THE REGULATION OF PLATELET-AGGREGATION IN-VITRO BY INTERLEUKIN-1-BETAAND TUMOR-NECROSIS-FACTOR-ALPHA - CHANGES IN PREGNANCY AND IN PREECLAMPSIA

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.