Abstract
A steady stream of advances in allogeneic hematopoietic stem-cell transplantation has not only improved the clinical outcome in a variety of malignant and nonmalignant diseases but also widened the indications for such transplants. One important advance is the use of sources of hematopoietic stem cells other than bone marrow from HLA-identical siblings, which is a resource available to only about 30 percent of potential recipients.By searching international databases, which contain more than 9 million potential volunteer stem-cell donors,1 a matched unrelated donor can be found for an additional 50 to 80 percent of patients, depending on ethnic group. In . . .