T-PA AND PAI-1 SYNTHESIS OF HUMAN ENDOTHE LIAL-CELLS IS INCREASED AFTER STIMULATION WITH SERA OF PREECLAMPTIC PATIENTS

t-PA and PAI-I Synthesis of Human Endothelial Cells is Increased after Stimulation with Sera of Preeclamptic Patients: The aim of our study was to determine the potential cytotoxicity of sera from patients with preeclampsia and HELLP syndrome, by investigating the influence of th ese sera on the expression of tissue-Plasminogen Activator (t-PA) and Plasminogen Activator Inhibitor-1 (PAI-1) into the supernatant of cult ured human endothelial cells. For this purpose, we stimulated human en dothelial cells, obtained from umbilical veins (HUVEC), over a period of 24 hours with sera of seven patients with HELLP-Syndrome and 12 pat ients with preeclampsia. The sera of 12 normotensive pregnant patients and nine non-pregnant women served as controls. We determined t-PA an d PAI-1 levels by ELISA, both in the maternal serum and in the superna tant of HUVEC. While t-PA levels were significantly higher in the seru m of patients with preeclampsia and HELLP syndrome when compared to th e controls (median: 8.0 ng/ml and 6.2 ng/ml vs. 3.9 ng/ml and 3.1 ng/m l), levels of PAI-1 did not show any significant differences between t he study groups. The supernatant of the endothelial cell cultures demo nstrated significantly elevated levels of both t-PA (p <0.001) and PIA -1 (p< 0.01) when stimulated with serum obtained from patients with pr eeclampsia or HELLP-syndrome. The increased expression of t-PA and PAI -1 from human endothelium cells after stimulation with serum of preecl amptic patients supplies evidence of increased endothelial cell activa tion.