The use of an oral fluid immunoglobulin G ELISA for the detection of Helicobacter pylori infection in children.

Abstract

Enzyme linked immunosorbent assay (ELISA) evaluation of oral fluid immunoglobulin G (IgG) antibodies to Helicobacter pylori is a unique approach for both epidemiological studies and the diagnosis of infection, especially in children. The use of oral fluid sampling to evaluate specific H. pylori IgG antibodies has advantages over serum, including reduced biohazard risk and noninvasive collection. Oral fluid sampling is fast and involves minimal patient discomfort. Since children facilitate transmission of H. pylori infection, a simple, accurate, noninvasive diagnostic test is necessary for large epidemiologic studies. The aim of our study was to evaluate a new oral fluid ELISA for detection of IgG antibodies to H. pylori in children. We compared this new oral fluid ELISA with the HM-CAPTM serum ELISA and gastric biopsy histology using 779 oral fluid samples from children collected at 11 clinical sites across the United States. This cohort included 315 children symptomatic for abdominal pain and 464 asymptomatic. All samples were evaluated in a double blind manner. The oral fluid ELISA demonstrated a sensitivity of 76.2% and a specificity of 94.0% in children 2 months old to 201/2 years, as compared with the HM-CAPTM serologic assay. The assay's sensitivity improved to 81.3% in children aged 5 or greater and the specificity remained at 94.0%. When compared with gastric biopsy histology in the same age group, the oral fluid ELISA demonstrated a sensitivity of 71.7% and a specificity of 90.4%. This new oral fluid ELISA is moderately sensitive and offers a very specific method for detecting H. pylori infection in older children, but it is of little value in children under the age of 5 years. Overall, we conclude that this oral fluid ELISA does not appear to be a helpful clinical tool for the diagnosis of H. pylori infection in children.