umbilical cord blood transplant
Stem cells are taken from an umbilical cord immediately after delivery of an infant.
These stem cells reproduce into mature, functioning blood cells quicker and more
effectively than do stem cells taken from the bone marrow of another child or adult.
The stem cells are tested, typed, counted, and frozen until they are ready to be
transplanted.
How are a donor and recipient matched?
Matching involves typing human leukocyte antigen (HLA) tissue. The antigens on the
surface of these special white blood cells determine the genetic make-up of a person's
immune system. There are at least 100 HLA antigens, however, it is believed that
there are a few major antigens that determine whether a donor and recipient match.
The others are considered "minor" and their effect on a successful transplant
is not as well defined.
Medical research is still investigating the role all antigens play in the process
of a bone marrow transplant. The more antigens that match, the better the engraftment
of donated marrow. Engraftment of the stem cells occurs when the donated cells make
their way to the marrow and begin reproducing new blood cells.
The bone marrow transplant team:
The group of specialists involved in the care of patients going through transplant
is often referred to as the "transplant team." All individuals work together
to provide the best chance for a successful transplant. The team consists of the
following:
- physicians - physicians who specialize in oncology, hematology, immunology, and
bone marrow transplantation.
- bone marrow transplant nurse coordinator - a nurse who organizes all aspects of
care provided before and after the transplant. The nurse coordinator will provide
patient education, and coordinates the diagnostic testing and follow-up care.
- social workers - professionals who will help your family deal with many issues that
may arise including lodging and transportation, finances, and legal issues.
- dietitians - professionals who will help you meet your nutritional needs before
and after the transplant. They will work closely with you and your family.
- physical therapists - professionals who will help you become strong and independent
with movement and endurance after the transplantation.
- pastoral care - chaplains who provide spiritual care and support.
- other team members - several other team members will evaluate you before transplantation
and will provide follow-up care as needed. These include, but are not limited to,
the following:
- pharmacists
- respiratory therapists
- lab technicians
- infectious disease specialists
- dermatologists
- gastroenterologists
- psychologists
An extensive evaluation is completed by the bone marrow transplant team. The decision
for you to undergo a bone marrow transplant will be based on many factors, including
the following:
- your age, overall health, and medical history
- extent of the disease
- availability of a donor
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the disease
- expectations for the course of the transplant
- your opinion or preference
Preparation for the recipient
For a patient receiving the transplant, the following will occur in advance of the
procedure:
- Prior to the transplant, an extensive evaluation is completed by the bone marrow
transplant team. All other treatment options are discussed and evaluated for risk
versus benefit.
- A complete medical history and physical examination are performed, including multiple
tests to evaluate the patient's blood and organ functions (i.e., heart, kidney,
liver, lungs).
- A patient will often come into the transplant center up to 10 days prior to transplant
for hydration, evaluation, placement of the central venous line, and other preparations.
A catheter, also called a central venous line, is surgically placed in a vein in
the chest area. Blood products and medications will be administered through the
catheter.
- A suitable (tissue typed and matched) donor must be available. Finding a matching
donor can be a challenging and lengthy process. Voluntary marrow donors are registered
in several national and international registries. A bone marrow search involves
searching these registries for donors whose blood most closely resembles or matches
the individual needing the transplant.
Preparation for the donor
- Donor sources available include: self, sibling, parent or relative, non-related
person, or umbilical cord from a related or non-related person. There are national
and international registries for non-related persons and cord blood. For family
members, they may be typed because of the desire to help. These relatives may or
may not elect to have their type registered for use with other recipients.
- If the potential donor is notified that they may be a match for a patient needing
a transplant, they will undergo additional tests. Tests related to their health,
exposure to viruses, and complete genetic analysis will be done to determine the
extent of the match. The donor will be given instructions on how a bone marrow donation
will be made.
