Abstract
Background
The lymphocyte dose (LY-DO) infused during an autograft influences absolute lymphocyte (ALC) recovery and survival following autologous stem cell transplantation (ASCT) in multiple myeloma (MM) patients. Factors influencing lymphocyte yield (LY-C) during leukapheresis have been poorly studied.
Methods
Factors that could influence survival, LY-C and CD34+ cell yield were analyzed in 122 MM patients. Three mobilization regimens were used, granulocyte–colony-stimulating factor (G-CSF) alone (n=13), cyclophosphamide 1–2 g/m2 plus G-CSF (LD-CY, n=62) and cyclophosphamide 3–4 g/m2 and G-CSF (ID-CY, n=47).
Results
Using multivariate analysis, age, LY-C, ALC on day 30 (ALC-30) and International Staging System stage significantly influenced overall (OS) and progression-free survival (PFS) following ASCT. PFS (56 versus 29 months, P=0.05) and OS (72 versus 49 months; P=0.07) were longer in the LY-C≥0.12×109/kg group than the LY-C<0.12×109/kg group. LY-C also influenced ALC on day 15 (ALC-15). Mobilization regimen, lymphocytes on the day of leukapheresis, prior radiotherapy and number of leukaphereses significantly influenced LY-C. Significantly higher LY-C was obtained with G-CSF alone compared with the LD-CY and ID-CY groups. CD34+ count on the day of leukapheresis, prior chemotherapy with prednisone, cyclophosphamide, adriamycin and BCNU or melphalan, and stem cell mobilization regimen significantly influenced CD34+ cell yield.
Discussion
LY-C influenced ALC-15 and survival following ASCT. Factors that influenced CD34+ cell yield and LY-C during leukapheresis were different. Mobilization should be tailored to maximize the LY-C and CD34+ cell yield.