S1766 Ocrelizumab-Induced Colitis: A Case Report

Abstract

INTRODUCTION: >Monoclonal antibodies are employed in the treatment of malignancies and auto-immune disorders > Case reports demonstrate colitis in patients prescribed monoclonal antibody therapies > Ocrelizumab is an anti-CD20 monoclonal antibody approved in 2017 for treatment of multiple sclerosis > Herein, we present the first documented case of Ocrelizumab-induced colitis. CASE DESCRIPTION/METHODS: >61-year-old female with history of multiple sclerosis presents to the gastroenterology clinic due to recurrent diarrhea. >She was started on Ocrelizumab (dosed every 6 months) prior to the development of diarrhea > Colonoscopy including random colonic biopsies 5 months after initiation of Ocrelizumab were unremarkable. >Diarrhea transiently worsened following each infusion. >Flexible sigmoidoscopy 2 months after third dose of Ocrelizumab was notable for moderate inflammation and histology consistent with drug-induced colitis (Figure 1). >She was hospitalized due to worsening diarrhea and dehydration. >She was started on budesonide and mesalamine. >Three-month follow-up flexible sigmoidoscopy demonstrated improving colitis (Figure 2). DISCUSSION: >Ocrelizumab is a humanized anti-CD20 monoclonal antibody approved for multiple sclerosis > There are no known case reports of Ocrelizumab-induced colitis. >Drug-induced colitis has been reported with the use of Rituximab, a chimeric anti-CD20 monoclonal antibody. >Colitis is postulated to stem from disruption in equilibrium of the gastrointestinal mucosa between proinflammatory and anti-inflammatory stimuli from the innate immune system. Inactivation of B-lymphocytes via monoclonal antibodies may lead to the activation of cytotoxic T cells and subsequent colitis. >Course of drug induced colitis is typically mild, and supportive management and withdrawal of offending agent usually reverses colitis. Steroids has been used with success for more severe inflammation.Figure 1.: Flexible sigmoidoscopy 5 months after first dose of Ocrelizumab showing diffuse moderate inflammation in recto-sigmoid and descending colon.Figure 2.: Follow-up flexible sigmoidoscopy 3 months after withdrawal of Ocrelizumab and treatment with mesalamine and budesonide. Scattered non-bleeding aphthae in the rectum and sigmoid colon.