Autografting with CD34+ peripheral blood stem cells: retained engraftment capability and reduced tumour cell content.
The efficacy of an immunomagnetic purging method and the Isolex 300 devices were assessed for selecting CD34+ cells from leukapheresis products of 29 patients with non-Hodgkin's lymphoma (NHL), 39 with multiple myeloma and 34 with breast cancer. The mean purity of the CD34+ cell population was 93.6% and the mean recovery was 67.7%. Following enzymatic cleavage by chymopapain the expression of Thy-1 and Leu-8 was significantly reduced without affecting haematological recovery. The population of selected CD34+ cells of 4/8 patients with follicular lymphoma became PCR-negative. A 2.5 log reduction of tumour cells could be achieved in four patients with multiple myeloma as shown by a quantitative PCR assay. There were no tumour cells detectable in any of the 19 CD34+ cell preparations of patients with breast cancer. In 64 patients who received 94 cycles of high-dose therapy, a mean number of 4.7x 10(6) CD34+ cells/kg were autografted. The time needed for platelet reconstitution was different when a comparison was made with 156 patients, who had received unmanipulated leukapheresis products (10 v 12 d, P = 0.006). No significant differences with regard to neutrophil recovery were noted. Five patients had a graft failure. Two of them died (on day 78 and 88 following PBSCT), and three patients were rescued with unmanipulated back-up transplants. In conclusion, the immunomagnetic selection of CD34+ cells provides autografts with reduced tumour cell content and an engraftment ability similar to that of unmanipulated autografts.
German Cancer Research Centre, Heidelberg.
M T
MT
Voso
S
S
Hohaus
M
M
Moos
M
M
Pförsich
F W
FW
Cremer
R F
RF
Schlenk
S
S
Martin
U
U
Hegenbart
H
H
Goldschmidt
R
R
Haas
D018952:Antigens, CD34; D001792:Blood Platelets / Q000473:pathology; D001943:Breast Neoplasms / Q000628:therapy*; D005260:Female; D019337:Hematologic Neoplasms / Q000628:therapy*; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual; D009504:Neutrophils / Q000473:pathology; D014182:Transplantation, Autologous
D018952:Antigens, CD34