title: Abnormal fetal immunological development in Down's syndrome.
abstract: OBJECTIVE
  To investigate the intrauterine development of the immune system in Down's syndrome.
  
  
  METHODS
  Cross sectional study.
  
  
  METHODS
  Harris Birthright Research Centre for Fetal Medicine, London, UK.
  
  
  METHODS
  16 fetuses with Down's syndrome and 104 fetuses with a normal karyotype at 17-24 weeks gestation.
  
  
  METHODS
  Flow cytometry was used to enumerate T (CD3+), B (CD19+) and NK (CD3- & CD16+/CD56+) lymphocyte subpopulations in fetal blood obtained by cordocentesis.
  
  
  RESULTS
  The median numbers of T, B and NK lymphocytes in fetuses with Down's syndrome (1.52 x 10(9)/l, 0.08 x 10(9)/l, and 0.10 x 10(9)/l, respectively) were significantly lower than in the chromosomally normal fetuses (T lymphocytes: 1.98 x 10(9)/l, z = 3.04, P < 0.01; B lymphocytes: 0.50 x 10(9)/l, z = 5.84, P < 0.0001; and NK lymphocytes: 0.19 x 10(9)/l, z = 3.14, P < 0.01).
  
  
  CONCLUSIONS
  These data demonstrate that in Down's syndrome, there is abnormal intra-uterine development of the immune system.
authors.affiliation: Department of Obstetrics and Gynaecology, King's College School of Medicine and Dentistry, Denmark Hill, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Thilaganathan
authors.forename: D
authors.initials: D
authors.lastname: Tsakonas
authors.forename: K
authors.initials: K
authors.lastname: Nicolaides
mesh_terms: D001402:B-Lymphocytes / Q000502:physiology; D003430:Cross-Sectional Studies; D004314:Down Syndrome / Q000276:immunology*; D005865:Gestational Age; D006801:Humans; D007107:Immune System / Q000196:embryology*; D007694:Killer Cells, Natural / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology