RESUMO
BACKGROUND: Guidelines recommend treatment with 4-5 days of granulocyte colony-stimulating factor (G-CSF) for optimal donor peripheral blood progenitor cell (PBPC) mobilization followed by day 5 collection. Given that some autologous transplant recipients achieve adequate collection by day 4 and the possibility that some allogeneic donors may maximally mobilize PBPC before day 5, a feasibility study was performed evaluating day 4 allogeneic PBPC collection. METHODS: HLA-matched sibling donors underwent collection on day 4 of G-CSF for peripheral blood (PB) CD34+ counts ≥0.04â¯×â¯106/mL, otherwise they underwent collection on day 5. Those with inadequate collected CD34+ cells/kg recipient weight underwent repeat collection over 2 days. Transplant and PBPC characteristics and cost analysis were compared with a historical cohort collected on day 5 per our prior institutional algorithm. RESULTS: Of the 101 patient/donor pairs, 50 (49.5%) had adequate PBPC collection on day 4, with a median PB CD34+ cell count of 0.06â¯×â¯106/mL. Day 4 donors were more likely to develop bone pain and require analgesics. Median collected CD34+ count was significantly greater, whereas total nucleated, mononuclear and CD3+ cell counts were significantly lower, at time of transplant infusion for day 4 versus other collection cohorts. There were no significant differences in engraftment or graft-versus-host disease. Cost analysis revealed 6.7% direct cost savings for day 4 versus historical day 5 collection. DISCUSSION: Day 4 PB CD34+ threshold of ≥0.04â¯×â¯106/mL identified donors with high likelihood of adequate PBPC collection. Day 4 may be the optimal day of collection for healthy donors, without adverse effect on recipient transplant outcomes and with expected cost savings.