1st Department of Obstetrics and Gynaecology, Athens University School of Medicine, Athens, Greece.
Prenat Diagn. 2013 Jul;33(7):682-7. doi: 10.1002/pd.4093. Epub 2013 Mar 22.
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.
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.
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 Εq/mL for cfDNA and 512 Εq/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.
The study demonstrates potential use of cfDNA and cffDNA in maternal plasma as markers for the early prediction of women at risk for PE.
本研究旨在通过检测随后发生子痫前期（PE）的孕妇和正常妊娠孕妇在酶消化前后母体外周血游离（cf）和游离胎儿（cff）DNA 中 RASSF1A 水平，定量分析其水平，并对两者进行比较。
分析了 24 例发生 PE 的孕妇和 48 例正常妊娠孕妇的血样。在 11-13 周时采集血样。采用 qRT-PCR 定量检测 RASSF1A 以确定 cfDNA。用 BstUI 进行甲基化敏感酶消化后进行第二次 qRT-PCR，以定量胎儿来源的高甲基化 RASSF1A 序列。ACTB 基因用作确认完全酶消化的对照。
与正常妊娠孕妇相比，发生 PE 的孕妇的 cfDNA 和 cffDNA 水平显著升高（cfDNA 中位数：9402 与 2698，cffDNA 中位数：934.5 与 62）。通过接受者操作特征曲线分析，选择 cfDNA 的截断值为 7486Εq/mL 和 cffDNA 的截断值为 512Εq/mL，可分别提供 75%和 100%的敏感性以及 98%和 100%的特异性，以识别发生 PE 的高危孕妇。
该研究表明母体外周血 cfDNA 和 cffDNA 可作为预测发生 PE 高危孕妇的标志物。
