hematology and oncology
Secondary Iron Overload
Etiology of Secondary Iron Overload
Secondary iron overload typically occurs in patients who have Hemoglobinopathies (eg, Sickle Cell Disease , Overview of Hemolytic Anemia (eg, Myelodysplasia and Iron-Transport Deficiency Anemia None Iron overload results from the following mechanisms: Increased iron absorption Exogenous iron given to treat anemia Repeated blood transfusions (each unit of blood provides about 250 mg of iron; tissue deposition becomes significant when more than about 40 units of blood are transfused) Increased iron absorption in patients with ineffective erythropoiesis may be partly due to the secretion, by erythroid precursors, of erythroferrone (ERFE), which suppresses hepcidin (an inhibitor of iron absorption). Patients with hemoglobinopathies and congenital hemolytic anemias now typically live into adulthood, so complications of iron overload are now common and clinically important. In such patients, iron overload involving the heart, the liver, and endocrine organs has become a common cause of death, but survival can be prolonged by iron removal. 