ENDOTHELIAL TIE RECEPTOR ANTIGEN IN MATERNAL AND CORD-BLOOD OF HEALTHY AND PREECLAMPTIC SUBJECTS

Objective: To measure the vascular endothelial receptor tyrosine kinas e Tie, essential in the process of angiogenesis, in blood from healthy and preeclamptic pregnant women, in umbilical cord blood from both, a nd in blood from nonpregnant women. Methods: A total of 143 women part icipated in four arms of the study. blood samples were collected from 54 healthy nonlaboring pregnant women (gestational weeks 14-41). Sampl es were collected immediately prepartum and postpartum from another 40 healthy women (15 delivered vaginally and 25 by cesarean) and 15 pree clamptic women tall delivered by cesarean). Arterial and venous cord s amples were collected, when possible, from infants born by cesarean. S ingle blood samples were drawn from 34 nonpregnant controls. Of these, weekly samples from II were drawn during one menstrual cycle. A time- resolved fluoroimmunoassay was developed for the detection of the solu ble extracellular domain of Tie. Results: Maternal serum Tie levels de creased with advancing gestational age after 26 weeks (r = .6, P < .00 1). They were significantly higher in healthy women at term (median 23 3 ng/mL, range 152-414 ng/mL) compared with nonpregnant controls (medi an 173 ng/mL, range 107-333 ng/mL, P <.001) or with preeclamptic women at term (median 152 ng/mL, range 90-372 ng/mL, P < .05). This differe nce between healthy and preeclamptic women persisted on the first post partum day (median 221 ng/mL, range 128-343 and median 152 ng/mL, rang e 90-372 ng/mL, respectively, P < .05). The highest levels of serum Ti e receptor were observed in umbilical arterial and venous blood (media n 240 ng/mL, range 174-474 ng/mL and median 340 ng/mL, range 245-690 n g/mL, respectively). In nonpregnant women, serum Tie levels did not va ry with menstrual cycle. Conclusion: The high levels of the extracellu lar domain of Tie in healthy term maternal and cord blood may indicate a role for Tie in the vascular development of human fetuses and place ntas. (Obstet Gynecol 1998;92:179-83. (C) 1998 by The American College of Obstetricians and Gynecologists.)