Autoimmune gastritis: a comprehensive review of pathophysiology, risk stratification, and management

Autoimmune gastritis (AIG) is a chronic, organ-specific autoimmune disease characterized by the immune-mediated destruction of gastric parietal cells, leading to impaired acid secretion, vitamin B12 deficiency, and an increased risk of gastric malignancies. The diagnosis of AIG relies on endoscopic findings combined with serological markers and histopathological confirmation. This review synthesizes current knowledge on the pathophysiology, diagnosis, and management of AIG, with a special focus on familial aggregation, polyglandular autoimmunity, and emerging therapeutic strategies. We discuss the diagnostic challenges posed by serological variability, the complex interplay with Helicobacter pylori infection, and the diagnostic pitfalls of macrocytic anemia. Furthermore, we explore precision risk stratification models for gastric neuroendocrine tumors (gNETs) and gastric adenocarcinoma, emphasizing the roles of endoscopic surveillance and molecular biomarkers. Finally, we review emerging therapeutic options, including novel immunomodulators and microbiome-targeted interventions. This review provides a comprehensive framework for clinicians to navigate the complexities of AIG, from early diagnosis to long-term management, with the goal of improving patient outcomes and mitigating the risk of malignant transformation.