Allogeneic Stem Cell Transplant
Allogeneic Stem Cell Transplant
What is a stem cell transplant?
Most stem cells are in your bone marrow. You also have some that circulate from your marrow into your blood. stem cells turn into red blood cells, white blood cells, or platelets to help your body stay healthy. If your is damaged or destroyed, it can no longer make normal blood cells. In a , healthy stem cells are placed in your body through an IV to help your start to work right.
When the stem cells come from another person, it is called an allogeneic transplant. The donor may be a relative or a complete stranger. The important thing is that the donor's immune system markers are closely matched to yours. This is more likely when the donor is your brother or sister.
When the stem cells come from your own blood or autologous transplant., it is called an
Stem cells can also be found in your bloodstream and in the blood inside a newborn's.
When is a stem cell transplant needed?
- Treat diseases that damage or destroy the non-Hodgkin's lymphoma and Hodgkin's lymphoma, leukemia, multiple myeloma, and aplastic anemia. , such as
- Restore that has been damaged by total body radiation and high doses of used for cancer treatment.
How do you know if you are a good candidate for a stem cell transplant?
Your doctor will consider your health and your. People who are good candidates usually are younger than 70, do not have other diseases such as heart disease or diabetes, and have a normal kidney and liver. Your doctor will also consider how much your disease has grown and how aggressive your cancer is. People with aggressive cancer that has spread to many areas of the body are not usually good candidates. Your doctor may also consider if you have cancer that has come back, such as relapsed non-Hodgkin's lymphoma or leukemia.
How are stem cells collected?
It depends on where the stem cells come from.
Fortransplantation (BMT), a small amount of the liquid portion of the is removed through a needle inserted into the . This is done many times to collect enough stem cells for the person receiving the donated . This is called harvesting the . The cells are put into a blood bag. They are often frozen for future use.
For peripheral blood stem cell transplantation (PBSCT), stem cells are taken from blood. The growth factor G-CSF may be used to stimulate the growth of new stem cells so they spill over into the blood. G-CSF is a central venous catheter. This way of collecting stem cells is called apheresis.that is produced naturally in the body. The blood is removed from the vein and passed through a machine that takes out the stem cells. The machine then returns the remaining blood through a needle in the person's arm or through a
Stem cells may also be taken from umbilical cord blood. This is something that must be arranged with a blood bank before a baby's birth.
Why are chemotherapy and radiation therapy used before a transplant?
Doctors use chemotherapy and radiation to destroy your. This also gets rid of the cancer cellsâ€”along with the normal cellsâ€”in your and the rest of your body. Later, when you get healthy stem cells from a donor, those new cells will go to the marrow and be able to take over the job of making new blood cells.
How are stem cells transplanted?
Ais inserted into your chest. The stem cells travel through the catheter into your blood, and to your , where they will begin to produce new cells in 1 to 3 weeks. During this time:
- You may be in isolation and given to prevent or treat infection. Because the destroys your , your body will not be able to fight infection until it starts making new .
- Your blood will be tested often to check the levels of , , and in your body.
- You may need to receive several transfusions of blood cells and until your body begins to produce its own.
- You may need more or other medicines if you get an infection.
Who can donate stem cells?
Healthy adults ages 18 to 60 can donate stem cells. Children may be donors for themselves or a brother or sister. In some cases, people who are older than 60 can donate.
If you wish to be a stem cell donor, a blood sample is taken from you and tested for tissue type. It is then compared with the tissue types of people needing a transplant. If a match is found, another blood sample will be drawn to see if your tissue type matches well enough for the transplant.
If you are selected as a stem cell donor, you will have a complete. You will also be asked questions about your health and your of diseases. You will also be asked to sign a consent form to have the procedure.
If you are a stem cell donor, you will receive injections of a drug called filgrastim for several days. (It is also called G-CSF, for "granulocyte colony-stimulating factor.") Filgrastim is a drug that helps your body move moreout of your and into your bloodstream. Blood will be removed from your arm, sent through a machine to remove the stem cells, and returned to your bloodstream through your other arm.
What about umbilical cord blood banking?
