Helicobacter pylori infections:: antigen detection in stool samples

BACKGROUND. The aim of this study is to evaluate a new diagnostic test to detect Helicobacter pylori antigen in stool samples (HpSA), and compare the results with those obtained by standard techniques (rapid urease test, culture, histological examination of gastric biopsy specimens, C-13-urea breath test and serology), in a paediatric population with gastrointestinal symptomatology. PATIENTS AND METHODS. Sixty patients with dyspeptic symptoms (37 females and 23 males; mean age 10.9 years) attending the Gastroenterology Service were included in the study. Exclusion criterium was previous treatment with proton pump inhibitors, bismuth compounds or antibiotics. Rapid urease test, culture and histologic study of gastric biopsies, C-13-urea breath test and serology, as well as HpSA, were performed to all patients. RESULTS. Forty seven patients were considered infected by H.pylori on the basis of bacterium isolation and C-13-urea breath test positivity. HpSA was detected in 45 of the 47 H.pylori positive patients (95.7%). There were no HpSA false positive. CONCLUSION. Our results show that this new test is highly sensitive (95%) and specific (100%) for detection of H.pylory infection. It has some advantages over other non invasive thecniques: it is easy to perform, requires no blood samples and its cost is lower than that of C-13-urea breath test.