H. pylori ; Serologic diagnosis ; GAP test ; HM-CAP test
Abstract
Background/Aims: We have compared the sensitivities and specificities of two commercial serological enzyme-linked immunosorbent assays(ELISA) for the diagnosis of Helicobacter pylori infection. Methods: GAP(Bio-Rad) test to detect IgG antibody against H. pylori outer membrane antigen and HM-CAP(Epl) test against high molecular weight cell-associated proteins of H. pylori were used in 87 patients(chronic superficial gastritis 24 patients, gastric erosion 33 patients, gastric ulcer 1S patients, duodenal ulcer 1 l patients, and gastric and duodenal combined ulcer 4 patients). The presence of H. pylori was established when the results of histology of the gastric biopsies taken were positive. Negative for H. pyk>ri infection was determined when H. pylori in histology was abscent and also rapid urease test(CL.O te.t) was negative. When H. pylori was absent microscopically but positive in CLO test, it was regarded as indeterminate. Results: Sixty-three patients(72.4%) were positive f'or H. pylori infection, 16 patients(18.4%) were negative and 8 patients(9.2%) were indeterminate. Sensitivities and specificitie. Were 89% and 50% for HM-CAP test, l00% and 19% for GAP test, respectively. Conclusion: GAP test was very sensitive but non- specific. HM-CAP test was less sensitive than GAP test, but more specific than GAP test.