Comparison of erythrocyte antioxidative enzyme activities between two types of haemoglobin H disease

Abstract

The activities of erythrocyte antioxidative enzymes were measured in two groups of patients with different genotypes of haemoglobin (Hb) H disease: 21 with α-thalassaemia or α-thalassaemia 2 (α-thalassaemia 1/2) and 21 with α-thalassaemia l/Hb Constant Spring (HbCS). They were compared with 21 normal subjects. Both genotypes of Hb H disease had increased activities of erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase when compared with those of controls. Comparison of the two genotypes showed that subjects with α-thalassaemia /Hb CS, the more severe disease, had higher SOD and GSH-Px activities but lower catalase activity than those with α-thalassaemia 1/2. This indicates that there are compensatory mechanisms in Hb H erythrocytes to cope with increased generation of oxygen free radicals as a result of increased excess ,β chain.