candidiasis, herpes zoster virus, cytomegalovirus, and Epstein-Barr virus. A pooled analysis of 2266 patients given adalimumab found that higher disease activity was associated with significantly increased risks of both serious and opportunistic infections at 1 year. Furthermore, vedolizumab, a humanised monoclonal antibody with gut selectivity, has been associated with airway and bowel infections, although to a lesser extent than with anti-TNF drugs. The risk of opportunistic infection seems to be increased in patients with inflammatory bowel disease who are older than 50 years and receiving immunosuppression.6, 7

As a result of this increased risk of opportunistic infections, inflammatory bowel disease guidelines suggest giving patients a viral screening before starting biologics. In particular, the screening should include serology for hepatitis B virus, hepatitis C virus, HIV, and varicella zoster virus (in patients without a clear history of previous infection or vaccination), and tuberculosis screening through a combination of clinical risk stratification, chest x-ray, and IFN-γ release assays. Additionally, an assessment of history of specific infections is suggested, including herpes simplex virus, varicella zoster virus, and tuberculosis, and of immunisation status.

Patients with inflammatory bowel disease might be at an increased risk of SARS-CoV-2 infection, and the risk of a severe clinical course of COVID-19 might be increased in individuals with chronic disease on immunomodulatory treatment. Furthermore, the risk of inducing clinical activation in individuals with asymptomatic SARS-CoV-2 infection cannot be excluded. As such, we believe that current recommendations for screening before initiation of biologics should be updated (at least temporarily) to include testing for SARS-CoV-2. In view of the rapid spread of the COVID-19 pandemic, we believe physicians should screen for COVID-19 even if patients are asymptomatic or do not have a history of high-risk travel or contact. However, importantly, the exact method of such screening should be decided on the basis of local policy and available health-care resources.