RESUMO
BACKGROUND: Tuberculosis (TB) is associated with oxidative stress and is traditionally linked to vitamin C deficiency. OBJECTIVE: To evaluate the time course of the oxidative stress marker, malondialdehyde (MDA), and vitamin C status during the clinical treatment of tuberculous meningitis (TBM). METHOD: MDA and vitamin C reduction/oxidation (redox) status were spectrophotometrically measured at admission and during hospital treatment in cerebrospinal fluid (CSF) and serum from 27 TBM patients and 20 controls. RESULTS: Baseline CSF and serum MDA levels in TBM patients were higher than in controls (both P < 0.05), and remained elevated throughout the study. CSF MDA steadily increased from baseline 0.66 ± 0.24 mol/l to 1.02 ± 0.33 µmol/l at the end of the sixth week of treatment (P < 0.05), and then returned to baseline levels. Baseline CSF and serum total vitamin C were lower in TBM patients than in controls, but were soon normalised. CSF and serum ascorbate, reduced/oxidised vitamin C ratios and ascorbate CSF/serum ratio were markedly decreased in TBM patients (P < 0.05), and showed no improvement during treatment. CONCLUSION: These results indicate increased local and systemic oxidative stress, accompanied by impaired redox status, but not total vitamin C deficiency, which persisted during conventional clinical treatment of TBM.