Pöge U, Gerhardt T, Stoffel-Wagner B, Palmedo H, Klehr H U, Sauerbruch T, Woitas R P
Department of Internal Medicine I, University of Bonn, Bonn, Germany.
Kidney Int. 2006 Jul;70(1):204-10. doi: 10.1038/sj.ki.5001502. Epub 2006 May 24.
Cystatin C (Cys C) has been shown to be an alternative marker of renal function. However, estimation of the glomerular filtration rate (GFR) based on Cys C has received little attention. Recently, several Cys C-based equations were developed in different patient cohorts. To date, the benefit of a Cys C-based GFR calculation in patients after renal transplantation (RTx) remains to be elucidated. We compared the diagnostic accuracy of three Cys C-based formulae (Larsson, Hoek, Filler which used an immunonephelometric method) with the results of the Modification of Diet in Renal Disease (MDRD) formula. GFR was measured by means of technetium-diethylenetriamine pentaacetic acid ((99m)Tc-DTPA) clearance in 108 consecutive patients after RTx. Correlation coefficients of all calculated GFR estimates with the true GFR were high but did not differ significantly from one another (0.83-0.87). The MDRD and Filler equations overestimated GFR significantly, whereas the Larsson equation significantly underestimated GFR. Bias of the Hoek formula was negligible. Precision of the Hoek (8.9 ml/min/1.73 m(2)) and Larsson equations (9.6 ml/min/1.73 m(2)) were significantly better than MDRD equations (11.4 ml/min/1.73 m(2); P< or =0.035 each). Accuracy within 30% of real GFR was 67.0 and 65.1% for the MDRD and Filler formulae, and 77.1% for the Larsson and Hoek formulae, respectively. Accuracy within 50% of true GFR for the Hoek formula (97.2%) was better than for the MDRD equations (85.3%). Cys C-based formulae may provide a better diagnostic performance than creatinine-based equations in GFR calculation after RTx.
胱抑素C（Cys C）已被证明是肾功能的替代标志物。然而，基于胱抑素C估算肾小球滤过率（GFR）却很少受到关注。最近，在不同患者队列中开发了几个基于胱抑素C的方程。迄今为止，肾移植（RTx）后患者基于胱抑素C计算GFR的益处仍有待阐明。我们将三个基于胱抑素C的公式（采用免疫比浊法的拉尔森公式、赫克公式、菲勒公式）的诊断准确性与肾脏病饮食改良（MDRD）公式的结果进行了比较。通过锝-二乙三胺五乙酸（（99m）Tc-DTPA）清除率对108例连续肾移植术后患者的GFR进行了测量。所有计算得到的GFR估计值与真实GFR的相关系数都很高，但彼此之间差异不显著（0.83 - 0.87）。MDRD公式和菲勒公式显著高估了GFR，而拉尔森公式则显著低估了GFR。赫克公式的偏差可忽略不计。赫克公式（8.9 ml/min/1.73 m²）和拉尔森公式（9.6 ml/min/1.73 m²）的精密度显著优于MDRD公式（11.4 ml/min/1.73 m²；均P≤0.035）。对于MDRD公式和菲勒公式，GFR在真实值30%以内的准确率分别为67.0%和65.1%，而拉尔森公式和赫克公式分别为%77.1%。赫克公式在真实GFR 50%以内的准确率（97.2%）优于MDRD公式（85.3%）。在肾移植术后GFR计算中，基于胱抑素C的公式可能比基于肌酐的公式具有更好的诊断性能。
