What medical procedure replaces diseased bone marrow with healthy marrow to restore blood cell production?

• A. Bone marrow transplant
• B. Heart transplant
• C. Kidney transplant
• D. Liver transplant

Answer: (A)

Replacing diseased bone marrow with healthy marrow to restore blood cell production is known as a bone marrow transplant. The bone marrow houses hematopoietic stem cells that generate red cells, white cells, and platelets. When marrow is damaged or diseased, blood cell production drops, so introducing healthy marrow can reestablish normal hematopoiesis. The healthy cells can come from a donor (allogeneic) or be the patient’s own cells collected beforehand and then reinfused (autologous). Before the transplant, a conditioning regimen of high-dose chemotherapy and sometimes radiation helps eliminate disease and create space for new marrow to engraft. Once infused, the stem cells travel to the marrow and begin producing blood cells, restoring the blood system. This procedure is used for conditions like certain cancers, aplastic anemia, and some genetic disorders. Risks include infection during the period of low blood counts and, in donor transplants, graft-versus-host disease, where the donor immune cells attack the recipient’s tissues. In contrast, heart, kidney, or liver transplants replace a failing organ and do not directly restore blood cell production.