PERIPHERAL-BLOOD STEM-CELLS HARVESTED DURING MARROW RECOVERY FROM DISEASE-SPECIFIC CHEMOTHERAPY SHORTEN DURATION OF NEUTROPENIA IN PATIENTS UNDERGOING AUTOLOGOUS BONE-MARROW TRANSPLANTATION

A total of 41 patients who underwent autologous bone marrow transplantation without the use of granulocyte-macrophage colony-stimulating factor were retrospectively evaluated to determine whether the infusion of peripheral blood stem cells collected during the period of recovery of bone marrow from previous disease-specific chemotherapy could shorten the time to bone marrow engraftment after transplantation. Of the 41 patients, 24 patients received bone marrow only (group 1), 8 patients received bone marrow plus steady-state peripheral blood stem cells (group 2) and 9 patients received bone marrow plus rebound peripheral blood stem cells collected during the period of recovery from disease-specific chemotherapy (group 3). Infusion of rebound peripheral blood stem cells (group 3) accelerated recovery of white blood cells and neutrophils and resulted in a white blood cell count of > 10(9)/L by day 15 compared with day 25 in group 1 (P < 0.0001), and a neutrophil count of > 0.5 x 10(9)/L by day 16 versus day 26 in group 1 (P = 0.0034). Addition of steady-state peripheral blood stem cells (group 2) did not hasten myeloid engraftment, and recovery of platelets was not improved in either group given peripheral blood stem cells. Compared with patients in group 1, patients in group 3 required 7 fewer days of parenteral antibiotics (25 days versus 18 days, respectively; P = 0.0072) and were discharged about 3 weeks earlier than patients in group 1 (day + 41 versus day +21; P = 0.0002). These results demonstrate that infusion of peripheral blood stem cells collected during the period of recovery of bone marrow from disease-specific chemotherapy hastens recovery of white blood cells and neutrophils after transplantation. Whether administration of granulocyte-macrophage colony-stimulating factor during the rebound phase from disease-specific chemotherapy will yield peripheral blood stem cells that further reduce the time to recovery of neutrophils or hasten recovery of platelets or both, remains to be determined.