Extensive platelet activation in preeclampsia compared with normal pregnancy: Enhanced expression of cell adhesion molecules

Abstract

Extensive platelet activation in preeclampsia compared with normal pregnancy: enhanced expression of cell adhesion molecules Konijnenberg, A.; Stokkers, E.W.; van der Post, J.A.M.; Schaap, M.C.L.; Boer, K.; Bleker, O.P.; Sturk, A. Published in:American journal of obstetrics and gynecology DOI:10.1016/S0002-9378(97) Link to publication Citation for published version (APA): Konijnenberg, A., Stokkers, E. W., van der Post, J. A. M., Schaap, M. C. L., Boer, K., Bleker, O. P., & Sturk, A. (1997). Extensive platelet activation in preeclampsia compared with normal pregnancy: enhanced expression of cell adhesion molecules. American journal of obstetrics and gynecology, 176, 461-469. https://doi.org/10.1016/S0002-9378(97)70516-7 General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Amsterdam and Leiden, The Netherlands OBJECTIVES= Platelets play an important role in the pathophysiologic mechanisms of preeclampsia. Our purpose was to investigate by means of flow cytometry to what extent platelets circulate in an activated state during normal pregnancy and whether this activation is more extensive in preeclampsia. STUDY DESIGN= Platelets in whole blood from 10 preeclamptic third-trimester pregnant women (highest diastolic blood pressure range 100 to 130 mm Hg, proteinuria range 0.59 to 11.5 gm/24 hr) and from 10 normotensive third-trimester pregnant controls were analyzed with the following activation markers: anti-P-selectin (a-granule secretion), anti-CD63 (lysosomal secretion), PAC-1 (monoclonal antibody against fibrinogen receptor conformation of the glycoprotein lib/Ilia complex), anti-platelet endothelial cell adhesion molecule-I, and annexin-V (a placental protein that binds to negatively charged phospholipids, present on the outside of the platelet plasma membrane after activation). The differences in surface antigen exposure between the two groups were determined by double-label flow cytometry. Flow cytometric data were analyzed in two ways: first, the percentages of activated platelets above a certain threshold compared with a nonpregnant control sample were determined, indicative for activation of a subpopulation of cells, and, second, the mean fluorescence intensities were determined, indicative of the mean surface antigen expression of the total platelet population...

Can flow cytometric detection of platelet activation earlyin pregnancy predict the occurrence of preeclampsia?A prospective study

“…6 We did not find any significant correlation between these factors. This may be due to the lower extent of platelet activation found in first-trimester pregnant women in whom preeclampsia will develop (median percent of activated platelets 0.67%, range -1.09% to 9.05%) compared with the extent of platelet activation in diseased third-trimester preeclamptic patients (median percent of activated platelets 8.0%, range -1.6% to 38.6%).…”

“…And third, we found an increased expression of CD63 in combination with an increased expression of the cell adhesion molecules P-selectin and PECAM-1 in third-trimester preeclamptic patients. 6 Remarkably, we did not find activated platelets at a gestational age of 20 weeks in the women in whom preeclampsia will develop, which is difficult to explain. We can only hypothesize that the second wave of trophoblast invasion is less immunogenic than the first wave, causing no detectable platelet activation.…”

“…4 Like others, we found with use of flow cytometry an increased platelet activation status in preeclamptic patients compared with normotensive pregnant women. 5,6 During platelet activation several changes occur at the platelet surface. Currently flow cytometry is the most sensitive technique to detect increased surface exposure of activation antigens on the platelet surface.…”

“…12 We recently described an increased expression of CD63 and in addition an increased expression of P-selectin (e~-granule secretion) and platelet endothelial cell adhesion molecule-1 (PECAM-1) on the surface of platelets of preeclamptic patients compared with those of pregnant women with an uncomplicated pregnancy. 6 Therefore we anticipated that CD63 expression might be increased before the full development of preeclampsia and probably the expression of P-selectin and PECAM-1 as well. In the current study we used the antibodies anti-CD63, anti-P-selectin, and anti-CD31 (anti-PECAM-1).~2-14 P-selectin and PECAM-1 are cell adhesion molecules, which regulate interactions of endothelial cells with activated leukocytes and platelets and thus may also be of importance in the pathophysiologic mechanisms of preeclampsia.…”

Physiological Changes in Hematological Parameters During Pregnancy

“…Leucocytosis, occurring during pregnancy is due to the physiologic stress induced by the pregnant state [8]. Neutrophils are the major type of leucocytes on differential counts [9,10]. This is likely due to impaired neutrophilic apoptosis in pregnancy [9].…”