In vitro studies of ulcerative ileojejunitis.

A patient with ulcerative ileojejunitis was studied by determination of HL-A phenotype, by measurement of jejunal IgA synthesis using a labeled amino acid incorporation technique, and by in vitro organ culture. The patient carried the HL-A8 phenotype in common with 87.5% of patients with gluten-sensitive enteropathy. During a period of exposure to dietary gluten, jejunal tissue from the patient exhibited in high IgA synthetic rate. In organ culture of the jejunal biopsy specimen there was an increase in alkaline phosphatase activity in the absence, but not in the presence, of gluten peptides. The synthetic rate value and the organ culture behavior are similar to those observed in patients with gluten-sensitive enteropathy in exacerbation. During a period in which the patient was not exposed to dietary gluten, including prolonged period of intravenous alimentation, jejunal IgA synthesis and organ culture behavior were studied repeatedly. In contrast to patients with gluten-sensitive enteropathy in remission (i.e., on a gluten-free diet), jejunal IgA synthesis did not decline. However, in organ culture in the patients tissue now behaved like that of other patients with gluten-sensitive enteropathy in remission: alkaline phosphatase activity increased during culture in the presence and absence of gluten peptides. These studies support the concept that ulcerative ileojejunitis is a complication of gluten-sensitive enteropathy in which escape from control by gluten restriction has occurred. They suggest that ulcerative ileojejunitis due to a supervening pathological process which is, at least in part, immunological in nature.