Antioxidant status in beta thalassemia major: a single-center study

Homozygous β thalassemia may lead to a marked reduction or absence of normal β chain production and accumulation of unpaired alpha-globin chains. A crucial component in the oxidant susceptibility of the thalassemic RBC is the release of heme and iron from the excessive, unpaired α-globin chains. This release can initiate self-amplifying redox reactions, which deplete the cellular reduction potential (e.g., GSH), oxidize additional hemoglobin and accelerate RBC destruction. Furthermore, β-thalassemia patients are under continuous blood transfusion, which, although life-saving, leads to an iron overload with a resultant increase in non-transferrin-bound iron that may cause greater tissue toxicity than iron in other forms. Iron-induced oxidative stress is known to be one of the most important factors determining cell injury in thalassemic patients. Therefore, we designed this study to obtain a comprehensive picture of the iron overload, antioxidant status and cell damage in β thalassemia major patients undergoing regular blood transfusion.

A total of 48 diagnosed patients of β thalassemia major and 30 age- and sex-matched healthy subjects were included in the study. Estimation of hemoglobin, hematocrit, glutathione peroxidase (GPX), superoxide dismutase (SOD),vitamin E, serum ferritin, total and direct bilirubin, AST and ALT was carried out.

The levels of vitamin E, antioxidant enzymes GPX and SOD were significantly lowered in β thalassemic patients as compared with the control group (P<0.001). Serum total and direct bilirubin, AST and ALT were significantly elevated in thalassemic subjects as compared with the control group, indicating liver cell damage.

Thus, our findings indicate that thalassemics are in a state of enhanced oxidative stress and that the administration of selective antioxidants would represent a promising approach toward counteracting oxidative damage and its deleterious effects on the disease status.