Effects of beta2-glycoprotein-I on platelet aggregation in cord versus adult whole blood.
Platelets
; 18(1): 24-8, 2007 Feb.
Article
em En
| MEDLINE
| ID: mdl-17365850
ABSTRACT
We present a peculiarity of the neonatal hemostatic system that might contribute to establish a procoagulant readiness in neonatal blood by sensitizing neonatal platelets for ADP stimulation. beta2-glycoprotein-I (beta2-GP-I) is a plasma constituent capable of suppressing ADP-induced platelet aggregation. We found significant lower levels of beta2-GP-I in cord vs. adult plasma (120 +/- 27 vs. 180 +/- 37 microg/mL, P<0.001). We demonstrate dose-dependent inhibition of ADP-induced platelet aggregation in cord whole blood (WB) in the presence of increasing amounts of beta2-GP-I, evaluated by means of WB aggregometry employing the impedance method. Particularly, raising the beta2-GP-I concentration in cord WB from neonatal level up to the respective adult value caused significant reduction of amplitude (from 9.5 +/- 2.7 to 2.8 +/- 0.9 Omega, P<0.001) and of slope (from 5.9 +/- 2.4 to 1.89 +/- 0.9 Omega/min, P<0.001), and a significant prolongation of the aggregation time (from 51.8 +/- 22.9 to 110.8 +/- 60.3 s, P<0.001). In conclusion, physiological low levels of beta2-GP-I in cord WB cause enhanced responsiveness of neonatal platelets to ADP stimulation. This mechanism might help to explain the clinically observed well-functioning hemostasis in neonates.
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Base de dados:
MEDLINE
Assunto principal:
Recém-Nascido
/
Agregação Plaquetária
/
Beta 2-Glicoproteína I
/
Sangue Fetal
/
Hemostasia
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article