PLASMA PLATELET AGGREGATING FACTOR AND PLATELET-AGGREGATION STUDIES IN PREECLAMPSIA

Objective. A plasma platelet aggregating factor (PAF) has been implica ted in the pathogenesis of platelet activation in thrombotic thrombocy topenic purpura (TTP) and hemolytic uremic syndrome (HUS). Similar mec hanism may be operative in pre-eclampsia. Methods. Coagulation profile and detailed in vitro platelet aggregation with various agonists were studied. PAF tvas demonstrated by spontaneous aggregation of normal p latelets with test plasma. Non-parametric Wilcoxon's rank sum test and Krauskal Wally's one was analysis of variance were applied. Result. T wenty-two pre-eclamptic patients and 20 normal pregnant controls were studied. Anti-thrombin III levels were within normal range and fibrin degradation products were only border line raised (>10 <40 mu g/ml) in 14 (65.4%) patients. In vitro platelet aggregation was abnormal in 17 (77.2%) patients. PAF was demonstrable in 10 of 22 (45.5%) patients, Conclusion. Platelet aggregation studies indicated the presence of bot h activated (hyperaggregable) as well as exhausted (hypoaggregable) pl atelets in circulation, PAF demonstrable in 45.4% pre-eclampsia patien ts would suggest its role in the pathogenetic mechanism of platelet ac tivation in this disease.