Abnormal fetal immunological development in Down's syndrome.
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.
Thilaganathan
B
B
Department of Obstetrics and Gynaecology, King's College School of Medicine and Dentistry, Denmark Hill, London, UK.
Tsakonas
D
D
Nicolaides
K
K
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