基于半胱氨酸蛋白酶抑制素C建立的肾小球滤过率预测公式的适用性研究

Application of Cystatin C-based formulas for prediction of glomerular filtration rate

目的探讨基于CysC建立的GFR预测公式在我国CKD患者及其分期中的适用性。方法选择2007年9月至2009年7月我国不同区域（北京、上海、大连、长沙）4家三级甲等医院就诊的CKD患者176例，其中男90例，女86例。通过双血浆法99mTc-二乙三胺五乙酸（99mTc—DTPA）血浆清除率测定入选对象rGFR。应用PETIA和PENIA两种方法检测血浆CysC浓度，分别将Larsson公式、Grubb公式、Hoek公式、Filler公式、Rule公式、Stevens公式和Hojs公式的eGFR与rGFR进行一致性、偏差、精确度、准确度和分期正确性比较。结果176例CKD患者rGFR水平为[40．70（19．09～86．49）]ml·min^-1·（1．73m^2）^-1。同一公式采用不同CysC检测方法计算的eGFR结果差异有统计学意义（P均〈0．01）。各公式的eGFR与rGFR存在相关，组内相关系数（ICC）在0．874～0．938之间。所有预测公式应用两种方法检测eGFR的30％准确性均低于60％；CKD各期正确分期百分比不理想，2～4期正确分期百分比低于65％。在CKDI期，由PENIA法建立的预测公式低估GFR水平；在CKD5期，由两种方法建立的公式均高估GFR水平。结论本研究验证的8个基于CysC建立的GFR预测公式不是我国CKD人群GFR预测的理想公式，不能直接应用于我国CKD患者，需综合种群殿年龄等名方面因素进一步修正基于CysC的GFR预测公式。

Objective To investigate the applicability of Cys C-based formulas for prediction of GFR in Chinese patients with CKD. Methods A total of 176 adult patients with CKD including 90 males and 86 females collected from 4 hospitals located in different geographic regions of China （Beijing, Shanghai, Dalian and Changsha） were enrolled in this study from September 2007 to July 2009. The rGFR was measured using 99mTc-DTPA clearance rate two-sample method. Cystantic C was measured by PETIA and PENIA respectively. The results of eGFR in the Larsson formula, Grubb formula, Hoek formula, Filler formula, Stevens formula and Hojs formula were compared with the rGFR to evaluate the calculation coherence, bias, precision, accuracy and the performance of correct phasing of the formulas. Results The mean 99mTc-DTPA clearance was [40.70 （19.09 - 86. 49） ] ml·min^-1·（1.73m^2）^-1.Significant difference was witnessed in the evaluation of GFR estimation formulas calculated by PETIA and PENIA （ P 〈0. 01 ）. ICC and Spearman correlation analysis revealed a significant correlation between eGFR and rGFR. The ICCs of eGFR and rGFR ranged from 0. 874 to 0. 938. Compared with rGFR, the 30% accuracy of all the eight evaluation formulas using PETIA and PENIA method were lower than 60%. The percentages of correct phasing in all the 5 stages of CKD were not ideal. With these formulas, percentages of correct phasing from CKD stage 2 to CKD stage 4 were lower than 65%. The eGFRs were underestimated by formulas evaluated by PENIA in CKD stage 1. All the eGFRs were overestimated remarkably by all equations in CKD stage 5. Conclusions None of the eight Cys C based formulas are ideal for estimation of GFR in Chinese CKD patients, and they can not be applied to Chinese patients directly. For this patient population, further studies will be needed to develop a more accurate Cys C-based GFR estimation formula that includes ethnicity, age and other factors.