The Accuracy of the Serum Antibody Test for Helicobacter pylori Infection among Junior High School Students

Objective: Recently, screening for Helicobacter pylori infection has been performed among children in Japan as a prevention strategy for gastric cancer. However, the diagnostic accuracy of the serum antibody test, using the ELISA-kit, for screening in children has not been confirmed, and it is unknown whether the cutoff value used for adults is appropriate for children. The aim of this study was to evaluate the accuracy of the serum antibody test for H. pylori infection for the mass screening of junior high school students in Japan.

Subjects and methods: H. pylori infection testing and eradication therapy in junior high schools began in the 2015 fiscal year for students in Yurihonjo and Nikaho cities, located in the Akita prefecture. The data of 410 students who underwent both stool antigen tests (SATs) and serum antibody test, between 2016 and 2018, were used for analysis. Students who had positive results on the SATs test were diagnosed with H. pylori infection.

Results: The rate of H. pylori infection was 3.7% (15/410). The optimal cutoff of serum antibody for children was identified to be 5.4 U/mL, with this cutoff having an area under the curve of 0.94 (95% CI 0.83-1.00), specificity of 99.5% (95% CI 98.2-99.9) and sensitivity of 93.3% (95% CI 68.1-99.8), which was wide because of the small sample size.

Conclusion: The accuracy of the serum antibody test may be enough for practical use in children 13-14 years old.