Why hematopoietic stem cell transplantation and for whom?

Hematopoietic stem cell transplantation has been used to treat humans for nearly 40 years; it was fi rst given in 1968 for an infant with a severe combined immune defi ciency who was unable to reject a graft and then a year later in 1969 for a patient with leukemia who had been given lethal total body irradiation. In both cases genetically HLAidentical siblings were used and gave bone marrow. Treatment in these early cases demonstrated that leukemia could be cured, that immune defi ciency could be corrected, and that long-term survival was possible. However, problems with infections, graft-vs.-host disease, and graft failure meant that this was considered a very risky technique for many years. In the last 10 years HSCT has become much more successful because of the steady improvements across the fi eld. These have included: • better tissue type matching of donor and recipient using molecular DNA techniques; • greater availability of matched unrelated donors; • refi nements in pre-transplant conditioning regimens; • improved methods for early detection of infection; • new anti-infective agents, ciclosporin and other immunosuppressive drugs to reduce the risk of graft-vs.-host disease; • better supportive care, with protective isolation and improved techniques for nutritional support. Introduction