Reliability of Stool Antigen Tests: Investigation of the Diagnostic Value of a New Immunochromatographic Helicobacter pylori Approach in Dyspeptic Patients

Background: A diagnosis of H. pylori infection can be made by invasive or non-invasive methods. Severalnoninvasive diagnostic tests based on the detection of H. pylori stool antigen (HpSA) have been developed.The Genx H. pylori stool antigen card test is a new rapid, non-invasive test that is based on monoclonalimmunochromatographic assay. The aim of this study was to determine its sensitivity, specificity, and diagnosticaccuracy for diagnosing H. pylori infection in adult patients. Materials and
Methods: A total of 162 patients wereincluded in the study. A gastric biopsy was collected for histopathology and rapid urease testing. Stool specimensfor HpSA testing were also collected. Patients were considered H. pylori positive if two invasive tests (histologicaland rapid urease tests) were positive.
Results: Using the reference test, 50.6% of the samples were positive forH. pylori infection. The Genx H. pylori antigen test was positive in 19.7% of patients. The sensitivity, specificity,positive predictive value, negative predictive value, and diagnostic accuracy of the Genx H. pylori antigen testwere 51.6%, 96.0%, 88.8%, 76.1%, and 79.0%, respectively.
Conclusions: The Genx H. pylori stool antigen cardtest is a new non-invasive method that is fast and simple to perform but provides less reliable results.