Allogeneic
transplantation Autologous
transplantation ·
Apheresis ·
Blast Cells
Blood Stem Cells ·
Bone Marrow ·
Chemotherapy ·
Conditioning ·
Cord Blood ·
Cord Blood Bank
Cryopreservation ·
Donor
Workup ·
DNA Based HLA Typing ·
Engraftment ·
Filgrastim
Graft Versus Host Disease ·
Hematopoietic
stem cells ·
Human Leukocyte Antigens
·
HLA Typing
Leukemia ·
Marrow Donation ·
Peripheral blood ·
Peripheral Blood Stem Cell
(PBSC) Donation
Peripheral Blood or Peripheral
Blood Stem Cells (PBSC) ·
Pre-transplant
Conditioning
Radiation therapy ·
National Marrow Registry
· Stem
Cells ·
Stem Cell Transplant
Transplantation ·
Umbilical Cord Blood Stem
Cell ·
Volunteer Donor
Allogeneic Transplantation
In an allogeneic transplant, the patient gets blood stem cells
from a donor. The donor's tissue type must closely match the patient's.
The donor can be either related or unrelated. Related donors are
usually a brother or sister, however, only 25% of all patients
find a match in their own family. This means 75%, the overwhelming
majority of patients, will need to find an unrelated donor! 6,000
people are looking for their life-saving match each day! That
is why it's so important for every eligible adult to join the
Marrow Registry!
Autologous transplantation
In an autologous transplant, the patient's own blood
stem cells are collected from either the marrow or blood and frozen.
The patient then receives high-doses of chemotherapy and/or radiation
therapy to destroy the cancerous cells. The extracted stem cells
are also treated to destroy the cancer cells, and then put back
into the patient.
Apheresis
A procedure where blood is drawn from a patient's or donor's arm
and circulated through a machine that removes certain cells such
as stem cells, white blood cells or platelets. The rest of the
blood is returned to the patient or donor. This is the procedure
used for a Peripheral Blood Stem Cell Transplant.
Blast Cells
Blast cells are immature white blood cells. Healthy bone marrow
makes stem cells that grow into the three types of blood cells:
red blood cells, white blood cells, and platelets. A Leukemia
patient's bone marrow makes too many blast cells (immature white
blood cells). Normal blast cells turn into a type of white blood
cell called granulocytes. Leukemic blasts are abnormal because
they remain immature and do not function like mature white blood
cells.
The main function of granulocytes is to destroy
infection by bacteria and fungi. Immature blasts cannot carry
out the functions of the mature granulocytes. This results is
the patient becoming anemic and prone to infection. As the leukemic
blast cells accumulate in the bone marrow, they begin to crowd
out the normal blood cells that develop there. Eventually, they
take up so much room that red blood cells, platelets, and normal
white blood cells cannot be produced.
Blood Stem Cells
Stem cells are any of the cells in the body that can grow into
other kinds of cells. Blood stem cells are one of several types
of stem cell. Healthy blood stem cells are vital because they
replace our supply of red blood cells, white blood cells, and
platelets. Red blood cells carry oxygen throughout the body, white
blood cells fight infection, and platelets clot blood (control
bleeding) when the skin or other tissue is cut.
When a person's blood stem cells become diseased
or cancerous, it is a life-threatening situation. Often, the only
hope for a cure is a blood stem cell transplant, which replaces
the patient's diseased cells with healthy new cells. For the transplant
to be a success, however, these cells must match the patient's
own cells as closely as possible.
Bone Marrow
A soft, spongy tissue that fills the cavities inside most bones
in the human body. Bone marrow is a source of stem cells that
manufacture red blood cells, white blood cells, and platelets.
It is a conventional source for stem cell transplantation.
Chemotherapy
Treatment of cancer or other malignant diseases by the
use of specific drugs that selectively destroy rapidly growing
cells. Extremely high doses will also kill the body's stem cells
in the bone marrow and peripheral blood stream. This is done in
preparation for a bone marrow or stem cell transplant.
