Global Diversity in Autoimmune Gastritis: Deciphering Regional Phenotypes and Neoplastic Risks

Introduction: The Shifting Landscape of Autoimmune Gastritis

Autoimmune gastritis (AIG) is a chronic, progressive inflammatory condition characterized by the immune-mediated destruction of parietal cells in the gastric corpus and fundus. Historically viewed as a rare cause of pernicious anemia in elderly populations of Northern European descent, our understanding of AIG has undergone a paradigm shift. Recent evidence suggests that AIG is more prevalent and geographically diverse than previously recognized, often presenting in younger cohorts and manifesting through a variety of clinical phenotypes beyond classical vitamin B12 deficiency.

Crucially, the long-term sequelae of AIG include a significantly elevated risk for gastric neoplasia, specifically gastric adenocarcinoma and type 1 gastric neuroendocrine tumors (NETs). However, until recently, large-scale international data comparing the clinical profile and neoplastic outcomes across different ethnic and geographic populations have been scarce. A landmark multicentre study led by Lenti et al., published in Gut, provides essential insights into these regional variations and identifies key clinical predictors for malignant progression.