Stem Cells, Vol 13, 548-555, Copyright © 1995 by AlphaMed Press
Quantitative and qualitative comparative analysis of gradient-separated hematopoietic cells from cord blood and chemotherapy-mobilized peripheral blood
J Sato, Y Kawano, Y Takaue, A Hirao, A Makimoto, Y Okamoto, T Abe, T Shimokawa, A Iwai and Y Kuroda
Department of Pediatrics, University Hospital of Tokushima, Japan.
Some of the uncertainty regarding the use of cord blood (CB) in transplant
settings includes the suspected relative rarity of hematopoietic stem cells
(SC) in CB and the feasibility of incorporating a cell separation protocol
to remove red blood cells, which may result in an unacceptable loss of SC.
To address this uncertainty, we isolated a SC fraction by Percoll or Ficoll
gradients from CB and peripheral blood (PB), which had been mobilized by
chemotherapy. The frequencies of mononuclear cells (MNC), CD34+ cells,
colony-forming units granulocyte-macrophage (CFU-GM), and the output of
colony-forming cells (CFC) after five weeks in long-term culture (LTC)
assay were then evaluated. The mean numbers of these cells per ml of CB
sample before gradient separation were, respectively, 4.9 x 10(6), 13.8 x
10(4), 3.0 x 10(3) and 681 (n = 37). In the recovery phase of PB, these
numbers were, respectively, 2.0 x 10(6), 14.9 x 10(4), 3.5 x 10(3) and 270
per ml of processed blood at apheresis (n = 35). After Percoll separation,
the recovery rates of these cells were, respectively, 29%, 92%, 97% and 95%
in CB, and 65%, 87%, 123% and 102% in PB. After Ficoll separation of CB,
the rates were, respectively, 55%, 107%, 92% and 105%. These results
suggest that CB contains an adequate number of more immature progenitors
which can be retained after cell separation with Percoll or Ficoll, thereby
making it feasible to incorporate a cell processing procedure into a CB
transplant protocol. Percoll separation provided a greater enrichment of
cells than Ficoll.
