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75% of patients needing a stem cell
transplant do not have a suitable donor in their family and need an
unrelated bone marrow donor. |
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Patient Services :: Frequently Asked Questions (FAQs)
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Q. Why stem cell transplants?
A. Stem cell transplantation
(previously referred to as bone marrow transplantation) offers the
possibility of many years of healthy, normal life for the 30,000
children and adults in the U.S. stricken with a number of diseases,
including various types of leukemia, aplastic anemia, severe combined
immune deficiency syndrome, sickle cell anemia, other cancers, and
radiation poisoning. For many of these patients, a stem cell transplant
offers their best chance of overcoming an otherwise fatal disease.
Thousands of stem cell transplants are performed annually at approved
medical centers worldwide.
Q. What is a stem cell transplant and what is the relationship to bone marrow transplantation?
A. Bone marrow transplantation
has been used to treat blood diseases such as leukemia and disorders of
the immune system for over 25 years. Stem cells are immature cells
generally found in bone marrow. Stem cells have the potential to
develop into the three types of blood cells: red blood cells, white
blood cells and platelets. These important cells are used by the blood
and the immune system to fight infections and disease and are
continually replaced by the marrow throughout an individual's lifetime.
In some diseases like leukemia, when the marrow can no longer produce
healthy blood and immune system cells, a stem cell transplant from a
suitable donor can be life-saving. In a stem cell transplant, the
donated stem cells are infused or put into the patient whose diseased
blood cells have been destroyed by radiation and or chemotherapy. With
a successful transplant, the donated stem cells will rapidly grow in
number and restore the patient's normal stem cell function and its
blood-forming capacity.
Three sources of stem cells for transplantation are available:
marrow, peripheral blood stem cells and umbilical cord blood stem
cells. Each has the potential to successfully repopulate a patient's
own stem cells.
Marrow: Stem cells residing in the bone marrow have
traditionally been the most important source of stem cell transplants.
Marrow is removed from the upper area of the donor's pelvic bone while
the donor is under general or regional anesthesia. On average, one
liter of marrow is removed. The exact amount is determined by the needs
of the patient. Donors may have some mild discomfort after the
procedure but the remaining stem cells in their marrow will
reconstitute themselves within a few weeks.
Peripheral Blood Stem Cell (PBSC):
Stem cells are also present in the blood stream, although in much
smaller amounts than in the marrow. A growth factor known commercially
as Figrastim is usually given to donors to stimulate development of a
sufficient number of stem cells for a transplant. These peripheral
blood stem cells are then collected through apheresis, a simple process
whereby the donor's blood is circulated through a collection filter.
Cord Blood:
Blood collected from an infant's umbilical cord is rich in stem cells,
and cord blood banks worldwide have been collecting, processing, tissue
typing and freezing cord blood for use in stem cell transplants since
1988. If a search through the cord blood registries locates a suitable
matched cord blood unit, the patient and his/her physician decide
whether cord blood is the best option for a stem cell transplant. If
so, the cord blood unit can be transported from the cord blood bank to
the patient. Each of these approaches can produce a successful stem
cell transplant.
The donation process is summarized below for anyone giving stem cells.
Related family members or outside of the Network donors may not need to
join a registry to donate.
Q. What is HLA? And why is it so important?
A. HLA stands for "Human
Leukocyte Antigen." These are protein molecules that we inherit from
our parents. Nearly 1300 different HLA molecules have been identified
and matching essential HLA types is critical to the potential success
of a stem cell transplant. This is done by first taking a small sample
of blood from the patient.
It is important in stem cell transplants to determine how closely the
HLA type of the patient matches the HLA type of the stem cell donor.
The HLA "match" is the number of HLA molecules that any two people have
in common. HLA matching is usually based on six HLA molecules. The more
molecules two people share, the better the match. That is, their immune
systems are less likely to see each other as "foreign" and are
therefore also less likely to attack each other.
The most likely place to find an HLA match between two people is among
siblings (that is brother and sister who share the same parents.) If
two siblings inherit the same HLA molecules from both parents as the
patient, they are said to be an "HLA identical match."
There is a 25% or one in four chance of being an identical match with a
sibling, therefore doctors will frequently ask additional family
members to be tested. These are usually aunts, uncles, cousins and
grandparents.
However, two unrelated people can also be a good HLA match. Although it
is less likely, it is possible that you could have some of the same HLA
molecules as a friend or someone you don't even know. If you and the
patient share three HLA molecules, for example, then you are said to be
a "three HLA antigen match."
Q. Why is it important to have a specific donor "match"?
A. Because stem cells are
specific to certain aspects of the individual's genetic make-up,
transplants must be matched to the patient's HLA type to minimize any
immunologic reactions. This laboratory analysis is also referred to as
"tissue typing". The better the match on HLA parameters, the higher the
likelihood of a successful transplant for the patient. Regardless of
race or ethnicity, each person has a unique tissue type inherited from
his or her parents, which is why the chances of finding a match is best
among family members. The chance of two siblings matching each other is
one in four. This is why physicians first look for a match within the
patient's immediate family.
