| [ Summary ] |
Type A gastritis, one from of chronic atrophic gastritis, is precipitated by an autoimmune mechanism and causes pernicious anemia, achlorhydria and hypergastrinemia. It correlates with anti-intrinsic factor antibodies, anti-gastric receptor antibodies and anti-parietal cell antibodies which recognize the H+ / K+ ATPase as an antigen. Though the mechanism of gastric carcinogenesis in type A gastritis is unknown, hypergastrinemia is one of the causes of gastric cancer since gastrin factors activate the protein kinase C via gastric / CCK-B receptors. Hypergastrinemia, with type A gastritis, also causes gastric carcinoid tumors originating from ECL cells. Gastric carcinoid tumors in hypergastrinemia are generally less malignant. However, caution should be taken in cases of endocrine carcinoma, which resemble carcinoid tumors with hypergastrinemia. |