What are stem cells?
Stem cells are immature cells that can develop into any cell present in the bloodstream: red blood cells, white blood cells, platelets and other blood components. Blood stem cells are not embryonic stem cells. They come from bone marrow, circulating (peripheral) blood or umbilical cord blood. People whose diseases inhibit their ability to produce these kinds of cells need a transplant of healthy stem cells from a donor. Donors may be asked to donate either peripheral blood stem cells or bone marrow depending on the physician’s choice of therapy for the patient. After donating, most donors are back to their usual routine in a few days.
Peripheral stem cells are collected from circulating (peripheral) blood. Because only a small number of stem cells is released into the bloodstream, a cell growth stimulating drug is administered to donors prior to the donation to dramatically increase the volume of stem cells in the blood for collection and transplant.
Bone marrow is the soft, jelly-like tissue found in the hollow centre of bones. It is like a factory that produces stem cells, which are the building blocks of blood.