Development of FIRS RNA marker in maternal plasma

众所周知，胎儿炎症反应综合征（FIRS）可导致胎儿或新生儿严重的多器官功能衰竭。虽然胎膜早破和绒毛膜炎可发展为FIRS，但诊断FIRS的评估方法尚未建立。因此，开发预测FIRS发生的方法非常重要。另一方面，我们已经开发了通过使用孕妇血液中的游离RNA和细胞RNA来预测先兆子痫的方法。我们计划将这种方法应用于预测FIRS，我们从入院的先兆早产、胎膜早破、宫颈炎和绒毛膜炎患者中采集血样。同时检测宫颈粘液中的血细胞计数、CRP、弹性蛋白酶和纤维连接蛋白。在进行腹膜穿刺术的病例中，还定量了弹性蛋白酶和纤连蛋白的浓度。但在本研究期间，我们未能从胎儿感染的孕妇中获得样本，因此我们期望IL-6和IL-8等炎性细胞因子作为检测FIRS发病机制的分子标志物。然而，初步的研究表明，这些标志物的表达水平已经改变，在这种情况下，这些候选标志物不能用于预测FIRS。因此，我们评估了通过分析母血中的细胞RNA预测侵入性胎盘。胎盘特异性蛋白-1（PLAC-1）和血管内皮生长因子A（VEGFA）在侵袭性胎盘中的表达水平高于正常妊娠妇女。相反，患者中KISS-1的水平较低。这些基因可能是预测胎盘异常粘附的潜在标志物，因此，显示了母体血液中细胞RNA的分析允许评估胎儿和/或胎盘的病理生理学改变。

It is well known that fetal inflammatory response syndrome(FIRS) causes severe multi-organ failures in the fetus or neonate. Although premature rupture of membrane and chorioamnionitis can be developed to the FIRS, the evaluation method to diagnose the onset of FIRS has not been established. To develop the method to predict the occurrence of FIRS is therefore very important. On the other hand, we have developed the prediction method for preeclampsia by using cell-free RNA and cellular RNA in maternal blood. We planned to apply this method to the prediction of FIRS.We obtained blood samples from admitted patients with threatened preterm birth, PROM, cervicitis, and chorioamnionitis. We further obtained the data of blood counts, CRP value, elastase and fibronectin values in the cervical mucus. In cases that were performed amniocentesis, the concentrations of elastase and fibronectin were also quantified. However, in the study period, we could not obtain samples from pregnant women with fetal infection.We expect inflammatory cytokines such as interleukin-6 and interleukin-8 as molecular markers for detecting the pathogenesis of FIRS. However, the preliminary study showed that the expression levels of these markers were already altered in such situation and these candidate markers could not be used for the prediction of FIRS.Therefore, we assessed the prediction of invasive placenta by using the analysis of cellular RNA in maternal blood. The expression levels of placenta specific-1(PLAC-1) and vascular endothelial growth factor A(VEGFA) in patients with invasive placenta were higher than those in normal pregnant women. In contrast, the level of KISS-1 was lower in the patients. These genes can be potential markers to predict the abnormal adherence of the placenta.It is thus revealed that the analysis of cellular RNA in maternal blood allowed the evaluation of fetal and/or placental pathophysiological alterations.