USE OF A RECEIVER OPERATING CHARACTERISTIC IN THE EVALUATION OF 2 COMMERCIAL ENZYME IMMUNOASSAYS FOR DETECTION OF HELICOBACTER-PYLORI INFECTION

Two novel commercial IgG enzyme immunoassay (EIA) systems based on aci d-glycine-extracted (Pyloriset IgG EIA, Orion Diagnostica) or fast pro tein liquid chromatography-purified (Cobas Core Anti-H. pylori EIA, Ro che Diagnostic Systems) Helicobacter antigens were evaluated in a pros pective study involving 127 patients. All patients underwent upper end oscopy with biopsy, and biopsies were examined for the presence of Hel icobacter pylori by a rapid urease test, microscopy and culture. Of th e 71 patients found to be infected with Helicobacter pylori, 69 (97.2 %) and 65 (91.5 %) tested positive with the Cobas Core and Pyloriset t est, respectively. A detailed receiver operating characteristic analys is of the two tests showed that the Cobas Core assay was more sensitiv e and specific at every possible cut-off level; gave a better resoluti on of individual results, indicating a greater fine-sensitivity; and h ad no grey zone compared to a large grey zone encompassing 13.4 % of t he serum samples tested with the Pyloriset EIA. The Cobas Core assay a ppears to be a valuable tool for epidemiological purposes as well as f or pre-endoscopic screening of dyspeptic patients.