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Sinuhe Hahn

Publications and source records attributed to Sinuhe Hahn.

61 records · Page 4Linked to original sources
PubMed2002

The levels of circulatory cell free fetal DNA in maternal plasma are elevated prior to the onset of preeclampsia.

OBJECTIVE: Elevations in cell free fetal DNA has previously been determined in pregnancies affected by preeclampsia. A recent report has indicated that cell free fetal DNA concentrations are elevated early in pregnancy before disease onset. As we have recently performed a prospective study to examine fetal cell traffic in pregnancies at risk for developing preeclampsia, we now quantify cell free fetal DNA concentrations in these samples. METHODS: Blood samples were collected in the second trimester of pregnancy from pregnancies at risk for preeclampsia. Cell free fetal DNA amounts were quantified by real-time PCR. These results were then correlated with subsequent pregnancy outcome. RESULTS: Free fetal DNA levels were significantly higher (median of 422.9 vs. 128.5 copies/mL maternal plasma; p=0.005) in plasma samples from women who developed preeclampsia ( n=10) when compared to those who had unremarkable pregnancies ( n=40). CONCLUSIONS: Our data independently confirm the finding that maternal plasma cell free fetal DNA levels are elevated early in pregnancies, which later develop preeclampsia.

DNA↗
PubMed2002

Cell-free fetal DNA in the maternal circulation does not stem from the transplacental passage of fetal erythroblasts.

Fetal cells, specifically fetal erythroblasts, as well as cell-free fetal DNA are present in the maternal circulation. Both are currently being investigated as a means for the non-invasive risk-free analysis of fetal genetic traits. The origin of this cell-free fetal DNA in the maternal circulation is currently unclear. Since numerous fetal erythroblasts have been demonstrated to exhibit an apoptotic phenotype in the form of fragmented nuclear DNA, it has been proposed that such trafficking fetal cells may be a possible source. This hypothesis is supported by reports of elevated numbers of fetal erythroblast and cell-free fetal DNA concentrations in pregnancies affected by pre-eclampsia or polyhydramnios. To address this question, we have examined fetal erythroblast numbers and cell-free DNA concentrations in the same maternal blood samples. Our study, performed on both normal and pathologically-affected pregnancies, indicates that no correlation exists between these two fetal cellular and molecular species. This is most evident in pregnancies affected by onset of preterm labour, where significant elevations in cell-free fetal DNA concentrations were detected without any concomitant elevation in fetal erythroblast numbers. Our data therefore suggest that an alternative cell type is the source of cell-free fetal DNA. Furthermore, it appears that the release of cell-free fetal DNA from this cell type is affected by pathological placental conditions which are not associated with an increase in fetal cell trafficking.

Blood Cell Count↗
PubMed2002

[Non-invasive prenatal diagnosis--already a reality?].

The genetic analysis of fetal cells enriched from the blood of pregnant women has been a long-standing goal of those researchers and clinicians who want to use this technology for the development of a non-invasive risk-free method for prenatal diagnosis. Recent large-scale studies, such as the NIH 'NIFTY Study', have reiterated that promise of this approach, but have reinforced also the consensus amongst researchers that current technology is not yet sufficiently advanced to permit routine use. The new observation of cell-free fetal DNA in maternal plasma has been eagerly seized upon by several research groups, who have shown in independent large-scale studies that this technology can be used for the extremely reliable identification of facile fetal genetic traits such as the fetal RhD status. Consequently, this approach has been the first to make the transition from the laboratory 'bench' to the 'bed'.

Congenital Abnormalities↗
PubMedDate not supplied

Fetal cells and cell-free fetal DNA in maternal blood: new insights into pre-eclampsia.

The examination of fetal cells, specifically erythroblasts, and cell-free fetal DNA from the blood of pregnant women is currently the subject of intense research with the aim of developing new risk-free methods for prenatal diagnosis. An unexpected finding made during these studies was that the traffic of fetal erythroblasts into the maternal peripheral circulation was enhanced in pre-eclampsia. Independent prospective studies examining samples collected in the second trimester indicated that this perturbation in fetal cell trafficking occurs early in pregnancy, well before the onset of pre-eclampsia symptoms. The quantitative analysis of cell-free fetal and maternal DNA levels indicated that these concentrations were elevated in a co-ordinate manner in manifest pre-eclampsia, and that these elevations corresponded to disease severity. On the other hand, analysis of prospectively collected samples indicated that only cell-free fetal but not maternal DNA levels were elevated before onset of symptoms in pregnancies which subsequently developed pre-eclampsia. These data support hypotheses suggesting that pre-eclampsia is a multi-step disorder, initiated by a placental lesion that occurs early in pregnancy and which subsequently leads to a systemic maternal inflammatory response and associated endothelial cell damage.

DNA↗