Diagnosis of Helicobacter pylori infection in dyspeptic patients by stool antigen detection: Usefulness of a new monoclonal enzyme immunoassay test

BACKGROUND: Helicobacter pylori antigens can be measured in human stools with an enzyme immunoassay, which may prove to be a valuable non-invasive diagnostic tool. Aim. To evaluate the usefulness of a new monoclonal enzyme immunoassay for detecting H. pylori antigens in dyspeptic patients' faeces (FemtoLab H. pylori, Connex, Martinsried, Germany). PATIENTS: H. pylori infection was determined in 75 patients (49 men, 26 women, mean age 52 + 16.5) for histology and rapid urease test. METHODS: H. pylori status was established by concordance of the reference tests. FemtoLab H. pylori was measured in triplicate. In addition, two determinations of a polyclonal faecal antigen test (HpSA, Platinum Premier HpSA, Meridian Diagnostic Inc., Cincinnati, USA) were also performed. Sensitivity, specificity, positive and negative predictive values were calculated. Concordance between different measurements was estimated by Kappa statistics. RESULTS: The sensitivity of the FemtoLab H. pylori immunoassay ranged from 98 to 100% and its specificity was 76%. Positive and negative predictive values were 91 and 94-100%, respectively. Concordance coefficients ranged from 0.81 to 0.92. Corresponding HpSA values were 69, 86, 92 and 53%, respectively. Concordance coefficient was 0.61. CONCLUSIONS: FemtoLab H. pylori is a very sensitive, specific, highly reproducible and easy-to-perform tool for diagnosis of H. pylori infection.