Department of Paediatrics, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.
Pediatr Nephrol. 2010 Mar;25(3):485-90. doi: 10.1007/s00467-009-1355-y. Epub 2009 Dec 1.
Beta-trace protein (BTP) is a novel marker of glomerular filtration rate (GFR). To date, no pediatric formula for calculating GFR based on BTP has been developed. We measured GFR, serum creatinine and BTP in 387 children who underwent 474 (99m)Tc-diethylene triamine pentaacetic acid renal scans. A BTP-based formula for estimating GFR was derived using stepwise linear regression analysis. A separate control group of 116 measurements in 99 children was used to validate the novel formula. A formula was also developed for each gender. The novel formula is: [formula: see text]. The Spearman rank correlation coefficient between the BTP-derived GFR estimate and the measured GFR was 0.80 [95% confidence interval (CI) 0.76-0.83], which is substantially better than that derived with the Schwartz formula (r = 0.70, 95% CI 0.65-0.74). The Bland-Altman analysis revealed a mean bias of 1.21% [standard deviation (SD) 28%] in the formula development dataset, which was virtually identical to the 1.03% mean bias (29.5% SD) in the validation group and no different from the Schwartz formula bias. The percentage of values within 10% (33.0 vs. 28.3%) and 30% deviation (76.8 vs. 72.6%) were better for BTP-based formula than for the Schwartz formula. Separate formulas according to gender did not perform better than that for the pediatric population. This BTP-based formula was found to estimate GFR with reasonable precision and provided improved accuracy over the Schwartz GFR formula.
β-痕迹蛋白（BTP）是肾小球滤过率（GFR）的一种新型标志物。迄今为止，尚未开发出基于 BTP 计算 GFR 的儿科公式。我们对 387 名接受 474（99m）Tc-二乙三胺五乙酸肾扫描的儿童测量了 GFR、血清肌酐和 BTP。使用逐步线性回归分析得出了基于 BTP 的 GFR 估算公式。使用来自 99 名儿童的 116 项独立对照测量来验证新公式。还为每个性别开发了一个公式。新公式为：[公式：见正文]。BTP 衍生的 GFR 估计值与实测 GFR 之间的 Spearman 秩相关系数为 0.80 [95%置信区间（CI）0.76-0.83]，明显优于 Schwartz 公式（r = 0.70，95%CI 0.65-0.74）。Bland-Altman 分析显示，在公式开发数据集中，公式的平均偏差为 1.21% [28%标准差]，与验证组中的 1.03%平均偏差（29.5%标准差）几乎相同，与 Schwartz 公式的偏差无差异。10%（33.0%与 28.3%）和 30%偏差（76.8%与 72.6%）内的数值百分比，BTP 公式比 Schwartz 公式更好。根据性别制定的单独公式并不比儿科人群的公式更好。该基于 BTP 的公式被发现可合理精确地估算 GFR，并比 Schwartz GFR 公式提供更高的准确性。
