Colonic Ischemia Without Mesenteric Occlusion: A Case Implicating Interferon-β

Type I interferons are commonly used immunomodulatory agents. Interferon-α (interferon-α) has been associated with ischemic colitis, but cases linking interferon-β (IFN-β) to ischemic colitis are rare. We present a 66-year-old woman with multiple sclerosis treated with IFN-β who developed acute abdominal pain and diarrhea. Imaging demonstrated right-sided colonic inflammation with pneumatosis. Colonoscopy with tissue biopsy confirmed ischemic colitis, despite patent mesenteric vasculature on angiographic imaging. Her symptoms resolved after discontinuation of IFN-β. This case highlights IFN-β as a potential cause of nonocclusive ischemic colitis and underscores the importance of recognizing ischemic complications in patients treated with IFN-β.