Analysis of lymphocyte phenotypes in cord blood from early gestation fetuses

Clin Exp Immunol. 1992 Nov;90(2):345-50. doi: 10.1111/j.1365-2249.1992.tb07953.x.


Using cord blood samples obtained from fetuses between 16 and 40 weeks gestation, we have used a lysed whole blood flow cytometric technique to study the natural history of lymphocyte phenotypes known to be highly represented in cord blood at birth. The majority (51.0 +/- 14.7%) of lymphocytes expressed CD45RA, a marker of 'virgin' cells and there was a correlation between increasing percentages of CD45RA+lymphocytes and gestational age (r = 0.44, P < 0.01). Few cells (8.5 +/- 4.2%) expressed the CD45RO marker of primed lymphocytes and very few (1.0 +/- 0.7%) co-expressed CD45RA and RO, indicating little traffic between the two maturation markers. The percentage of B lymphocytes co-expressing CD5 was high in the fetal circulation (55.5 +/- 10.5%) compared with healthy adults (23.2 +/- 14.3%; P < 0.00001) and the level of CD5+ B cells declined with gestational age in an exponential manner (r = -0.45, P < 0.05). Similarly, levels of T lymphocytes expressing the gamma delta T cell receptor (TCR) declined exponentially (r = -0.59, P < 0.005). These results demonstrate that lymphocytes remain almost entirely unprimed before birth. In addition, CD5+ B lymphocytes and TCR-gamma delta+ T lymphocytes decline exponentially towards birth, in a manner suggesting that they may be seeding peripheral sites such as the spleen, skin and mucosae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / metabolism*
  • Antigens, CD20
  • Antigens, Differentiation, B-Lymphocyte / metabolism
  • CD5 Antigens
  • Fetal Blood / cytology*
  • Gestational Age
  • Humans
  • Leukocyte Common Antigens / metabolism
  • Lymphocyte Subsets / cytology*
  • Receptors, Antigen, T-Cell, alpha-beta / metabolism
  • Receptors, Antigen, T-Cell, gamma-delta / metabolism


  • Antigens, CD
  • Antigens, CD20
  • Antigens, Differentiation, B-Lymphocyte
  • CD5 Antigens
  • Receptors, Antigen, T-Cell, alpha-beta
  • Receptors, Antigen, T-Cell, gamma-delta
  • Leukocyte Common Antigens