Sickle Cell Unit, Tropical Medicine Research Institute, University of the West Indies, Mona Campus, Kingston, Jamaica.
PLoS One. 2013 Jul 19;8(7):e69922. doi: 10.1371/journal.pone.0069922. Print 2013.
Various estimating equations have been developed to estimate glomerular filtration rate (GFR) for use in clinical practice. However, the unique renal physiological and pathological processes that occur in sickle cell disease (SCD) may invalidate these estimates in this patient population. This study aims to compare GFR estimated using common existing GFR predictive equations to actual measured GFR in persons with homozygous SCD. If the existing equations perform poorly, we propose to develop a new estimating equation for use in persons with SCD.
98 patients with the homozygous SS disease (55 females: 43 males; mean age 34±2.3 years) had serum measurements of creatinine, as well as had GFR measured using (99m)Tc-DTPA nuclear renal scan. GFR was estimated using the Modification of Diet in Renal Disease (MDRD), Cockcroft-Gault (CG), and the serum creatinine based CKD-EPI equations. The Bland-Altman limit of agreement method was used to determine agreement between measured and estimated GFR values. A SCD-specific estimating equation for GFR (JSCCS-GFR equation) was generated by means of multiple regression via backward elimination.
The mean measured GFR±SD was 94.9±27.4 mls/min/1.73 m(2) BSA, with a range of 6.4-159.0 mls/min/1.73 m(2). The MDRD and CG equations both overestimated GFR, with the agreement worsening with higher GFR values. The serum creatinine based CKD-EPI equation performed relatively well, but with a systematic bias of about 45 mls/min. The new equation developed resulted in a better fit to our sickle cell disease data than the MDRD equation.
Current estimating equations, other than the CKD-EPI equation, do not perform very accurately in persons with homozygous SS disease. A fairly accurate estimating equation, suitable for persons with GFR >60 mls/min/1.73 m(2) has been developed from our dataset and validated within a simulated dataset.
已经开发出各种估算方程来估算肾小球滤过率（GFR），以便在临床实践中使用。然而，镰状细胞病（SCD）中发生的独特的肾脏生理和病理过程可能会使这些估计值在该患者群体中失效。本研究旨在比较使用常见的现有 GFR 预测方程估算的 GFR 与纯合 SS 疾病患者的实际测量 GFR。如果现有方程表现不佳，我们建议为 SCD 患者开发新的估算方程。
98 名纯合 SS 疾病患者（55 名女性：43 名男性；平均年龄 34±2.3 岁）进行了血清肌酐测量，以及使用（99m）Tc-DTPA 核肾扫描测量 GFR。使用改良肾脏病饮食研究（MDRD）、 Cockcroft-Gault（CG）和基于血清肌酐的 CKD-EPI 方程估算 GFR。使用 Bland-Altman 协议限法确定测量和估计 GFR 值之间的一致性。通过逐步回归法生成用于估算 GFR 的 SCD 特异性方程（JSCCS-GFR 方程）。
平均测量 GFR±SD 为 94.9±27.4 mls/min/1.73 m(2)BSA，范围为 6.4-159.0 mls/min/1.73 m(2)。MDRD 和 CG 方程均高估了 GFR，随着 GFR 值的升高，一致性变差。基于血清肌酐的 CKD-EPI 方程表现相对较好，但存在约 45 mls/min 的系统偏差。与 MDRD 方程相比，新开发的方程更适合我们的镰状细胞病数据。
除了 CKD-EPI 方程外，目前的估算方程在纯合 SS 疾病患者中的表现并不非常准确。已经从我们的数据集开发了一个相当准确的估算方程，适用于 GFR>60 mls/min/1.73 m(2)的患者，并在模拟数据集中进行了验证。
