J. Bar et al., THE REGULATION OF PLATELET-AGGREGATION IN-VITRO BY INTERLEUKIN-1-BETAAND TUMOR-NECROSIS-FACTOR-ALPHA - CHANGES IN PREGNANCY AND IN PREECLAMPSIA, Thrombosis and haemostasis, 78(4), 1997, pp. 1255-1261
Platelet activation occurs in early pregnancy in women at risk of deve
loping pre-eclampsia. Cytokines have been implicated in the pathogenes
is of pre-eclampsia, so we determined the effects of interleukin-1 bet
a (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) on the in vi
tro aggregation of human platelets. IL-1 beta increased aggregation of
platelets from non-pregnant and pre-eclamptic women, and inhibited th
e aggregation of platelets from normal pregnant women. This latter eff
ect was linked to a diminished P-selectin expression on ADP-stimulated
whole blood platelets in normal pregnant women (p = 0.011). Platelet
aggregation in response to ADP was found to be inhibited after preincu
bation with TNF-alpha in non-pregnant (38%, p = 0.01) and in normal pr
egnant women (54%, p = 0.001) and not affected in pre-eclamptic women,
The inhibitory effects of TNF-alpha were mediated through the P75 rec
eptor for TNF-alpha.