Automated assays for sVEGF R1 and PlGF as an aid in the diagnosis of preterm preeclampsia: a prospective clinical study

OBJECTIVE: The purpose of this study was to assess the utility of soluble vascular endothelial growth factor 1 (sVEGF R1) and placental growth factor (PlGF) levels in the clinical diagnosis of preeclampsia. STUDY DESIGN: Plasma was collected prospectively from 457 subjects (n = 409 without preeclampsia, n = 48 with preeclampsia) at 20-36 weeks' gestation. Automated immunoassays were used to measure free sVEGF R1 and free PlGF. RESULTS: Clinical sensitivities of 0.96 and specificities of 0.96 and 0.95 were calculated for sVEGF R1 and PlGF, respectively, for aiding in the diagnosis of preeclampsia. Among subjects with chronic hypertension, sVEGFR1 was dramatically elevated and PlGF decreased in those with superimposed preeclampsia (P < .001 for superimposed preeclampsia vs chronic hypertension for both biomarkers). The ratio of sVEGFR1/PlGF provided a better test to aid in the diagnosis of preeclampsia than either analyte alone (3% false positive rate). CONCLUSION: Free sVEGF R1 and PlGF were useful in differentiating women with preterm preeclampsia from normotensive and hypertensive subjects.