Hojs Radovan, Bevc Sebastjan, Ekart Robert, Gorenjak Maksimiljan, Puklavec Ludvik
Department of Nephrology, Clinical Department of Internal Medicine, Teaching Hospital Maribor, Maribor, Slovenia.
Nephrol Dial Transplant. 2006 Jul;21(7):1855-62. doi: 10.1093/ndt/gfl073. Epub 2006 Mar 8.
Estimation of the glomerular filtration rate (GFR) is essential for the evaluation of patients with chronic kidney disease (CKD). Recently, serum cystatin C was proposed as a new endogenous marker of GFR and in our study its diagnostic accuracy was compared with that of other markers of GFR.
In this study, 164 patients with CKD stages 2-3 (GFR 30-89 ml/min/1.73 m2), who had performed 51Cr-labelled ethylenediaminetetra-acetic acid clearance, were enrolled. In each patient, serum creatinine and serum cystatin C were determined. Creatinine clearance was calculated using the Cockcroft-Gault (C&G) and the modification of diet in renal disease (MDRD) formulas.
The mean 51CrEDTA clearance was 57 ml/min/1.73 m2, the mean serum creatinine 149 micromol/l and the mean serum cystatin C 1.74 mg/l. We found significant correlation between 51CrEDTA clearance and serum creatinine (R = -0.666), serum cystatin C (R = -0.792), reciprocal of serum creatinine (R = 0.628), reciprocal of serum cystatin C (R = 0.753) and calculated creatinine clearance from the formulas C&G (R = 0.515) and MDRD formulas (R = 0.716). The receiver operating characteristic (ROC) curve analysis (cut-off for GFR 60 ml/min/1.73 m2) showed that serum cystatin C had a significantly higher diagnostic accuracy than serum creatinine (P = 0.04) and calculated creatinine clearance from the C&G formula (P < 0.0001), though only in female patients. No difference in diagnostic accuracy was found between serum cystatin C and creatinine clearance calculated from the MDRD formula.
Our results indicate that serum cystatin C is a reliable marker of GFR in patients with mildly to moderately impaired kidney function and has a higher diagnostic accuracy than serum creatinine and calculated creatinine clearance from the C&G formula in female patients.
肾小球滤过率（GFR）的评估对于慢性肾脏病（CKD）患者至关重要。最近，血清胱抑素C被提议作为GFR的一种新的内源性标志物，在我们的研究中，将其诊断准确性与其他GFR标志物进行了比较。
本研究纳入了164例2-3期CKD患者（GFR 30-89 ml/min/1.73 m²），这些患者均已进行了51Cr标记的乙二胺四乙酸清除率检测。测定了每位患者的血清肌酐和血清胱抑素C。使用Cockcroft-Gault（C&G）公式和肾脏病饮食改良（MDRD）公式计算肌酐清除率。
51CrEDTA清除率的平均值为57 ml/min/1.73 m²，血清肌酐平均值为149 μmol/L，血清胱抑素C平均值为1.74 mg/L。我们发现51CrEDTA清除率与血清肌酐（R = -0.666）、血清胱抑素C（R = -0.792）、血清肌酐的倒数（R = 0.628）、血清胱抑素C的倒数（R = 0.753）以及根据C&G公式（R = 0.515）和MDRD公式计算的肌酐清除率（R = 0.716）之间存在显著相关性。受试者工作特征（ROC）曲线分析（GFR的截断值为60 ml/min/1.73 m²）显示，血清胱抑素C的诊断准确性显著高于血清肌酐（P = 0.04）和根据C&G公式计算的肌酐清除率（P < 0.0001），不过仅在女性患者中如此。血清胱抑素C与根据MDRD公式计算的肌酐清除率在诊断准确性上未发现差异。
我们的结果表明，血清胱抑素C是肾功能轻度至中度受损患者GFR的可靠标志物，并且在女性患者中，其诊断准确性高于血清肌酐和根据C&G公式计算的肌酐清除率。
