Application of serum cystatin-C for renal function in chronic kidney disease

Objective To compare of the serum Cystatin-C and serum creatinine with Glomerularflltrationrate measured by clearance of 99 Tc m-DTPA.Methods The Glomerularflltrationrate was measured by clearance of 99 Tc m-DTPA and the serum Cystatin-C and serum creatinine(Scr) were also measured in 38 patients with chronic kidney disease.Accuracy,sensitivity and specificity of serum Cystatin-C for renal function were evaluated by receiver operating characteristic curve(Roc curve).Results The mean values in serum CysC、Scr and GFR in 38 patients were(1.67±0.25)mg/L,(198.77±98.01)μmol/L and(50.55±35.62)mL/(min.1.73 m2).There were negative correlations between CysC、Scr and GFR.The correlation coefficients were-0.74 and-0.61.Cys-C of the Roc area under the curve(AUC) were 0.822,0.857,0.920;Scr area under the Roc curves were 0.775,0.801 and 0.922 at the boundary points of GFR 90 mL/(min.1.73 m2),GFR 60 mL/(min.1.73 m2) and GFR 30 mL/(min.1.73 m2) respectively.Conclusion Compared with serum creatinine,the serum Cystatin-C is a good endogenous targets evaluation of GFR,and can better reflect the early changes in GFR.