Soluble and Membranous Vascular Endothelial Growth Factor Receptor-2 in Pregnancies Complicated by Pre-Eclampsia

PURPOSE There is a paucity of information on the serum soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) concentrations, membranous VEGFR-2 expression and the mechanism involved in their modulations during the clinical onset of pre-eclampsia. This cross-sectional study was conducted to evaluate the concentration of sVEGFR-2 in serum and to investigate the expression of membranous VEGFR-2 in placentae of pre-eclampsia group. MATERIALS AND METHODS The serum levels of sVEGFR-2 (n = 120) and the expression of membranous VEGFR-2 in placentae (n = 100) were analysed at third trimester of pregnancy by enzyme linked immunosorbent assay (ELISA) and immunohistochemistry respectively. The diagnostic parameters of sensitivity, specificity and association of soluble and membranous VEGFR-2 in these patients were evaluated. RESULTS The serum levels of sVEGFR-2 in pre-eclampsia patients were found to be significantly reduced (p = 0.01, p = 0.001) in early and late pre-eclamptic sub-groups as compared to their respective third trimester control sub-groups. Also, the receiver operating characteristic (ROC) curve analysis showed a cut-off value of 7350.4 pg/mL, higher sensitivity (76%) and specificity (76%) for sVEGFR-2 in late onset (> 34 weeks) pre-eclamptic group. Significant down-regulation of membranous VEGFR-2 immunoreactivity was observed in all the placental cells (p = 0.0001) at > 34 weeks preeclamptic group. CONCLUSION The reduced serum levels of soluble VEGFR-2 and the down-regulated expression of membranous VEGFR-2 in the study group denoted abnormality in VEGF mediated placental function in all placental cells and thus VEGFR-2 may be a key factor, intimately associated with pre-eclampsia. This study shows the clinical utility of soluble and membranous VEGFR-2 in pre-eclampsia patients.