Total antioxidant capacity – a novel early bio-chemical marker of oxidative stress in HIV infected individuals

BACKGROUND: Oxidative stress induced by the production of reactive oxygen species may play a critical role in the stimulation of HIV replication and the development of immunodeficiency. This study was conducted as there are limited and inconclusive studies on the significance of a novel early marker of oxidative stress which can reflect the total antioxidant capacity in HIV patients, METHODS: Total antioxidant capacity (TAC) and lipid peroxidation were evaluated in 50 HIV-1 seropositive patients (including HIV-1 symptomatics and asymptomatics). Controls included 50 age and sex matched and apparently healthy HIV-1 seronegative subjects. Serum malondialdehyde (MDA), Total antioxidant capacity [TAC] (by ferric reducing antioxidant power assay), vitamin E, vitamin C and superoxide dismutase (SOD) enzyme activity were estimated among controls and cases. Statistical comparisons and correlations at 5% level of significance were determined. RESULTS AND DISCUSSION: The mean MDA concentrations were significantly elevated in both HIV-1 asymptomatic (CD4+ count > 500 cells/microliter) and HIV-1 symptomatic (CD4+ count <500 cells/microliter) groups (Mean ± S.D values were 2.2 +/- 0.7 nmol/ml and 2.8 +/- 0.8 nmol/ml respectively) when compared with the control group (Mean ± S.D value was 0.9 +/- 0.2 nmol/ml) (p < 0.01). The mean TAC of HIV- 1 asymptomatic and HIV-1 symptomatic (Mean ± S.D values were 754.6 ± 135.6 μmol/L and 676.6 ± 154.1 μmol/L respectively) patients were significantly reduced compared with the control group (Mean ± S.D value was 1018.7 ± 125.6 μmol/L) (p < 0.01). Also, there were significantly decreased levels of vitamin E, vitamin C and SOD among HIV-1 seropositive patients(controls > asymptomatic > symptomatic) compared to controls (p < 0.01). TAC showed significant negative correlation with MDA among HIV-1 infected patients (p < 0.01). CONCLUSION: Our results clearly show that severe oxidative stress occurs in the HIV-1 seropositive patients in comparison with controls, and increases significantly with the progression of disease, i.e. HIV-1 symptomatics > asymptomatics > controls. TAC can be used as a novel early bio-chemical marker of oxidative stress in HIV-1 infected patients which may result in reduced tissue damage by free radicals and help to monitor and optimize antioxidant therapy in such patients.