Division of Renal Diseases and Hypertension, University of Minnesota, Minneapolis, MN, USA
Nephrol Dial Transplant. 2010 May;25(5):1653-61. doi: 10.1093/ndt/gfp668. Epub 2010 Jan 29.
How to best estimate glomerular filtration rate (GFR) in kidney transplant recipients on steroid-free immunosuppression has not been established.
Within 3 months of transplantation, iothalamate GFR (iGFR) was measured in 107 recipients on steroid-free and 27 on steroid-maintenance immunosuppression. A year later, a second GFR was performed. Serum creatinine was calibrated against a reference laboratory, and GFR was estimated (eGFR) using the re-expressed Cockcroft-Gault equation, eGFRCG; the Mayo Clinic equation, eGFRMC; the Modification of Diet in Renal Disease (MDRD) study equation, eGFRMDRD; and the newly introduced Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.
All models overestimated GFR regardless of steroid use or timing of GFR. In those not receiving steroids, eGFRCG was least biased: 1.85 +/- 15.2 ml/min at the first GFR and 0.23 +/- 15.2 ml/min at the second. eGFRMC and eGFRCKD-EPI were most biased and were within 30% of iGFR less than 60% of the time in contrast to eGFRCG which was within 30% of iGFR 80.2% of the time. eGFRMDRD was intermediate in its performance at the first GFR but was comparable to eGFRCG at the second measurement. Importantly, the four models had comparable but poor precision. Exposure to steroids for a whole year did not appreciably alter the models' bias or relative accuracy but resulted in a dramatic fall in their precision, R2 = 0.05-0.12.
GFR prediction equations overestimate measured GFR in recipients on and off steroid regimens. Long-term exposure to steroids results in a marked reduction in the precision of all models. In all, eGFRCG and eGFRMDRD are the two best available models.
在接受无类固醇免疫抑制治疗的肾移植受者中，如何最佳估计肾小球滤过率（GFR）尚未确定。
在移植后 3 个月内，对 107 例接受无类固醇免疫抑制治疗和 27 例接受类固醇维持免疫抑制治疗的患者进行碘海醇 GFR（iGFR）测量。一年后，进行第二次 GFR 检查。血清肌酐经参考实验室校准，并使用再表达的 Cockcroft-Gault 方程（eGFRCG）、Mayo 诊所方程（eGFRMC）、改良肾脏病饮食研究方程（eGFRMDRD）和新引入的慢性肾脏病流行病学合作方程（CKD-EPI）估算 GFR（eGFR）。
无论是否使用类固醇或 GFR 测量时间，所有模型均高估了 GFR。在未接受类固醇治疗的患者中，eGFRCG 的偏差最小：第一次 GFR 为 1.85 +/- 15.2ml/min，第二次 GFR 为 0.23 +/- 15.2ml/min。eGFRMC 和 eGFRCKD-EPI 的偏差最大，在不到 60%的时间内，它们与 iGFR 的差值小于 30%，而 eGFRCG 在 80.2%的时间内与 iGFR 的差值小于 30%。eGFRMDRD 在第一次 GFR 时的表现居中，但在第二次测量时与 eGFRCG 相当。重要的是，这四个模型的精度相当，但都较差。接受一整年的类固醇治疗并不会显著改变模型的偏差或相对准确性，但会显著降低其精度，R2=0.05-0.12。
在接受和不接受类固醇方案的受者中，GFR 预测方程均高估了测量的 GFR。长期暴露于类固醇会导致所有模型的精度显著降低。总体而言，eGFRCG 和 eGFRMDRD 是两种最可用的模型。
