Most stem cells
are in your
bone marrow. You also have some that circulate from
your marrow into your blood. Bone marrow stem cells turn into
red blood cells,
white blood cells, or
platelets to help your body stay healthy. If your bone
marrow is damaged or destroyed, it can no longer make normal blood cells. In a
stem cell transplant, healthy stem cells are placed in your body through an
IV to help your bone marrow start to work
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
When the stem cells come from your own blood or bone
marrow, it is called an
Stem cells can
also be found in your bloodstream and in the blood inside a newborn's
stem cell transplants to:
Other uses for stem cells are being studied, such as the
treatment of immune system defects,
sickle cell disease, and
Your doctor will consider your health and your age.
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
It depends on where
the stem cells come from.
For bone marrow transplantation (BMT), a small
amount of the liquid portion of the bone marrow is removed through a needle
inserted into the bone. This is done many times to collect enough stem cells
for the person receiving the donated bone marrow. This is called harvesting the bone marrow. The bone marrow 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 protein 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
central venous catheter. This way of collecting stem
cells is called
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.
Doctors use chemotherapy and radiation to destroy
your bone marrow. This also gets rid of the cancer cells-along with the normal
cells-in your bone marrow 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.
A central venous
catheter is inserted into your chest. The stem cells travel through the
catheter into your blood, and to your bone marrow, where they will begin to
produce new cells in 1 to 3 weeks. During this time:
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.
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
If you are selected as a stem cell donor, you will
have a complete physical exam. You will also be asked questions about your
health and your family history 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 more white blood cells out of your bone
marrow 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.
The bone marrow collection process is a
surgical procedure done under a
general anesthetic. The procedure takes 1 to 2 hours.
Bone marrow is usually removed from the back of your pelvic bone using sterile
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 with bone marrow or peripheral stem cells.
Umbilical cord blood transplants also cause fewer problems with
If the donated stem cells came from bone
marrow or umbilical cord blood, it usually takes about 20 days for your bone
marrow to start producing new blood cells. If the donated cells came from
someone's blood, it may not take that long.
spend 4 weeks or longer in the hospital after an allogeneic stem cell
transplant. 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
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.
complications can occur after a stem cell transplant. They include:
When stem cells are collected from another person, the
cells are tested to make sure they match your cells.
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.
Allogeneic transplants are used to
treat many diseases, including:
Allogeneic transplants are also used experimentally for
other diseases, such as:
The success of a stem cell transplant
depends on your age and general health, the type and stage of disease, and how
well the donor matches. Serious complications can develop after a stem cell
The original disease often comes back, or relapses,
after an allogeneic transplant. If relapse occurs, it can be treated with a
second transplant, chemotherapy, or other treatments.
Early complications usually occur within 5 to 10
days and include:
Other possible complications include:
Serious, long-term complications include:
every hospital is able to perform transplants. You may have to travel to a
hospital that has special equipment and specially trained doctors and
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ByHealthwise StaffPrimary Medical ReviewerAnne C. Poinier, MD - Internal MedicineKathleen Romito, MD - Family MedicineE. Gregory Thompson, MD - Internal MedicineSpecialist Medical ReviewerDouglas A. Stewart, MD - Medical OncologyBrian Leber, MDCM, FRCPC - Hematology
Current as ofMay 3, 2017
Current as of:
May 3, 2017
Anne C. Poinier, MD - Internal Medicine & Kathleen Romito, MD - Family Medicine & E. Gregory Thompson, MD - Internal Medicine & Douglas A. Stewart, MD - Medical Oncology & Brian Leber, MDCM, FRCPC - Hematology
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Last modified on: 8 September 2017