The description below applies to allogeneic (non-self), as opposed to autologous (self) transplants. Allogeneic includes related and unrelated donors.

ALLOGENEIC TRANSPLANT TYPES

Conventional Stem Cell Transplants
These transplants typically involve approximately seven days of conditioning that consists of chemotherapy and total body irradiation to destroy the existing bone marrow and immune system. Patients enter the hospital at the time of conditioning, and remain in isolation after the transplant until their blood counts recover sufficiently so that they may be released.

Non-Myeloablative Stem Cell Transplants
These so-called "mini" transplants typically involve much smaller doses of chemotherapy or irradiation. The use of certain immunosuppressive drugs are administered to facilitate engraftment, and the immune system itself may destroy the leukemic host cells. This takes place through a reaction knows as the Graft Versus Leukemia (GVL) effect. Older patients who would not have qualified for conventional bone marrow transplants in the past may now be eligible candidates for mini-transplants. Some centers perform these transplants on an outpatient basis. While preliminary results are encouraging, this is a relatively new procedure, and there is currently no long-term data on survival rates.

ALLOGENEIC STEM CELL SOURCES

Bone Marrow
Bone marrow is a substance found in the hollow cavities of the body’s large bones. Marrow contains stem cells, which are the progenitors that produce healthy blood cells (including red cells, white cells and platelets) necessary to sustain life. Marrow is withdrawn from the iliac crest, located in the posterior aspect of the pelvic bone. This is done under general or regional anesthesia and generally requires an overnight hospital stay for the donor.