title: The influence of the menstrual cycle, normal pregnancy and pre-eclampsia on platelet activation.
abstract: Platelet activation has a key role in mediating thrombotic and inflammatory events. This study aimed to determine the influence of the menstrual cycle, pregnancy and pre-eclampsia on in vivo platelet activation. Twelve healthy nulliparous, non-smoking women with regular menses were studied over a single menstrual cycle. Twenty-one healthy primigravida pregnant women were studied longitudinally at 16, 24, 32 and 37 weeks gestation and seven weeks post-partum. Sixteen primigravida women with pre-eclampsia were studied at time of diagnosis and at seven weeks post-partum. Platelet-monocyte aggregates and platelet-surface P-selectin expression were assessed by flow-cytometry. Soluble P-selectin and CD40 ligand (CD40L) were measured by ELISA. Markers of platelet activation did not vary over the menstrual cycle. Platelet-monocyte aggregates were greater in the third trimester of pregnancy compared to non-pregnant women (p=0.003). Platelet surface and plasma soluble P-selectin concentrations increased with gestation (p<0.0001) and were raised by 24 weeks of pregnancy compared to non-pregnant women (p< or =0.02 for both) and together with platelet monocyte aggregates, decreased post-partum (p< or =0.02). Soluble CD40L concentrations fell in pregnancy, reaching a nadir at mid-gestation (p=0.002). There were no differences in markers of platelet activation between normal and pre-eclamptic pregnancies. In conclusion, platelet activation is increased in pregnancy and increases with gestation but is unaffected by pre-eclampsia. This suggests that systemic platelet activation is a feature of pregnancy but this is not affected by established pre-eclampsia.
authors.affiliation: TheSimpson Centre for Reproductive Health, The Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, UK.
authors.forename: A O
authors.initials: AO
authors.lastname: Robb
authors.forename: J N
authors.initials: JN
authors.lastname: Din
authors.forename: N L
authors.initials: NL
authors.lastname: Mills
authors.forename: I B J
authors.initials: IB
authors.lastname: Smith
authors.forename: A
authors.initials: A
authors.lastname: Blomberg
authors.forename: M N L
authors.initials: MN
authors.lastname: Zikry
authors.forename: J B
authors.initials: JB
authors.lastname: Raftis
authors.forename: D E
authors.initials: DE
authors.lastname: Newby
authors.forename: F C
authors.initials: FC
authors.lastname: Denison
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D005865:Gestational Age; D020073:Gravidity; D006801:Humans; D008137:Longitudinal Studies; D008597:Menstrual Cycle / Q000097:blood*; D008875:Middle Aged; D015539:Platelet Activation; D049590:Postpartum Period; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D055815:Young Adult
chemical_list: D015415:Biomarkers