Bone marrow transplantation for chronic myeloid leukemia: the use of histocompatible unrelated volunteer donors.
Mackinnon S., Hows JM., Goldman JM., Arthur CK., Hughes T., Apperley JF., Jones L., Batchelor JR., Brookes P., Catovsky D.
We treated 17 patients with chronic myeloid leukemia (CML) by bone marrow transplantation using marrow from human leukocyte antigen (HLA)-matched unrelated donors. Patients were conditioned with a combination of in vivo monoclonal antibodies, chemotherapy with daunorubicin (n = 7) or busulfan (n = 10) and cyclophosphamide, and both total body and total lymphoid irradiation. Donor marrow was depleted of T cells by incubation with monoclonal antibodies of the Campath series. Fourteen (88%) of 16 evaluable patients had sustained engraftment. Four (27%) of the 15 evaluable patients developed acute graft-versus-host disease (GVHD) of grade II or greater, and 4 of 12 evaluable patients developed chronic GVHD. Three patients developed hematological and two developed cytogenetic evidence of relapse. Eight patients (47%) survive at a median follow-up of 32 months (range 10-51 months), giving an actuarial survival of 44%. Five patients remain alive without evidence of hematological or cytogenetic relapse, giving an actuarial disease-free survival of 27%. Pneumonitis caused or contributed to death in six of the nine patients who died. We conclude that T-cell depletion can prevent the severest forms of GVHD but also increases the risk of relapse after transplant with unrelated donors, as it does with HLA-identical siblings. Nevertheless the use of matched unrelated donors should be considered for CML patients who lack HLA-identical siblings.