Adult-Onset Autoimmune Enteropathy: A Case Report

Abstract

Purpose: A 25-year-old white female status post repair of Tetralogy of Fallot presented with severe diarrhea and weight loss following cholecystectomy. Initial evaluation was negative for an infectious source. Colon biopsies were normal and terminal ileum biopsies showed focal active ileitis and prominent lymphoid hypertrophy. EGD with small bowel biopsies demonstrated villous atrophy. Celiac serologies and quantitative immunoglobulins were normal. She was initiated on a gluten free diet for possible celiac disease. Two weeks later, she returned with worsening diarrhea and dehydration. TPN was initiated for malnutrition. Despite bowel rest and a trial of cholestyramine, she failed to improve. Mildly scalloped small bowel mucosa was seen on enteroscopy. Biopsies revealed villous blunting but no intraepithelial lymphocytosis. These findings, combined with lack of response to a gluten free diet, made celiac disease unlikely. A Prometheus panel was suggestive of Crohn's disease and she was started on IV steroids and Pentasa. She improved rapidly and was discharged on prednisone. Within two weeks, she returned with severe diarrhea. An empiric trial of antibiotics provided no benefit. Slides from repeat enteroscopy were sent for secondary review. Again, villous blunting was seen. An ill-defined granuloma was noted. More significantly, a fairly destructive enteritis was described, raising the differential consideration of autoimmune enteropathy (AIE). She was then restarted on IV steroids, and Pentasa was discontinued. Prior to discharge, azathioprine was started, and her steroids were changed to oral budesonide. She continued to improve following discharge. Anti enterocyte IgG antibody subsequently returned positive for linear staining along the apex of the enterocytes, consistent with AIE. AIE is a rare disorder characterized by uncontrolled immune activation targeting the intestines with resultant protracted diarrhea. Although historically considered a pediatric disease, cases of adult onset have been described. Unsworth and Walker-Smith's diagnostic criteria include severe villous atrophy not responding to dietary restriction, circulating gut autoantibodies and/or associated autoimmune conditions, and lack of severe immunodeficiency. Due to its low incidence, there is limited data regarding the epidemiology, course and therapeutic options for AIE. Treatments are primarily based on case reports and immunosuppressive drugs such as corticosteroids, azathioprine, cyclophosphamide, tacrolimus, cyclosporine, and infliximab have been used with varying success. We describe a case of adult onset AIE responsive to budesonide and azathioprine.