Autoimmune enteropathy in an infant, a rare entity possibly triggered in utero

Autoimmune enteropathy is a rare immune mediated disorder with incidence of less than 1 in 100 000 that primarily involves infants and children. It characterized by severe and protracted diarrhea, weight loss and immune-mediated damage to the intestinal mucosa. We report a case of previously healthy infant that developed acute diarrhea at 7 weeks with a large volume of watery stool. A trial with amino acids-based formula was unsuccessful. Biopsies taken during esophagogastroduodenoscopy and ileo-colonoscopy performed at 8 weeks were consistent with autoimmune enteropathy. Treatment with intravenous steroid and Sirolimus was initiated with an excellent response. At 16-week follow-up the child was doing well without need for immunosuppression. Neonatal immune system is naïve with scant plasma cells normally found at this age. Considering the presence of numerous of plasma cells in the biopsy material, both IgM and IgG class, we postulate that this process was possibly triggered in utero.