Detection of Helicobacter pylori antibodies in a pediatric population: Comparison of three commercially available serological tests and one in-house enzyme immunoassay

A serum immunoglobulin G enzyme immunoassay (EIA) for Helicobacter pylori a ntibodies already in use in adults was evaluated with 99 pediatric serum sa mples to determine its usefulness for the study of H, pylori disease in chi ldren. The reference method used was either the C-13-urea breath test or a biopsy culture of gastric mucosa, In children, an EIA cutoff of 0.35 absorb ancy unit yielded sensitivity, specificity, and positive and negative predi ctive values of 93, 97, 93, and 97%, respectively, The cutoff recommended w hen this EIA was published for use in adults was 0.70 absorbancy unit (H. G narpe, P, Unge, C, Blomqvist, and S, Makitalo, APMIS 96:128-132, 1988), Ano ther subset of 169 serum samples taken from children was analyzed by four s erological tests in order to compare the performance of the in-house ELA wi th the Pyloriset, HILI-CAP, and Helico-G kits. For the 169 samples, 10 (5.9 %) false-positives and no false-negatives occurred with the Helico-G, 3 (1. 8%) false-positives and no false-negatives occurred with the Pyloriset, and 3 (1.8%) false-positives and 1 (0.6%) false-negative occurred with the HM- CAP. For the 169 samples, 1 (0.6%) false-positive and no false-negatives oc curred with the in-house ELA. Serological detection of H, pylori antibodies with our ELA seems to be valuable in diagnosing H. pylori infection in chi ldren, but only if a lowered, specific pediatric cutoff is established. The commercial kits, particularly the Helico-G, seem to overdiagnose pediatric H. pylori infection. A positive serological test for H, pylori infection, particularly for children, needs to be confirmed by a reference method beca use of the possibility of spontaneous eradication of infection, with a ling ering serological response.