FLOW CYTOMETRIC DETECTION OF ACTIVATED PLATELETS IN PREGNANT-WOMEN PRIOR TO THE DEVELOPMENT OF PREECLAMPSIA

Pre-eclampsia is a common complication of pregnancy, in which platelet s may have an early pathogenetic role. In this prospective study a who le blood flow cytometric method has been used to detect circulating ac tivated platelets in pregnant women prior to the development of pre-ec lampsia. Activated platelets were identified by bound fibrinogen or by CD63 antigen expression. Of 121 healthy primiparous women studied at 28 weeks of pregnancy, 18 (15%) developed clinical pre-eclampsia six t o thirteen weeks later, The platelets of these women showed increased fibrinogen binding ex vivo (5.1% platelets positive, compared with 3.4 % in those who completed a normal pregnancy, p <0.02), and increased C D63 antigen expression (0.73% positive compared to 0.45%, p = 0.01). I n contrast, no differences between the women with different outcomes w ere detected at 28 weeks in platelet counts, or plasma 13-thromboglobu lin levels. These findings confirm that whole blood flow cytometry is a sensitive technique for investigating platelet activation in a clini cal setting and support the hypothesis that platelets have a critical role in the pathogenesis of pre-eclampsia.