ENGRAFTMENT WITH PERIPHERAL-BLOOD STEM-CELLS USING NONCONTROLLED-RATECRYOPRESERVATION - COMPARISON WITH AUTOLOGOUS BONE-MARROW TRANSPLANTATION

Peripheral blood stem cells (PBSC) are used increasingly as a source o f stem cell support following myeloablative therapy. In this report, t he results of 33 patients undergoing PBSC transplantation were compare d to 17 concurrent patients undergoing autologous bone marrow transpla ntation (ABMT). PBSC were cryopreserved using 6% pentastarch and 5% di methyl sulfoxide (DMSO) with noncontrolled-rate freezing. Many patient s in the PBSC group were selected because they were excluded as candid ates for ABMT due to prior pelvic irradiation, marrow tumor involvemen t, or other factors. PBSC were mobilized with high-dose cyclophosphami de (CY), CY + granulocyte-macrophage colony-stimulating factor (GM-CSF ), or GM-CSF alone. Colony-stimulating factors were not administered a fter transplantation. A median of 7.4x10(8) mononuclear cells (MNC)/kg were collected containing a median of 3.2x10(4) granulocyte-macrophag e colony-forming units (CFU-GM)/kg and 5.7x10(4) burst-forming units ( BFU-E)/kg. After thawing, CFU-GM recovery was 67% and BFU-E recovery w as 59%. The thawed, pooled PBSC contained 6.4x10(6) CD34(+) cells/kg. The entire PBSC volume (median 870 mt) was infused over a median of 15 7 minutes. PBSC patients required a median of 15 days to achieve an AN C of 500/mu L and 22 days for a platelet count of 50,000/mu L. Neutrop hil recovery was inversely correlated with the number of harvested pro genitor cells (p=0.014); the time to achieve a platelet count of 50,00 0/mu L was inversely associated with CD34(+) cells/kg (p=0.005). PBSC transplant patients achieved an ANC of 500/mu L 6 days faster (p<0.05) and had a 10-day shorter hospitalization (p<0.05) than ABMT patients. Use of noncontrolled-rate cryopreserved PBSC is associated with faste r engraftment and shorter hospital duration than ABMT.