A preliminary analysis of the balance between Th1 and Th2 cells after CD34+ cell-selected autologous PBSC transplantation.
BACKGROUND
CD34+ cell-selected autologous PBSC transplantation (CD34+ APBSCT) is a procedure used for the treatment of patients with malignant disease that is intended to eliminate residual tumor cells from autologous grafts. However, frequent infectious complications after CD34+ APBSCT can occur. A delay of recovery of the absolute number of CD4+ T cells after transplantation was reported to be one disadvantageous factor. As data on T-cell function after CD34+ APBSCT are scanty, we analyzed changes in T-helper cell 1 (Th1) and T-helper cell 2 (Th2) after CD34+ APBSCT to evaluate immune reconstitution.


METHODS
Twelve patients underwent APBSCT (CD34+APBSCT group, n=4, and unselected APBSCT, n=8). Peripheral blood (PB) samples were obtained at 2, 4, 8, 12 and 16 weeks after the transplantation. The dynamics of the Th1 and Th2 were analyzed at a single-cell level, using flow cytometry.


RESULTS
In the CD34+ APBSCT group, not only the absolute count of CD4+ T cells but also the proportion of Th1 cells in CD4+ T cells and the ratio of Th1 to Th2 after transplantation were significantly decreased at 2 and 4 weeks after transplantation compared with findings in the unselected APBSCT group.


CONCLUSIONS
We suggest that higher rates of infectious complications after CD34+ APBSCT may be due to the inability of residual T cells from the CD34+ cell selection to generate mature T cells that function adequately against infection. Although further study would be required, our preliminary data provide some information on the immune reconstitution after CD34+ APBSCT and differentiation of T lymphocytes into Th1 and Th2 in vivo.
Endo
T
T
Department of Internal Medicine II Hokkaido University Graduate School of Medicine Sapporo Japan.
Sato
N
N
Koizumi
K
K
Nishio
M
M
Fujimoto
K
K
Yamamoto
S
S
Sakai
T
T
Bohgaki
T
T
Sawada
K
K
Koike
T
T
D000328:Adult; D018952:Antigens, CD34 / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D006084:Graft Rejection; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000097:blood / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood / Q000628:therapy; D036102:Peripheral Blood Stem Cell Transplantation; D012595:Scleroderma, Systemic / Q000097:blood / Q000628:therapy; D018417:Th1 Cells / Q000378:metabolism / Q000473:pathology*; D018418:Th2 Cells / Q000378:metabolism / Q000473:pathology*; D014182:Transplantation, Autologous
D018952:Antigens, CD34