Superoxide dismutase activity in sickle cell anemia patients during crisis and in steady State

INTRODUCTION: Sickle cell anemia is associated with intense oxidative stress, and optimal antioxidant levels are essential to prevent continuous oxidant tissue damage. The role of oxidant damage to red blood cells in sickle cell anemia (SCA) has been of interest in recent years, and some available results indicate that sickled red blood cells produce almost twice as much superoxide, hydrogen peroxide, and hydroxyl free radicals compared with normal red cells. To counter the effects of oxidants, red blood cells have evolved a number of self-sustaining activities of antioxidant defense enzymes including but not limited to superoxide dismutase (SOD). This study aimed to measure serum SOD activity in patients SCA patients (as a measure of antioxidant defense) during the crisis and in steady state and to compare this with the activity in HbAA normal controls. SUBJECTS AND METHODS: Eighty-eight participants were recruited into this case control study and comprised 34 HbAA controls, 12 HbSS patients in crisis, and 42 HbSS patients in steady state. Five milliliter of venous blood was collected from each participant and 3 ml was dispensed into plain tubes and centrifuged. The serum was used for the estimation of SOD activity. The remaining 2 ml was used for hemoglobin electrophoresis. RESULTS: SOD levels were highest in the HbAA control group (1.928 ± 0.051 U/mL) followed by the HbSS patients in steady state (1.844 ± 0.118 U/mL) and lowest in the HbSS patients in crisis (1.755 ± 0168 U/mL). This difference was statistically significant with P = 0.001. CONCLUSION: SOD levels are reduced during vaso-occlusive crisis.