Comparison of the coexpression of CD38, CD33 and HLA-DR antigens on CD34+ purified cells from human cord blood and bone marrow.
Human umbilical cord blood (UCB) cells are currently considered as a potential source of stem cells for transplantation. However, it remains unclear whether a single collection of UCB contains enough progenitors to allow a successful engraftment in adult patients. We were interested in the comparison of the frequency of primitive progenitors in UCB and in human bone marrow (BM). UCB and BM CD34+ cells were purified and compared for their coexpression of CD38, CD33 and HLA-DR. UCB and BM mononuclear fractions were enriched in CD34+ cells using the CEPRATE LC system (CellPro, Bothell, WA). Double-labeling analysis with a flow cytometer showed that 67.9 +/- 7.2% of UCB CD34+ cells are CD38-, while in BM only 10.9 +/- 4.9% of CD34+ are CD38- (p < 0.001). Moreover, our study indicated that a significantly higher percentage of UCB CD34+ is CD33- (97.1 +/- 1.2%) compared to BM (61.8 +/- 8.6%) (p = 0.013). The coexpression of CD34 with HLA-DR was not significantly different in UCB and in BM (respectively, 86.3 +/- 2.7% and 92.7 +/- 5.1%). On the other hand, in vitro assays showed that the number of multipotent (colony-forming units granulocyte-erythroid-macrophage-megakaryocyte [CFU-GEMM]), myeloid (colony-forming units granulocyte-macrophage [CFU-GM]) and erythroid (burst-forming units-erythroid [BFU-E]) progenitors is lower in the CD34+ population from UCB than from BM. In conclusion, in UCB, we have found a significantly higher percentage of CD34+ cells which lacked the expression of CD38 and CD33 antigens suggesting that UCB contains higher proportions of immature progenitor cells (CD34+CD38- and CD34+CD33-) than BM. It seems thus likely that fewer UCB CD34+ cells than BM CD34+ cells would be required for sustained engraftment following transplantation.
De Bruyn
C
C
Service de Médecine Interne et Laboratoire d'Investigation Clinique Henri Tagnon, Institut Jules Bordet, Brussels, Belgium.
Delforge
A
A
Bron
D
D
Bernier
M
M
Massy
M
M
Ley
P
P
de Hemptinne
D
D
Stryckmans
P
P
D015703:Antigens, CD / Q000032:analysis* / Q000097:blood; D001854:Bone Marrow Cells; D002469:Cell Separation; D015672:Erythroid Precursor Cells / Q000166:cytology / Q000276:immunology*; D005312:Fetal Blood / Q000166:cytology*; D006684:HLA-DR Antigens / Q000032:analysis* / Q000097:blood; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans
D015703:Antigens, CD; D006684:HLA-DR Antigens