Bowel ulceration following tocilizumab administration in a COVID-19 patient

Abstract
Tocilizumab, a monoclonal antibody against interleukin-6, has been used to treat cytokine release syndrome (CRS) in a subset of patients with severe COVID-19 disease. Acute ulcerative bowel disease has been only rarely documented in patients treated for rheumatological conditions. The gastrointestinal side effects seen when used in the context of COVID-19 are unknown. We present a case of COVID-19 CRS in which acute terminal ileum and perforated caecal ulceration evolved after tocilizumab exposure. We raise awareness of a possible causal relationship between even a single dose of tocilizumab and gut ulceration in patients with COVID-19. Any such drug enteropathy relationship requires watchful monitoring during upcoming trials of tocilizumab in patients with COVID-19.