[Appearance of Helicobacter pylori antigen in stool specimens of children with chronic gastritis].

Various examinations are successfully applied for the diagnosis of Helicobacter pylori infection, but non-invasive techniques are still required for the therapeutic monitoring after eradication therapy, especially in children. In the search for new non-invasive techniques to diagnose H. pylori infection, we evaluated an EIA for H. pylori antigen in stool (HpSA). Our study included 62 H. pylori-positive children with chronic gastritis. H. pylori infection was diagnosed by using the culture of gastric mucosa before treatment (clarithromycin, amoxicillin, omeprazole for 7 days) and after 3 months following treatment. Before therapy, stool antigen was detected in 55 out of 62 H. pylori-positive patients, which indicates that the sensitivity of the test was 88.7%. After therapy, eradication was obtained (and confirmed by culture) in 53 out of 62 subjects. When the HpSA test was used, the ratio was 52 out of 62. The sensitivity, specificity of HpSA was 88.9% and 96.2, respectively. The accuracy of the HpSA test for the detection of H. pylori in human stool 3 months after treatment is comparable with the accuracy of the culture results.