CD34+ cells from first-trimester fetal blood are enriched in primitive hemopoietic progenitors.
OBJECTIVE
The purpose of this study was to investigate whether purified CD34(+) cells from first-trimester fetal blood are a source of primitive and committed hemopoietic progenitors.


METHODS
CD34(+) cells from first-trimester fetal blood and term cord blood were assayed for committed hemopoietic progenitor cells, high proliferative potential colony-forming cells, and long-term culture-initiating cells.


RESULTS
First-trimester CD34(+) cells that were compared with cells at term generated fewer hemopoietic progenitor cells and fewer high proliferative potential colony-forming cells with lower recloning efficiency(P <.001). First-trimester CD34(+) cells tended to contain more long-term culture-initiating cells, both in bulk cultures and by limiting dilution analysis. The ratio between committed and primitive progenitors was 3 in the first-trimester and 20 in the term cord blood, respectively.


CONCLUSIONS
First-trimester fetal blood is enriched in primitive (compared with committed) hemopoietic progenitors and may be an advantageous source of stem cells for prenatal therapy.
Tocci
Angelo
A
Wolfson and Weston Research Centre for Family Health, Institute of Reproductive and Developmental Biology, London, United Kingdom.
Roberts
Irene A G
IA
Kumar
Sailesh
S
Bennett
Phillip R
PR
Fisk
Nicholas M
NM
D018952:Antigens, CD34 / Q000032:analysis*; D001773:Blood Cells / Q000166:cytology* / Q000276:immunology*; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D005260:Female; D005312:Fetal Blood; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D013997:Time Factors
D018952:Antigens, CD34