Plasma mRNA concentrations of placenta‐specific 1 (PLAC1) and pregnancy associated plasma protein A (PAPP‐A) are higher in early‐onset than late‐onset pre‐eclampsia

Abstract

Some mRNA concentrations are observed to increase in the maternal circulation in association with pre-eclampsia, including placenta-specific 1 (PLAC1) and pregnancy associated plasma protein A (PAPP-A), which were previously proposed as predictive markers for pre-eclampsia. Here, we investigated their concentrations in early-onset and late-onset pre-eclampsia maternal plasma to determine whether different mechanisms are involved in these two forms of the disorder. Peripheral blood and placental samples were collected from patients with pre-eclampsia. RNA was extracted and levels of PLAC1 and PAPP-A mRNAs were determined using real-time quantitative PCR. PLAC1 and PAPP-A mRNA levels were significantly increased in plasma from pregnant women with pre-eclampsia compared with those from healthy pregnant women. The median concentration of PLAC1 was 5.5 times higher (P<0.01) and that of PAPP-A was 5.1 times higher (P<0.01) in early-onset than in late-onset pre-eclampsia. The expression of these mRNAs in the placenta showed no significant difference in early-onset pre-eclampsia, late-onset pre-eclampsia and healthy pregnant women. These findings suggest that the concentration of mRNAs in maternal plasma reflect leakage from damaged villus cells rather than expression levels in the placenta. Injury to chorionic villus cells might be more severe in early-onset pre-eclampsia than in late-onset pre-eclampsia.