Immune reconstitution after autologous selected peripheral blood progenitor cell transplantation: comparison of two CD34+ cell-selection systems.
BACKGROUND
Selection of CD34+ PBPCs has been applied as a method of reducing graft contamination from neoplastic cells. This procedure seems to delay lymphocyte recovery, while myeloid engraftment is no different from that with unselected PBPC transplants.


METHODS
Lymphocyte recovery was studied in two groups of patients who underwent autologous CD34+ PBPC transplant with two different technologies (Ceprate SC, Cellpro [n = 17]; CliniMACS, Miltenyi Biotech [n = 13]). The median number of CD34+ cells transfused was 3.88 x 10(6) per kg and 3.32 x 10(6) per kg, respectively. Residual CD3 cells x 10(6) per kg were 4.97 and 0.58, respectively (p = 0.041). Residual CD19 cells x 10(6) per kg were 1.33 and 0.73, respectively (NS).


RESULTS
No differences were found between the two groups in total lymphocyte recovery to >0.5 x 10(9) per L, which achieved a stable count by Day 30. During the study period, the CD4+ cell count remained below 0.2 x 10(9) per L, and the B-cell subset showed a trend toward normalization. CD3/HLA-DR+ and CD16/56 increased markedly in both groups by Day 30. An increase in CMV (13%) and adenovirus (17.4%) infection was found in both groups.


CONCLUSIONS
Both CD34+ cell selection technologies used here determined an excellent CD34+ cell purity and an optimal depletion of T cells. The high rate of viral complications is probably due to the inability of residual T cells left from the CD34+ cell selection to generate, immediately after transplant, an adequate number of virus-specific lymphocytes.
Laurenti
L
L
Department of Haematology, Catholic University School of Medicine, Rome, Italy. emacat@rm.unicatt.it
Sorà
F
F
Piccirillo
N
N
Chiusolo
P
P
Cicconi
S
S
Rutella
S
S
Serafini
R
R
Garzia
M G
MG
Leone
G
G
Sica
S
S
D000293:Adolescent; D000328:Adult; D018952:Antigens, CD34; D005260:Female; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007109:Immunity; D008297:Male; D008875:Middle Aged; D014181:Transplantation Immunology; D014182:Transplantation, Autologous
D018952:Antigens, CD34