The immunohistochemical evaluation of VEGF in placenta biopsies of pregnancies complicated by preeclampsia

Objective The study was designed to determine the protein levels of vascular endothelial growth factor (VEGF) in the placenta biopsies of patients with preeclampsia and compare with normal controls. Design Prospective cohort study. Methods The placental biopsies were obtained from ten patients with preeclampsia and ten patients of control group at the time of delivery. Avidin-biotin-peroxidase immunohistochemistry was then performed to identify levels of VEGF protein within the tissue and a semi-quantitative method was devised to score the amount of staining present in the sample. Two histopathologists who were blinded to the groups were asked to score each sample for the intensity of staining and the number of cells stained in a randomly selected per high-power fields of each sample. The resulting "H-score" was computed as a product of intensity and percent of cells stained. Results The VEGF expression was significantly higher in placenta biopsies of preeclamptic patients compared to that of controls (271.2 +/- 22.65 vs. 201.9 +/- 12.33, P = 0.000). Conclusion Immunostaining of VEGF is significantly higher in placenta biopsies of patients with preeclampsia.