Cystatin C assay for the detection of renal dysfunction in Chinese renal transplant recipients

Background: Accurate and rapid assessment of kidney function in patients after renal transplantation is of major significance. We investigated whether cystatin C can accurately reflect creatinine clearance over the entire range of kidney graft function. The performance of serum cystatin C as a screening marker of reduced creatinine clearance in renal transplantation was evaluated and compared to serum creatinine. Methods: Serum cystatin C, serum creatinine and creatinine clearance were measured in 103 adult renal transplant recipients. The cystatin C assay was performed using particle-enhanced immunonephelometry. Results: We demonstrated a significant linear correlation between 1/cystatin C and creatinine clearance over the entire range of transplant function, comparable to that of creatinine. Cystatin C detected reduced creatinine clearance with higher sensitivity of 92.9% (95% CI 80.5-98.4%) than serum creatinine, 71.4% (95% CI 55.4-84.3%). From the receiver operating characteristic (ROC) plots, serum cystatin C is superior to serum creatinine at 90% and 95% sensitivity. Conclusions: Serum cystatin C accurately reflects creatinine clearance over the entire range of transplant kidney function and is more efficacious than serum creatinine to detect reduced creatinine clearance in renal transplant recipients. (C) 2002 Elsevier Science B.V. All rights reserved.