Conditioning
The chemotherapy and/or radiation that is given to patients before
the marrow or blood stem cell transplant. The purpose is to kill
diseased cells so the new cells can grow.
Cord Blood
Blood remaining in the umbilical cord immediately following the
birth of the baby. It contains a rich concentration of stem cells
and has other unique biological and therapeutic properties. Cord
blood provides an alternative source of stem cells in many situations
where bone marrow is used.
Cord Blood Bank
An organization that helps to collect and store umbilical cord
blood for transplant. Cord blood banks recruit expectant mothers
to donate their baby's umbilical cord blood for stem cell transplants.
The blood in the umbilical cord and placenta is unique because
it contains large numbers of blood stem cells. The cord blood
banks collect, process, test and store the donated umbilical cord
blood. Blood from each cord is frozen (cryopreserved) as an individual
cord blood unit that is available to transplant.
Cryopreservation
Storage of biological materials in a constant steady state at
extremely cold temperatures. The cells remain frozen at -196°C
(-321°F) until needed.
Donor Workup
The process that a closely matched potential donor goes through
to make sure he or she is healthy and ready to donate marrow or
blood stem cells. Workup includes a detailed information session
at the Donor Center, a complete physical examination and donation
of blood samples for testing and research.
DNA based HLA
Typing
Determining a person's HLA type by direct examination of the DNA.
DNA-based typing is favored by the NMDP because it is very accurate
and efficient.
Engraftment
The process by which newly transplanted stem cells migrate to
and nest in the appropriate site of the recipient’s body
and start producing normal quantities of normal mature cells.
Filgrastim
A protein that helps bone marrow make more white blood cells.
Filgrastim is also known as GCSF (granulocyte-colony stimulating
factor) or by the trade name Neupogen®. It is given to donors
who have agreed to donate peripheral blood stem cells. This moves
blood stem cells from the marrow into the blood stream so that
they can be collected by apheresis. It is also given to patients
to help increase their white blood cell count after the transplant.
Graft Versus
Host Disease (GVHD)
A potential complication of transplants associated with the use
of blood or tissue from a different person (allogeneic). In GVHD,
the transplanted cells recognize the recipient’s tissue
as foreign and attack the recipient. GVHD in stem cell transplants
appears to be less severe with umbilical cord blood due to its
immunologically immature cell content, that appears to be more
tolerant of the new body’s environment.
Hematopoietic
stem cells
The “Master” (blood forming) stem cells that are capable
of recreating themselves and creating all of the other types of
blood cells. They are a valuable but scarce resource, comprising
only 1 in 10,000 cells in bone marrow, but 1 in 1,000 cells in
umbilical cord blood.
Human Leukocyte
Antigens (HLA)
Proteins on white blood cells that make each person's tissue unique.
The HLA A, B, C and DR proteins are important in matching patients
and donors for a marrow or blood stem cell transplant.
Human Leukocyte Antigens are specific cell surface
molecules (antigens) that are found on almost all human tissues.
These antigens are identified for both the potential recipient
and donor candidates prior to any transplantation procedure. This
identification process is known as “HLA typing”.
The more closely matched the recipient and donor’s
HLAs are, the more likely the transplanted tissue will be compatible
with and tolerated by the recipient. Registries, or databases,
containing information on HLA-typed bone marrow and umbilical
cord blood donors are maintained in many countries to help facilitate
the location of an appropriately matched stem cell source for
potential transplantation procedures.
