Allogeneic peripheral blood stem cell transplantation results in less alteration of early T cell compartment homeostasis than bone marrow transplantation.
Since low T cell counts evaluated 1 month after allogeneic bone marrow transplantation (BMT) are associated with an increased risk of leukemia relapse (Powles et al., Blood 1998; 91: 3481-3486), we compared, in a randomized multicentric clinical study, the peripheral blood cells obtained 30 days after allogeneic BMT vs allogeneic G-CSF-mobilized peripheral blood stem cell transplantation (BCT) in an HLA-identical setting. T cell counts were higher 30 days after BCT (718+/-142 cells/microl, n = 20) than after BMT (271+/-53 cells/microl, n = 26, P = 0.006). However, T cells were less activated after BCT than after BMT, as demonstrated by a lower expression level of CD25 and a lower percentage of HLA-DR+ and CD95+ T cells. Furthermore, CD4+, CD8+ and CD45RA+ post-BCT T cell counts correlated with the number of cells infused with the PBSC graft, while such a correlation was not observed between post-BMT counts and BM graft cell numbers, suggesting that the intensity of post-transplant peripheral lymphoid expansion and/or deletion differed between BCT and BMT. A comparison of the input of T cells expressing different CD45 isoforms with the post-transplant cell recovery further confirmed that, within the CD4+ T cell subset, post-transplant expansions occurred at a higher level after BMT than after BCT, affecting mainly the CD4+ CD45RO+ subset. Altogether, our data demonstrate for the first time in a randomized setting that homeostasis of the T cell pool is less altered early after BCT than after BMT. This may have a strong impact on the graft-versus-leukemia (GVL) effect and subsequent relapse rate.
Tayebi
H
H
Etablissement Français du Sang-Bourgogne/Franche-Comté, Besaçon, France.
Tiberghien
P
P
Ferrand
C
C
Lienard
A
A
Duperrier
A
A
Cahn
J Y
JY
Lapierre
V
V
Saas
P
P
Kuentz
M
M
Blaise
D
D
Hervé
P
P
Robinet
E
E
D000328:Adult; D015703:Antigens, CD; D016026:Bone Marrow Transplantation; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D019650:Hematopoietic Stem Cell Mobilization; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007938:Leukemia / Q000276:immunology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*; D014181:Transplantation Immunology; D014184:Transplantation, Homologous
D015703:Antigens, CD; D016179:Granulocyte Colony-Stimulating Factor