A stem cell transplant is a transfusion of healthy stem cells collected from either a donor or the patient. The stem cells are obtained from bone marrow or the bloodstream. When stem cells are collected from bone marrow, the procedure is called a bone marrow harvest. When they are collected from the bloodstream, the procedure is called hematopoietic progenitor cell (stem cell) collection or apheresis.
Autologous (aw-tol¢-o-gus) Transplant
In an autologous transplant the patient is both the donor and the recipient. Healthy stem cells are collected and stored before the patient receives high dose chemotherapy and/or radiation therapy. On some occasions, the stem cells may be treated before they are stored to remove any cancer cells mixed in with them. After chemotherapy and/or radiation therapy is completed the stem cells are returned to the donor. Patients with Hodgkin's disease, myeloma, non-Hodgkin's lymphoma and select other types of cancer may be candidates for autologous transplantation.
Allogeneic (al-o-je-nay¢-ik) Transplant
In an allogeneic transplant the stem cells are collected from a donor. The donor is usually a family member, most commonly a brother or a sister, but can also be an unrelated person from a donor registry. Allogeneic transplants are used in the treatment of bone marrow-based diseases such as leukemia, malignant lymphoma and aplastic anemia. Because the donated cells may react to the cells in the recipient's body, allogeneic transplant patients are prone to more complications than other transplant patients are.
A syngeneic transplant is an allogeneic transplant in which the stem cells come from an identical twin.
This transplant uses standard doses of chemotherapy followed by infusion of donor stem cells. The theory behind this type of transplant is that the same graft versus tumor effect can be achieved with less toxicity of a standard allogeneic transplant. The Blood and Marrow Transplantation Program at Saint Francis does not offer this type of transplant, but can refer to a participating facility.
As the name implies, a tandem transplant occurs when two transplants are performed back to back. Once the patient has enough cells collected for two autologous transplants upfront, the patient then receives nonmyeloablative chemotherapy followed by stem cell reinfusion twice. A tandem transplant may also refer to an autologous transplant, followed by a planned nonmyeloablative allogeneic transplant.
Dose Intensive Treatment (DIT)
Some cancers that do not respond to standard therapy do respond to high-dose chemotherapy. This type of high-dose chemotherapy can be given without a transplant. In these cases, the patient is admitted to the hospital and receives treatment strong enough to suppress, yet not destroy, the bone marrow. As the marrow recovers, the remaining normal stem cells slowly begin to produce healthy blood cells.