Stem Cell Sources

Since the first published reports of bone marrow transplants in 1968, the traditional source of stem cells has been bone marrow. However, during the past decade, stem cells from peripheral blood or umbilical cord blood have been used for autologous and allogeneic transplantation.
Hematopoietic stem cells are very immature cells found in the cavities of the body’s bones, which is the bone marrow. Bone marrow is a substance that resembles blood and produces the body’s blood components, including red blood cells (which carry oxygen), platelets (which are essential for blood clotting), and white blood cells (which are the main agents of the immune system).
Hematopoietic stem cell transplants are used to treat patients whose marrow stops producing the correct amounts or types of various blood cells, or those who have solid tumors and whose marrow is destroyed by high doses of chemotherapy. Treatment with chemotherapeutic agents, growth factors, or both can cause stem cells that were in the bone marrow to circulate in the bloodstream.