Types of bone marrow transplants

There are two major types of bone marrow transplants, autologous and allogenec transplants.

Autologous stem cell transplants are performed with stem cells that are collected from the patient's own blood stream. These are called "peripheral stem cells" because they do not come directly from the marrow. These cells are collected, stored in a frozen state, and later thawed and given back to the patient after completion of high dose chemotherapy.

Allogeneic transplants use bone marrow from a healthy donor, usually a brother or sister who has the same tissue type.  If a sibling is not available, a search of the National Marrow Donor Program registry of tissue-typed volunteers can be made for a non-related donor.

How are donors and recipients matched?

Tissue typing, or histocompatability, evaluates six different antigens (HLAs) within the blood. A favorable match is someone whose blood matches the patient's blood in five or six of these HLAs. When the stem cell donor is related to the patient, peripheral blood stem cells are used rather than cells from the bone marrow. For unrelated donors, the chief source of stem cells is bone marrow stem cells; however, with medical advancements, peripheral stem cells may become the preferred method for transplantation in the future.