ABSTRACT
In recent years, there has been a dramatic increase in the use of bone marrow transplantation for the treatment of a variety of diseases, particularly refractory cancer. 1 The feasibility of transplanting marrow for hematological reconstitution was first demonstrated in the early 1950s, 2 and to date, more than 11,000 patients have been treated. About three quarters of these procedures have been carried out since 1983. 1 In the treatment of malignant diseases, bone marrow transplantation has been used extensively as rescue, following marrow-ablative high dose therapy for refractory leukemia, lymphoma, and certain solid tumors. An impediment to its more extensive application has been the scarcity of suitable tissue-matched normal marrow donors. Within the immediate family of a patient, the probability of finding a match is one in four, although in practice, this chance is closer to one in three, 3 since patients usually have multiple siblings. The probability of finding a donor in the general population is correspondingly smaller, 4 even if the HLA-typing information was readily available. Two approaches are being used to circumvent this scarcity. The first is the use of mismatched marrow. 3,5
