Metabolic pathways related to oxidative stress in patients with hemoglobin h disease and iron overload.

BACKGROUND: Iron overload is a major complication in patients with hemoglobin H (Hb H) disease and causes damage of tissues.

METHODS: We investigated 26 Hb H patients and 75 controls to evaluate their oxidative stress and antioxidant statuses.

RESULTS: There were significantly increased levels of superoxide anion in leucocytes, nitrite (NO2-), and malondialdehyde (MDA) in plasma, and activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRx) and oxidized glutathione (GSSG) in erythrocytes, decreased levels of nitrate (NO3-) and vitamin C in plasma, and reduced glutathione (GSH) in erythrocytes, in addition to the abnormal iron status in the patients when compared with those in the controls. Meanwhile, levels of serum ferritin were positively correlated with serum iron, plasma MDA, and erythrocyte SOD in the patients. In addition, the activities of SOD were positively correlated with those of GPx and GRx, and the levels of GSSG and MDA, but negatively correlated with those of GSH. Furthermore, the levels of MDA were negatively correlated those of vitamin C.

CONCLUSIONS: These results demonstrate the presence of oxidative stress and decreased levels of antioxidants; moreover, the related metabolic antioxidant pathway is active in Hb H patients with iron overload.