Preeclampsia, characterized by the new onset of hypertension and proteinuria after 20 weeks of gestation, is a systemic disorder, unique to human, and affects 2-10% of pregnancies worldwide. It is characterized by an ineffective remodeling of maternal vessels perfusing the placenta. Semaphorin 3F is a well-known anti-angiogenic mediator. We aimed to investigate whether semaphorin 3F placenta expression and serum and amniotic levels are modulated in preeclampsia.
MATERIALS AND METHODS
To this purpose, we performed, after approval by our Ethical Committee, (protocol number 53/EC/2013), in the period from March 2013 to July 2014, an observational single center cohort study. We enrolled 132 consecutive pregnant women, undergoing an elective cesarean section and 150 consecutive pregnant women undergoing amniocentesis for routine clinical indications at 16-18 week of gestation. Semaphorin 3F concentration was evaluated in maternal peripheral blood, venous umbilical blood and amniotic fluid at the time of delivery in the first group. In addition, in this group we examined placental semaphorin 3F protein expression. We then investigated amniotic fluid semaphorin 3F level at 16-18 weeks of gestation in the second group of pregnants.
Semaphorin 3F placenta expression was significantly reduced in women with preeclampsia (Fig. 1-2). In addition, semaphorin 3F level at the time of delivery was significantly lower in serum, amniotic fluid and venous umbilical blood of patients with preeclampsia compared with normal pregnant women (Fig. 3). In the prospective cohort study 14 women developed preeclampsia. In this setting, semaphorin 3F level in the amniotic fluid at 16-18 weeks of gestation was reduced in women who subsequently developed preeclampsia compared to women with a normal pregnancy (Fig. 4).
In conclusion, our findings demonstrate for the first time that semaphorin 3F, are significantly reduced in pre-eclamptic placenta. Moreover, our results support the hypothesis that amniotic fluid levels of semaphorin 3F might represent a biomarker of preeclampsia.