Abstract for presentation at 11th International Congress of Human Genetics

Purpose: Recently, placental mRNAs circulating independently of cells present new possibilities for noninvasive profiling of gene expression. Quantitative analysis of placental mRNAs in maternal plasma provides a way to monitor placental status. In this study we measured plasma concentrations of placenta-specific 1 (PLAC1) and glial cells-missing 1 (GCM1) mRNAs, which have not been measured during the course of normal pregnancy.
Methods: Firstly, peripheral blood samples were taken from 21 subjects at 11 and 24 weeks, from 38 subjects at 15 weeks, from 26 subjects at 36 weeks, from 22 subjects just before delivery, 30 min after delivery, 1 day postpartum and from 10 subjects 1 month after delivery to clarify the time course of placental mRNAs. Secondly, 10 subjects at 36 weeks with pre-eclampsia were obtained to examine whether placental mRNAs change in pre-eclampsia. Blood samples were collected from pregnant women receiving ambulatory prenatal care in the Department of Obstetrics and Gynecology at Hiroshima University Hospital who had provided written informed consent. Plasma was separated from these samples for extraction of RNA, followed by reverse transcription polymerse chain reaction analysis.
Results: PLAC1 and GCM1 mRNA concentrations increased gradually during pregnancy, being highest just before and after delivery (medians: 880.5 and 1672.4 copies/ml, 1966.3 and 1857.8 copies/ml), then showing a decrease on the first day of the puerperium followed by disappearance at 1 month. Median concentrations of PLAC1 and GCM1 mRNA in plasma at 36 weeks of gestation of pre-eclamptic subjects were 1625 and 2141 copies/ml, significantly higher than 195 and 881 copies/ml, the values for controls (Mann–Whitney test, p <0.001).
Conclusions: Our results suggested that quantitative analysis of several placental mRNAs (e.g. PLAC1 and GCM1) in maternal plasma might represent a useful way to monitor placental status.