Allogeneic stem cell transplant
Overview
An allogeneic stem cell transplant uses healthy blood stem cells from a donor to replace bone marrow that's not making enough healthy blood cells. An allogeneic stem cell transplant also is called an allogeneic bone marrow transplant.
Some bone marrow transplants for adults and children involve using their own stem cells. These are called autologous transplants.
The blood stem cells used in an allogeneic stem cell transplant can be:
- A donor's blood.
- Cells from the bone marrow inside a donor's hip bone.
- Cells taken right after birth from the cord that brings nutrients and oxygen to a baby during pregnancy. This is called a cord blood transplant. These cells often are stored in a cord blood bank.
Before having an allogeneic stem cell transplant, you get high doses of chemotherapy, radiation or both. This is to rid your body of the cells that aren't working well and to get your body ready for the donor cells.
Why it's done
An allogeneic stem cell transplant may help treat or cure more than 75 conditions.
Blood and bone marrow cancers
These include:
- Hodgkin disease.
- Non-Hodgkin lymphoma.
- Leukemia.
- Multiple myeloma.
- Myelodysplastic syndromes, a group of blood cancers in which blood cells in bone marrow don't mature.
- Myeloproliferative neoplasms, a group of blood cancers in which the bone marrow makes too many red blood cells, white blood cells or platelets.
Blood conditions
Other conditions that an allogeneic stem cell transplant may help treat include:
- Adrenoleukodystrophy, a condition passed through families that damages the membrane that protects the nerve cells in the brain.
- Aplastic anemia, a condition in which the bone marrow stops making enough new blood cells.
- Immune deficiencies, conditions that make it hard for the body to fight infections.
- Gene changes that affect the body's process of turning food into energy, called metabolism.
- Sickle cell disease, a blood condition passed through families that causes red blood cells to take a different shape, block blood flow and cause pain.
Risks
The main risks of allogeneic stem cell transplant include:
- Rejection. Your body may reject the donated cells before they can begin making new cells in your bone marrow.
- Graft-versus-host disease (GVHD). This is when the immune cells from the donor's stem cells, called the graft, attack your cells, called the host.
Side effects of chemotherapy or radiation. These may include tiredness, not wanting to eat, stomach upset, mouth sores, hair loss, infections and skin rash.
Other side effects may include organ damage, new cancers and not being able to have children, called infertility. Talk with your care team about what to expect from your treatment.
What you can expect
Before
Before you have an allogeneic stem cell transplant, you:
Get high doses of cancer treatment. This process is called conditioning. During conditioning, the high doses of chemotherapy or radiation therapy kill cancer cells. This is done if you're being treated for cancer that might spread to other parts of the body.
The treatment also weakens your immune system to keep it from rejecting the donor cells. And the treatment gets your bone marrow ready for new stem cells.
The treatment you have depends on your condition and other factors. Some older adults or people who aren't strong enough for the full conditioning treatment have what's called a reduced-intensity allogeneic stem cell transplant or a mini-transplant. They get stem cells from a donor, but the conditioning uses lower doses or other types of chemotherapy and radiation.
Get matched to a donor. Healthcare professionals compare a sample of your blood with blood from possible donors. The match is based on markers that are on most cells in the body, called human leukocyte antigens. A close match raises the chances of a successful transplant and lowers the risk of complications.
The donor may be a family member or someone from a donor registry who isn't related to you. To raise the number of possible donors, some transplant centers have started to do half-match transplants. These are called haploidentical transplants. More study is needed on the long-term results of half-match transplants.
During
The procedure involves getting stem cells from a donor through a vein. This is called an infusion. The procedure takes 1 to 5 hours to transfer all the cells.
From your bloodstream, the donor cells travel to your bone marrow and begin making new blood cells. This is called engraftment.
After
After your transplant, your care team watches you for complications. You may spend 60 to 100 days in or near the hospital. Expect to have blood tests and appointments often to check your body's response to the transplant and to watch for infection. You may need to get donor blood through a vein, called a transfusion, until your bone marrow starts to make enough cells on its own.
You may stay under the care of your transplant center during follow-up. Or your transplant team may make a care plan for you to follow with your main healthcare professional.
After the first 100 days, you have follow-up appointments every three months for a year. For year two, you go every six months. After that, your appointments are every 12 months.
It may take a few weeks for the donor cells to settle into your bone marrow and begin making new cells. Even after the cells engraft, your immune system may be weakened for a year or two.
You may need to take medicines to help prevent complications such as graft-versus-host disease and infections. You also may take medicines for the side effects of chemotherapy and radiation. And you need to eat a healthy diet and exercise after your transplant.
Results
An allogeneic stem cell transplant can cure some conditions and help manage others. It can extend your life and improve your quality of life.
Jan. 31, 2025