Harmoinen A, Ylinen E, Ala-Houhala M, Janas M, Kaila M, Kouri T
Centre for Laboratory Medicine, Tampere University Hospital, Finland.
Pediatr Nephrol. 2000 Nov;15(1-2):105-8. doi: 10.1007/s004670000421.
Cystatin C is a non-glycated, 13-kDa basic protein produced by all nucleated cells. Recent studies have indicated that the plasma concentration of cystatin C is a better marker for glomerular filtration rate (GFR) than plasma creatinine, which is most commonly used for this purpose. We established reference values for plasma cystatin C in pre- or full-term infants and children. For comparison we also measured the creatinine concentration in the same samples. Cystatin C was measured by a commercially available immunoturbidimetric method with a Hitachi 704 analyzer in sera obtained from 58 pre-term infants, 50 full-term infants and 299 older children (132 girls, 167 boys, median age 4.17 years, range 8 days to 16 years). No sex differences were found. The pre-term infants had higher cystatin C concentrations (mean 1.88 mg/l, SD 0.36 mg/l) than the full-term (mean 1.70 mg/l, SD 0.26 mg/l, P=0.0145). The reference interval for pre-term infants calculated non-parametrically was 1.34-2.57 mg/l and for full-term infants 1.36-2.23 mg/l. The cystatin C concentration decreased rapidly after birth, and above 3 years of age did not depend on age. The reference interval for children 3-16 years of age calculated non-parametrically was 0.51-1.31 mg/l. Younger children (<1 year: 0.75-1.87 mg/l; 1-3 years: 0.68-1.60 mg/l) had slightly, but significantly, higher plasma cystatin C levels.
胱抑素C是一种由所有有核细胞产生的非糖化碱性蛋白，分子量为13 kDa。最近的研究表明，与最常用于此目的的血肌酐相比，血浆胱抑素C浓度是肾小球滤过率（GFR）更好的标志物。我们建立了早产或足月婴儿及儿童血浆胱抑素C的参考值。为作比较，我们还测定了相同样本中的肌酐浓度。采用市售免疫比浊法，使用日立704分析仪，对58例早产儿、50例足月儿和299例大龄儿童（132例女孩，167例男孩，中位年龄4.17岁，范围8天至16岁）的血清进行胱抑素C测定。未发现性别差异。早产儿的胱抑素C浓度（均值1.88 mg/l，标准差0.36 mg/l）高于足月儿（均值1.70 mg/l，标准差0.26 mg/l，P = 0.0145）。非参数计算得出的早产儿参考区间为1.34 - 2.57 mg/l，足月儿为1.36 - 2.23 mg/l。出生后胱抑素C浓度迅速下降，3岁以上则与年龄无关。非参数计算得出的3 - 16岁儿童参考区间为0.51 - 1.31 mg/l。年龄较小的儿童（<1岁：0.75 - 1.87 mg/l；1 - 3岁：0.68 - 1.60 mg/l）血浆胱抑素C水平略高，但有显著差异。
