Hematopoietic stem-cell transplantation ( HSCT ) is the
transplantation of multipotent hematopoietic stem cells, usually derived from
bone marrow, peripheral blood, or umbilical cord blood in order to replicate
inside of a patient and to produce additional normal blood cells. It may be
autologous (the patient's own stem cells are used), allogeneic (the stem cells
come from a donor) or syngeneic (from an identical twin).
It is most often performed for patients with certain cancers of the blood or
bone marrow, such as multiple myeloma or leukemia. In these cases, the
recipient's immune system is usually destroyed with radiation or chemotherapy
before the transplantation.