Transplantation of mobilized peripheral blood stem cells: role of filgrastim

Autologous bone marrow transplantation, although successful, is limited in the rate of hematopoietic recovery achieved. Myeloablative chemotherapy results in prolonged pancytopenia with standard autologous bone marrow support. High-dose myelosuppressive chemotherapy results in severe but short-term pancytopenia, and hematopoietic recovery is routine without cellular support. Cellular support becomes necessary when multiple-cycle, severely myelosuppressive regimens are used because of the cumulative stem cell damage and unacceptably long duration of severe pancytopenia. Peripheral blood progenitor cells (PBPCs) may be used as cellular support, and colony-stimulating factors with or without chemotherapy are currently the most potent available PBPC-mobilizing tools. Filgrastim (rmethG-CSF) has been shown to enhance the number of PBPCs for harvest in both cancer patients and normal donors. When Filgrastim is used in conjunction with chemotherapy, there appears to be greater PBPC mobilization, which seems to be dependent on dose and schedule of chemotherapy as well as the type of chemotherapeutic agent used. Platelet recovery has been shown to be more rapid when PBPCs are used compared with historical controls given autologous bone marrow infusions. It may be concluded that PBPC transplantation is useful supportive care following myeloablative chemotherapy.