Acute Flare of Adult-Onset Autoimmune Enteropathy Associated With Cyclophosphamide

This is a case of adult-onset autoimmune enteropathy (AIE) in a 46-year-old man with multiple autoimmune conditions who presented with worsening disease process after receiving cyclophosphamide. We describe the investigations and management of this patient over a 6-year timeline. The diagnosis and management of AIE is challenging given the heterogeneity in clinicopathologic findings and a small number of adult case reports. We describe the current diagnostic criteria, review the literature on treatment options and outcomes, and discuss the evidence for cyclophosphamide in the treatment of AIE. Adult-onset AIE should be considered in the differential diagnosis of refractory diarrhea and weight loss.