The Clinical Usefulness of Cystatin C in Evaluating Renal Function in Children with Various Renal Diseases

Kim, Khi Joo; Kim, Joung A; Shin, Jae Il; Hwang, You Sik; Cheung, Il Chun; Lee, Jae Seung; Lim, Jong Baeck

Abstract

PURPOSE: GFR(glomerular filtration rate) is a fundamental parameter in detecting renal impairment and predicts the progression of renal disease. Because serum creatinine has several disadvantages, serum cystatin C has been recently proposed as a new endogenous marker for GFR. We compared serum cystatin C with creatinine and creatinine clearance to investigate the clinical usefulness of cystatin C.
METHODS
We retrospectively analyzed 46 patients(60 case numbers) who had various renal diseases and classified them into 3 groups according to creatinine clearance(Group 1 : CrCl <40 mL/min/1.73m2, Group 2 : CrCl 40-60 mL/min/1.73m2, Group 3 : CrCl >60 mL/min/1.73 m2). We measured serum creatinine, cystatin C and creatinine clearance and also analyzed the correlations among them.
RESULTS
Serum cystatin C and creatinine showed a similar correlation to creatinine clearance (r=0.685, r=0.640, respectively) and showed similar diagnostic accuracy in detecting decreased GFR(AUC, cystatin C 0.829 vs. creatinine 0.826, P=0.848). Serum cystatin C showed a greater sensitivity for detecting a decreased GFR than creatinine in Group 2 and 3(Group 1 : 100% vs. 100%, Group 2 : 70% vs. 35%, Group 3 : 46% vs. 15%).
CONCLUSIONS
Serum cystatin C could be a useful endogenous marker for GFR and would be superior to serum creatinine in early detection of renal impairment in pediatric patients with renal diseases.