Systemic immune response to Campylobacter pylori was detected by the immunoblot technique in serum samples from 200 patients, 129 blood donors, and 96 children. The results of the IgG immunoblot test showed excellent correlation with the detection of C pylori by culture and also with histopathological examination of the antrum, as well as with peptic ulcer disease. An IgA response also occurred and gave results comparable with those of the IgG immunoblot test, although on a quantitatively lower scale. The IgM immunoblots were of no help in the serodiagnosis of C pylori infection. The protein bands that seemed to be the most specific for C pylori and which were consistently observed in patients positive for C pylori were a 110 kilodalton and a 63 kilodalton band on the IgG immunoblot and an 89 kilodalton band on the IgA immunoblot. A 94 kilodalton and a 28 kilodalton band were also included in the evaluation. While immunoblot analysis may be used effectively for the serodiagnosis of C pylori infection and can distinguish between patients with normal antrum mucosa and those with gastritis, the test does not help to distinguish between those patients with antrum gastritis who subsequently develop peptic ulcers and those who do not.
