Autoimmune Metaplastic Atrophic Gastritis By Nimish Vakil, MD, University of Wisconsin School of Medicine and Public Health Reviewed / Revised Mar 2023 View Patient Education Etiology Complications Symptoms and Signs Diagnosis Treatment More Information Topic Resources Atrophic Gastritis Autoimmune metaplastic atrophic gastritis is an inherited autoimmune disease that attacks parietal cells, resulting in hypochlorhydria and decreased production of intrinsic factor.