Types of Hematopoietic Stem Cell Transplants
Bone marrow from one identical twin to another. Identical twins have identical genetic types and are a "perfect" match.
Related - Marrow from a donor who genetically matches, as close as possible, that of a patient. This may be a brother or sister, or parent. Siblings have a 1 in 4 chance of being a match. The degree to which the donor's and patient's tissue match is done by a blood test called HLA typing.
Unrelated (MUD) - Marrow from another person who is not related to the patient but has similar genetic typing. Through the National Marrow Donor Program (NMDP) it is possible to find similar matches for patients that do not have a related donor. The NMDP registry is comprised of volunteer donors and new donors are added to the list daily. The donors usually have the marrow harvest within 24 hours of the transplant date at the transplant center located closest to them. The marrow is sent via plane with a courier to the patient's BMT center.
Patient's own marrow is harvested (removed), purged or treated (if necessary),and stored (frozen) and re-infused.
Peripheral Stem Cell
Type of transplant in which apheresis is used to collect stem cells from the blood rather than using bone marrow cells. Apheresis is a process where blood is removed from the patient via an IV catheter, the stem cells are selected out by a machine and the remainder of the blood is returned to the patient. The process takes 3-4 hours/day for 2-5 days total.
Stem cells can also be collected from the umbilical cord/placenta immediately following birth. The cells can be stored (frozen) for future use. This can be from a sibling or unrelated donor.