Surprising good antioxidant status in patients with Balkan Endemic Nephropathy on hemodialysis undergoing vitamin C therapy. A pilot study.

AIMS: End Stage Renal Disease (ESRD) represents a microinflammatory state accompanied by oxidative stress and an imbalance between pro- and antioxidants. Vitamin C is a highly effective antioxidant, acting to lessen oxidative stress. The aim of our study was to assess the Antioxidant Capacity of Water soluble substances (ACW) and the Antioxidant Capacity of Liposoluble substances (ACL) in patients with Balkan Endemic Nephropathy (BEN) on hemodialysis undergoing Vitamin C therapy as compared to healthy controls.

METHODS: Twenty-one patients with BEN on hemodialysis (HD), mean age: 63.33 +/- 5.42 years, 6 M and 15 F, were enrolled into the study. All patients received 10 vials of Vitamin C 750 mg/5 ml every 2 months. Eleven apparently healthy subjects, mean age: 63.73 +/- 5.21 years, 6 M and 5 F, served as controls. The photochemiluminescence assay was used to measure the antioxidant activity of plasma samples. The results are presented in equivalent concentration units of Vitamin C for water soluble antioxidants and in equivalent concentration units of Trolox (synthetic Vitamin E) for lipid soluble antioxidants. Both concentrations are expressed in micromols/L. Statistical analysis (non-parametric Wilcoxon test) was performed using NCSS.

RESULTS: Mean duration since BEN diagnosis was: 8.24 +/- 3.5 years. Mean duration since HD initiation was: 4.92 +/- 3.4 years. Smoking status was negative in all patients. Hypertension was present in 15 patients (71.42%), cardiovascular disease in 10 (47.61%), HCV infection in 13 (61.9%), 1 patient had HBV + HCV infection, 1 had renal tuberculosis, 1 had upper urinary tract cancer, 1 genital cancer, and I autoimmune thyroid disease. The Antioxidant Capacity of Water soluble substances (ACW) in patients with BEN was 477.6 +/- 177.63 micromols/L, significantly higher as compared to controls: 198.05 +/- 196.63 micromols/L; p = 0.01, whereas the Antioxidant Capacity of Liposoluble substances (ACL) in patients with BEN was 33.9 +/- 22.99 micromols/L, non-significantly different as compared to controls: 27.38 +/- 4.21 micromols/L; p = 0.22.

CONCLUSIONS: We conclude that Vitamin C therapy in patients with BEN on HD significantly increases the Antioxidant Capacity of Water soluble substances (ACW) as compared to controls and could be used to counter oxidative stress in patients with ESRD.