Familial versus environmental factors in Balkan endemic nephropathy in Mehedinti county, Romania, by means of albuminuria and tubular biomarkers: preliminary study.

INTRODUCTION AND AIMS: Balkan endemic nephropathy (BEN), a regional tubulointerstitial kidney disease encountered in South-Eastern Europe, with still undefined etiology and inexorable evolution towards end stage renal disease, raises the question of the relative contribution of family and environmental factors in its etiology. In order to evaluate the intervention of these factors, markers of tubular injury have been assessed, this lesion being considered an early renal involvement in BEN. METHODS: The paper studies relatives of BEN patients currently included in dialysis programmes (for involvement of the family factor) and their neighbors (for involvement of environmental factors) and analyzes them with regard to tubular injury by means of tubular biomarkers (N-acetyl-beta-d-glucosaminidase-NAG and alpha-1-microglobulin), and albuminuria. At the same time, glomerular filtration rate (GFR) (CKD-EPI) was measured. It is considered that, in order to acquire the disease, one should have lived for 20 years in the BEN area. The relatives have been classified according to this criterion. RESULTS: More evident tubular injury was found in the neighbors of BEN patients living for more than 20 years in the endemic area, which argues in favor of environmental factors. Higher levels of urinary alpha-1-microglobulin and albumin in relatives of BEN patients who had been living for more than 20 years in the area than in relatives with a residence under 20 years, plead for the same hypothesis. GFR was lower in persons who had been living for more than 20 years in the BEN area (neighbors and relatives). CONCLUSIONS: Environmental factors could be more important in BEN than family factors.

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.

Evidence of exposure to aristolochic acid in patients with urothelial cancer from a Balkan endemic nephropathy region of Romania.

Recently, chronic Aristolochia poisoning was found responsible for the aetiology of Balkan endemic nephropathy (BEN) in Croatia, Serbia, and Bosnia, and diet was the likely route of exposure to aristolochic acid (AA). BEN, often associated with an increased incidence of upper urinary tract carcinoma (UUC), also affects residents of certain rural villages in Romania. AA is a nephrotoxin and human carcinogen that forms DNA adducts after metabolic activation, which induce characteristic TP53 mutations in urothelial tumours. Here we present the first evidence linking AA exposure to UUC in residents of an endemic region in the Romanian Mehedinti County. DNA was extracted from kidney and tumour tissue of seven patients who underwent nephroureterectomy for UUC and resided in BEN villages (endemic group). Five patients with UUC from nonendemic villages served as controls. AA-DNA adducts (7-(deoxyadenosin-N(6) -yl)-aristolactam I), established biomarkers of AA exposure, were identified by (32)P-postlabelling in renal DNA of six patients from the endemic group and in one of the nonendemic group (adduct levels ranged from 0.3 to 6.5 adducts per 10(8) nucleotides). Additionally, an A to T transversion in TP53, a base substitution characteristic of AA mutagenic activity was found in urothelial tumour DNA of one patient from the endemic group. Our results provide a molecular link to the cause of urothelial tumours in BEN regions of Romania indicating that AA is the common aetiological agent for BEN across its numerous geographical foci.