Flat small intestinal mucosa and autoantibodies against the gut epithelium.

A male infant, aged 1 year 3 months, was admitted to the hospital with protracted diarrhoea, vomiting, and weight loss. The diarrhoea and vomiting coincided with an outbreak of acute diarrhoea and vomiting affecting other family members. Biopsy showed a flat small intestinal mucosa which did not respond to a diet free of gluten, cow's milk, and eggs, or during 8 weeks of intravenous alimentation. Steroids were given, and courses of nalcrom and later cimetidine, but these did not produce any significant improvement. A rare IgG autoantibody specific for gut epithelium was found, which, when present, was associated with a cytological abnormality of crypt enteroblasts. The autoantibody disappeared after treatment with cyclophosphamide, and the cytological abnormality subsequently diminished. However, the mucosa remained severely abnormal and has been so for 23 months. It is possible that an autoimmune reaction against the patient's small intestinal mucosa has led to persistence of the enteropathy.