Evaluation of Pepsinogen I, II, Gastrin 17 and Helicobacter pylori IgG in Atrophic Gastritis: A Head‐To‐Head Comparison of Lateral Flow and Enzyme‐Linked Immunosorbent Assays

A lateral flow assay (LFA) incorporating several biomarkers, including pepsinogen I (PGI), pepsinogen II (PGII), Gastrin-17 (G-17), and Helicobacter pylori IgG, enables the rapid non-invasive detection of atrophic gastritis (AG). However, its diagnostic performance compared to conventional enzyme-linked immunosorbent assay (ELISA) has not been established. This head-to-head comparison study included participants from a prospective and multicenter cohort. Patients with gastric premalignant lesions underwent endoscopy, and fasting serum samples were collected for biomarker analysis using both LFA and ELISA. A total of 204 patients were included in this study. LFA demonstrated diagnostic specificity for AG comparable to ELISA, with specificity rates of 95.74% (95% CI [85.75%-99.24%]) for LFA and 100.00% (95% CI [92.44%-100.00%]) for ELISA (p = 0.49). Both methods showed similar performance in detecting H. pylori infection, with an AUC of 0.754 (95% CI [0.616-0.891]) for LFA and 0.778 (95% CI [0.633-0.922]) for ELISA (p = 0.70). For identifying autoimmune gastritis in corpus AG, a reduced PGI/PGII ratio combined with elevated G-17 levels provided excellent discrimination, achieving an AUC of 0.926 (95% CI [0.870-0.926]) for LFA and 0.924 (95% CI [0.861-0.924]) for ELISA. The LFA assay is a feasible, rapid, and non-invasive tool for assessing gastric functional mucosa. Its diagnostic performance for detecting AG is comparable to ELISA, making it a supplementary tool in point-of-care settings to improve the early detection of AG. This study was not registered as a clinical trial, as it is based on an observational study, Progression and Regression of precancerous Gastric Lesions (PROREGAL) study.