en ایمنی شناسی Immunology پژوهشي Research <p><strong>Background and Aims:</strong> <em>Helicobacter pylori (H. Pylori)</em> is the microorganism that infects nearly half of word&#39;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 <em>H. Pylori</em> in feces <em>with H. pylori</em> stool antigen (HpSA) test and comparison with rapid urease test (RUT) in the patients suspected to be infected.</p> <p><strong>Material and Methods:</strong> 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.</p> <p><strong>Results:</strong> The mean age was 40.4&plusmn;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.</p> <p><strong>Conclusions:</strong> Our findings showed that the stool enzyme immunoassay for <em>H. pylori </em>is a useful method for the primary diagnosis of <em>H. pylori </em>in the patients suspected to be infected.</p> ELISA, H.Pylori, HpSA, Rapid Urease Test 63 68 http://ijml.ssu.ac.ir/browse.php?a_code=A-10-1-45&slc_lang=en&sid=1 Reza Marvinam No Department of Immunology, Reproductive Immunology Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Hossein Hadinedoushan No Department of Immunology, Reproductive Immunology Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Mahdi Dehghanmanshadi No Department of Immunology, Reproductive Immunology Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Fateme Zare Yes Department of Immunology, Reproductive Immunology Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.