Prolonged CD4 depletion after sequential autologous peripheral blood progenitor cell infusions in children and young adults.
Administration of mobilized peripheral blood progenitor cells (PBPCs) after high-dose chemotherapy rapidly restores multilineage hematopoiesis, but the ability of such products to restore lymphocyte populations remains unclear. In this report, we evaluated immune reconstitution in a series of patients treated with sequential cycles of high-dose chemotherapy, followed by autologous PBPC infusions (median CD34(+) cell dose 7.2 x 10(6) cells/kg [range 2-29.3]). Although patients experienced rapid reconstitution of B cells and CD8(+) T cells, we observed CD4 depletion and diminished immune responsiveness in all patients for several months after completion of therapy. Mature CD4(+) T cells contained within the grafts did not appear to contribute substantially to immune reconstitution because CD4 counts did not differ between recipients of unmanipulated T-cell replete infusions versus CD34 selected, T-cell-depleted infusions. Rather, at 12 months after therapy, total CD4 count was inversely proportional to age (rho = -0.78, P =.04), but showed no relationship to CD34 cell dose (rho = -0.42, P =.26), suggesting that age-related changes within the host are largely responsible for the limited immune reconstitution observed. These results demonstrate that in the autologous setting, the infusion of large numbers of PBPCs is not sufficient to restore T-cell immune competence and emphasize that specific approaches to enhance immune reconstitution are necessary if immune-based therapy is to be used to eradicate minimal residual disease after autologous PBPC transplantation. (Blood. 2000;96:754-762)
Mackall
C L
CL
Pediatric Oncology Branch, Medicine Branch, Experimental Immunology Branch, National Cancer Institute and Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, 20892 USA. cm35c@nih.gov
Stein
D
D
Fleisher
T A
TA
Brown
M R
MR
Hakim
F T
FT
Bare
C V
CV
Leitman
S F
SF
Read
E J
EJ
Carter
C S
CS
Wexler
L H
LH
Gress
R E
RE
D000293:Adolescent; D000328:Adult; D000375:Aging; D018952:Antigens, CD34 / Q000032:analysis; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage* / Q000627:therapeutic use; D001402:B-Lymphocytes; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes; D002648:Child; D002675:Child, Preschool; D006410:Hematopoiesis; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology; D006801:Humans; D007109:Immunity; D007694:Killer Cells, Natural; D018655:Lymphocyte Count; D009447:Neuroblastoma / Q000188:drug therapy; D012509:Sarcoma / Q000188:drug therapy; D014182:Transplantation, Autologous
D018952:Antigens, CD34