OXIDATIVE STRESS AND ANTIOXIDANT DEFENSE-MECHANISM IN GLOMERULAR-DISEASES

The changes in red blood cell (RBC) lipid peroxidation [measured via t he malonyl dialdehyde (MDA) concentration], reduced (GSH), and oxidize d glutathione (GSSG) levels, hemoglobin (Hb) oxidation and antioxidant enzyme [catalase (Cat), glutathione peroxidase, and superoxide dismut ase (SOD)] activities were studied in 45 pediatric patients with vario us glomerular diseases [minimal change nephrotic syndrome (MCNS) in re lapse or in remission, lupus nephropathy (SLE), poststreptococcal glom erulonephritis (APSGN), IgA nephropathy (IGA gn)], and in 20 adult pat ients with IGA gn and also in 15 pediatric and 14 adult controls. The in vitro effects of hydrogen peroxide [acetyl phenylhydrazine (APH) te st] on the GSH and Kb metabolisms were likewise investigated. There wa s an increased oxidative stress in MCNS with relapse, IGA gn, SLE gn, and APSGN, which could be detected in the GSH and Hb oxidation and in the lipid peroxidation on the peripheral RBC-s. The RBC SOD and Cat ac tivities were significantly lower in all patients than in the controls . The RBC GSSG level was significantly elevated in all patients, with the exception of MCNS in remission. This stimulated a compensatory GSH production in MCNS with relapse and in IGA gn, but not in SLE or APSG N. The regeneration of GSH from GSSG was reduced in MCNS with relapse, SLE, and IGA gn, but not in APSGN. In remission, the GSH-GSSG redox s ystem normalizes, but in vitro the APH test stimulates an intensive Hb oxidation. In conclusion, there is a correlation between the presence of active glomerular disease and the evidence of oxidative changes in the various parameters measured in peripheral RBCs. Copyright (C) 199 6 Elsevier Science Inc.