Autoimmune gastritis: emerging insights and clinical management.

Autoimmune gastritis (AIG) is an immune-mediated condition that affects the oxyntic mucosa of the stomach, leading to progressive atrophy and deficiencies in vitamin B12, iron and other micronutrients. Our understanding of the pathogenesis, clinical manifestations and management of AIG has improved in the past 20 years. Initially thought to be associated mainly with pernicious anaemia and limited to certain geographical areas, AIG is now recognized as a global disorder with a broad clinical spectrum, ranging from asymptomatic cases to gastrointestinal, haematological, neurological and gynaecological manifestations. The role of Helicobacter pylori in the development of AIG has been debated, with evidence suggesting that AIG might arise through distinct pathogenic pathways both related and unrelated to H. pylori infection. The risk of gastric adenocarcinoma in AIG has also been reassessed on the basis of studies exploring its natural history. Finally, novel insights have emerged regarding the characterization of 'potential AIG' and 'seronegative AIG', two distinct conditions that were previously overlooked. In this Review, we discuss the latest advances in the field of AIG.