Interaction between Iron Deficiency and α-Thalassaemia: the in vitro Effect of Haemin on α-Chain Synthesis

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Abstract
Two conditions are liable to lower the .alpha.:.beta. globin biosynthesis ratio in reticulocytes: iron deficiency and .alpha.-thalassemia. The effect of hemin was studied on reticulocytes from 12 patients who had .alpha.-thalassemia and/or were iron deficient. The .alpha.:.beta. biosynthesis ratio was improved in all these cases. Four initially showed an .alpha.:.beta. synthesis ratio usually associated with .alpha.-thalassemia type-1; on the addition of hemin the ratio rose to that associated with .alpha.-thalassemia type-2. In the other 8 patients the ratio was initially typical for .alpha.-thalassemia type-2, and on addition of hemin the ratio became normal. In iron deficient patients a diagnosis of .alpha.-thalassemia type-1 or type-2 may not be made unless hemin has been added to the test system. If this is not done, iron deficiency alone can cause the .alpha.:.beta. globin synthesis ratio to resemble that associated with .alpha.-thalassemia type-2, and iron deficiency in combination with .alpha.-thalassemia type-2 can cause the ratio to resemble that typical for .alpha.-thalassemia type-1. Reticulocytes from 8 .alpha.-thalassemic patients without iron deficiency did not showed a marked hemin effect (< 5%), and in 1 patient with iron overload, the ratio actually fell by about 10%.
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