Biomedical Diagnostics Institute, Royal College of Surgeons in Ireland and Dublin City University, Dublin, Ireland.
Department of Neonatology, National Maternity Hospital, Dublin, Ireland.
J Thromb Haemost. 2016 Oct;14(10):2027-2035. doi: 10.1111/jth.13414. Epub 2016 Aug 20.
Essentials It is unclear if platelet function differs between preterm and full-term neonates. Platelet behavior was characterized using a flow-based assay on von Willebrand Factor (VWF). Preterms had increased platelet interaction with VWF and glycoprotein Ibα expression. Platelets from preterm neonates behave differently on VWF compared to full-term neonates.
Background Very low birth weight (VLBW) preterm neonates have an increased risk of hemorrhage-related morbidity and mortality as compared with their full-term counterparts. It is unclear whether platelet function differs between preterm and full-term neonates. This is partly because of the large volumes of blood required to perform standard platelet function tests, and the difficulty in obtaining such samples in neonates. Objectives This study was designed to characterize platelet behavior in neonates with a physiologic flow-based assay that quantifies platelet function in microliter volumes of blood under arterial shear. Methods Blood from VLBW preterm neonates of ≤ 32 weeks' gestation (n = 15) and full-term neonates (n = 13) was perfused under arterial shear over surface-immobilized von Willebrand factor (VWF). Platelet behavior was recorded by digital-image microscopy and analyzed. Surface expression of platelet glycoprotein (GP) Ibα and GPIIIa of VLBW preterm and full-term neonates was also measured. Results VLBW preterm neonates had increased numbers of platelets interacting with VWF, and increased GPIbα expression on the platelet surface. Despite the increased numbers of VWF interactions as reflected by flow-driven platelet translocation along the protein surface, no significant differences were observed in the numbers of platelets that adhered in a stationary fashion to VWF. Platelets from VLBW preterm neonates and those from full-term neonates behaved differently on VWF. Conclusions These differences in platelet function may contribute to the higher incidence of bleeding observed in VLBW preterm neonatal populations, or may represent a compensatory mechanism to counteract this risk of bleeding.
极低出生体重（VLBW）早产儿与足月儿相比，出血相关发病率和死亡率增加。目前尚不清楚早产儿和足月儿的血小板功能是否存在差异。这在一定程度上是因为进行标准血小板功能测试需要大量血液，并且难以在新生儿中获得此类样本。目的：本研究旨在通过生理流动基础测定法来描述新生儿的血小板行为，该测定法可在动脉剪切下以微升体积的血液定量血小板功能。方法：将≤32 周胎龄的 VLBW 早产儿（n=15）和足月儿（n=13）的血液经表面固定的血管性血友病因子（VWF）进行动脉剪切灌注。通过数字图像显微镜记录血小板行为并进行分析。还测量了 VLBW 早产儿和足月儿血小板表面糖蛋白（GP）Ibα和 GPIIIa 的表达。结果：VLBW 早产儿与 VWF 相互作用的血小板数量增加，血小板表面 GPIbα的表达增加。尽管反映在沿蛋白表面流动驱动的血小板易位的 VWF 相互作用数量增加，但以固定方式黏附在 VWF 上的血小板数量没有明显差异。VLBW 早产儿的血小板和足月儿的血小板在 VWF 上的行为不同。结论：血小板功能的这些差异可能导致 VLBW 早产儿人群中出血发生率增加，或者可能代表一种代偿机制以抵消这种出血风险。
