Cole M, Price L, Parry A, Keir M J, Pearson A D J, Boddy A V, Veal G J
Northern Institute for Cancer Research, Medical School, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK.
Br J Cancer. 2004 Jan 12;90(1):60-4. doi: 10.1038/sj.bjc.6601484.
Estimation of glomerular filtration rate (GFR) using the clearance of chromium 51 EDTA ((51)Cr-EDTA) (or other radiolabelled isotopes) is reliable, but invasive and not always practicable. Mathematical models have been devised for estimating GFR using readily obtainable patient characteristics. Unfortunately, these models were developed using various patient populations and may not provide the optimal prediction of GFR in children with cancer. The current study uses population pharmacokinetics to determine the relationship between (51)Cr-EDTA clearance, and patient covariates in 50 paediatric cancer patients. These models were validated using a separate group of 43 children and were compared with previously published models of renal function. Body size was the major determinant of (51)Cr-EDTA clearance and inclusion of weight or surface area reduced the residual variability between individuals (coefficient of variation) from 61 to 32%. Serum creatinine was the only other parameter that significantly improved the model. Mean percentage error values of -5.0 and -1.1% were observed for models including weight alone or weight and creatinine, respectively, with precision estimates of 21.7 and 20.0%. These simple additive models provide a more rationale approach than the use of complex formulae, involving additional parameters, to predict renal function.
利用铬51标记的乙二胺四乙酸（⁵¹Cr-EDTA）（或其他放射性标记同位素）的清除率来估算肾小球滤过率（GFR）是可靠的，但具有侵入性且并非总是可行。已经设计出数学模型，利用易于获取的患者特征来估算GFR。不幸的是，这些模型是使用不同的患者群体开发的，可能无法为癌症患儿的GFR提供最佳预测。本研究采用群体药代动力学来确定50例儿科癌症患者中⁵¹Cr-EDTA清除率与患者协变量之间的关系。这些模型在另一组43名儿童中进行了验证，并与先前发表的肾功能模型进行了比较。体型是⁵¹Cr-EDTA清除率的主要决定因素，纳入体重或体表面积可将个体间的残余变异性（变异系数）从61%降低至32%。血清肌酐是唯一能显著改善模型的其他参数。仅包含体重或同时包含体重和肌酐的模型的平均百分比误差值分别为-5.0%和-1.1%，精确估计值分别为21.7%和20.0%。这些简单的加法模型比使用涉及额外参数的复杂公式来预测肾功能提供了更合理的方法。
