Hari Pankaj, Ramakrishnan Lakshmy, Gupta Ruby, Kumar Rakesh, Bagga Arvind
Departments of Pediatrics, *Cardiac Biochemistry and #Nuclear Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi. India. Correspondence to: Dr Pankaj Hari, Professor, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029, India.
Indian Pediatr. 2014 Apr;51(4):273-7. doi: 10.1007/s13312-014-0400-5.
To compare performance of combined creatinine and cystatin C-based equation with equations based on either cystatin C or creatinine alone, in early chronic kidney disease.
Diagnostic accuracy study.
Tertiary-care hospital.
One hundred children with chronic kidney disease who underwent 99mTc diethylenetriamine pentaacetic acid (DTPA) glomerular filtration rate measurement.
Estimating equations for glomerular filtration rate (GFR) based on serum cystatin C alone and in combination with serum creatinine were generated using regression analyses. These equations and the creatinine-based equation [0.42 x height/creatinine] were validated in 42 children with glomerular filtration rate between 60 and 90 mL/min/1.73 m2. Bias, precision and accuracy of estimating equations using DTPA glomerular filtration rate as gold standard.
Cystatin C-based equation (GFR=96.9 - 30.4 x cystatin) overestimated while the combined cystatin C-and creatinine-based equation [GFR=11.45 x (height/creatinine) 0.356 x (1/cystatin) 0.188] underestimated the measured GFR. Cystatin C-based equation had less bias (1.9 vs. 12.4 ml/min/1.73 m2), and higher precision (13.1 vs. 25.6 mL/min/1.73 m2) and accuracy (92.1% vs. 75.7%) than creatinine-based equation. The combined cystatin C and creatinine equation had bias (-1.4 mL/min/1.73 m2) precision (15.2 mL/min/1.73 m2) and accuracy (91.2%) similar to cystatin C-based equation.
Cystatin C-based equation has a better performance in estimating glomerular filtration rate than creatinine-based equation in children with early chronic kidney disease. Addition of creatinine equation does not improve the performance of the cystatin C-based equation.
比较基于肌酐和胱抑素C的联合方程与仅基于胱抑素C或肌酐的方程在早期慢性肾病中的表现。
诊断准确性研究。
三级医疗医院。
100例接受99mTc二乙三胺五乙酸（DTPA）肾小球滤过率测量的慢性肾病儿童。
通过回归分析生成基于血清胱抑素C单独以及与血清肌酐联合的肾小球滤过率（GFR）估算方程。这些方程以及基于肌酐的方程[0.42×身高/肌酐]在42例肾小球滤过率为60至90 mL/min/1.73 m2的儿童中进行验证。以DTPA肾小球滤过率作为金标准评估估算方程的偏差、精密度和准确性。
基于胱抑素C的方程（GFR = 96.9 - 30.4×胱抑素）高估了测量的GFR，而基于胱抑素C和肌酐的联合方程[GFR = 11.45×（身高/肌酐）0.356×（1/胱抑素）0.188]低估了测量的GFR。基于胱抑素C的方程比基于肌酐的方程偏差更小（1.9对12.4 ml/min/1.73 m2），精密度更高（13.1对25.6 mL/min/1.73 m2），准确性更高（92.1%对75.7%）。胱抑素C和肌酐联合方程的偏差（-1.4 mL/min/1.73 m2）、精密度（15.2 mL/min/1.73 m2）和准确性（91.2%）与基于胱抑素C的方程相似。
在早期慢性肾病儿童中，基于胱抑素C的方程在估算肾小球滤过率方面比基于肌酐的方程表现更好。添加肌酐方程并不能改善基于胱抑素C的方程的表现。
