In a stem cell transplant, cancerous or abnormal blood-producing cells (haemopoietic stem cells) are replaced with healthy ones. Before a stem cell transplant, the recipient is given chemotherapy and radiotherapy to eliminate his or her own, abnormal, stem cells; immunosuppressant drugs may also be given to prevent rejection of the donated stem cells. The healthy stem cells may have been supplied by a donor or by the patient when the underlying disease was inactive. The healthy stem cells are usually obtained directly from the blood using a procedure similar to that of a normal blood donation. Healthy stem cells may also sometimes be obtained from the bone marrow, in which case the transplant procedure is usually known as a bone marrow transplant.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.