A Multiserological Line Assay to Potentially Discriminate Current from Past Helicobacter Pylori Infection.

Objectives: Early diagnosis is important in controlling Helicobacter pylori-induced gastritis and pro-gression to gastric malignancy. Serological testing is an efficient non-invasive diagnostic method, but currently does not allow differentiation between active and past infections. To fill this diagnostic gap we investigated the diagnostic value of a panel of ten H. pylori-specific antibodies in individuals with different H. pylori infection status within a German population. Methods: We used the recomLine Helicobacter IgG 2.0 immunoblotting assay to analyse ten H. pylori- specific antibodies in serum samples collected from 1108 volunteers. From these, 788 samples were used to build exposure and infection status models and 320 samples for model validation. H. pylori infection status was verified by histological examination. We applied logistic regression to select antibodies correlated to infection status and developed, with independent validation, discriminating models and risk scores. Receiving operating characteristic analysis was performed to assess the accuracy of the discriminating models. Results: Antibody reactivity against cytotoxin-associated gene A (CagA), H. pylori chaperone (GroEL), and hook-associated protein 2 homologue (FliD) was independently associated with the risk of H. pylori exposure with ORs and 95% CIs of 99.24 (46.50-211.80), 46.17 (17.45-122.17), and 22.16 (8.46-55.04), respectively. A risk score comprising these three selected antibodies differentiated currently H. pylori infected or eradicated participants from negatives with an area under the curve of 0.976 (95% CI: 0.965-0.987) (Model 1). Sero-positivity for vacuolating cytotoxin A (VacA), GroEL, FliD, H. pylori adhesin A (HpaA), and g-glutamyl trans-peptidase (gGT) was associated with a current infection with an area under the curve of 0.870 (95% CI: 0.837-0.903), which may help discriminate currently infected patients from eradicated ones (Model 2). Discussion: The recomLine assay is sensitive and specific in determining H. pylori infection and eradi-cation status and thus represents a valuable tool in the management of H. pylori infection. Zhe-Xuan Li, Clin Microbiol Infect 2024;30:114