IRON-ABSORPTION IN THALASSEMIA SYNDROMES AND ITS INHIBITION BY TEA

To determine the hemoglobin concentration at which iron absorption is minimal, five subjects with thalassemia major and one with thalassemia intermedia underwent a series of iron-absorption studies. The effect of tea as an inhibitor of non-heme iron absorption was also tested. Iron absorption increased as the hemoglobin concentration decreased, although iron absorption was much higher at any given hemoglobin level in the subject with thalassemia intermedia. In the subjects with thalassemia major, iron absorption averaged 10 per cent at hemoglobin concentrations between 9 and 10 and 2.7 per cent between 11 and 13 g per deciliter. The percentage of iron absorbed could be accurately predicted from the nucleated red-cell count (r = 0.91, P<0.001). Tea produced a 41 to 95 per cent inhibition of iron absorption. Since patients with thalassemia intermedia may absorb a large percentage of dietary iron, inhibitors of iron absorption, such as tea, may be useful in their management. (N Engl J Med 300:5–8, 1979) HOMOZYGOUS β-thalassemia is an inherited red-cell disorder characterized by severe anemia beginning at a few months of age, bone-marrow hyperplasia and a typical hemoglobin electrophoresis with markedly decreased or absent hemoglobin A and elevations of hemoglobins A2 and F. With the advent of intensive transfusion therapy for this disease,1 iron overload has become the most important complication of thalassemia.2 3 4 5 The problem of transfusional iron overload may be compounded by increased intestinal absorption of iron.6 7 8 9 10 Iron overload has been documented in persons who have never received blood transfusions.11 12 Furthermore, even in subjects receiving multiple transfusions, the amount of iron found. © 1979, Massachusetts Medical Society. All rights reserved.