Michelson A D
Center for Platelet Function Studies, Department of Pediatrics, University of Massachusetts Medical School, Worcester 01655, USA.
Semin Thromb Hemost. 1998;24(6):507-12. doi: 10.1055/s-2007-996049.
Whole blood flow cytometry, an important new method for the assessment of platelet function, is particularly advantageous for neonatal studies because only minuscule volumes (approximately 2 microL) of blood are required. By this method, we have demonstrated that neonatal platelets are less reactive than adult platelets to physiological agonists in whole blood, as determined by the activation-induced increase in the platelet surface expression of P-selectin and the glycoprotein (GP) IIb-IIIa complex and by the activation-induced decrease in the platelet surface expression of the GPIb-IX complex. Our data suggest that the mechanism of neonatal platelet hyporeactivity is, at least in part, a relative defect in a common signal transduction pathway. We have further demonstrated that the platelets of very low birth weight (VLBW) preterm neonates are maximally hyporeactive on days 3 to 4 of life but return to almost the adult range by days 10 to 14. Given that intraventricular hemorrhage (IVH) is also maximal on days 3 to 4, these defects may contribute to the propensity of VLBW preterm neonates to IVH.
全血流式细胞术是评估血小板功能的一种重要新方法，对于新生儿研究尤为有利，因为仅需极微量（约2微升）的血液。通过这种方法，我们已经证明，在全血中，新生儿血小板对生理激动剂的反应性低于成人血小板，这是通过激活诱导的P-选择素和糖蛋白（GP）IIb-IIIa复合物在血小板表面表达增加以及激活诱导的GPIb-IX复合物在血小板表面表达降低来确定的。我们的数据表明，新生儿血小板低反应性的机制至少部分是常见信号转导途径中的相对缺陷。我们进一步证明，极低出生体重（VLBW）早产儿的血小板在出生后第3至4天反应性最低，但在第10至14天几乎恢复到成人水平。鉴于脑室内出血（IVH）在第3至4天也最为严重，这些缺陷可能导致VLBW早产儿易患IVH。
