Corrao A M, Lisi G, Di Pasqua G, Guizzardi M, Marino N, Ballone E, Chiesa P Lelli
Pediatric Surgery Unit, "Spirito Santo" Hospital of Pescara, Pescara, Italy.
J Urol. 2006 Jan;175(1):303-9. doi: 10.1016/S0022-5347(05)00015-7.
Cystatin C has been suggested as a simple method of estimating GFR more accurately than creatinine in children. We compared the diagnostic accuracy of cystatin C with serum creatinine and the Schwartz formula for estimating GFR in patients with UTMs.
We prospectively compared 72 patients with UTMs (20 days to 36 months old, 58 males and 14 females) with a group of 72 healthy controls (10 days to 48 months old, 53 males and 19 females). All patients underwent nuclear medicine clearance investigations with (99m)Tc DTPA.
Serum concentration of cystatin C revealed a higher correlation with (99m)Tc DTPA (r = 0.62, p <0.001) than serum concentration of creatinine (r = 0.30, p <0.01) or Schwartz formula (r = 0.51, p <0.001). These results were more evident in patients with uropathy (19) with mild renal impairment. Agreement between methods was assessed using Bland Altman analysis. Mean differences between GFR calculated with (99m)Tc DTPA and cystatin C based GFR estimation or Schwartz formula were -2.6% +/- 46.7% and -73.4% +/- 53.6%, respectively. Diagnostic accuracy in identifying decreased GFR measured as AUC was always highest for cystatin C but hardly sufficient for the 3 variables. Cystatin C performed better in the 0 to 6-month-olds (0.70 +/- 0.08 for cystatin C, 0.58 +/- 0.07 for Schwartz estimate) and patients older than 12 months (0.82 +/- 0.09 for cystatin C, 0.65 +/- 0.11 for Schwartz estimate).
Cystatin C proved to be a superior marker rate over serum creatinine in estimating glomerular filtration in children younger than 3 years with UTMs and mild renal impairment, thus, offering a more specific and practical measure for monitoring GFR.
胱抑素C已被认为是一种比肌酐更准确地估算儿童肾小球滤过率（GFR）的简单方法。我们比较了胱抑素C与血清肌酐以及施瓦茨公式在估算上尿路畸形（UTM）患者GFR方面的诊断准确性。
我们前瞻性地比较了72例UTM患者（年龄20天至36个月，男58例，女14例）和72例健康对照者（年龄10天至48个月，男53例，女19例）。所有患者均接受了用（99m）锝-二乙三胺五乙酸（Tc DTPA）进行的核医学清除率检查。
胱抑素C的血清浓度与Tc DTPA的相关性（r = 0.62，p <0.001）高于血清肌酐浓度（r = 0.30，p <0.01）或施瓦茨公式（r = 0.51，p <0.001）。这些结果在患有轻度肾功能损害的19例肾病患者中更为明显。使用布兰德-奥特曼分析评估了各方法之间的一致性。用Tc DTPA计算的GFR与基于胱抑素C的GFR估算值或施瓦茨公式之间的平均差异分别为-2.6%±46.7%和-73.4%±53.6%。以曲线下面积（AUC）衡量，胱抑素C在识别降低的GFR方面的诊断准确性始终最高，但这三个变量的准确性均不足。胱抑素C在0至6个月大的婴儿（胱抑素C为0.70±0.08，施瓦茨估算值为0.58±0.07）和12个月以上的患者（胱抑素C为0.82±0.09，施瓦茨估算值为0.65±0.11）中表现更好。
在估算患有UTM且有轻度肾功能损害的3岁以下儿童的肾小球滤过率时，胱抑素C被证明是比血清肌酐更优的标志物，因此，为监测GFR提供了一种更具特异性和实用性的方法。
