Evaluation of rapid antibody tests for the diagnosis of Helicobacter pylori infection

OBJECTIVE: The aim of this study was to compare the performance characteris tics of one serum and four whole blood rapid antibody tests for Helicobacte r pylori infection. METHODS: A total of 97 outpatients referred for endoscopic evaluation of dy spepsia were included. Antral biopsies were obtained for histology and rapi d urease test. Serum was tested with an enzyme-linked immunoassay (HM-CAP) and a rapid serology test (FlexSure HP). A commercially available C-13-urea breath test was performed. Capillary blood obtained by fingerstick was tes ted with FlexSure HP, QuickVue, Accustat, and StatSimple pylori tests. Sens itivity, specificity. and accuracy of each rapid test was calculated relati ve to a criterion standard of histological gastritis and at least two of th e four following tests positive: identifiable organisms on specially staine d slides, rapid urease test, urea breath test, or serum immunoassay. RESULTS: A total of 30 patients (31%) were infected. The FlexSure HP Serum, and FlexSure HP, QuickVue, Accustat, and StatSimple pylori whole blood tes ts had sensitivities of 90%, 87%, 83%, 76%, and 90%; specificities of 94%, 90%, 96%, 96%, and 98%, and accuracies of 93%, 88%, 92%, 87%, and 96%. resp ectively. Sensitivities were not statistically different. StatSimple pylori was more specific than FlexSure HP whole blood (p < 0.03), and more accura te than FlexSure whole blood (p < 0.024) and Accustat (p < 0.01). Serum imm unoassay was significantly more sensitive (97%) than FlexSure whole blood, QuickVue, and Accustat (p < 0.01), but its specificity (95%) was not statis tically different from the rapid tests. CONCLUSION: Rapid antibody testing provides an accurate diagnosis of H. pyl ori infection. In general, these tests are less sensitive than, but as spec ific as, standard serology.