title: Fetal blood natural killer cells in human pregnancy.
abstract: Flow cytometry was used to determine the number of circulating natural killer (NK) cells in 170 pregnancies undergoing cordocentesis for prenatal diagnosis at 17-38 weeks gestation and 16 undergoing cardiocentesis before social termination of pregnancy at 13-17 weeks. The number of NK cells decreased exponentially with gestation from a mean of 0.26 x 10(9)/l at 13 weeks to 0.09 x 10(9)/l at 38 weeks (r = -0.356, p < 0.001). When expressed as a percentage of the total number of lymphocytes, the proportion of NK cells decreased from a mean of 29% at 13 weeks to 6% at 38 weeks (r = 0.680, p < 0.0001). These data suggest that in early pregnancy the fetal immune response is dependent on innate rather than adaptive mechanisms.
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital School of Medicine, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Thilaganathan
authors.forename: A
authors.initials: A
authors.lastname: Abbas
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D017218:Cordocentesis; D003430:Cross-Sectional Studies; D005260:Female; D005312:Fetal Blood / Q000166:cytology*; D005333:Fetus / Q000276:immunology*; D005434:Flow Cytometry; D005865:Gestational Age; D006801:Humans; D007111:Immunity, Cellular; D007694:Killer Cells, Natural; D007958:Leukocyte Count; D011247:Pregnancy; D012044:Regression Analysis