Characteristics of proteinuria in endemic nephropathy.

Subjects living in the endemic area of Posavina round Slavonski Brod have a significantly greater incidence of proteinuria (13.6%) than those living under the same conditions in the area where endemic nephropathy has not been observed (5.5%). Following determination of the grade and type of proteinuria, physiologic proteinuria was found in 36% of subjects from the endemic area. In nonphysiologic proteinuria the incidence of tubular proteinuria was 41%. A slight selective glomerular proteinuria was found in 51%, and other types of proteinuria in 8% of subjects. Tubular proteinuria was significantly higher in the endemic area than in the control area. The subjects with tubular proteinuria from the endemic area excrete significantly greater amounts of beta 2-microglobulin and light immunoglobulin chains.