Novel conditioning regimens for bone marrow transplantation

Ming Shi, Ming Li, Susumu IkeharaDepartment of Stem Cell Disorders, Kansai Medical University, Moriguchi City, Osaka, JapanAbstract: Bone marrow transplantation (BMT) has evolved into an effective strategy for the treatment of hematological and oncological disorders. Radiotherapy and chemotherapy are used as conditioning regimens prior to BMT to suppress host immunity and reduce tumor burden. High doses of total body irradiation are conventionally administered along with alkylating agents, ie, the myeloablative regimen, to help ensure rapid engraftment of donor cells and to prevent relapse. However, the toxicity of the myeloablative conditioning regimen and unacceptable nonrelapse mortality rules out this approach for older patients by whom less intense preparative regimens are likely to be better tolerated. The reduced-intensity and nonmyeloablative conditioning regimens have been demonstrated by many investigators to be novel approaches resulting in a lower nonrelapse mortality rate and lower incidence of severe acute graft versus host disease. Here, we review the conditioning regimens employed as a pretreatment for BMT, and focus on the novel conditioning regimens and cutting edge developments.Keywords: myeloablative conditioning regimen, reduced-intensity conditioning, nonmyeloablative conditioning regimen, relapse, nonrelapse mortality, graft versus host disease