Abstract
Ocrelizumab is a monoclonal anti-CD20 antibody used as disease modifying therapy in multiple sclerosis (MS). Inflammatory bowel disease (IBD) occurs with rituximab, another anti-CD20 therapy, but has only recently been recognised as a potential complication of ocrelizumab. This series details three cases of IBD after ocrelizumab therapy.
Cases Patient 1: 36-year-old woman managed with ocrelizumab for 15 months presented with profuse diarrhoea, fevers, and abdominal pain with a raised faecal calprotectin. Colonoscopy demonstrated pan-colonic ulceration and histology consistent with acute inflammation. She received IV hydrocortisone, infliximab and azathioprine with improvement in bowel symptoms. Ocrelizumab was switched to natalizumab.
Patient 2: 38-year-old woman with acute abdominal pain and diarrhoea 18 months after initiation of ocrelizumab. Her faecal calprotectin was raised, endoscopy demonstrated inflammation of the ascending colon. Histopathology showed crypt abscess formation and granulomas. She received IV hydrocortisone and ocrelizumab was switched to natalizumab. Stem cell transplant was later performed with control of both MS and IBD.
Patient 3: 32-year-old man developed anorexia and diarrhoea with a raised faecal calprotectin 2 years after ocrelizumab initiation. Colonoscopy demonstrated active inflammation and ulceration of the terminal ileum. He received pulse steroids and ustenkinumab with overall improvement. Ocrelizuab was ceased and stem cell transplant is planned.
Conclusion Anti-CD20 therapy may contribute to immune dysregulation and subsequent inflammation in the gut. Although this has been described with rituximab, it has only recently been recognised with ocrelizumab. This has implications for MS management and highlights a need for surveillance for abdominal symptoms in this population.
