Types of transplants
The center performs two basic types of stem cell transplant.
- Autologous transplant is a procedure in which the child's own stem cells are removed, treated with anticancer drugs or radiation, then returned to the patient. Autologous transplants are performed for the treatment of neuroblastoma, Wilm tumor, Hodgkins disease and other rare solid tumors.
- Allogeneic transplant is a procedure in which the child receives stem cells from a compatible donor — related and unrelated. Allogeneic transplants are performed for the treatment of leukemia, bone marrow failure syndromes, hemoglobinopathies, metabolic diseases and severe immune deficiencies.
Differences in allogeneic transplants
The difference between a full intensity and reduced intensity transplant is dependent upon the amount of conditioning therapy (chemotherapy and sometimes radiation) that a patient needs. This is often dictated by the type of cancer or disease being treated, and why the stem cells are being given.
- Full intensity transplant: Higher doses of chemotherapy are given with this transplant. First, the patient's own bone marrow is "ablated" or wiped out. Next, the donor's cells are introduced with the intention of replacing the patient's own cells and bone marrow with the donor's cells.
- Reduced intensity transplant: Lower doses of chemotherapy are given with this transplant. The donor and recipient's stem cells will likely co-exist in the patient's body after the transplant. This "co-existing" is called mixed chimerism. For patient's with malignancies, it is believed that the donor's immune system will fight the disease. For patients with immune deficiency diseases or inherited hematologic disorders, it is believed that the health donor cells will correct the dysfunction.
Stem cell sources
The cells used in transplants can come from three different sources:
- Umbilical cord blood, collected from the cord blood and placenta after a baby is born.
- Bone marrow, collected in the operating room while the donor is asleep (under general anesthesia).
- Peripheral blood stem cells, collected through a procedure called stem cell apheresis. The donor's blood is removed and run through an apheresis machine that selects out the stem cells. The rest of the donor's blood is returned to them.
Stem cell transplants performed by our team in calendar year 2009 (52 total)
Allogeneic transplants (45)
- Stem cell sources:
- Matched siblings: 12 (Peripheral blood stem cells 5, marrow 7)
- Unrelated adult donors: 25 (Peripheral blood stem cells 23, marrow 2)
- Unrelated umbilical cord: 8
- Conditioning regime:
- Myeloablative: 32
- Reduced intensity/toxicity: 13
- Patients with malignancies: 31
- Acute lymphoblastic leukemia: 18
- Acute myeloblastic leukemia: 8
- Myelodysplasia/chronic leukemia: 5
- Patients with non-malignant conditions: 14
- Immune deficiencies: 4
- Congenital metabolic disorder: 1
- Marrow failure syndrome/Hemoglobinopathy (thalassemia)
Autologous transplants (7)