CD34(+) Cell Mobilization, Autograft Cellular Composition and Outcome in Mantle Cell Lymphoma Patients

BACKGOUND: Autologous stem cell transplantation (ASCT) is a standard treatment in transplant-eligible mantle cell lymphoma (MCL) patients after first-line chemoimmunotherapy. STUDY DESIGN AND METHODS: This prospective multicenter study evaluated the impact of CD34(+) cell mobilization and graft cellular composition analyzed by flow cytometry on hematologic recovery and outcome in 42 MCL patients. RESULTS: During CD34(+) cell mobilization, a higher blood CD34(+) cell count (>30 × 10(6)/L) was associated with improved overall survival (median not reached [NR] vs. 57 months, p = 0.04). The use of plerixafor did not impact outcome. Higher number of viable cryopreserved graft CD34(+) cells (>3.0 × 10(6)/kg) was associated with faster platelet (median 11 vs. 15 days, p = 0.03) and neutrophil (median 9 vs. 10 days, p = 0.02) recovery posttransplant. Very low graft CD3(+)CD8(+) cell count (≤10 × 10(6)/kg) correlated with worse progression-free survival (PFS) (HR 4.136, 95% CI 1.547–11.059, p = 0.005). On the other hand, higher absolute lymphocyte count >2.5 × 10(9)/L at 30 days after ASCT (ALC-30) was linked with better PFS (median NR vs. 99 months, p = 0.045) and overall survival (median NR in either group, p = 0.05). CONCLUSIONS: Better mobilization capacity and higher graft CD3(+)CD8(+) cell count had a positive prognostic impact in this study, in addition to earlier lymphocyte recovery (ALC-30>2.5 × 10(6)/L). These results need to be validated in another study with a larger patient cohort.