A New Marker Set That Identifies Fetal Cells in Maternal Circulation with High Specificity.

OBJECTIVE:Fetal cells from the maternal circulation (FCMBs) have the potential to replace cells from amniotic fluid or chorionic villi in a diagnosis of common chromosomal aneuploidies. Good markers for enrichment and identification are lacking.METHOD:Blood samples from 78 normal pregnancies were used for testing the marker-set CD105 and CD141 for fetal cell enrichment. Fetal cell candidates were subsequently stained by a cocktail of cytokeratin antibodies, and the gender of the fetal cells was explored by fluorescence in situ hybridization (FISH) of the X and Y chromosomes.RESULTS:Fetal cell candidates could be detected in 91% of the samples, and in 85% of the samples, it was possible to obtain X and Y chromosomal FISH results for gender determination. The concordance between gender determined by FISH on fetal cells in maternal blood and gender found at birth reached 100% if three or more fetal cells with FISH signals could be found in a sample.CONCLUSION:The marker set identifies fetal cells with specificity high enough to make cell-based noninvasive prenatal diagnosis realistic.