Culture conditions affect the ability of ex vivo expanded peripheral blood progenitor cells to accelerate hematopoietic recovery.
OBJECTIVE
The aim of this study was to evaluate the effect of various ex vivo expansion conditions on the cell products and their ability to accelerate hematopoietic recovery in patients undergoing stem cell transplantation.


METHODS
Unselected peripheral blood progenitor cells (PBPCs) from 43 breast cancer patients were seeded into gas-permeable bags containing serum-free media, granulocyte colony-stimulating factor, stem cell factor, and pegylated megakaryocyte growth and development factor. Between 2 and 24 x 10(9) PBPCs were cultured at 1, 2, or 3 x 10(6) cells/mL for 9 to 14 days. The expanded PBPCs and cryopreserved PBPCs containing at least 5 x 10(6) CD34(+) cells/kg were infused following completion of high-dose chemotherapy.


RESULTS
Increasing culture duration from 9 to 11-14 days significantly improved the expanded cell yield and fold expansion, whereas increasing PBPC seeding density above 10(6) cells/mL had the opposite effect. The expanded cell dose was the only culture variable that correlated significantly with the time to neutrophil recovery (r = -0.66; p = 0.0001). Study patients had significantly faster neutrophil (p < 0.0001) and platelet (p = 0.001) recovery, reduced red cell transfusions (p = 0.01), and shorter hospital stays (p < 0.0001) than historical controls. The most clinically efficacious expanded cell product was seeded with 10(10) PBPCs at 10(6) cells/mL, then cultured for 11 days. The six patients in that cohort experienced 2.8 +/- 1 days of absolute neutropenia and had neutrophil recovery 5.7 +/- 0.8 days post-transplant; none had a neutropenic fever or required intravenous antibiotics.


CONCLUSIONS
Unselected PBPCs expanded ex vivo significantly impact hematopoietic recovery following high-dose therapy. Optimization of the expansion conditions enhances the efficacy of this cell product.
Paquette
Ronald L
RL
Department of Medicine, Division of Hematology/Oncology, 42-121 UCLA Center for the Health Sciences, 10833 Le Conte Avenue, Los Angeles, CA 90095-1678, USA. paquette@ucla.edu
Dergham
Sanaa T
ST
Karpf
Ellen
E
Wang
He-Jing
HJ
Slamon
Dennis J
DJ
Souza
Larry
L
Glaspy
John A
JA
D001943:Breast Neoplasms / Q000628:therapy; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods; D005260:Female; D006085:Graft Survival; D006410:Hematopoiesis; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006760:Hospitalization; D006801:Humans; D007937:Leukapheresis; D009503:Neutropenia / Q000209:etiology; D009504:Neutrophils / Q000166:cytology; D013997:Time Factors; D014182:Transplantation, Autologous / Q000009:adverse effects / Q000379:methods