Lipid peroxidase and erythrocyte redox system in systemic vasculitides treated with corticoids. Effect of vitamin E administration.

The level of plasma lipid peroxidation was followed up in 66 patients with systemic vasculitides with autoimmune pathogeny (SLE and SV) treated with corticoid compounds. The effect of vitamin E associated to this treatment was also studied. The change of the redox cycle, of the red cell glutathione, and of the glutathione peroxidase activity, an enzyme supplying antioxidant protection, were studied in parallel. The results obtained demonstrated: an increased level of lipid peroxidation in the patients treated with corticoid substances, an increase that can be explained by the dyslipidemias induced by these compounds; a decrease of the red cell G-SH concentration owing to the continuous oxidative stress in this group of diseases. This decrease was associated with a concomitant increase of oxidated glutathione. The decrease of GSH, a substrate for glutathione peroxidase, induces an inhibition of this enzyme activity. The GSH/GSSH ratio may represent a useful marker of the evolution of disease. Administration of vitamin E in association with corticotherapy has a relatively reduced effect due to the complex metabolic disturbances with a continuous character in the autoimmune pathogenic processes. The chronic disturbance of the oxidants-antioxidants balance in patients with systemic vasculitides seems to create favourable conditions for the early onset of a process of atherogenesis with severe vascular effects.