Metabolism of Iron, Calcium and Magnesium in Homozygous Thalassemia*

Abstract

Problems related to metabolism of iron in homozygous thalassemia are of two main varieties.One appears to be an inability to adequately utilize iron in the formation of hemoglobin.The second is accumulation of excessive amounts of iron in a number of organs within the body.Inadequate utilization of iron for synthesis of hemoglobin is probably the defect responsible for increased amounts of the metal found in erythrocytes from such patients by a number of investigators.','Values for serum iron and latent iron-binding protein for 10 patients with homozygous thalassemia major a t times of initial diagnoses or before receipt of any transfusion therapy are shown in FIGURE 1. Values of serum iron were normal or elevated when determined by the method of Peters et aL" Latent iron-binding protein as determined by the method of Rath and Finch was markedly diminished or absent.'For several reasons we have assumed that these findings are additional reflections of inadequate utilization of iron.(a) They have been noted when intake of dietary iron was of necessity small both because of the patients' ages (5-16 months), and because of the presence of untreated severe anemia with consequent irritability and anorexia.(b) A similar pattern has been recorded in patients having aplastic anemia, during aplastic crises in the presence of congenital spherocytosis, in pernicious anemia in relapse, in pyridoxine deficiency and after suppression of erythropoiesis following transfusions of blood."-"In each of these situations there is inadequate utilization of iron for hemoglobin synthesis.Amounts of iron in serum are consistently elevated in similar patients following administration of numbers of transfusions as demonstrated in the lower portion of FIGURE 1.The iron-binding protein is, as a rule, saturated.Evidence for accumulation of excessive amounts of iron by patients with homozygous thalassemia receiving multiple transfusions of blood has been found both in the clinical courses and also in histologic examinations and chemical analyses of tissues.Death has occurred in 25 patients in our institution who had homozygous thalassemia and received multiple blood transfusions.In 16 cases the death was attributable to cardiac failure which developed after the onset of *These investigations have been supported by the