Autoimmune enteropathy and colitis in an adult patient

Abstract

The presence of circulating autoantibodies to gut enterocytes has been very rarely described in adults and is considered a possible cause of refractory sprue. Our aims was to describe the case of an adult patient with serum anti-enterocyte autoantibodies associated with a clinical picture characterized by involvement of both the small intestine and colon. A female, age 50, had suffered from diarrhea with mucus and blood, abdominal pain, thinness, anemia, and leukopenia since the age of 20. She also suffered from HCV infection and had mild chronic hepatitis. Family history was positive for autoimmunity. Symptoms were reported to worsen after eating gluten-containing foods, but anti-transglutaminase and anti-endomysial antibodies were negative. Intestinal histology showed mild, patch villous atrophy with a high intraepithelial lymphocyte count, but a normal number of intraepithelial lymphocytes carrying the gamma/delta+ receptor. HLA was: A11, A31 (19), B52 (5), DR 15 (2), DR 14 (6), DR 51, DR 52, DQ1. Colonoscopy did not show ulcerations or erosions and colon histology showed a moderate inflammatory infiltrate without minor crypt distortion or granuloma. RAST tests were positive for lactalbumin, lactoglobulin, casein, egg, and gliadin. After commencement of an oligoantigenic diet, stool frequency initially decreased, but the presence of mucus in the stools persisted, with episodes of bloody diarrhea. After one year of diet, nutritional parameters were low and anemia associated with a low leukocyte count persisted. Upper and lower gastrointestinal endoscopy and histology of the small intestine and colon were virtually unchanged. Consequently, natural autoantibodies and enterocyte autoantibodies were assayed. The patient was positive for IgG class enterocyte autoantibodies at a titer of 1:34. No other organ-specific or non-organ-specific autoantibodies were positive. Prednisolone treatment was started and the symptoms improved. After one year of this treatment plus elimination diet she was reevaluated. Bowel movement frequency was normal, body weight increased, and the asthenia had completely regressed. IgG anti-enterocyte autoantibodies were absent. Histology of the distal duodenum showed a normal villus/crypt ratio and IEL infiltration was reduced. Colon histology showed a reduction in inflammatory infiltrate in the lamina propria. In conclusion, we report a case of generalized gut disorder in an adult patient, affecting both the small intestine and the colon and characterized by the presence of circulating anti-enterocyte autoantibodies. Systematic testing for enterocyte autoantibodies should be performed not only in patients with refractory sprue, but also in subjects with upper and lower intestinal symptoms who have not been definitively diagnosed.