COMPARISON OF RAPID SEROLOGICAL TESTS (FLEXSURE HP AND QUICKVUE) WITHCONVENTIONAL ELISA FOR DETECTION OF HELICOBACTER-PYLORI INFECTION

Background: There is a need for accurate and rapid tests for Helicobac ter pylori infection especially since the recent National Institutes o f Health Consensus Development Conference on H. pylori in peptic ulcer disease charged the medical community with treating H. pylori infecti on in all patients with H. pylori and ulcer disease. Methods: We prosp ectively compared a simple, rapid serological test (FlexSure HP, Smith Kline Diagnostics) for the detection of serum IgG antibodies against H . pylori with another rapid test (QuickVue, Quidel) and two enzyme imm unoassays (HM-CAP, Enteric Products, and PyloriStat, BioWhittaker). Se rum samples from 551 individuals including both symptomatic patients ( 196) and asymptomatic volunteers (355) were tested for the presence of IgG antibodies against H. pylori. The presence or absence of active H . pylori infections was determined using the [C-13]-urea breath test. Results: All of the serological tests performed well. FlexSure HP had calculated sensitivity, specificity, and accuracy of 94.4, 87.6, and 9 1.1%, respectively, relative to the urea breath test. In 49 of the 551 samples, the urea breath test and FlexSure HP did not agree. Those sa mples were tested with HM-CAP immunoassay to confirm presence or absen ce of IgG antibodies against H. pylori. After the resolution of the di scordant results, the sensitivity, specificity, and accuracy of FlexSu re HP were 96.0, 95.1, and 95.6%, respectively, and were comparable to HM-CAP and PyloriStat. FlexSure HP was compared with histology or cul ture in 75 cases, and the accuracy was 100%. FlexSure HP and QuickVue were compared using 200 serum samples. FlexSure HP was more specific ( 88.7 vs 79.4%) and accurate (91 vs 84%) than QuickVue (p < 0.05 for bo th), relative to the urea breath test with discordant samples unresolv ed. FlexSure HP was also simpler to use, easier to interpret, and fast er than QuickVue. FlexSure HP required no sample dilution, one reagent , four steps, and 5 min to complete. Conclusion: FlexSure HP is an exc ellent option for in-office tests for the physician who desires immedi ate results or for small laboratories that do not have the volume of H .pylori testing to justify ELISA test formats.