Types of Transplants
Patients with certain types of diseases such as lymphoma, leukemia or multiple myeloma may be referred to a transplant center to undergo a stem cell or bone marrow transplant. Your own cells or a donor’s cells can be collected and stored before high-dose chemotherapy is given for treatment of the underlying disease.
The stored stem cells are returned to you intravenously to replace the stem cells that are destroyed from the high-dose chemotherapy. The stem cells can be collected either directly from the bone marrow (bone marrow stem cells) or from the peripheral blood stream (peripheral stem cells). The different types of transplants we perform include:
- Autologous – a transplant in which your own peripheral stem cells are collected and given back to you after high-dose chemotherapy treatment
- Allogeneic – a transplant of stem cells taken either from the bone marrow cavity or the peripheral blood stream from a donor of someone other than yourself. This is also known as a matched unrelated donor (MUD) transplant. The stem cells are given back to you after high-dose chemotherapy, with or without radiation therapy
- Reduced intensity chemotherapy transplant – uses stem cells donated by a relative or unrelated donor, but with lower doses of chemotherapy
- Syngeneic – the collection of stem cells from an identical twin and given to the patient
Your transplant physician will discuss with you the advantages of one collection method over another for your specific situation.
Autologous transplant involves administering very high doses of chemotherapy to the patient in an effort to eradicate the underlying disease. This high dose of chemotherapy cannot tell the difference between cancer cells and healthy cells. The chemotherapy destroys not only the cancerous cells, but also all the cells that divide and reproduce rapidly, including the cells in the bone marrow that produce our blood cells – white cells, red cells and platelets.
Without these blood cells, the risk of infections, bleeding problems and anemia is present. In order to repopulate the bone marrow so that blood cells will be made again, stem cells can be collected from the patient before the administration of high-dose chemotherapy, frozen, stored, and then returned to the patient after the high-dose chemotherapy treatment.
Because the stem cells used in this treatment are the patient’s own cells, this treatment is also referred to as “high-dose chemotherapy followed by stem cell rescue."
Allogeneic transplant uses high-dose chemotherapy, sometimes with radiation therapy. The stem cells collected either from a relative (matched related transplant) or an unrelated donor (matched unrelated donor – MUD transplant) are then reinfused into the patient.
An unrelated donor is often located through the National Marrow Donor Program that maintains a registry of more than 8 million registered potential donors.
The stem cells are collected from the donor, either directly from the bone marrow cavity or from the peripheral blood stream. The patient (recipient) undergoes high-dose chemotherapy either with or without radiation therapy to treat the underlying disease. The effect of the chemotherapy on the body's blood cells is the same as with an autologous transplant. The donor stem cells are given back to the patient following the high dose chemotherapy. The patient once again is able to manufacture their own blood cells.
Reduced intensity chemotherapy transplant
This type of transplant, also known as non-myeloablative or mini-transplant, uses stem cells donated by either a relative or an unrelated donor followed by chemotherapy. The doses of chemotherapy are smaller and do not destroy the ability of the bone marrow to produce blood cells.
Donor stem cells carry along with them the immune system of the donor, which is “foreign” to the patient/recipient. The goal is for the foreign donor immune system to flourish in the patient and set up an immunologic response against the cancer cells. This is called "graft vs. tumor effect."
This treatment is used for patients who would otherwise not be able to withstand the rigors of the high-dose chemotherapy given in an allogeneic transplant due to age or other medical conditions.
Syngeneic transplant collects the stem cells from an identical twin sibling and gives the cells to the patient after the patient receives high-dose chemotherapy. This is similar to an autologous transplant since each twin has identical stem cells. But the patient does not have to undergo the collection process.