Cu/Zn superoxide dismutase plasma levels as a new useful clinical biomarker of oxidative stress in patients with end-stage renal disease

Objectives: We wanted to study the imbalance between antioxidant and oxidant generating systems resulting in oxidative stress (SOX) in end-stage renal disease (ESRD). We suggest that the plasma levels of Cu/Zn superoxide dismutase (Cu/Zn SOD) may be a new, sensitive marker of SOX in this population. Design and methods: We measured the levels of Cu/Zn SOD and the traditional SOX markers—malondialdehyde (MDA), total peroxide, and autoantibodies against oxidized LDL (OxLDL-Ab) in the plasma of 132 uremic patients. In addition, circulating enzyme levels were analyzed in relation to the inflammation and presence of diabetes mellitus (DM). Results: Cu/Zn SOD levels were significantly higher in chronic renal failure (CRF) patients (P< 0.05), and in both dialyzed groups (both P< 0.001) than in controls, and were positively correlated with MDA, creatinine (both P< 0.001) and OxLDL-Ab (P< 0.01) in the whole uremic group. Conclusions: The plasma levels of Cu/Zn SOD may be a simple, sensitive marker of SOX in ESRD, independent from DM and inflammation