Major approaches in auto-immune gastritis: a systematic review

Introduction: Autoimmune gastritis (AIG) is a subtype of chronic gastritis that is characterized by autoimmunity to parietal cells, leading to inflammation and atrophy restricted to the oxyntic mucosa, resulting in hypergastrinemia, which can lead to vitamin B12 deficiency and, consequently, pernicious anemia. Standardization of AIG histology reports and classifications in diagnostic practice is a prerequisite. Thus, in the light of endoscopy, the AIG assessment includes a degree of atrophy, remaining oxyntic mucosa, the property of mucus, and tiny whitish scattered protrusions. Objective: To analyze through systematic review the main endoscopic approaches and micronutrient deficiencies of autoimmune gastritis, in order to know and present the main medical guidelines to the scientific medical community. Methods: The model followed for the systematic review was PRISMA. A total of 54 clinical studies were compared and submitted to the eligibility analysis and, after that, 17 studies were selected to compose the study. The PubMed, Embase, Ovid and Cochrane Library, Web Of Science, ScienceDirect Journals (Elsevier), Scopus (Elsevier), OneFile databases were used. Main findings: The present study demonstrated some prominent clinical features and endoscopic findings from AIG. The diagnosis of chronic autoimmune atrophic gastritis (CAAG) can be challenging and usually requires the combination of endoscopic, clinical, serological, and histopathological data. Iron deficiency in AIG is more common than celiac disease. Serological suspicion of AIG helps pre-select patients for endoscopic work. Still, another study showed that there is a significant reduction in the levels of 25 (OH) D in patients with CAAG and a possible impairment of vitamin D absorption can be postulated. Conclusion: The standardization of autoimmune gastritis in diagnostic practice is a prerequisite for the implementation of definitive secondary prevention strategies based on multidisciplinary diagnostic approaches that integrate endoscopy, serology, histology, and molecular profile. Upper gastrointestinal endoscopy with pH-measurement of gastric juice and histology can be performed to confirm positive serological results.