Stem Cell / Bone Marrow Transplant: Allogeneic Stem Cell / Bone Marrow Transplant
Alternate Names: bone marrow transplant, BMT, hematopoietic stem cell transplant, HSCT
An allogeneic stem cell / bone marrow transplant replaces damaged or destroyed bone marrow stem cells with healthy ones from a donor. The “allo” prefix means “other,” meaning that healthy cells are taken from someone other than your child. (Learn about a transplant that uses your child’s own stem cells: autologous stem cell / bone marrow transplant.)
Stem cells are produced in the spongy area of bones known as marrow. These cells develop into all types of blood cells in the body. In an allogeneic stem cell / bone marrow transplant, the donated healthy cells grow and produce normal blood cells that help fight disease.
This procedure may also be used when, as part of treatment, your child’s diseased marrow has been destroyed using chemotherapy or radiation therapy.
What are allogeneic stem cell / bone marrow transplants used to treat?
These transplants are used to treat a number of blood-related cancers and other diseases, including:
- High-risk leukemias or lymphomas
- Immunodeficiencies (immune system diseases)
- Sickle cell anemia
- Aplastic anemia
- Metabolic storage disorders
What happens before an allogeneic stem cell / bone marrow transplant?
First, a donor must be found whose healthy bone marrow, or stem cells from it, can be transplanted into the patient’s bone marrow. The donor can be a relative or an unrelated person. Stem cells can also be collected after birth from the blood left in the placenta or the baby’s umbilical cord.
- A related donor is often a brother or sister with the same tissue type as your child. A parent’s cells may be used if there is a close match. St. Jude pioneered a process known as a haploidentical transplant, which uses a donor—usually a parent—who is only a partial genetic match. Today, the hospital performs more pediatric haploidentical transplants than any other medical facility in the country.
- When no relatives are available, the cells may come from a volunteer donor listed in the National Marrow Donor Program registry.
- Once identified, the donor will undergo tissue typing, also called human leukocyte antigen (HLA) matching:
- HLAs are markers the body uses to decide if a “foreign” substance belongs in the body or should be destroyed. When marrow or stem cells are rejected, the body attacks its own tissues in a process known as graft-versus-host disease (GVHD).
- HLA matching is used to check that the donor’s marrow or stem cells will work in your child’s body and will not trigger graft-versus-host disease.
- If marrow is to be transplanted, doctors usually insert a needle into a bone (often the pelvis) of the donor to pull out the marrow.
- Another method uses blood stem cells that circulate throughout the body. This method obtains stem cells from a vein in a method similar to a blood donation.
Before the transplant, the patient typically receives chemotherapy, radiation therapy or both. This kills at least some of the cancer cells and increases the chance that the transplant will be successful. At the same time that these therapies kill cancer cells they can also destroy many healthy blood cells.
- Chemotherapy (“chemo”) - uses powerful medicines to kill cancer cells or stop them from growing (dividing) and making more cancer cells.
- Chemo may be injected into the bloodstream, so that it can travel throughout the body.
- Some chemo may be given by mouth.
- Combination therapy uses more than one type of chemo at a time.
- Ablative therapy (also called myeloablative therapy) - uses high-dose chemo to kill both healthy and cancerous bone marrow cells, leaving the transplanted cells more room to grow. The dose can be adjusted depending on your child’s ability to withstand this strong form of treatment.
- Radiation therapy - uses high-energy X-rays or other types of radiation to kill cancer cells or stop them from growing.
How are allogeneic stem cell / bone marrow transplants done?
After the chemotherapy and / or radiation treatment is complete, the donor’s healthy stem cells are transplanted into your child’s bloodstream:
- The procedure is similar to a blood transfusion. The cells are given slowly through a vein.
- The cells travel through the blood until they reach the marrow and start growing new, healthy cells.
What problems can occur with allogeneic stem cell / bone marrow transplants?
During the time before your child’s treated bone marrow can begin producing new, healthy cells:
- Infection may occur because fewer white blood cells are present to fight it.
- Fewer red blood cells can cause anemia.
- Low platelet levels can cause blood-clotting problems and dangerous bleeding.
- GVHD can occur if the child’s body does not accept the new cells (rejection.
What are the survival rates for allogeneic stem cell / bone marrow transplants?
Five-year survival rates for patients treated with allogeneic stem cell / bone marrow transplants vary widely, depending on:
- What disease is being treated
- How far it has advanced
- What other health problems the child may have
Findings have been encouraging in recent St. Jude studies. Researchers report the following five-year survival rates after allogeneic stem cell transplantation (despite half of the patients having persistent leukemia at the time of transplant and less than one-third having a well-matched sibling donor):
- For high-risk patients treated for acute lymphoblastic leukemia (ALL): 65 percent
- For patients treated for acute myeloid leukemia (AML): 74 percent
Why come to St. Jude for allogeneic bone marrow / stem cell transplantation?
- St. Jude is the only National Cancer Institute-designated Comprehensive Cancer Center devoted solely to children.
- St. Jude has created more clinical trials for cancer than any other children’s hospital in the United States.
- The nurse-to-patient ratio at St. Jude is unmatched— averaging 1:3 in hematology and oncology, and 1:1 in the Intensive Care Unit.
- St. Jude has one of the world’s largest hematopoietic stem cell transplant programs dedicated to caring for children, teens and young adults. Since the first hematopoietic stem cell transplant at St. Jude was performed in 1982, the Transplant Program has performed more than 2,500 transplants.
- St. Jude is accredited by the Foundation for the Accreditation of Cellular Therapy (FACT) for autologous and allogeneic peripheral blood and marrow transplantation in children and adults.
- The Transplant Program at St. Jude has been a part of the National Marrow Donor Program (NMDP) since 1990. Our center also provides data to the International Bone Marrow Transplant Registry and the Autologous Bone Marrow Transplant Registry.
- St. Jude was the first institution to perform an allogeneic stem cell/bone marrow transplant in a patient with sickle cell anemia.
- To improve outcomes and reduce side effects associated with transplants, doctors in the St. Jude Transplant Program work closely with laboratory scientists to rapidly move discoveries from the lab to the clinic.
- St. Jude support staff members have been specially trained to care for children receiving hematopoietic stem cell transplants.
- St. Jude scientists discovered that certain cancer-fighting immune cells, called natural killer (NK) cells are potent if they have a certain protein called KIR on their surface. Patients have lower risk of relapse and much better outcomes when they receive NK cells from donors that have the potent form of the KIR gene.
- The St. Jude transplant team developed a simple blood test to reveal whether a potential donor’s NK cells contain the KIR protein. This test is now part of the routine donor screening process at St. Jude. St. Jude has licensed the test, which will soon be available to transplant centers worldwide.
- Transplants of NK cells are performed alone or in combination with bone marrow transplants.
- St. Jude scientists are researching gene modifications and cell processing to increase the potency of donor T cells and NK cells, which could improve the chance of cure for high-risk childhood cancers.
The St. Jude Web site is designed for educational purposes only and is not engaged in rendering medical advice or professional services. The information provided through this site should not be used for diagnosing or treating a health problem or a disease. It is not a substitute for professional care. If you have or suspect you may have a health problem, you should consult your health care provider.