Q. What are the actual chances of finding a suitable marrow donor?
A. The chances of finding an
unrelated matched donor vary widely, depending on the uniqueness of the
patient's tissue type. In order to offer each patient a good chance of
finding a stem cell donor, volunteer donors representing a wide variety
of ethnicities and regions of national origin are encouraged to
register to be stem cell donors.
Q. Are donors sought only for American patients?
A. No, the patient could live
anywhere in the world. Many American patients also have received
successful transplants from international donors.
Q. Who can become a stem cell donor?
A. Donors who are interested
in joining public registries must be between 18 and 59* years old; have
no history of hepatitis, heart disease, cancer or AIDS; and sign a
standard consent form. Potential donors can be tested for a specific
patient's campaign or they can allow a registry to include their HLA
tissue type in its confidential, computerized files for future
matching. Potential donors always have the right to choose whether or
not they want to become a donor at a future time if a match to a
patient in need occurs.
* Note: Age criteria may vary. Please check with your local donor center or registry.
Q. And it only takes a simple cheek swab to get started?
A. Once the consent form is
signed, YES. It's that simple. If a donor is a potential match on the
basis of the initial (first level) test, a second (second level) test
will be conducted for more detailed assessment. Some labs are now able
to store the initial sample to be used for "second level" testing when
there is a "first level" match. Potential donors are notified, and
their consent is obtained before any additional testing is done.
Q. What is meant by a simple cheek swab?
A. HLA testing is performed
using molecular methodologies for the A, B and DR antigens. A special
sponge-tipped or soft brush swab is used to collect tissue from inside
the cheek.
Q. How is donor marrow collected?
A. When you donate marrow, it
is removed with a surgical needle from the back of your pelvic bone.
All marrow donors are given either general or regional anesthesia to
minimize any discomfort. Usually four to eight tiny incisions are made
in the pelvic area. The incisions are so small that stitches are not
necessary. The procedure lasts between 45 and 90 minutes Typically, the
donor enters the hospital on the day of the marrow donation. Donors
remain in the hospital for several hours or occasionally, overnight to
minimize any discomfort. The amount of marrow taken depends on the
weight of the patient, but the donation does not affect the donor's
blood platelet count or health of the immune system health. The donated
marrow is generally replenished by the donor's own system within one
month.
For a donation of peripheral blood stem cells, the donor receives one
injection of the prescription drug Filgrastim, per day for four to five
days. Filgrastim is a medication that increases the number of stem
cells released from the bone marrow into the blood stream. The stem
cells are collected from the blood stream through a process called
apheresis. During apheresis, which is done at a blood center or a
hospital, the donor's blood is removed through a sterile needle placed
in a vein in one arm and passed through an apheresis machine that
separates out the stem cells. The remaining blood, minus the stem
cells, is returned through a sterile needle placed in a vein in the
other arm.
Q. Does bone marrow or stem cell donation hurt?
A. Because anesthesia is used,
the bone marrow collection process is virtually painless. Donors can
expect to feel a little discomfort in the lower back region for several
days following the procedure. Donors usually report that this minor
discomfort is a small price to pay for the chance to save another
person's life. Peripheral stem cell donors rarely experience discomfort
either during or after the procedure.
Q. Are there any risks?
A. As with any medical
procedure, there is a small amount of risk associated with marrow or
stem cell collection. Complications are extremely rare but could
include anesthesia reactions, infection and transfusion reactions, or
injuries at or around the needle insertion area. A number of questions
are asked at the time individuals volunteer to be tested to ensure they
are in general good health.
Q. How are the marrow or stem cells given to the patient?
A. The patient's marrow is
first treated with chemotherapy and/or radiation to wipe out diseased
cells, and then he or she receives the new healthy stem cells through
an IV transfusion similar to a blood transfusion. The stem cells travel
through the patient's blood steam to the marrow spaces where they begin
to grow and provide health new blood cells. It takes about a month for
the first signs of engraftment to be evident, meaning that the
transplant has begun to work and is producing new healthy cells. During
this time the patient is vulnerable to infection and remains
hospitalized.
Q. Does the donor have to travel to the patient's location? How is the marrow transported?
A. The stem cell collection is
performed at a local hospital convenient to the donor. The donated stem
cells are then hand-carried to the patient's transplant center.
Q. Are donors paid?
A. There is no monetary compensation for the donation.
Q. What are the risks to the patient?
A. Not all patients survive
the pre-transplant procedures of chemotherapy and radiation. In
addition, other patient complications including non-engraftment,
rejection, graft-versus-host disease (the donated stem cells cause an
immune reaction attacking the patient's body), infection and relapse of
the original condition. However, thousands of patients receiving stem
cell transplants do recover and go on to lead healthy, productive lives.
Q. Can my children, who are under 18 years old, be privately tested to see if they match a family member or friend?
A. Yes, you can authorize
testing for any child who is under the age of 18 as long as you are
their legal guardian and you sign our Release/Consent for testing minor
children as indicated on the Kashi Clinical Laboratories' "Private Test
Requisition (Consent) Form".
Q. Do I need a doctor's order for private testing?
A. No, you do not need a
doctor's order for private testing. You can order a Stem Cell HLA
Typing test directly through us here at www.BoneMarrowTest.com or by contacting
Kashi Clinical Laboratories. We would be glad to assist you.
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