The Wikipedia web site's entry on Human Leukocyte Antigens:
http://en.wikipedia.org/wiki/Human_leukocyte_antigen
HLA Typing
A person's own specific HLA A, B, C and DR proteins. Patients
are matched with stem cell donors or cord blood units by comparing
their HLA tissue types. HLA is the name given to the system used
to identify the unique markers (antigens) that the immune system
recognizes. These unique markers are found on virtually all cells
in the body, including white blood cells. In a stem cell transplant,
six HLA antigens are considered most important for matching: two
A antigens, two B antigens and two DR antigens. HLA type is inherited
through the genes passed down from parents. The genes are linked
together in strands of three: three antigens from the mother and
three from the father. This is why siblings are the first place
to look for a match, since a brother or sister may have inherited
the same HLA type. But even with siblings, there is only a 25%
chance for a match, leaving 75% of all patients seeking a life-saving
match from an unrelated donor.
Leukemia
A group of cancers of the white blood cells. Leukemias can be
acute (fast forming) or chronic (slow growing). Leukemia causes
excessive growth of immature white blood cells called "blasts."
These blasts do not perform any of the beneficial functions of
a healthy, mature white blood cell, such as fighting off disease
and infection. Furthermore, they multiply in such enormous volume
as to crowd out the healthy cells that remain. This often leads
to anemia, impaired blood clotting, and bruising easily in the
Leukemia patient.
Marrow Donation
A surgical procedure by which a person donates a portion of their
bone marrow for a patient who has diseased marrow and needs a
bone marrow transplant.
Peripheral blood
Blood derived from a patient’s blood stream, as opposed
to blood in the bone marrow where it is made.
Peripheral Blood
Stem Cell (PBSC) Donation
Hematopoietic stem cells are collected from a donor's circulating
blood through an apheresis procedure following mobilization from
the marrow with Filgrastim. The stem cells are then transplanted
into a recipient.
Peripheral
Blood or Peripheral Blood Stem Cells (PBSC)
Peripheral blood flows through the bloodstream in the body. Some
blood stem cells are found in the peripheral blood.
Pre-transplant
Conditioning
A regimen of chemotherapy with or without radiation therapy that
destroys a patient's marrow. The marrow is then restored by transplanting
stem cells.
Radiation therapy
Radiation is used to kill rapidly growing cancer cells or other
malignancies. High doses of radiation, especially when used in
combination with chemotherapy, also kills the body's stem cells
in the bone marrow and peripheral blood stream. This is done in
preparation for a bone marrow or stem cell transplant.
National Marrow
Registry
A confidential national database of potential volunteer stem cell
donors established and maintained by the National Marrow Donor
Program.
Stem Cells
Certain cells in the body that can grow into other kinds of cells.
Each tissue within the body contains a unique type of stem cell
that can renew and replace that tissue (e.g. nerve, brain, cartilage,
blood) when needed due to damage or wear. Stem cells of the blood
(hematopoietic stem cells) generate all other blood cells in the
human body, including red blood cells, platelets, and white blood
cells. Sources of hematopoietic stem cells include umbilical cord
blood, bone marrow, peripheral blood and embryos.
Stem Cell Transplant
The process of infusing healthy blood stem cells into persons
who have undergone high-dose chemotherapy for one of many forms
of leukemia, immunodeficiency, lymphoma, anemias, or metabolic
disorders. There are three types of blood stem cell transplants:
autologous, allogeneic and syngeneic. Healthy stem cells are collected
from bone marrow, peripheral blood, and umbilical cord blood.
Once the healthy stem cells are infused into the patient's blood
stream, the cells move from the blood vessels to the center of
the bones, where they begin making new blood cells.
Transplantation
The process of giving tissues or cells to treat a disease. The
tissue or cells transplanted may come from the same patient (autologous)
or from another person (allogeneic). A hematopoietic stem cell
transplant procedure is used to replace dead or diseased stem
cells with healthy stem cells capable of rebuilding the body’s
blood supply and immune system.
Umbilical Cord
Blood Stem Cell
A stem cell from the blood of the umbilical cord and placenta.
These cells have the potential to produce all the components of
blood in the same manner as stem cells derived from marrow.
Volunteer Donor
A person who has agreed to donate marrow or stem cells for transplant.
Volunteer donors are listed in the National Marrow Donor Program
(NMDP) Registry. |