Serodiagnosis of Helicobacter pylori infections by detection of immunoglobulin G antibodies using an immunoblot technique and enzyme immunoassay.

A transferable solid phase enzyme immunoassay (TSP-EIA) and an immunoblot technique were evaluated for the detection of IgG antibodies against Helicobacter pylori. Using the biopsy urease test as reference method, the sensitivity and specificity of the EIA were 96% and 100%, respectively. Immunoblot analysis was carried out by testing sera from patients with a positive urease test who suffered from type B gastritis, gastric and duodenal ulcers, and a negative control group. The immunoblotted Helicobacter pylori proteins showed reproducible immunoreactive bands at molecular weights of 130, 93, 75 and 67 kDa. The molecular weight protein fractions of Helicobacter pylori of 180 kDa and higher were found to be of minor immunological significance. Proteins of less than 60 kDa exhibited wide serum-specific variations in reactivity after immunostaining. No correlation between specific immunoblot patterns and clinical signs induced by Helicobacter pylori infection was observed.