Diagnostic Accuracy of Serum Antibody, Urine Antibody, and Stool Antigen Tests for Helicobacter pylori in Japan: A Systematic Review and Meta-Analysis.

BACKGROUND: Non-invasive Helicobacter pylori (H. pylori) tests are widely used in clinical practice in Japan; however, their diagnostic accuracy may vary with the composition of the target population, and no systematic review has synthesized their performance specifically in Japanese populations. Therefore, we conducted a systematic review and meta-analysis to evaluate the diagnostic accuracy of serum antibody, urine antibody, and stool antigen tests for H. pylori infection in Japanese populations. MATERIALS AND METHODS: MEDLINE, Embase, and Ichushi-Web were searched for studies published between 2005 and 2024 evaluating serum antibody, urine antibody, or stool antigen tests in Japanese participants. The primary objective involved evaluation of diagnostic accuracy for current H. pylori infection, and the secondary objective involved assessment of accuracy for ever-infected individuals. Summary estimates were calculated using bivariate random-effects models. A subgroup analysis was performed under clinically relevant conditions, restricted to studies without previously infected individuals, with composite reference standards, and without application of post hoc cutoff values. RESULTS: Among 806 publications, 43 studies were selected (serum antibody, 29; urine antibody, six; stool antigen, eight). For diagnosing current H. pylori infection, the summary sensitivity/specificity measured 0.922/0.956 for serum antibody, 0.885/0.970 for urine antibody, and 0.928/0.972 for stool antigen tests. For diagnosing ever-infected individuals, the summary sensitivity/specificity measured 0.908/0.960 for serum antibody and 0.888/0.969 for stool antigen. Under clinically relevant conditions, serum antibody and stool antigen yielded sensitivities/specificities of 0.908/0.968 and 0.935/0.985, respectively. In serum antibody studies, studies with previously infected individuals showed lower accuracy (sensitivity/specificity, 0.876/0.861) than studies without previously infected individuals (0.929/0.967). CONCLUSIONS: Serum antibody and stool antigen tests demonstrated high diagnostic accuracy for current H. pylori infection in Japanese populations, although accuracy declined in studies with previously infected individuals.