High-dose CD34+ cells are not clinically relevant in reducing cytopenia and blood component consumption following myeloablative therapy and peripheral blood progenitor cell transplantation as compared with standard dose.
BACKGROUND
No agreement exists about the number of autologous peripheral blood progenitor cells (PBPCs) to transfuse for optimal hematologic recovery after high-dose chemotherapy.


METHODS
To determine CD34+ cell dosage following high-dose chemotherapy (in terms of hematologic recovery and blood component consumption), the effects of two schedules of CD34+ cell transfusions in a cohort of patients with myeloma or non-Hodgkin's lymphoma were examined. Forty patients (Group 1) received between 2.5 and 5 x 106 CD34+ cells per kg, with a median of 3.4 x 106 per kg following high-dose chemotherapy, and 40 patients (Group 2), selected to match Group 1 for age, diagnosis, prior therapies, and procedure for PBPC mobilization, received a dose of CD34+ cells >5 x 106 per kg, with a median of 8.4 x 106 per kg (5-33).


RESULTS
The median number of days to achieve a neutrophil count of >0.5 x 109 per L and unsupported platelets of >20 x 109 per L was identical for the two groups, but the time required to reach 1.5 x 109 neutrophils per L and 50 x 109 platelets per L was greatly delayed in Group 1. No significant difference was observed for the median number of RBC and platelet transfusions, or for the proportion of patients in each group that did not require either platelet or RBC transfusions.


CONCLUSIONS
Our data confirm a dose-response relationship between CD34+ cell dose transfused and time to hematologic recovery after high-dose chemotherapy. However, the minimal Hb and platelet counts for transfusion independence in the two groups are similar when the CD34+ cell dose is greater than 5 x 106 CD34+ cells per kg. Therefore, our data suggest that it is not necessary to go on with apheresis procedures after 5 x 106 CD34+ cells per kg are harvested to sustain one high-dose chemotherapy.
Lefrère
François
F
Department of Hematology and the Blood Center, Necker Hospital, Paris, France. francois.lefrere@nck.ap-hop-paris.fr
Delarue
Richard
R
Somme
Dominique
D
Levy
Vincent
V
Damaj
Gandhi
G
Tu
Angela
A
Porcher
Raphael
R
Audat
Françoise
F
Boulat
Claire
C
Cavazzana-Calvo
Marine
M
Buzyn
Agnès
A
Belanger
Coralie
C
Maillard
Natacha
N
Hermine
Olivier
O
Varet
Bruno
B
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000032:analysis*; D000970:Antineoplastic Agents / Q000008:administration & dosage; D016913:Blood Component Transfusion; D002452:Cell Count; D017707:Erythrocyte Transfusion; D005260:Female; D006085:Graft Survival; D006402:Hematologic Diseases / Q000139:chemically induced / Q000628:therapy*; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D006801:Humans; D007958:Leukocyte Count; D007970:Leukopenia / Q000139:chemically induced / Q000628:therapy; D008228:Lymphoma, Non-Hodgkin / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000628:therapy; D009504:Neutrophils; D017713:Platelet Transfusion; D019172:Transplantation Conditioning
D018952:Antigens, CD34; D000970:Antineoplastic Agents