- Once a match for a patient needing a bone marrow transplant is found, then stem
cells will be collected either by a bone marrow harvest (collection of stem cells
with a needle placed into the soft center of the bone marrow) or peripheral blood
stem cell collection (stem cells are collected from the circulating cells in the
blood). Cord blood has already been collected at the time of a birth and stored
for later use.
How are the stem cells collected?
A bone marrow transplant is done by transferring stem cells from one person to another.
Stem cells can either be collected from the circulating cells in the blood (the
peripheral system) or from the bone marrow.
- peripheral blood stem cells (PBSCs)
Peripheral blood stem cells (PBSCs) are collected by a apheresis, a process in which
the donor is connected to a special cell separation machine via a needle inserted
in the vein. Blood is taken from one vein and is circulated though the machine which
removes the stem cells and returns the remaining blood and plasma back to the donor
through another needle inserted into the opposite arm. Several sessions may be required
to collect enough stem cells to ensure a chance of successful engraftment in the
recipient.
A medication may be given to the donor for about one week prior to apheresis that
will stimulate the bone marrow to increase production of new stem cells. These new
stem cells will be released from the marrow and into the circulating or peripheral
blood system.
- bone marrow harvest
Bone marrow harvesting involves collecting stem cells with a needle placed into
the soft center of the bone, the marrow. Most sites used for bone marrow harvesting
are located in the hip bones and the sternum. The procedure takes place in the operating
room. The donor will be anesthetized during the harvest and will not feel the needle.
In recovery, the donor may experience some pain in the areas where the needle was
inserted.
If the donor is the person him/herself, it is called an autologous bone marrow transplant.
If an autologous transplant is planned, previously collected stem cells, from either
peripheral (apheresis) or harvest, are counted, screened, and ready to infuse.
The bone marrow transplant procedure
The preparations for a bone marrow transplant vary depending on the type of transplant,
the disease requiring transplant, and your tolerance for certain medications. Consider
the following:
- Most often, high doses of chemotherapy and/or radiation are included in the preparations.
This intense therapy is required to effectively treat the malignancy and make room
in the bone marrow for the new cells to grow. This therapy is often called ablative,
or myeloablative, because of the effect on the bone marrow. The bone marrow produces
all the blood cells in our body. Ablative therapy prevents this process of cell
production and the marrow becomes empty. An empty marrow is needed to make room
for the new stem cells to grow and establish a new production system.
- After the chemotherapy and/or radiation is administered, the marrow transplant is
given through the central venous catheter into the bloodstream. It is not a surgical
procedure to place the marrow into the bone, but is similar to receiving a blood
transfusion. The stem cells find their way into the bone marrow and begin reproducing
and establishing new, healthy blood cells.
- Supportive care is given to prevent and treat infections, side effects of treatments,
and complications. This includes frequent blood tests, close monitoring of vital
signs, strict measurement of input and output, daily weigh-ins, and providing a
protected and sterile environment.
The days before transplant are counted as minus days. The day of transplant is considered
day zero. Engraftment and recovery following the transplant are counted as plus
days. For example, a patient may enter the hospital on day -8 for preparative regimen.
The day of transplant is numbered zero. Days +1, +2, etc., will follow. There are
specific events, complications, and risks associated with each day before, during,
and after transplant. The days are numbered to help the patient and family understand
where they are in terms of risks and discharge planning.
During infusion of bone marrow, the patient may experience the following:
- pain
- chills
- fever
- hives
- chest pain
After infusion, the patient may:
- spend several weeks in the hospital.
- be very susceptible to infection.
- experience excessive bleeding.
- have blood transfusions.
- be confined to a sterile environment.
- take multiple antibiotics and other medications.
- be given medication to prevent graft-versus-host disease - if the transplantation
was allogeneic. The transplanted new cells (the graft), tend to attack the patient's
tissues (the host), even though the donor is a relative, such as a brother, sister,
or parent.
- undergo continual laboratory testing.
- experience nausea, vomiting, diarrhea, mouth sores, and extreme weakness.
- experience temporary mental confusion and emotional or psychological distress.
