Ritter D A, Kenny J D
J Pediatr. 1985 Jan;106(1):118-21. doi: 10.1016/s0022-3476(85)80479-0.
The effect of gestational age on bilirubin binding was studied using cord serum from 22 preterm infants and 13 term infants and serum from 17 adults. Using the peroxidase oxidation method, a bilirubin titration curve was obtained by adding bilirubin to serum and measuring the apparent unbound bilirubin concentration. The resultant curve was analyzed using the least-squares fit of the empiric equation Y = aXb. After correction for albumin concentration by plotting the apparent unbound bilirubin concentration against the molar ratio of total bilirubin/albumin, term and preterm infants had identical titration curves, which remained inferior to that of adults. In addition, the apparent primary bilirubin association constant Ka'1 was similar for all infants but was two to three times less than that for adults. We conclude that bilirubin binding by cord serum is equivalent regardless of gestational age. However, adult serum binds bilirubin qualitatively better than does serum from infants of all gestational ages. We suggest that the adverse effect of prematurity on bilirubin binding noted in previous studies may have reflected postnatal complications rather than gestational age as such.
利用22例早产儿、13例足月儿的脐血血清以及17例成年人的血清，研究了胎龄对胆红素结合的影响。采用过氧化物酶氧化法，通过向血清中添加胆红素并测量表观未结合胆红素浓度，获得胆红素滴定曲线。使用经验方程Y = aXb的最小二乘法拟合对所得曲线进行分析。通过绘制表观未结合胆红素浓度与总胆红素/白蛋白摩尔比的关系图来校正白蛋白浓度后，足月儿和早产儿具有相同的滴定曲线，但仍低于成年人的滴定曲线。此外，所有婴儿的表观一级胆红素缔合常数Ka'1相似，但比成年人的低两到三倍。我们得出结论，无论胎龄如何，脐血血清对胆红素的结合能力是相同的。然而，成人血清对胆红素的结合在质量上优于所有胎龄婴儿的血清。我们认为，先前研究中提到的早产对胆红素结合的不利影响可能反映的是出生后的并发症，而非胎龄本身。
