A 63‐year‐old white woman with a medical history of hypothyroidism, hypertension, hypercholesterolemia, and recent deep vein thrombosis on Coumadin presented to the emergency department with dehydration because of intractable diarrhea and intermittent emesis. She had a 6‐month history of daily greenish watery diarrhea with abdominal cramps. She also lost about 100 pounds. Her family history was remarkable for colon cancer in her mother and fatal pulmonary embolism in her daughter. She had a 30‐pack‐year smoking history. Her prior workup at an outside hospital included a CT of the abdomen and pelvis, which showed no definite inflammatory changes. Her esophagogastroduodenoscopy (EGD) showed a small hiatal hernia and gastritis. Her duodenal biopsy showed duodenitis with villous atrophy. She also underwent a colonoscopy, which showed some erythema in the sigmoid and descending colon with a normal terminal ileum. Random biopsies throughout the colon were negative for active chronic colitis. Physical exam revealed very dry skin with decreased turgor, occasional expiratory wheezes, and mild left lower quadrant tenderness. Laboratory was significant for white blood cell count of 15, INR of 1.8, normal thyroid‐stimulating hormone, erythrocyte sedimentation rate, and C‐reactive protein, negative stool infectious workup, and negative celiac disease serologies. Her repeated EGD showed diffuse mildly scalloped mucosa in the entire duodenum, which was suspicious of celiac disease. Yet duodenum biopsy revealed intense active chronic enteritis with loss of Goblet and Paneth cells, which was suggestive of autoimmune enteropathy (AE). Her symptoms improved significantly after prednisone was started. Subsequently she was transitioned to azathioprine as an outpatient.
AE is a rare cause of intractable diarrhea in adults associated with circulating gut autoantibodies and a predisposition to auto‐immunity. In children it can be a part of IPEX (immunodysregulation, polyendocrinopathy, enteropathy, and X‐linked) and APS‐1 (autoimmune polyglandular syndrome 1). The prevalence and incidence is unknown because of limited epidemiological data. The diagnosis of this disorder is based on proposed Mayo criteria: chronic diarrhea (>6 weeks), malabsorption, exclusion of similar disorders, the presence of specific antibodies such as antienterocyte and anti–Goblet cell antibodies, and specific histological findings including partial/complete villous atrophy, increased crypt apoptotic bodies, deep crypt lymphocytosis, and minimal intraepithe‐lial lymphocytosis. It is caused by dysregulation of CD4/ CD25 T cells, whereas the presence of antienterocyte auto‐antibodies seems to be secondary. Immunosuppressive agents such as corticosteroids, azathioprine, cyclosporine, tacrolimius, and mycophenolate have been used with apparent benefits. In refractory cases, infliximab, intravenous immunoglobulin, and cyclophosphamide can be used.
Hospitalists should consider AE in the differential diagnosis of chronic intractable diarrhea. Because of its many similarities with celiac disease, small‐bowel biopsy is a cornerstone of investigation.
B. Xue ‐ none; M. Jiang ‐ none