After leaving the hospital, the recovery process continues for several months or
longer, during which time the patient cannot return to work or many previously enjoyed
activities. The patient must also make frequent follow-up visits to the hospital
or physician's office.
When does engraftment occur?
Engraftment of the stem cells occurs when the donated cells make their way to the
marrow and begin reproducing new blood cells. Depending on the type of transplant
and the disease being treated, engraftment usually occurs around day +15 or +30.
Blood counts will be performed frequently during the days following transplant to
evaluate initiation and progress of engraftment. Platelets are generally the last
blood cell to recover.
Engraftment can be delayed because of infection, medications, low donated stem cell
count, or graft failure. Although the new bone marrow may begin making cells in
the first 30 days following transplant, it may take months, even years, for the
entire immune system to fully recover.
What complications and side effects may occur following BMT?
Complications may vary, depending on the following:
- type of marrow transplant
- type of disease requiring transplant
- preparative regimen
- age and overall health of the recipient
- variance of tissue matching between donor and recipient
- presence of severe complications
The following are complications that may occur with a bone marrow transplantation.
However, each individual may experience symptoms differently. These complications
may also occur alone, or in combination:
- infections
Infections are likely in the patient with severe bone marrow suppression. Bacterial
infections are the most common. Viral and fungal infections can be life threatening.
Any infection can cause an extended hospital stay, prevent or delay engraftment,
and/or cause permanent organ damage. Antibiotics, anti-fungal medications, and anti-viral
medications are often given to prevent serious infection in the immunosuppressed
patient.
- low platelets and low red blood cells
Thrombocytopenia (low platelets) and anemia (low red blood cells), as a result of
a non-functioning bone marrow, can be dangerous and even life threatening. Low platelets
can cause dangerous bleeding in the lungs, gastrointestinal (GI), and brain.
- pain
Pain related to mouth sores and gastrointestinal (GI) irritation is common. High
doses of chemotherapy and radiation can cause severe mucositis (inflammation of
the mouth and GI tract).
- fluid overload
Fluid overload is a complication that can lead to pneumonia, liver damage, and high
blood pressure. The primary reason for fluid overload is because the kidneys cannot
keep up with the large amount of fluid being given in the form of intravenous (IV)
medications, nutrition, and blood products. The kidneys may also be damaged from
disease, infection, chemotherapy, radiation, or antibiotics.
- respiratory distress
Respiratory status is an important function that may be compromised during transplant.
Infection, inflammation of the airway, fluid overload, graft-versus-host disease,
and bleeding are all potential life-threatening complications that may occur in
the lungs and pulmonary system.
- organ damage
The liver and heart are important organs that may be damaged during the transplantation
process. Temporary or permanent damage to the liver and heart may be caused by infection,
graft-versus-host disease, high doses of chemotherapy and radiation, or fluid overload.
- graft failure
Graft failure is a potential complication. Graft failure may occur as a result of
infection, recurrent disease, or if the stem cell count of the donated marrow was
insufficient to cause engraftment.
- graft-versus-host disease
Graft-versus-host disease (GVHD) can be a serious and life-threatening complication
of a bone marrow transplant. GVHD occurs when the donor's immune system reacts against
the recipient's tissue. The new cells do not recognize the tissues and organs of
the recipient's body. The most common sites for GVHD are GI tract, liver, skin,
and lungs.
Long-term outlook for a bone marrow transplantation
Prognosis greatly depends on the following:
- type of marrow transplant
- type and extent of the disease being treated
- disease response to treatment
- genetics
- your age and overall health
- your tolerance of specific medications, procedures, or therapies
- severity of complications
As with any procedure, such as bone marrow transplant, prognosis, and long-term
survival can vary greatly from person to person. The number of transplants occurring
for an increased number of diseases and medical developments has greatly improved
the outcome for bone marrow transplant in children and adults. Continuous follow-up
care is essential for the patient following a bone marrow transplant. New methods
to improve treatment and to decrease complications and side effects of a bone marrow
transplant are continually being discovered.