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.
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.
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.
Diagnosis of PA relies on histologically proven atrophic body gastritis, peripheral blood examination showing megaloblastic anemia with hypersegmented neutrophils, cobalamin deficiency and antibodies to intrinsic factor and to gastric parietal cells.
Cubulin mutations cause a hereditary form of megaloblastic anemia secondary to vitamin B(12) deficiency, and proteinuria occurs in 50% of cases since cubilin is coreceptor for both the intestinal vitamin B(12)-intrinsic factor complex and the tubular reabsorption of protein in the proximal tubule.