Determination of Helicobacter pylori Antigen in Stool Samples and Comparison with Rapid Urease Test in Patients Suspected of Helicobacter Infection

Helicobacter pylori (H. Pylori) is the microorganism that infects nearly half of word's population. There are several invasive and non-invasive methods for diagnosis of infection. The main objective of this study was to evaluate antigen of H. Pylori in feces with H. pylori stool antigen (HpSA) test and comparison with rapid urease test (RUT) in the patients suspected to be infected.
Material and one hundred thirty-seven subjects (56 males, 81 females) were recruited from those patients undergoing a gastrointestinal endoscopic examination in the endoscopy units of Shahid Sadoughi university of medical sciences. One biopsy specimen was obtained from the stomach and each biopsy specimen per subject was tested for the presence of urease using the commercially available CLO test. Stool specimens were taken concurrently with the endoscopic examination and tested by Enzyme-linked immunosorbent assay (ELISA) method for presence of HpSA. In this study, RUT was considered as a gold standard test.
The mean age was 40.4±1.12 years. 13.3% of samples were shown HpSA-positive and negative RUT and 12.9% were shown HpSA-negative and positive RUT. Sensitivity and specificity of HpSA test was 86.6% and 87.1%, respectively. Positive and negative predictive values and accuracy were 89%, 84.3%, 86.2%, respectively.
Our findings showed that the stool enzyme immunoassay for H. pylori is a useful method for the primary diagnosis of H. pylori in the patients suspected to be infected.