What is Balkan endemic nephropathy?

Balkan endemic nephropathy is a form of interstitial nephritis causing kidney failure. It was first identified in the 1920s among several small, discrete communities along the Danube River and its major tributaries, in the modern countries of Croatia, Bosnia and Herzegovina, Serbia, Romania, and Bulgaria. It is caused by small long-term doses of aristolochic acid in the diet. The disease primarily affects people 30 to 60 years of age. Doses of the toxin are usually low and people moving to endemic areas typically develop the condition only when they have lived there for 10-20 years. People taking higher doses of aristolochic acid have developed kidney failure after shorter durations of exposure.