Usefulness of Helicobacter pylori stool antigen test to monitor response to eradication treatment in children

Background: The monitoring of the results of eradication treatment is a crucial step for patients with Helicobacter pylori gastritis. A non-invasive test for H. pylori antigens in stools (HpSA) was recently validated for children. Aim: To evaluate the accuracy of HpSA in monitoring eradication treatment in children. Methods: In 60 children, H. pylori gastritis was diagnosed by endoscopy and the ¹³C-urea breath test. The children were treated and returned for a follow-up ¹³C-urea breath test 6 weeks after the end of treatment. Children were considered cured when the ¹³C-urea breath test was negative. Stool were collected at baseline, and at 2 and 6 weeks. Stool antigens were measured by HpSA. Results: According to ¹³C-urea breath test, 6 weeks after the end of treatment 49 children were cured and 11 were still H. pylori-positive. The sensitivity and specificity of HpSA on stools collected 2 weeks after therapy were 100%. At 6 weeks specificity was 93.9 and sensitivity 100%. Results by visual reading were concordant with the plate-reader in all but two cases at baseline. Conclusions: HpSA is accurate for monitoring treatment in children as early as 2 weeks after therapy, when information is most useful and unachievable with other tests. Results by visual reading are accurate, and this can make the test cheaper and more practical.