Circulating concentrations of soluble endoglin (CD105) in fetal and maternal serum and in amniotic fluid in preeclampsia

We explored whether concentrations of soluble endoglin in fetal serum and amniotic fluid and in maternal serum were elevated in preeclampsia.Umbilical vein serum, amniotic fluid, and maternal serum from 42 preeclamptic and 43 uncomplicated pregnancies that were delivered by cesarean section were analyzed by enzyme-linked immunosorbent assay for soluble endoglin.Median maternal serum and amniotic fluid soluble endoglin concentrations were elevated in preeclampsia, compared with control pregnancies (66.9 ng/mL vs 15.1 ng/mL; P < .001, and 1.9 ng/mL vs 0.6 ng/mL; P < .001). Low concentrations of soluble endoglin were found in fetal circulation, which did not differ between preeclampsia and control pregnancies (5.0 ng/mL vs 4.7 ng/mL; P = .2). Maternal serum soluble endoglin levels correlated with circulating soluble fms-like tyrosine kinase 1 concentrations.We confirmed elevated soluble endoglin in maternal circulation in preeclampsia, which correlated with soluble fms-like tyrosine kinase 1 concentrations and soluble fms-like tyrosine kinase 1/placental growth factor ratio. The fetus appears not to contribute to elevated circulating maternal soluble endoglin concentrations in preeclampsia.