Enzymatic and Non-Enzymatic Antioxidant Defence in Sickle Cell Disease Patients During Vaso-Occlusive Crisis Versus Steady State in Enugu State

Oxidative stress plays a central pathophysiological role in sickle cell disease, and understanding the dynamics of antioxidant defence during vaso-occlusive crisis compared to steady state is essential for developing targeted antioxidant therapeutics in Nigerian patients. This study empirically compares enzymatic and non-enzymatic antioxidant defence parameters between the steady state and vaso-occlusive crisis phases of sickle cell disease at the University of Nigeria Teaching Hospital, Enugu State. Fifty sickle cell disease patients were evaluated during confirmed vaso-occlusive crisis and again at steady state, defined as at least four weeks after crisis resolution, creating a within-subject paired analytical design. Erythrocyte superoxide dismutase, catalase, and glutathione peroxidase activities were determined spectrophotometrically. Reduced glutathione and oxidized glutathione were measured to determine the glutathione redox ratio. Plasma vitamins C and E were quantified as non-enzymatic antioxidants. Lipid peroxidation was assessed by plasma MDA. Inflammatory markers including CRP and white blood cell count were concurrently measured to confirm crisis status. Results show significantly elevated MDA and significantly reduced SOD, catalase, GPx, GSH, vitamin C, and vitamin E during vaso-occlusive crisis compared to steady state. The glutathione redox ratio was markedly shifted toward oxidation during crisis. MDA correlated significantly with pain severity scores and with inflammatory markers. Even in steady state, antioxidant parameters remained significantly below healthy HbAA control values, indicating chronic baseline oxidative burden. The study provides biochemical evidence supporting antioxidant supplementation as an adjunct therapy during and between crises. Keywords: sickle cell disease, oxidative stress, vaso-occlusive crisis, antioxidant defence, Enugu State.