Serum erythropoietin in regularly transfused thalassemic patients.

Serum erythropoietin levels were measured in 67 regularly transfused thalassemic patients with pre-transfusion hematocrit ranging from 25-32% and in 40 normal individuals. In patients, mean erythropoietin levels were slightly increased (mean 91.5 miu/ml) as compared to normal individuals (mean 42 miu/ml). The distribution of erythropoietin (Ep) was wide in thalassemic patients. 40% had normal or decreased and 60% increased Ep levels. A reverse relation between pretransfusion Hct and erythropoietin activity was observed only among patients with normal erythropoietin levels and splenectomized patients with high erythropoietin titers suggesting that a normal feedback between tissue hypoxia and erythropoietin activity occurs in these groups. The effect of regular blood transfusions in reversing tissue hypoxia resulting from anemia in the majority of regularly transfused thalassemic patients seems to be satisfactory, as it is assessed by serum erythropoietin levels.