A Rare Cause of Chronic Diarrhea

Abstract

Introduction: Autoimmune enteropathy is a rare cause of intractable diarrhea associated with circulating gut autoantibodies. We report a case of an 83-year-old female with chronic diarrhea. Case Report: 83-year-old female presented with chronic diarrhea, abdominal bloating and pain in Mar 2009. Colonoscopy with biopsy showed evidence of lymphocytic colitis after which patient was started on oral budesonide. Her symptoms improved initially but she relapsed in 3-4 weeks. Complete work-up for a cause of diarrhea including C. difficile, ova, parasites, lactose intolerance, and small intestinal bowel overgrowth testing was negative. Due to persistence of symptoms and weight loss of approximately 20 pounds, a repeat endoscopy with small bowel biopsy and colonoscopy was done in Sep 2010. It showed mild villous blunting with increased intraepithelial lymphocytes. Prominent lymphoplasmacytic infiltration of submucosa was noted on the biopsy specimens. Extensive colon biopsies from right and left colon showed complete resolution of lymphocytic colitis. TTG and IgA levels were normal despite being on a gluten diet. Serologic and genetic testing for celiac disease was negative. By ruling out all other possibilities, a diagnosis of autoimmune enteropathy was made. Patient was treated with a course of prednisone for 6 weeks. She responded well to steroids with return of normal bowel movements. Repeat endoscopy and small intestinal biopsy in Feb 2011 showed normal mucosa. She has remained symptom free for the last 18 months. Discussion: Autoimmune enteropathy is an adult onset chronic diarrhea, malabsorption, lack of response to gluten free diet, specific small intestinal histologic features with presence of circulating gut epithelial cell antibodies. It is a part of generalized immune dysfunction with tendency to have other autoimmune disorders. The causative role of these antibodies has not yet been established. Diarrhea associated with AIE can improve only with aggressive immunosuppression. Conclusions: 1. Our case brings to light a rare cause of chronic diarrhea named autoimmune enteropathy. 2. It should be considered in the differential diagnosis of malabsorption with small bowel villous atrophy. 3. Immunosuppressive therapy is required for improvement in most cases.