Definition Bone marrow, or marrow, is a spongy tissue found in the centre of certain bones in the human body. Bone marrow makes blood cells. Immature blood cells in the marrow are called stem cells. Stem cells divide and mature to form various types of blood cells. These include the oxygen-carrying red blood cells, infection-fighting white blood cells, and platelets, which are cells that help make blood clot.
A bone marrow transplant (BMT) is done for some people when their marrow does not work properly. Healthy stem cells, usually from another person (the donor), are injected through a needle into a vein in another person (the recipient) who needs the cells. The stem cells travel to the recipient's marrow. Ideally, the stem cells attach and make new blood cells, thus fixing the problem.
Who is a candidate for the procedure? BMTs are used for people with many conditions, including:
aplastic anaemia, a condition in which damaged or destroyed stem cells or marrow cannot make red blood cells
cancers, such as the blood cancers called leukaemia and lymphoma
some immunodeficiency disorders, such as severe combined immunodeficiency syndrome, a rare inherited condition
other inherited blood disorders, such as thalassemia
How is the procedure performed? Usually, marrow comes from a donor. The procedure is much more likely to succeed when the donor's marrow "matches" that of the recipient as closely as possible. Close relatives of the recipient, such as a sibling or parent, are most likely to have matching marrow. In some cases, the person may donate his or her own marrow before treatment with Chemotherapy or radiation therapy. In this setting, the marrow is injected back into the same person after that person undergoes treatment for a disease.
A donor is taken to the operating room to remove marrow. The donor will feel no pain during the procedure. Bone marrow is usually removed from the hipbone with a special needle. The donor is usually able to go home the same or the next day.
chemotherapy and/or radiation treatments are needed in the recipient. These treatments destroy the immune system cells that might cause the body to reject the transplanted stem cells. Marrow is injected, or transfused, into the person through an intravenous tube (IV). An IV is a tube inserted through the skin and into a vein, usually in the chest or neck.
What happens right after the procedure? It may take 2 to 3 weeks or longer for the immune system and marrow to begin working again. During this time, the person is at high risk for infections. Isolation and infection control are used to protect the person from infection. The person may be in the hospital for 4 to 6 weeks, or longer.
What happens later at home? Recovery from BMT depends on many factors. These include the underlying disease and the body's reaction to the procedure. Close monitoring by healthcare professionals will be needed for months after the procedure. The doctor will advise a person on when he or she can return to normal activities.
What are the potential complications after the procedure? The donor has a very low risk of severe bleeding, infection, or allergic reactions to anaesthesia during the procedure.
The recipient of a bone marrow transplant has several serious risks. Side effects from the chemotherapy and the medications used to prevent rejection include sterility and kidney or liver damage. Other complications include life-threatening infections and graft-versus-host-disease (GVHD). In GVHD, the donated cells attack the recipient's body. This happens because the donated cells "see" the person's body as foreign. The person's body can also reject the donated marrow. In addition, the underlying disease may return, or long-term malfunction of the immune system may occur.
Author: Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
