Ocrelizumab-induced colitis acutely managed with ciclosporin.

Ocrelizumab is an anti-CD20 monoclonal antibody widely used in the treatment of multiple sclerosis (MS). Although rare, ocrelizumab-induced colitis is a recognised and potentially severe condition that may require life-saving surgical intervention if left untreated. Accurate diagnosis requires the exclusion of infective colitis or classical inflammatory bowel disease (IBD). Prolonged depletion of the CD20-positive B cell population by ocrelizumab may prolong the symptomatic trajectory and complicate the diagnosis. The lack of comprehensive data on ocrelizumab-induced colitis makes acute medical management of affected patients particularly challenging. This report details the case of a woman with steroid-refractory ocrelizumab-induced colitis, managed effectively with ciclosporin therapy in the salvage setting. Monitoring therapeutic drug levels, monitoring for neurotoxicity and early multidisciplinary team involvement facilitated safe titration of ciclosporin.