Involvement of Fibrinolytic Factors in Mid Trimester Amniotic Fluid with Development of Severe Early-Onset Preeclampsia

Abstract

Impaired placental development is a well-known pathogenesis in preeclampsia. The present study was undertaken to elucidate the involvement of fibrinolytic factors in amniotic fluid in midtrimester with development of severe early-onset preeclampsia. Amniotic fluid was obtained by amniocentesis at 15 to 18 weeks of gestation. All specimens were retrospectively identified according to the hospital records as coming from gestations that later had severe early-onset preeclampsia (severe preeclamptic group, n = 9) or gestations with normal outcomes (control group, n = 73). Fibrinolytic factors such as tissue plasminogen activator (t-PA), plasminogen activator inhibitor type 1 (PAI-1), and t-PA-PAI-1 complex (PAI-C) of specimens were measured by enzyme-linked immunoassay. In the control group, concentrations of t-PA as well as PAI-1 in amniotic fluid remained at similar levels from 15 to 18 weeks, although PAI-1 levels were more than 10 times higher compared with t-PA levels. Levels of t-PA and PAI-1 in the severe preeclamptic group were not different from those of the control group. PAI-C levels gradually decreased from 15 through 18 weeks of gestation in the control group. PAI-C levels of the severe preeclamptic group were significantly lower than those of the control group (55.5 ± 18.0% versus control; mean ± standard deviation [SD], p <0.001). PAI-C, as the most specific indicator of the early stage of fibrinolytic activities, showed lower levels in midtrimester amniotic fluid in the severe preeclamptic group, suggesting fibrinolytic activities of amniotic fluid may have a significant role in the development of severe early-onset preeclampsia via impaired placental development in the latent stage of preeclampsia.

Keywords:

Fibrinolytic factors - midtrimester amniotic fluid - severe early-onset preeclampsia - t-PA - PAI-1