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

OBJECTIVE: We explored whether concentrations of soluble endoglin in fetal serum and amniotic fluid and in maternal serum were elevated in preeclampsia. STUDY DESIGN: 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. RESULTS: 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. CONCLUSION: 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.