Stool Antigen Testsforthe DetectionofHelicobacterPyloriin Children

Objective:Reliable non-invasive methods for detection of Helicobacter pylori (H.pylori)infection are required to investigate the incidence, transmission, and clearance of infection in childhood. Detecting bacterial antigens in stool offer an alternative noninvasive diagnostic test. However its accuracy in developing countries is not wel l established. The aim of this study was to evaluate the performance of stool antigen test forH pyloriin Iranian children with recurrent abdomin al pain necessitating endoscopy . Methods:One hundred three children enrolled in this study. Endoscopy and bio psy was done on all patients providing acriterion standardfor validation of the H.pyloristool antigen (HpSA) tests. The presence of H. pyloriorganisms in stool was determined by an enzyme -linked immunosorbent assay using a commercially available polyclonal antibody. HpSA sensitivity, specificity, and positive and negative likelihood ratios were determined with reference to the results of cultures of gastric biopsy . Findings:Of the 103 children tested 41 (39.8%) and 39(37.8%) were positive for H.pyloriaccording to the results ofcultures of gastric biopsy and HpSA, respectively. The sensitivity, specificity, and positive and negative likelihood ratios of HpSA were found to be 85%, 93%, 89.7%, and 90%, respectively. Conclusion:In this pilot study, a low-cost and rapid diagnostic technique, stool antigen test proved to be highly sensitive and specific for detecting H pyloriinfection in children with recurrent abdominal pain. Our results are comparable to those reported elsewhere in children and demons trate that the HpSA test can replace endoscopy and biopsy for detecting H.pyloriinfection. IranianJournalofPediatrics,Volume 23(Number 2),April2013,Pages:138-142