Evaluation of Anti- Helicobacter pylori IgG Antibodies for the Detection of Helicobacter pylori Infection in Different Populations.

Serological testing (immunoassay) for Helicobacter pylori ( H. pylori ) is widely available and inexpensive, and does not require medication modifications before testing. It can also determine the type of infection, which helps with clinical diagnosis and treatment, and guides the use of medication. However, the performance of immunoblotting for the detection of H. pylori infections in different populations has still not been fully evaluated. We performed a retrospective analysis of patients in the Health Examination Center and Outpatient Department, from November 2017 to September 2020, at Peking Union Medical College Hospital. All the subjects were tested with the 13 C-urea breath test ( 13 C-UBT) and for IgG antibodies. A total of 1678 participants, including 1377 individuals who had undergone physical examinations, were recruited. The results of the immunoassay were significantly different from those of the 13 C-UBT for all the subjects and outpatients ( p < 0.001). For the physical examinations of individuals, the agreement between the immunoassay and the 13 C-UBT was 0.64 (95%CI: 0.59-0.68; p < 0.001), and the H. pylori immunoassay demonstrated a sensitivity and specificity of 74.24% and 90.45%, respectively, with a positive predictive value of 71.01% and negative predictive value of 91.76%. In addition, in patients with gastric mucosal atrophy or early gastric cancer, antibody typing tests can also detect infected patients with missed UBT. The prevalence of H. pylori in Beijing was 26.8%, and the serological positivity rate for H. pylori in the population of Beijing was about 31.7% (25.1% in the physical examination population). The rate of H. pylori antibody positivity among patients with allergic diseases was 73.5%, which is significantly higher than that of the non-allergic disease population (29.3%, p < 0.001). In conclusion, H. pylori antibody typing testing can be applied as a specific test in the healthy physical examination population, and the test can be performed with the remaining serum during the physical examination.