Erythrocyte δ-Aminolaevulinic Acid Dehydratase in Homozygous b-Thalassaemia

Erythrocyte δ-ALA dehydratase activity was quantitatively measured in 33 normal subjects and 50 patients with homozygous b-thalassaemia. It was found that, a) In thalassaemic erythrocytes the activity of this enzyme was usually higher than in the normals, the difference of the mean values being statistically highly significant (P < 0.0005). b) This increment of the enzyme activity was not related only to the increased number of immature erythrocytes in thalassaemic samples since it persists after their elimination.