Objectives This study aimed to quantitate cell free (cf) and cell free
fetal (cff) DNA in maternal plasma by determining RASSF1A levels before
and after enzyme digestion in women who subsequently developed
preeclampsia (PE) and compare them with uncomplicated pregnancies.
Methods Twenty-four samples from pregnant women who developed PE and 48
samples from women with uncomplicated pregnancies were analysed. Blood
samples were obtained at 11-13 weeks. cfDNA was determined by
quantifying RASSF1A using qRT-PCR. A second qRT-PCR was performed
following methylation-sensitive enzyme digestion by BstUI, to quantitate
hypermethylated RASSF1A sequences of fetal origin. ACTB gene was used as
control to confirm complete enzyme digestion.
Results cfDNA and cffDNA levels were significantly increased in women
who developed PE as compared with uncomplicated pregnancies (median
cfDNA: 9402 vs 2698, median cffDNA: 934.5 vs 62, respectively).
Following operating characteristic curve analysis, cut-off values of
7486.q/mL for cfDNA and 512.q/mL for cffDNA were chosen, which provided
a sensitivity of 75% and 100% and specificity of 98% and 100%,
respectively, to identify women at risk for PE.
Conclusions The study demonstrates potential use of cfDNA and cffDNA in
maternal plasma as markers for the early prediction of women at risk for
PE. (C) 2013 John Wiley & Sons, Ltd