Diagnosis of Autoimmune Gastritis

Abstract

Autoimmune gastritis (AIG) is an autoimmune disease where parietal cells are damaged by the autoimmune mechanism, ultimately resulting in significant atrophy of the gastric body. Patients with AIG are positive for anti-parietal cell antibodies (APCA) or anti-intrinsic factor antibodies (AIFA) or both. AIG is diagnosed when endoscopic and/or pathological findings are consistent with AIG, and blood tests show positive results for APCA and/or AIFA. Endoscopic findings in advanced stages are characterized by severe atrophy with uniform vascularity predominantly in the gastric body and fundus; however, the endoscopic appearance of early-stage AIG is currently under investigation. Pathological diagnostic criteria exist, and pathological examination is essential for the diagnosis of early-stage AIG. Because AIG can cause various complications, it is important not to overlook it in daily clinical practice.