Therapeutic remedies based on Aristolochia clematitis in the main foci of Balkan endemic nephropathy in Romania.

Balkan endemic nephropathy (BEN) is a disease found in Romania and neighboring countries in the Balkan area. In Romania, BEN is most prevalent in Mehedinti County, located in the South of Romania near the Danube River. The etiology of the disease is as yet unknown. One of the current hypotheses concerning BEN etiology is an involvement of aristolochic acid (AA). BEN bears many similarities to aristolochic nephropathy, which is developed due to the use of Chinese herbs as therapeutic remedies in slimming diets. This paper analyzes the involvement of therapeutic remedies based on AA in the BEN found in Mehedinti County, where these herbs have been traditionally used. The presence of AA in the plasma of BEN patients as well as of other subjects, including healthy relatives of these patients and other persons from the BEN-affected area, has been analyzed. No AA was detected in the plasma of the studied subjects. This proves the absence, at the current time, of an AA contribution in the analyzed subjects. Therapeutic remedies based on AA have been used in the BEN-affected area. We were not able to reveal direct relationships between these remedies and either the development of BEN in dialyzed patients or the development of urinary-tract tumors in dialyzed patients with urothelial tumors. Therapeutic remedies based on Aristolochiaclematitis may play a stimulating role in BEN with regard to its development and the development of urinary-tract tumors. There may be a relationship between BEN and cumulative previous exposure to low doses of AA due to the consumption of contaminated foodstuffs, which could add to any contributions by therapeutic remedies.

Differential methylation pattern of xenobiotic metabolizing genes and susceptibility to Balkan endemic nephropathy, in a cohort of Romanian patients.

A severe, chronic and irreversible kidney disease affecting discrete rural populations in the Balkan Peninsula countries, Balkan endemic nephropathy (BEN) has been a scientific puzzle for more than half a century. Many environmental and other factors have been suggested as the primary cause and recent significant findings have linked BEN to aristolochic acids, phytotoxins derived from the plant Aristolochia clematitis, found in high density in the endemic areas. However, given that the incidence of BEN is less than 10% in affected villages, and it tends to have a family aggregation, as yet unidentified genetic factors may also play a role. To further explore this possibility, a pilot study was initiated to investigate the DNA methylation of CYP1A1, CYP1A2, NAT1, NQO1 and GSTT1 in blood samples from a group of Romanian BEN patients, compared to healthy controls and non-BEN chronic kidney disease (CKD) subjects. Our study revealed a more pronounced hypomethylation pattern in BEN and non-BEN CKD groups, compared to the healthy control group at specific CpGs across all five genes interrogated. Average methylation across the five regions investigated indicated significant differences only at GSTT1, in both BEN patients (p = 0.028) and non-BEN disease subjects (p = 0.015), relative to healthy individuals. Since GSTT1 active genotype appears to be a common feature of Serbian and Romanian BEN patients, GSTT1 epigenetic variation and increased gene activity could act as a predisposing (co)factor in BEN populations from the affected countries. BEN and non-BEN CKD groups show similar methylation patterns with exception of GSTT1 CpG8 (p = 0.046).