Kinetics of hemopoietic recovery after peripheral blood stem cell transplantation: impact of stem cell purification and G-CSF

We investigated the role of stem cell purification and G-CSF (early vs. delayed vs. no G-CSF) administration on hemopoietic recovery and supportive care requirements after stem cell transplantation. Thirty-two patients submitted to autologous CD34(+) peripheral blood stem cell transplantation (PBSCT) were studied, and data were compared to patients undergoing unfractionated peripheral blood stem cell transplantation (uPBSCT) matched for age, disease, and conditioning regimen. Except for PMN, hemopoietic recovery was significantly slower and supportive care requirements were significantly higher after CD34(+) PBSCT. Median time to PMN >0.5 x 10(9)/l was 13 days (range 9-27) and 13 d (range 9-23); reticulocytes (Ret) >1% was 14.5 d (range 12-34) and 12 d (range 10-27); high-fluorescence reticulocytes (HFR) >5% was 12 d (range 9-26) and 9 d (range 7-11); platelets >50 x 10(9)/l and >100 x 10(9)/l was 20 d (range 10-240), 12 d (range 9-60) and 33 d (range 15-720), 15 d (range 11-210). When the analysis was performed on subgroups of patients (early/delayed/no G-CSF), early G-CSF significantly promoted PMN recovery (>0.5 x 10(9)/l and >1.0 x 10(9)/l) compared to no G-CSF, without affecting RBCs or platelet recovery. Delayed G-CSF did not improve PMN recovery compared to patients not receiving G-CSF, did not result in a significant reduction of drug requirements, and had a negative impact on erythroid and platelet recovery. In conclusion, these preliminary data suggest that G-CSF is useful if given early after CD34(+) PBSCT. CD34(+) PBSCT may overall require a significant increase of resource utilization that should be outweighed by proven clinical benefit.