VPB1420 - Systemic and local changes in the tissue factor activity and its inhibitor in early severe preeclampsia

Background: The contribution of disorders in the hemostasis system determines 5-15% of gestational complications including preeclampsia (PE). In this case, tissue factor (TF) plays a key role in the initiation of the pathological process, enhancing the processes of inflammation, angiogenesis, and apoptosis as key mechanisms for the development of PE.

Aims: To study the expression of tissue factor and tissue factor pathway inhibitor in the systemic circulation and by placental tissues during the development of early severe preeclampsia

Methods: a prospective observational cohort study was performed. The main group included 40 women at low risk of developing PE (according to the results of calculations in the Astraia program in the first trimester), but with realized early severe PE. The control group included 40 pregnant women with a physiological gestation course and delivery at term. The endpoint is delivery, surrogate points are levels of TF and tissue factor pathway inhibitor (TFPI) at 19-21 and 27-28 weeks of gestation. After delivery, the expression of TF and TFPI by placental tissues was studied by immunohistochemistry.

Results: At all control points, the patients of the main group had a significant increase in the level of TF in the blood plasma (figure 1), with a simultaneous decrease of TFPI (figure 2).TF expression in placenta in the case of realized PE was lower: Me=3.99% (95%CI:3.27-4.85) versus control values - Me=2.76% (95%CI:2.14-3.86) (p=0.0113). At the same time, TFPI expression in placenta in the compared groups did not differ from each other.

Conclusion(s): Early severe PE is characterized by increased expression of TF in the systemic circulation and a decrease in TF expression at the local level.