Immunohistochemical demonstration of RECK protein and interleukin-6 in fetal membranes from singleton pregnancies with late preterm delivery, intact membranes and histological chorioamnionitis.

We investigated whether chorioamnionitis affects immunohistochemical demonstration of RECK protein and interleukin-6 (IL-6) expression in fetal placental membranes following late preterm delivery with intact membranes. Fetal membranes of 28 women with single pregnancy, preterm delivery and histologically documented chorioamnionitis at gestational age 34-366/7 weeks constituted the chorioamnionitis study group. The control group consisted of 28 fetal membranes from women with preterm deliveries at the same gestational age without histological chorioamnionitis. Immunohistochemistry was performed using monoclonal antibodies against RECK protein and IL-6. We found a statistically significant difference in RECK expression between the chorioamnionitis and control groups; however, we found no difference in IL-6 expression between the groups. We demonstrated that RECK expression is down-regulated in fetal membranes from pregnancies with spontaneous late preterm birth and intact membranes, which suggests its role in preterm parturition. Equal expression of IL-6 in fetal membranes of pregnancies with and without histological chorioamnionitis is an intriguing and unexpected observation that requires further investigation.

Trophoblast apoptosis in placentas from pregnancies complicated by preeclampsia.

AIMS: To assess trophoblast apoptosis separately in the cytotrophoblast, syncytiotrophoblast, total villous trophoblast, syncytial knots and syncytial knot formation, and to investigate the expression of apoptotic factors Fas ligand (FasL), Bcl-2 and proliferation marker Ki-67 in the trophoblast of placentas from preeclamptic patients. METHODS: The study included placental samples from 25 preeclamptic and 25 normal pregnancies. For the detection of apoptosis and proliferation, antibody M30 and antibody against Ki-67 antigen were used. Expression of FasL and Bcl-2 was assessed using semi-quantitative HSCORE method. Syncytial knots were expressed as the number of syncytial knots per individual villus and as the total number of syncytial knots in each placental sample. RESULTS: Trophoblast apoptosis, number of syncytial knots per individual villus and the total number of syncytial knots in each placental sample were significantly higher in preeclamptic placentas than in control group placentas. FasL expression was significantly less, and Bcl-2 expression significantly greater in the villus trophoblast among the study subjects compared with controls. There was no difference in the trophoblast proliferation between groups. CONCLUSION: Our findings might suggest that increased apoptosis and syncytial knot formation combined with reduced FasL expression could be involved in pathophysiological mechanisms of preeclampsia.