Balkan endemic nephropathy

Balkan endemic nephropathy (BEN) is a chronic, slowly progressive tubulointerstitial nephritis, with familial clustering, occurring in several endemic rural regions in countries of the Balkan Peninsula. BEN is characterized by anaemia, tubular proteinuria, renal shrinkage, and slowly declining glomerular filtration rate (GFR). Up to one-third of patients may also develop upper urothelial tumours. The aetiology of BEN is unclear; chronic exposure to aristolochic acid and a polygenic predisposition are the most likely contributing factors. The major pathological characteristics of BEN are symmetrically shrunken, smooth-shaped kidneys, with interstitial fibrosis, mild interstitial inflammation, and tubular atrophy. Diagnosis is usually based upon positive family history of BEN, past or current residence in endemic regions, tubular proteinuria, tubular dysfunctions (such as urine acidification defects, salt wasting, and impaired excretion of ammonia, uric acid, and phosphate), scant urinary sediment, bilateral and symmetrically reduced kidney size, accompanied by severe anaemia, disproportionate to the degree of GFR reduction. There is no specific therapy for BEN; patients should therefore be treated as all patients with chronic kidney disease, in general. The use of distant water supplies or moving to another residence area should be advised to affected families. Careful evaluation for urothelial cancers is mandatory in patients with haematuria.