[Reduced-intensity hematopoietic stem cell transplantation and donor lymphocyte infusions for chronic myeloid...

Allogeneic hematopoietic stem-cell transplantation(allo-SCT) is a potentially curative treatment for patients with chronic myeloid leukemia(CML). However, a major obstacle to this approach is a considerably high risk for transplantation-related mortality(TRM) mostly associated with toxic conditioning and graft-versus-host disease(GVHD). Clinical observations that the infusions of allogeneic T-cells can successfully induce remissions in the majority of patients with CML in relapse after allo-SCT lead the way to the exploitation of non-myeloablative or reduced-intensity conditioning for the initial allografting. Current results of reduced-intensity transplants for CML in chronic phase are encouraging, although the incidence of graft rejection and intractable GVHD still remains a great challenge. To enhance graft-versus-leukemia without exacerbating GVHD, further efforts are required to develop cellular immunotherapy more selectively targeting malignant but not normal host cells.