Detection of antibodies to serum IgA and IgG in peptic ulcer cases by indirect haemagglutination test.

Autoantibodies to serum IgA and IgG were detected in 206 peptic ulcer patients (196 duodenal ulcer and 10 gastric ulcer) and 52 healthy age and sex-matched controls by indirect haemagglutination test. A significantly increased mean titre of autoantibodies to serum IgA was observed in the peptic ulcer patients. Forty-eight (24.61%) duodenal ulcer cases had autoantibody titre values above mean +/- 2 SD of controls. Titres of autoantibodies to serum IgG were significantly increased only in the gastric ulcer cases. The results suggest an immunologic abnormality in a sizeable fraction of these cases.