Association of erythrocytes antioxidant enzymes and their cofactors with markers of oxidative stress in patients with sickle cell anemia

BACKGROUND Sickle cell anemia (SCA) is an inherited blood disease with known complications as a result of certain pathophysiological dysfunctions. It has been suggested that an increase in oxidative stress contributes to the incidence of these changes. OBJECTIVES This study investigated the oxidant/antioxidant status of patients with SCA, and evaluated the effect of SCA on antioxidant enzymes and their cofactors. METHODS The study included 42 patients with SCA (in steady state), and a control group of 50 age-matched individuals without SCA. Serum malondialdehyde (MDA), copper, zinc, ferritin and iron levels, red blood cell (RBC) superoxide dismutase (SOD) and catalase levels were measured for the SCA and control groups. RESULTS Significantly lower levels of antioxidant enzymes (RBC SOD and catalase) and higher serum MDA levels (biomarker of oxidative stress) were found in SCA patients compared to the control group (all p < 0.001). Increased levels of serum ferritin, iron and copper and decreased zinc concentrations were also found in the SCA patients compared to the control group (all p < 0.001). In the SCA group, there were significant negative correlations between MDA levels and RBC SOD, RBC catalase, and serum zinc levels (p < 0.01), while a significant positive correlation between MDA with serum copper and iron levels (p < 0.01) was observed. CONCLUSION SCA is associated with alterations in markers of oxidative stress including an increased MDA level, decreased antioxidant enzyme levels, and altered levels of enzyme cofactors (zinc, copper, and iron). This suggests that these antioxidant enzymes could be used as effective therapeutic targets for the treatment of this disease and supplementation of patients with substances with antioxidant properties may reduce the complications of this disease.