Immunoglobulin A enteropathy: a possible variant of Henoch-Schönlein purpura.

This study calls attention to a new syndrome presenting with gastrointestinal symptoms including abdominal pain, vomiting, and/or hematemesis and endoscopic multiple lesions predominantly in the descending duodenum, without the skin rash observed in Henoch-Schonlein purpura. We examined the gastrointestinal mucosa for IgA deposits in nine children and compared the results with those for three patients with Henoch-Schönlein purpura. In addition, gastroduodenal biopsy specimens of 11 patients with various diseases were studied as controls for IgA staining. Intestinal histology showed nonspecific mucosal inflammation without vasculitis. In six patients without rash (67%), IgA deposition was observed in the capillary wall with the same staining pattern as seen in two patients with Henoch-Schonlein purpura. Compared with the controls (9%), the positive rate of IgA deposition was significantly higher in nonrash patients (P < 0.01). Deposited IgA showed immunoreactivities of polymeric IgAl containing J chain. IgA deposits were ultrastructually seen along the plasma membranes of the endothelial cells. Overall, the data suggest that IgA deposition played a pathogenetic role in the gastrointestinal damage in this group of patients presenting primarily with gastrointestinal complaints. Further studies are needed to clarify whether this patient population has a variant of Henoch-Schönlein purpura or a distinct "IgA enteropathy."