Parietal Cell Antibody Levels Among Chronic Gastritis Patients in a Country With Low Helicobacter pylori Infection: Epidemiology, Histopathological Features, and H. pylori Infection

ABSTRACT Background Despite the low prevalence of Helicobacter pylori in Indonesia, the high incidence of gastritis, predominantly atrophic gastritis, suggests that factors such as autoimmune gastritis (AIG) contribute to this unusual pattern. This study aims to investigate the epidemiology of AIG, histopathology, and its association with H. pylori status in Indonesia. Methods A cross‐sectional study was conducted in various regions in Indonesia between 2014 and 2017; 380 eligible sera and gastric biopsies were available when this study was conducted. As many as 138 sera samples were included in this study based on the initial examination by the updated Sydney system. The diagnosis of AIG was confirmed by serologic testing for parietal‐cell antibodies (PCA) and detailed histopathological assessment with sparing of antrum histopathological features. Results Among the included samples in this study, 78.99% (109/138) were PCA positive (≥ 10 RU/mL) and 0.72% (1/138) were considered to be diagnosed as AIG (spared from antrum histopathological features). The majority of PCA positive cases were H. pylori positive (61/109; 55.96%) with a significant correlation ( p < 0.05, R = 0.31). Additionally, a significant association was found between H. pylori infection and PCA level with gastric histopathological features ( p < 0.05). Conclusion This study demonstrates that the incidence of gastritis without H. pylori infection in Indonesia is not attributable to AIG, as only a single AIG‐positive case was found. These findings underscore the important role of H. pylori as a pathogenic factor in chronic gastritis and highlight its mechanisms in triggering immune responses and driving disease progression and histopathological changes.