Factors predicting engraftment of autologous blood stem cells: CD34+ subsets inferior to the total CD34+ cell dose.
Data were analyzed on 178 consecutive patients (median age 43 years) who underwent autologous blood stem cell transplantation (ABSCT) at a single institution to determine if CD34+ subsets (CD34+38-, CD34+33-, CD34+33+, CD34+41+) or various clinical factors affect hematopoietic engraftment independent of the total CD34+ cell dose/kg. Using Cox proportional hazards models, the factors independently associated with rapid neutrophil engraftment were higher CD34+ dose/kg, use of G-CSF post-ABSCT, and conditioning regimen (single-agent melphalan +/- TBI slower). Factors independently associated with rapid platelet engraftment were higher CD34+ cell dose/kg, higher ratio of CD34+33-/total CD34+ cells infused, conditioning regimen (mitoxantrone, vinblastine, cyclophosphamide faster), and no CD34+ cell selection of the autograft. The CD34+ cell selection process seemed to deplete CD34+41+ cells to a greater extent than total CD34+ cells which may explain our observation that it resulted in slower platelet engraftment. In conclusion, the total CD34+ dose/kg was a better predictor of hematopoietic engraftment following ABSCT than the dose of any CD34+ subset. Platelet engraftment, however, was also influenced by the ratio of CD34+33-/total CD34+ cells for unmanipulated autografts, and possibly by the CD34+41+ dose for autografts manipulated by CD34+ selection. The use of CD34+ subsets requires further investigation in predicting engraftment of autografts which undergo ex vivo manipulation.
Department of Medicine, Tom Baker Cancer Centre, Foothills Hospital and University of Calgary, Alberta, Canada.
D A
DA
Stewart
D
D
Guo
J
J
Luider
I
I
Auer
J
J
Klassen
E
E
Ching
D
D
Morris
A
A
Chaudhry
C
C
Brown
J A
JA
Russell
D000328:Adult; D018952:Antigens, CD34; D002469:Cell Separation; D005260:Female; D005434:Flow Cytometry; D006085:Graft Survival; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D014182:Transplantation, Autologous
D018952:Antigens, CD34