Evaluation of two commercially available rapid stool antigen tests for the diagnosis of Helicobacter pylori infection

Introduction: Helicobacter pylori (H. pylori) is one of the most prevalent infections, which can cause chronic gastritis, peptic ulcers and even gastric cancer. Prompt diagnosis and subsequent eradication are essential. Many commercially available H. pylori stool antigen diagnostic kits are used. However, the diagnostic performance of these tests has not yet been evaluated. This study aimed to evaluate two commercial rapid H. pylori Stool Antigen-Lateral Flow Immunochromatography Assay kits (HpSA-LFIA). Methodology: A total of 88 adult patients with dyspeptic symptoms were included in the study. Full case history was obtained, and fresh stool samples were tested for HpSA by two different kits: RightSign (R) (BiotesT, Hangzhou, China) and OnSite (R) (CTK biotech, Poway, USA) and HpSA-enzyme-linked immunosorbent assay (ELISA) as a reference standard.Results: Of the 88 patients, H. pylori infection was positive in 32 (36.4%), negative in 53 (60.2%), and indeterminate in 3 (3.4%) by ELISA. The sensitivity, specificity, positive predictive value, and negative predictive value were as follows: 96.6%, 66.1%, 62%, and 97.4%, respectively for RightSign (R) test and 96.9%, 50%, 52.5%, and 96.6%, respectively for OnSite (R) test.Conclusions: HpSA-LFIA, RightSign (R) and OnSite (R), are good negative tests, however they cannot be used as a sole test for diagnosis and needs other confirmatory tests in case of positive results.