Abstract

The accurate assessment of glomerular filtration rate (GFR) is important in the follow-up of kidney transplant recipients in order to identify graft dysfunction. A number of formulas have been proposed to calculate GFR from endogenous plasma markers such as creatinine or cystatin C since measuring GFR using exogenous markers is troublesome. This study compares and evaluates the ability of four different GFR formulas to estimate kidney graft function and to detect changes in GFR in kidney transplant recipients. The study included patients from the prospective, multicenter CONTEXT trial in kidney transplant recipients. GFR was measured using plasma clearance of ⁵¹Cr-EDTA and estimated using the MDRD, CKD-EPI Creatinine, CKD-EPI Cystatin C and CKD-EPI Cystatin C + Creatinine equations at three (n = 83) and twelve (n = 65) months post-transplantation. For each formula mean bias, precision, and accuracy were evaluated. The MDRD equation had the lowest mean bias (0.2 ml/min/1.73 m²), whereas the CKD-EPI Cystatin C + Creatinine equation had the highest precision (8 ml/min/1.73 m²). Accuracy at three months were similar for all equations (P30 > 80%) except for the CKD-EPI Cystatin C equation, which performed poorer (P30 = 55%). None of the formulas evaluated avoided misclassification of changes in GFR. The most optimal combination of precision and accuracy suggests the use of CKD-EPI Creatinine + Cystatin C equation in kidney transplant recipients.

摘要

肾小球滤过率 (GFR) 的准确评估对于肾移植受者的随访非常重要，以便识别移植物功能障碍。由于使用外源性标记物测量 GFR 很麻烦，因此已提出许多公式来根据内源性血浆标记物（例如肌酐或胱抑素 C）计算 GFR。本研究比较和评估四种不同 GFR 公式估计移植肾功能和检测肾移植受者 GFR 变化的能力。该研究包括来自肾移植受者的前瞻性多中心 CONTEXT 试验的患者。^使用51 Cr-EDTA的血浆清除率测量 GFR ，并使用 MDRD、CKD-EPI 肌酐、CKD-EPI 胱抑素 C 和 CKD-EPI 胱抑素 C + 肌酐方程在三个（n = 83) 和移植后 十二 ( n = 65) 个月。对于每个公式，均值偏差、精确度和准确度都进行了评估。MDRD 方程具有最低的平均偏差 (0.2 ml/min/1.73 m ² )，而 CKD-EPI 胱抑素 C + 肌酐方程具有最高的精度 (8 ml/min/1.73 m ² )。除了 CKD-EPI 胱抑素 C 方程表现较差 (P30 = 55%) 之外，所有方程在三个月时的准确度都相似 (P30 > 80%)。所评估的公式均未避免对 GFR 变化的错误分类。精确度和准确度的最佳组合建议在肾移植受者中使用 CKD-EPI 肌酐 + 胱抑素 C 方程。