Unexpected persistence of platelet hyporeactivity beyond the neonatal period: a flow cytometric study in neonates, infants and older children

Summary

Previous studies, using flow cytometry, have reported a lower platelet reactivity in neonates compared to adults. Only few studies were carried out in older children, and results were controversial in terms of age to reach adult platelet function. We studied a total of 125 healthy neonates, infants and older children, and 15 adults. αIIbβ3 expression on resting and activated platelets was lower in all children, with an impaired capability of αIIbβ3 activation (PAC1 and bound fibrinogen). This defect was observed until the age of fifteen with a gradual recovery with age. In neonates, we observed a defect of GPIbα internalization, and demonstrated that this defect persisted in older children as well. In contrast with αIIbβ3 integrin activation, we did not observe a gradual age-dependent recovery. These unexpected results point out the need for reference values in childhood.

Keywords

αllbβ3 - GPIbα - platelets - flow cytometry - children

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