Purging marrow or peripheral blood stem cells for autografting.

Myeloablative therapy followed by autologous bone marrow or peripheral blood stem cell rescue is an alternative therapeutic option for patients who are not candidates for allogeneic transplantation due to the lack of an appropriate HLA-matched donor or to advanced age. It allows therapy to be administered that is of comparable intensity to that used for allogeneic transplantation, and offers an alternative approach to achieving long-term disease-free survival. Although autologous transplantation obviates the risk of graft-versus-host disease, with its increased morbidity and mortality, it may also increase the rate of disease relapse due to the lack of an immune-mediated graft-versus-leukemia effect, as occurs in the allogeneic transplantation setting. The possibility that residual occult neoplastic cells, reinfused with the remission autografts following myeloablative therapy, can potentiate disease relapse has also been a concern in patients who undergo autologous bone marrow transplantation. This review discusses recent data concerning various strategies that are being used to "purge" autografts in patients undergoing autologous bone marrow transplantation in an effort to decrease the relapse rates and improve the disease-free and overall survival.