1H NMR spectroscopy of urine has been applied to exploring metabolomic differences between people diagnosed with Balkan endemic nephropathy (BEN), and treated by haemodialysis, and those without overt renal disease in Romania and Bulgaria. Convenience sampling was made from patients receiving haemodialysis in hospital and healthy controls in their village. Principal component analysis clustered healthy controls from both countries together. Bulgarian BEN patients clustered separately from controls, though in the same space. However, Romanian BEN patients not only also clustered away from controls but also clustered separately from the BEN patients in Bulgaria. Notably, the urinary metabolomic data of two people sampled as Romanian controls clustered within the Romanian BEN group. One of these had been suspected of incipient symptoms of BEN at the time of selection as a ‘healthy’ control. This implies, at first sight, that metabolomic analysis can be predictive of impending morbidity before conventional criteria can diagnose BEN. Separate clustering of BEN patients from Romania and Bulgaria could indicate difference in aetiology of this particular silent renal atrophy in different geographic foci across the Balkans.

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.