Soluble Endoglin and Other Circulating Antiangiogenic Factors in Preeclampsia

This nested case–control study of healthy nulliparous women within the Calcium for Preeclampsia Prevention trial shows that the circulating level of soluble endoglin, an antiangiogenic protein, increased markedly 2 to 3 months before the onset of preeclampsia and was generally accompanied by decreased levels of placental growth factor and increased levels of circulating soluble fms-like tyrosine kinase 1. These studies set the stage for a prospective study to determine if measurement of these markers could provide means of identifying women at high risk for preeclampsia. Circulating level of soluble endoglin increased markedly 2 to 3 months before the onset of preeclampsia and was generally accompanied by decreased levels of placental growth factor and increased levels of circulating soluble fms-like tyrosine kinase 1. Preeclampsia, characterized by hypertension and proteinuria after 20 weeks of gestation, complicates 3 to 5 percent of pregnancies and results in substantial maternal and neonatal complications and deaths. 1 , 2 It seems to be precipitated by the release of circulating factors from the placenta that induce endothelial dysfunction. 3 , 4 Soluble fms-like tyrosine kinase 1 (sFlt1) (also known as soluble vascular endothelial growth factor [VEGF] receptor 1 [sVEGFR1]), a circulating antiangiogenic protein that sequesters the proangiogenic proteins placental growth factor (PlGF) and VEGF, is increased before the onset of clinical disease in the circulation of women with preeclampsia. Circulating levels of sFlt1 . . .