Serum superoxide dismutase activity: A predictor of disease severity in nigerian sickle cell anemia patients in steady state

Abstract

Background: Sickle cell anemia (SCA) is associated with intense oxidative stress; optimal antioxidant levels are essential to prevent oxidant tissue damage. Objective: The objective of this study was to evaluate superoxide dismutase (SOD) activity and Vitamin C levels in individuals with SCA, heterozygous sickle cell (heterozygous hemoglobin AS [HbAS]), and normal (hemoglobin AA [HbAA]) hemoglobin phenotypes in comparison with objective scores of disease severity (in those with SCA). Subjects and Methods: A total of ninety participants were recruited, including thirty SCA (in steady state), thirty HbAS, and thirty HbAA. From each participant, 5 ml of venous blood was collected; 3 ml was dispensed into plain tubes and serum was extracted for the estimation of SOD activity and Vitamin C level. Serum SOD activity was measured using a semi-automated spectrophotometric procedure, while serum Vitamin C level was estimated by the enzyme-linked immunosorbent assay technique. The remaining 2 ml was used for hemoglobin electrophoresis and full blood count estimation. Objective score of disease severity was calculated for SCA individuals using a scoring system. Results: The mean serum activity of SOD was significantly lower in SCA compared with HbAS and HbAA participants (9.45 ± 3.39 U/ml vs. 12.87 ± 2.17 U/ml and 13.24 ± 2.10 U/ml, P < 0.001, respectively). No significant differences were observed between the mean serum Vitamin C levels of SCA, HbAS, and HbAA participants (1922.59 ± 771.56 ng/ml vs. 1631.10 ± 526.57 ng/ml and 2029.17 ± 902.99 ng/ml P > 0.05, respectively). Serum SOD activity was significantly correlated with objective score of disease severity in SCA participants, while Vitamin C level was not (r = -0.529, P = 0.02 and r = -0.349, P = 0.14, respectively). Conclusion: Serum SOD activity is a predictor of disease severity in Nigerian individuals with SCA.