Modern Understanding of the Role of Immune Factors in the Development of Megaloblastic Anemia: Literature Review

Megaloblastic anemia is a hematological disorder characterized by impaired DNA synthesis in erythroid precursor cells, leading to the formation of abnormally large but functionally deficient red blood cells. One of the primary causes of this condition is a deficiency of vitamin B12 and folic acid, which may result from malabsorption in the gastrointestinal tract, inadequate dietary intake, or genetically determined pathologies. In recent years, research has increasingly focused on the immune mechanisms underlying megaloblastic anemia, particularly autoimmune processes that cause chronic gastric damage. Autoimmune atrophic gastritis is a key mechanism leading to the gradual destruction of the gastric mucosa and a decrease in intrinsic factor secretion, which is necessary for vitamin B12 absorption. This deficiency results in megaloblastic anemia. Studies confirm that the pathogenesis is primarily associated with autoantibody formation against gastric parietal cells and intrinsic factor. This review summarizes current knowledge regarding the role of immune factors in the development of megaloblastic anemia and discusses possible diagnostic and therapeutic approaches.