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The platelet hyporeactivity of extremely low birth weight neonates is age-dependent
Francis J Bednarek1, Stephen Bean, Marc R Barnard
1Neonatology, Department of Pediatrics, University of Massachusetts Medical School and UMass Memorial Health Care, Worcester, MA 01655, USA.
Introduction:
We have previously demonstrated that, as compared to adults, the platelets of extremely low birth weight (ELBW) neonates are markedly hyporeactive on day 0-1 of life. The purpose of this study was to examine the age dependency of this hyporeactivity.
Materials And Methods:
On days 0-1, 3-4, and 10-14, peripheral blood was collected from 14 stable ELBW neonates and compared to peripheral blood from normal adults run in parallel. Whole blood flow cytometry was used to examine the activation-dependent increase in platelet surface P-selectin (reflecting degranulation) and platelet surface binding of factor V/Va (reflecting platelet surface procoagulant activity) and decrease in platelet surface glycoprotein (GP) Ib (the von Willebrand factor receptor).
Results:
In the physiologic milieu of whole blood, ELBW neonatal platelets on days 0-1 and 3-4 were markedly less reactive than adult platelets. However, by day 10-14, the platelet function of ELBW neonates improved significantly, although not completely to adult levels.
Conclusions:
The age-dependent platelet hyporeactivity of ELBW neonates demonstrated in this study may be a contributing factor to the similar age-dependent propensity of ELBW neonates to intraventricular hemorrhage.
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