Bone marrow transplantation from unrelated volunteer donors. An overview

Marrow transplantation from a phenotypically identical unrelated donor has become a feasible and curative form of treatment for patients with several malignant and nonmalignant disorders who lack an HLA-matched sibling donor. Given the rapid growth of registries of HLA-typed volunteers-including nearly 3,000,000 people-it is now possible to identify a suitable unrelated marrow donor for up to 50% of patients. In this review the recent acquisitions regarding the structure of HLA complex, the new molecular typing technologies and clinical results obtained with unrelated marrow transplants, will be considered.