Department of Pediatrics, School of Medicine, Stanford University, Stanford, CA, USA.
Pediatrics. 2010 Sep;126(3):e639-43. doi: 10.1542/peds.2010-0614. Epub 2010 Aug 2.
This study tests the hypothesis that the hourly rate of increase in plasma bilirubin concentration (DeltaBT) would increase significantly with increasing binding avidity.
The plasma total bilirubin concentration (B(T)), unbound bilirubin concentration, and albumin concentration values for healthy newborns with jaundice (<or=100 hours of age, >or=35 weeks of gestation, and >or=2.5 kg at birth) were obtained from medical records. DeltaBT (in milligrams per deciliter per hour) was calculated as the slope of BT versus age (in hours). Binding avidity was quantified as the product of the albumin concentration and its bilirubin binding constant (K). Linear correlation was used to test the hypothesis that DeltaBT would increase significantly with K.albumin concentration.
The ranges of BT, unbound bilirubin concentration, albumin concentration, and K values for the 21 patients studied were 7.6 to 28.5 mg/dL, 0.53 to 2.52 microg/dL, 2.9 to 4.6 g/dL, and 38 to 163 L/micromol, respectively. DeltaBT correlated significantly with K.albumin concentration (r2=0.23; P=.026).
Plasma bilirubin binding avidity contributes significantly to DeltaBT. This component of DeltaBT is associated with a lower risk of bilirubin neurotoxicity, and studies aimed at incorporating plasma bilirubin binding avidity measurements into the algorithms used for management of newborn jaundice seem warranted.
本研究检验了这样一个假设，即随着结合亲和力的增加，血浆胆红素浓度的每小时增加率（ΔBT）将显著增加。
从病历中获取了患有黄疸的健康新生儿（<100 小时龄、>35 周胎龄和>2.5kg 出生体重）的血浆总胆红素浓度（B（T））、未结合胆红素浓度和白蛋白浓度值。ΔBT（每小时每分升毫克数）计算为 BT 与年龄（小时）的斜率。结合亲和力通过白蛋白浓度与其胆红素结合常数（K）的乘积来量化。线性相关用于检验假设，即ΔBT 将随着 K.albumin 浓度显著增加。
研究的 21 例患者的 BT、未结合胆红素浓度、白蛋白浓度和 K 值范围分别为 7.6 至 28.5mg/dL、0.53 至 2.52μg/dL、2.9 至 4.6g/dL 和 38 至 163L/μmol。ΔBT 与 K.albumin 浓度显著相关（r2=0.23；P=.026）。
血浆胆红素结合亲和力对ΔBT 有重要贡献。ΔBT 的这一部分与胆红素神经毒性的风险较低相关，因此似乎有必要将血浆胆红素结合亲和力测量纳入用于管理新生儿黄疸的算法中。
