Should all unrelated donors for transplantation be matched?

Previous analyses have suggested that hematopoietic cell transplantation (HCT) from an unrelated donor results in better survival if the patient is younger and, possibly also if the donor is younger. Additionally, survival is improved if HCT is performed during early disease stage and if the recipient and possibly the donor are cytomegalovirus (CMV) seronegative. Equivocal data have been published comparing bone marrow vs. (granulocyte-colony stimulating factor) G-CSF-stimulated peripheral blood stem cells for transplantation. A randomized trial is underway by the Blood and Marrow Transplant Clinical Trials Network that is testing the prospective comparison of bone marrow vs. primed peripheral blood grafts from unrelated donors and patients with hematologic malignancies. Of most significance, however, is that the best donor is HLA-compatible, healthy, promptly available, and willing to give the requested product for HCT.