Pernicious anemia (PA) is an autoimmune disease of multifactorial etiologies characterized by autoimmune chronic atrophic gastritis, cobalamin deficiency (CD) due to defective absorption of dietary cobalamin from the terminal ileum, and by the presence of intrinsic factor and parietal cell antibodies.
This disease is characterized by the deficiency of vitamin B12 due to the presence of anti-intrinsic factor and anti-parietal cell antibodies which inhibit the absorption of the vitamin B12.
High frequency of anti-parietal cell antibody (APCA) and intrinsic factor blocking antibody (IFBA) in individuals with severe vitamin B12 deficiency - an observational study in primary care patients.