Current View on Autoimmune Gastritis

Abstract

Autoimmune gastritis (AIG) is a chronic inflammatory disease of the gastric corpus and fundus. Although still unclear, genetic and environmental factors, antigenic mimicry or cross-reactivity are proposed pathogenic mechanisms. Parietal cells destruction results in loss of intrinsic factor and increased gastric pH due to hypochlorhydria and G-cell proliferation. Furthermore, atrophy, intestinal, pancreatic and spasmolytic polypeptide-expressing metaplasia are observed. AIG is underdiagnosed, however, proper diagnostic approach, including endoscopic, serological and histopathological assessment, is required. Gastroscopy with corpus and fundus biopsies is a gold standard. A serological combination of anti-parietal cell antibodies, intrinsic factor antibody, anti-Helicobacter pylori IgG, gastrin, pepsinogen I and pepsinogen I/II ratio improves the diagnostic sensitivity and specificity and allows atrophy level prediction. AIG might manifest with multifactorial iron deficiency anemia, vitamin B12 deficiency (pernicious anemia), neurological and neuropsychiatric conditions, small intestinal bacterial overgrowth and gastrointestinal infections. AIG association with other autoimmune diseases is well-established. Gastric cancer and gastric carcinoid are neoplastic transformations of a continuous chronic inflammation. Patients with AIG should be carefully monitored as no specific AIG therapy is available and disease complication could be fatal