Prospective evaluation of platelet B2 bradykinin and thrombopoietin receptor levels from preeclamptic compared to non-preeclamptic pregnancy patients

Our recent study determined a difference between preeclamptic and non-preeclamptic patients in platelet potentiation by thrombopoietin (TPO) of reactivity to collagen. The main conclusion was that non-preeclamptic, but not preeclamptic, pregnancy patients' platelets showed significant TPO potentiation at first and third trimesters. Since TPO or B2 Bradykinin platelet receptor levels might influence TPO potentiation, we obtained platelet samples from 187 first trimester pregnant patients prospectively followed through pregnancy. Patients were additionally sampled at third trimester, delivery, and 4 to 6 weeks postpartum. A total of 43 patients, including 11 diagnosed as preeclamptic at third trimester, were sampled at least three different times. We used Western blotting normalized with glyceraldehyde 3 phosphate dehydrogenase as a loading and staining control. There were no significant differences in relative receptor levels between groups or sampling times using repeated measures ANOVA with the mixed model allowing for missing samples. While the mechanism for differences in thrombopoietin potentiation of platelet activation by collagen remains unknown, it may be a first trimester indicator of developing preeclampsia.