Low-dose peripheral blood stem cell graft after high-dose chemotherapy - an evaluation of hematopoietic reconstitution.
BACKGROUND
High-dose (HD) chemotherapy followed by autologous blood stem-cell transplantation (ASCT) is the standard treatment for multiple myeloma (MM) patients. However, the collection of sufficient peripheral blood stem cell (PBSC) grafts can be challenging, and the question arises whether reinfusion of low-dose grafts will lead to a hematopoietic recovery.


METHODS
The hematopoietic recovery of 148 MM patients who underwent HD melphalan chemotherapy and received PBSC transplants with varying CD34+ cells doses (3-4 × 106 [n = 86], 2-2.5 × 106 [n = 53], < 2 × 106 [n = 9] per kg body weight [bw]) was analyzed in this retrospective single-center study.


RESULTS
All patients reached hematopoietic reconstitution, even those who received < 2 × 106 CD34+ cells/kg bw. 62 (42%) patients received granulocyte-colony-stimulating factor (G-CSF). The median duration to leukocyte recovery ≥1.0 × 109/L was 12 days in every group. The median duration to platelet recovery ≥20 × 109/L was 11, 13 and 13 days, respectively. In the multivariate analysis, a low number of reinfused CD34+ cells was associated with prolonged time until leukocyte reconstitution (p = 0.010, HR 0.607) and platelet recovery (p < 0.001, HR 0.438). G-CSF support significantly accelerated leukocyte (p < 0.001, HR 16.742) but not platelet reconstitution.


CONCLUSION
In conclusion, reinfusion of low- and even very-low-dose PBSC grafts leads to sufficient hematopoietic reconstitution. No severe adverse events were observed during or after HD chemotherapy and ASCT in the analyzed cohort. While the impact of CD34+ cell dose is marginal, G-CSF significantly accelerates the leukocyte recovery.
['Sauer|Sandra|S|', 'Pavel|Petra|P|', 'Schmitt|Anita|A|', 'Cremer|Martin|M|', 'Kriegsmann|Mark|M|', 'Bruckner|Thomas|T|', 'Jordan|Karin|K|', 'Wuchter|Patrick|P|', 'Müller-Tidow|Carsten|C|', 'Kriegsmann|Katharina|K|']
D000328:Adult D000368:Aged D000971:Antineoplastic Combined Chemotherapy Protocols D003131:Combined Modality Therapy D005260:Female D005500:Follow-Up Studies D019650:Hematopoietic Stem Cell Mobilization D006412:Hematopoietic Stem Cells D006801:Humans D008297:Male D008875:Middle Aged D009101:Multiple Myeloma D036102:Peripheral Blood Stem Cell Transplantation D000072916:Peripheral Blood Stem Cells D011379:Prognosis D012189:Retrospective Studies D015996:Survival Rate D014182:Transplantation, Autologous
Peripheral blood stem cells Multiple myeloma Autologous stem-cell transplantation Insufficient graft