Urinary alpha 1 microglobulin levels in surveys of Balkan endemic nephropathy.

The urinary alpha 1-microglobulin (alpha 1m) concentration was measured in 644 adults living in districts where Balkan nephropathy (BEN) is endemic. Comparison of alpha 1m with other indicators of tubular proteinuria, which is a classical sign of BEN, showed alpha 1m was a satisfactory marker. Using a cut-off of 20 mg alpha 1m/L none of 102 normal UK residents had a positive level. Whilst a raised level of alpha 1m was present in 85.7% of definitive cases of BEN and in 8.1%, 10.2% and 50% of subjects previously classified as normal, at risk and suspicious respectively according to the criteria used for epidemiological surveys of BEN.