Use caution with serologic testing for Helicobacter pylori infection in children.

Commercial serologic assays accurately detect adult Helicobacter pylori infection. Their use in children remains controversial. An ELISA to detect H. pylori IgG in children was developed and compared with three commercial assays. ELISA standardization was done with sera from all ages and validation was done with another cohort of sera with known H. pylori status. Three commercial serologic assays were subsequently compared against this pediatric ELISA at independent sites, at which 142 pediatric serum samples from different countries were evaluated. The pediatric ELISA was 91.4% sensitive. Assay 3 demonstrated a sensitivity of 78%. Less sensitivity was observed for assay 1 (70%) and assay 2 (63%). Accuracy of commercial assays was greatly reduced when sera from developing countries and younger ages were evaluated. Results of serologic tests used to diagnose H. pylori should be interpreted with caution when evaluating children with abdominal pain. Accurate serologic assays in children may be more important for epidemiologic research than for clinical decision making.