Utility of stool sample-based tests for the diagnosis of Helicobacter pylori infection in children

Helicobacter pylori antigen or DNA in stool are meant to detect the bacteria; however, in children the colonization of the gastric mucosa by H pylori is usually weak and fecal excretion of antigen or DNA varies considerably, challenging the utility of these tests in this age group. The aim of the present study was to carry out a systematic review and meta-analysis to evaluate the performance of stool H pylori DNA and antigen tests for the diagnosis of infection in children.

We conducted a systematic review and meta-analysis to assess the accuracy of stool tests for diagnosis of H pylori infection in children. We searched PubMed, EMBASE, and LILACS databases. Selection criteria included participation of at least 30 children and the use of a criterion standard for H pylori diagnosis. In a comprehensive search, we identified 48 studies.

Regarding antigen-detection tests, enzyme-linked immunosorbent assay (ELISA) monoclonal antibodies showed the best performance, with sensitivity and specificity of 97%, positive likelihood ratio (LR+) of 29.9, and negative likelihood ratio (LR-) of 0.03. ELISA polyclonal antibodies had sensitivity of 92%, specificity of 93%, LR+ of 16.2, LR- of 0.09, and high heterogeneity (P < 0.0001). One-step monoclonal antibody tests demonstrated sensitivity of 88%, specificity of 93%, LR+ of 10.6, and LR- of 0.11. For DNA detection, polymerase chain reaction-based test showed sensitivity of 80.8%, specificity of 98%, LR+ of 17.1, and LR- of 0.18.

Detection of H pylori antigen in stools with ELISA monoclonal antibodies is a noninvasive efficient test for diagnosis of infection in children. One-step tests showed low accuracy and more studies are needed to obtain a useful office-based screening test. The available molecular tests are still unreliable.