title: Fetal cells in maternal plasma are found in a late state of apoptosis.
abstract: OBJECTIVE
  The present study was designed to give possible answers to some of the discrepancies regarding the presence or not of intact fetal cells in maternal plasma during pregnancy.
  
  
  METHODS
  12-mL peripheral blood was collected from 33 pregnant women in the second trimester: 6 mL was harvested by 3-step Percoll gradient centrifugation and plasma cells were analyzed by FISH with X/Y chromosome specific probes. From the remaining 6 mL, plasma-derived cells were isolated with three different gradient centrifugation protocols and apoptosis was determined following EthBr staining.
  
  
  RESULTS
  The number of cells recovered ranged from 900 to 3000. At least one Y positive signal was seen in 12 out of 17 cases with male fetuses at a frequency of 0.12% (range 0.05-0.27%). No XY cells were detected in the plasma of women carrying female fetuses. Hybridization efficiency was <60%. EthBr staining demonstrated that the majority of these cells were in their late apoptosis.
  
  
  CONCLUSIONS
  Our findings confirm the presence of intact fetal apoptotic cells in maternal plasma; however, their late apoptotic state and the low number does not as yet encourage their use in clinical practice.
authors.affiliation: Department of Medical Genetics, Athens University School of Medicine Aghia Sophia Children's Hospital, Athens, Greece. akolial@cc.uoa.gr
authors.forename: Aggeliki
authors.initials: A
authors.lastname: Kolialexi
authors.forename: George Th
authors.initials: GT
authors.lastname: Tsangaris
authors.forename: Aris
authors.initials: A
authors.lastname: Antsaklis
authors.forename: Ariadni
authors.initials: A
authors.lastname: Mavrou
mesh_terms: D017209:Apoptosis; D002498:Centrifugation; D005260:Female; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis; D013194:Staining and Labeling