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How can bone marrow transplantation help patients with defective marrow?

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Kidney transplant — transplant British surgeon Andrew Ready flushing a donated kidney during a transplant at Queen Elizabeth Hospital, Birmingham, England, 2006.

A bone marrow transplant helps patients with defective or diseased marrow by replacing it with healthy hematopoietic stem cells capable of producing new, functional blood and immune system cells.1

When a patient's own marrow is compromised—such as in cases of leukemia, aplastic anemia, or immune deficiency—an allogeneic transplant is typically performed. In this procedure, a donor with a matching tissue type provides healthy stem cells. To ensure the graft is accepted, physicians use human leukocyte antigen (HLA) matching to minimize the risk of graft-versus-host disease, where the donor cells attack the recipient's tissues.12

Before the infusion, recipients often undergo chemotherapy or radiation therapy and take immunosuppressive drugs to prepare the body and reduce the likelihood of rejection. Once infused into the bloodstream, the donor stem cells migrate to the marrow space to begin the process of healthy cell production.12