Circulating chromosome 19 miRNA cluster microRNAs in pregnant women with severe pre‐eclampsia

AimTo clarify the association between circulating chromosome 19 miRNA cluster (C19MC) microRNAs in maternal plasma and severe pre-eclampsia. MethodMaternal blood samples (7mL) at 27-34 weeks of gestation were obtained from 20 pregnant women with severe pre-eclampsia (sPE group) and from 20 uncomplicated pregnant women (NP group). Twenty cases of severe pre-eclampsia were classified into late onset (sPELO group; n = 14) and early onset (sPEEO group; n = 6). Plasma concentration of C19MC microRNAs (miR-518b, -1323, -516b, -516a-5p, -525-5p, -515-5p, -520h, -520a-5p, -519d and -526b) was measured on quantitative real-time reverse transcription-polymerase chain reaction. ResultsThe circulating levels of all 10 C19MC microRNAs in maternal plasma were significantly increased in the sPE group compared with the NP group. Plasma concentration of all 10 C19MC microRNAs tested was significantly increased in the sPEEO group compared with the NP group, while plasma concentration of nine miRNAs, except for miR-519d, was significantly increased in the sPELO group compared with the NP group. Of the 10 C19MC microRNAs measured, plasma concentration of eight miRNAs, except for miR-518b and miR-519d, was significantly increased in the sPEEO group compared with the sPELO group. ConclusionsIncreased levels of C19MC microRNAs in maternal plasma are a characteristic phenomenon of established severe pre-eclampsia, and it has been shown for the first time that the upregulation of C19MC miRNAs occurred as a consequence of, not in advance of, the onset of pre-eclampsia.