Prenatal Diagnosis of Genetic Abnormalities Using Fetal CD34⁺Stem Cells in Maternal Circulation and Evidence They Do Not Affect Diagnosis in Later Pregnancies

Abstract

In the present study, we report a new method for enrichment and analysis of fetal CD34 + stem cells after culture in order to determine whether it is feasible for noninvasive prenatal diagnosis. We also determined whether fetal CD34 + stem cells persist in maternal blood after delivery and assessed whether they have an impact on noninvasive prenatal diagnosis of genetic abnormalities.Peripheral blood samples were obtained from 35 pregnant women, 13 non-pregnant women who had given birth to male offsprings, 12 women who had never been pregnant, and eight pregnant women with male fetuses. CD34 + stem cells were enriched and either cultured for prenatal diagnosis or analyzed with fluorescence in situ hybridization (FISH)/polymerase chain reaction (PCR) to determine peristance in maternal blood. Fetal/maternal cells can be isolated and grown "in vitro" to provide enough cells for a more accurate fetal sex or aneuploid prediction than is provided by unenriched and uncultured CD34+ stem cells. The presence of fetal cells in maternal blood samples from mothers who had given birth to male offspring was found in 3 of 13 blood samples. PCR was positive for Y chromosome in one woman who had never been pregnant. Analysis of cultured CD34 + stem cells from mothers with Y PCR positivity did not detect any male cells in any samples. Even if PCR positivity is due to persistence of fetal stem cells from previous pregnancies, it does not seem to affect this new system of enrichment, culture, and FISH analysis of CD34 + fetal stem cells.

Invasive und nichtinvasive fetale Chromosomenanalyse

“…Im fetalen Blut liegen noch viele kernhaltige "jugendliche" rote Blutzellen ("nucleated red blood cells") vor, die sich in erster Linie für eine Untersuchung eignen, doch auch Lymphozyten und Granulozyten gelangen in den maternalen Kreislauf und können dann für eine Analyse in Betracht kommen [18]. Auch vitale fetale Stammoder Vorläuferzellen sind für die Untersuchung geeignet [7,8,15,22]. Fetale Zellbestandteile (fetale DNS) können nicht nur im maternalen Plasma, sondern auch im mütterlichen Urin und im Zervixschleim gefunden werden [14,19,23].…”

Aneuploidy screening using circulating fetal cells in maternal blood by dual‐probe FISH protocol: a prospective feasibility study on a series of 172 pregnant women

“…) appears as an exceptional event (accounting for 1–3 cells in 20 mL maternal blood) with very limited effect, if any, on the fetal cell search from the current pregnancy (Coata et al. , ; Guetta et al. ).…”

“…The very low number of fetal cells in maternal blood represents the most formidable obstacle for reliable genetic testing (Evans and Kilpatrick 2010;Fiddler 2014). In this context, the finding of fetal cells from prior pregnancies in maternal circulation (Bianchi et al 1996) appears as an exceptional event (accounting for 1-3 cells in 20 mL maternal blood) with very limited effect, if any, on the fetal cell search from the current pregnancy (Coata et al 2001(Coata et al , 2009Guetta et al 2003).…”

Automatic retrieval of single microchimeric cells and verification of identity by on‐chip multiplex PCR

“…This cell type can be expanded after enrichment by subsequent short‐term culture [22]. Although biochemical markers exist for specific labelling of trophoblast cells and Hbɛ‐positive erythroblasts, allowing them to be allocated to a candidate fetal cell status under the conditions of rare cell analysis, the identification of the fetal character of other interesting target cells such as fetal stem cells or progenitor cells [23–25] relies almost exclusively on a molecular genetic basis, using Y‐FISH or multiplex PCR of polymorphic small tandem repeat (STR) loci. FISH has been optimized to fit rare cell conditions using two different Y probes [26] and reverse XY‐FISH [27] but the identification of fetal cells based on Y‐FISH does not allow for a diagnosis in the case of female foetuses.…”