Umbilical cord blood banks have been established in some areas of the United States, Canada, and many countries in Europe to supply stem cells for related and unrelated people. Using blood from these banks decreases the time it takes to search for a match, because the samples are already typed for genetic information (HLA) and blood group and treated for infection. The match does not need to be as specific as it does withor peripheral stem cells. Umbilical cord blood transplants also cause fewer problems with graft-versus-host disease.
What To Expect
If the donated stem cells came fromor umbilical cord blood, it usually takes about 20 days for your to start producing new blood cells. If the donated cells came from someone's blood, it may not take that long.
You may spend 4 weeks or longer in the hospital after an allogeneic. About 1 out of 4 people need to be readmitted within the first 3 months because of complications.
After you are discharged from the hospital, you will continue to see your doctor often. Because you received someone else's stem cells, you will need treatment with medicines to prevent your immune system from attacking the donor stem cells as though it were a foreign substance. You may also take medicine to help prevent the donor cells from attacking your body. Most people who do not have an immune system reaction take these medicines for 2 to 6 months.
Serious complications can occur after a. They include:
- Graft-versus-host disease. The new cells may destroy other cells in your body. They most commonly attack the skin, , and . This happens less often when umbilical cord stem cells are used. Stem cells from umbilical cord blood are usually used to treat disease in a sibling or child who would otherwise not have a stem cell donor. There are very few stem cells found in cord blood, so these cells are not usually used to treat adults.
- Graft rejection. Your body may not accept the new stem cells.
- Severe life-threatening infection. When your has been weakened, even the most minor infection can be dangerous.
- Veno-occlusive disease. This is a serious liver problem caused by the high dose of chemotherapy or radiation given before a transplant. Symptoms will usually appear within 3 weeks of your transplant and include swelling and tenderness of the jaundice, and fluid buildup in the belly. , weight gain,
When stem cells are collected from another person, the cells are tested to make sure they match your cells.
A transplant from an unrelated donor is more likely to cause problems. But improvements in the way the cells are prepared and matched and in the care of the person after the transplant have helped reduce problems. It can take 4 months or longer to find a match from an unrelated donor.
Why It Is Done
Allogeneic transplants are used to treat many diseases, including:
- Acute lymphoblastic leukemia and acute myelogenous leukemia.
- Chronic myelogenous leukemia and chronic lymphocytic leukemia.
- Aplastic .
Allogeneic transplants are also used experimentally for other diseases, such as:
- Cancer of the , also called renal cell carcinoma.
- Diseases like juvenile idiopathic arthritis and lupus that don't improve with the usual treatments.
How Well It Works
The success of adepends on your age and general health, the type and stage of disease, and how well the donor matches. Serious complications can develop after a .
The original disease often comes back, or, after an allogeneic transplant. If occurs, it can be treated with a second transplant, , or other treatments.
Early complications usually occur within 5 to 10 days and include:
- Bleeding, because of severe reduction in , , and .
- Nausea and vomiting.
- Infection, such as pneumonia, shingles, or herpes simplex.
Other possible complications include:
- , , and heart complications.
- of the disease that the transplant was used to treat.
- Other cancers.
Serious, long-term complications include:
- Graft failure. The new stem cells do not work, or they work for a short time and then fail. If this occurs, the likelihood of a cure is low.
- Graft-versus-host disease (GVHD). The new stem cells attack other cells in your body. If it happens within 3 months, it is called acute GVHD. If it happens after 3 months, it is called chronic GVHD. After chronic GVHD develops, it may take as long as 3 years to go away. GVHD affects the skin, gastrointestinal tract, and immune system. GVHD does not occur when an identical twin is the donor. . It can cause death. GVHD is treated with medicine that lowers the activity of your
- Veno-occlusive disease. This is a serious liver problem caused by the high dose of chemotherapy or radiation given before a transplant. Symptoms include swelling and tenderness of the jaundice, and fluid buildup in the belly. , weight gain,
What To Think About
Not every hospital is able to perform transplants. You may have to travel to a hospital that has special equipment and specially trained doctors and nurses.