Increased cystatin C concentration in urine of nephrotic children

The aim of this study was to evaluate changes in urine and plasma concentrations of cystatin C in children with a relapse of the idiopathic nephrotic syndrome (INS). The study group comprised 12 children with INS with proteinuria and 12 children in an 8-week remission, both treated with steroids. Twelve healthy children served as controls. Cystatin C was detectable in the urine of children with proteinuria. The study suggests that massive proteinuria may influence renal cystatin C handling.