Evaluation of Oxidative Stress Indices and Inflammatory Marker in Sickle Cell Disease in Calabar, Nigeria: A Comparative Analysis of Interleukin-6, Total Plasma Peroxides and Total Antioxidant Capacity During Vaso-Occlusive Crises and Steady State

Introduction: Sickle cell disease is a genetic disorder characterized by abnormal hemoglobin called hemoglobin S (HbS). Sickle cell patients are faced with many complications that could lead to increase release of reactive oxygen species and inflammation that overwhelm the body’s antioxidants. Objectives: This study aimed to evaluate the levels of Interleukin-6 (IL-6), Total Plasma Peroxides (TPP) and Total Antioxidant Capacity (TAC) in sickle cell patients. The study also compared these parameters to 'AA' genotype subjects in Calabar, Cross River State. Methods: 100 subjects (males and females) were recruited in this study. The subjects comprised 25 sickle cell subjects in crisis, 25 sickle cell subjects not in crisis and 50 age/sex matched subjects as control group. Signed informed consent was obtained from each participant. Hemoglobin types were determined using cellulose acetate paper electrophoresis, IL-6 was determined using sandwich enzyme-linked immunosorbent assay, TAC and TPP were determined using colorimetric methods while OSI was calculated. Anthropometric indices, blood pressure and sociodemographic information were obtained using appropriate methods. Data were analyzed using Student’s t-test and Pearson's correlation at p < 0.05. Results: BMI, systolic and diastolic blood pressure, TPP and TAC were significantly lower (p< 0.05) while IL-6, OSI was significantly higher (p< 0.05) in sickle cell subjects when compared to apparently healthy subjects. TAC was significantly lower (p< 0.05) while IL-6, OSI were significantly higher (p< 0.05) in sickle cell subjects in crisis when compared to sickle cell subjects not in crisis. There was no significant difference (p˃ 0.05) in males when compared to females. Age and diastolic blood pressure were significantly lower (p< 0.05) and IL-6 was higher in subjects with BMI<20kg/m2 when compared to subjects ≥20kg/m². Oxidative stress index correlated negatively with TAC (r = -0.488, p < 0.05) in sickle cell patients. Interleukin 6 correlated positively with OSI (r = 0.446, p < 0.05). Conclusion: It is concluded that sickle cell disorder may decrease total antioxidant capacity (TAC), increased oxidative stress, increased interleukin 6 (about 18-fold increase) and hence increase release of free radicals may be associated with sickling of red cells.