Application of serum cystatin C assay in children with nephrotic syndrome

Objective To investigate the application of serum cystatin C (Cys-C) assay in children with nephrotic syndrome, and detect the changes in Cys-C levels after glucocorticoid therapy. Methods The levels of Cys-C, serum creatinine (SCr) and Urea in 40 children with nephrotic syndrome (the study group) were detected before and after glucocorticoid treatment, then the data was compared with that of 38 healthy individuals (the control group). Results The levels of serum Cys-C, Urea and SCr in the study group were significantly higher than that in the control group (P0.01). The positive rates of Cys-C, Urea and SCr in the study group were 85.0%, 52.5% and 35% before treatment, and 27.5%, 20.0% and 17.5% after treatment. In the study group, the levels of Cys-C before treatment were significantly increased compared with that of Scr and Urea (P0.01), and 20% of the patients has significantly higher Cys-C levels after treatment. Conclusion Cys-C assay has greater value in the diagnosis of nephrotic syndrome in children than Urea and Scr. Utility of high-dose of glucocorticoid may influence the levels of cystatin C.