Minimal alteration in the ratio of circulatory fetal DNA to fetal corticotropin-releasing hormone mRNA level in preeclampsia.

OBJECTIVES: We have recently observed that fetal DNA and fetal corticotropin-releasing hormone (CRH) mRNA are associated with in vitro generated syncytiotrophoblast-derived microparticles, and that the ratio of fetal DNA to mRNA (CRH) varied according to whether the particles were derived by predominantly apoptotic, apo-necrotic or necrotic pathways. Hence, we examined whether these ratios varied in maternal plasma samples taken from normotensive and preeclamptic pregnancies in vivo. METHODS: Maternal plasma samples were collected from 18 cases with preeclampsia and 29 normotensive term controls. Circulatory fetal CRH mRNA and DNA levels were quantified by real-time PCR and RT-PCR. RESULTS: Circulatory fetal mRNA and fetal DNA levels were significantly elevated in the preeclampsia study group when compared to normotensive controls. Alterations in the fetal mRNA to DNA ratio between the study and control groups were minimal, even when stratified into early (<34 weeks of gestation) and late (>34 weeks of gestation) onset preeclampsia. CONCLUSIONS: Our data suggest that although circulatory fetal DNA and mRNA levels are significantly elevated in preeclampsia, the ratios in maternal plasma are not dramatically altered.

Circulatory nucleosome levels are significantly increased in early and late-onset preeclampsia.

INTRODUCTION: Elevations in circulatory DNA, as measured by real-time PCR, have been observed in pregnancies with manifest preeclampsia. Recent reports have indicated that circulatory nucleosome levels are elevated in the periphery of cancer patients. We have now examined whether circulatory nucleosome levels are similarly elevated in cases with preeclampsia. METHODS: Maternal plasma samples were prepared from 17 cases with early onset preeclampsia (<34 weeks gestation) with 14 matched normotensive controls, as well as 15 cases late-onset preeclampsia (>34 weeks gestation) with 10 matched normotensive controls. Levels of circulatory nucleosomes were quantified by commercial ELISA (enzyme-linked immunosorbant assay). RESULTS: The level of circulatory nucleosomes was significantly elevated in both study preeclampsia groups, compared to the matched normotensive control group (p = 0.000 and p = 0.001, respectively). CONCLUSIONS: Our data suggests that preeclampsia is associated with the elevated presence of circulatory nucleosomes, and that this phenomenon occurs in both early- and late-onset forms of the disorder.