Transcript Cord blood testing

Practical
Blood Bank
Cord Blood
Umbilical cord
In placental mammals, the umbilical cord is the
connecting cord from the developing embryo or fetus to
the placenta.
 During prenatal development, the umbilical cord is
physiologically and genetically part of the fetus
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In humans normally contains two arteries (the umbilical
arteries) and one vein (the umbilical vein), buried within
Wharton's jelly.
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The umbilical vein supplies the fetus with oxygenated,
nutrient-rich blood from the placenta. Conversely, the fetal
heart pumps deoxygenated, nutrient-depleted blood
through the umbilical arteries back to the placenta.
Wharton's jelly
Wharton's jelly is a gelatinous substance within the
umbilical cord, largely made up of mucopolysaccharides
(hyaluronic acid and chondroitin sulfate). It also contains
some fibroblasts and macrophages.
 As a mucous tissue it protects and insulates umbilical
blood vessels.
 Wharton's jelly is a potential source of adult stem cells
(also see the more common method of storing cord blood).
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Cord blood testing
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Immediately after the birth of the baby, the umbilical cord is
clamped and cut. If cord blood is to be drawn, another clamp
is placed 8 to 10 inches away from the first, then the isolated
section is cut and a blood sample is collected into a specimen
tube.
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Cord blood testing is done to determine the following:
– Bilirubin levels
– Blood culture (if an infection is suspected)
– Blood gases, to evaluate the oxygen, carbon dioxide, and
pH levels
– Blood sugar level
– Blood type and Rh
– Complete blood count (CBC)
Cord blood testing is done to determine
the following
A low pH (less than 7.04 to 7.10) means there are higher
levels of acids in the baby's blood. This might occur when
the baby does not get enough oxygen during labor. One
reason for this could be that the umbilical cord was
compressed during labor or delivery.
 A blood culture that is positive for bacteria indicates
septicemia.
 High levels of blood sugar (glucose) in the cord blood may
be found if the mother has diabetes. The newborn will be
watched for hypoglycemia (low blood sugar) after delivery.
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High levels of bilirubin could be due to:
◦ Infections that the baby gets before birth, including:
 Congenital CMV
 Congenital hepatitis
 Congenital rubella
 Congenital toxoplasmosis
◦ Other possible causes include:
 Dubin-Johnson syndrome
 Jaundice in the mother
 Mother taking sulfa drugs during pregnancy
 Rh incompatibility
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A cord sample (about 5 to 10 mls) should be taken
from the babies of RhD negative women, women
with known antibodies or in cases where there is
insufficient documentation of maternal blood group
or antibody status.
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The cord sample should be tested for blood group
and direct antiglobulin test.
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Haemoglobin and bilirubin estimation should also
be performed if DAT is positive.
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When the cord blood is RhD negative, it is
recommended that testing for the presence of the weak
RhD antigen by the indirect antiglobulin test be
performed. If positive, RhD immunoglobulin is
indicated. If the direct antiglobulin test is positive, it
may indicate fetomaternal incompatibility
Antibody elution from the neonatal red cells can be
performed to confirm the identity of the antibody
coating the cord red blood cells.
When haemolytic disease of the newborn is suspected,
Hb, blood group, direct Coombs and bilirubin must be
checked. Otherwise cord blood samples are not routinely
tested though some collect the samples and store them
for up to a week at 4°C in case they should be needed.
Considerations
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Most hospitals routinely collect cord blood for testing at
birth, since it is relatively convenient and the only time
possible to collect such blood.
Besides cord blood testing, cord blood can be used to
treat certain types of bone marrow-related cancers. Some
parents may choose to save (bank) their child's cord
blood for this and other, future medical purposes.
Cord blood banking for personal use is done by private
companies, which charge for the service. Cord blood can
also be donated to your local blood bank for use by
others as needed to treat leukemia and other cancers.
Cord Blood Banking
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Cord blood is rich in potentially life-saving stem cells. When
they are transplanted, those stem cells are effective for the
treatment of patients with diseases of the immune system
(e.g., immunodeficiencies), blood (e.g., leukemia and sickle
cell anemia) and selected metabolic disorders.
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The umbilical cord, placenta, and the blood they contain
have no function after birth and they end up in waste. If
exploited, this resource can be used for the good of the
whole community.
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Stem cells in the cord blood similar to those found in bone
marrow. This is why cord blood can be used for
transplantation as an alternative to bone marrow.
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Stem-cell transplants have advantages over bone
marrow transplants in the treatment, with a lower risk of
tissue rejection. The collection process is noninvasive,
and involves a simple blood transfusion.
Qualification of Cord Blood Units for the
NYBC's National Cord Blood Program
Inventory.
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A cord blood unit must meet all of the criteria (at a
minimum) below to qualify for inclusion in the NCBP Search
Inventory and be available for transplantation:
1. The unit contains 1.1 billion total nucleated cells (TNC) or
more before processing.
2. The mother has given consent for donation
3. The unit has been typed for HLA-A, -B and –DRB1 (A
and B at low resolution and DRB1 at high resolution) and
for the blood group antigens A, B and Rh:1 (D);
4. The unit had acceptable results for CD34+ cells and CFU
(colony forming units). Note: CFU evaluation has not
been performed in all units;
5. There is no bacterial contamination of the unit;
6. The infant has no identified risks of genetic or infectious
disease that might be transmitted in the cord blood;
7. The unit and the mother’s blood are negative for
infectious disease markers;
8. The cord blood unit was processed and frozen following
the NCBP protocol validated to maintain nucleated cell
viability.
9. A sample of cord blood is available in a segment of the
tubing integral to the bag containing the cord blood unit,
for future confirmatory HLA typing.
What is cord blood used for?
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The most common disease category has been leukemia.
The next largest group is inherited diseases (of red
blood cells, the immune system and certain metabolic
abnormalities.)
Patients with lymphoma, myelodysplasia and severe
aplastic anemia have also been successfully transplanted
with cord blood.
How long do cord blood cells remain
viable?
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It is not known how long cord blood can be stored in
liquid nitrogen and its cells remain viable.
NCBP's earliest units were stored in 1993. In checking
the viability of cells in cord blood units that will not be
used for transplantation, they did not detect any
deterioration in the quality of the cells in cord blood
units stored for up to 16 years.
Units stored for up to 13 years have been used in
transplants and the outcomes have been similar to those
of newly collected units.
Checking Donor's and Blood Tests?
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Normal procedure includes
◦ Asking the mother and father for their health related history
◦ Blood tests to rule out
 HIV infections, other blood diseases human
immunodeficiency virus (HIV, the cause of AIDS),
 hepatitis B and C viruses (HBV and HCV),
 human T-lymphotropic virus (HTVL),
 syphilis,
 West Nile Virus (WNV)
 and Chagas disease (a disease common in South America).
 test the baby's blood for Cytomegalovirus (CMV)
 and for hemoglobin abnormalities such as sickle cell
disease..
◦ Signing of a consent form.
Methodology
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Collection
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Processing
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Storage
How is cord blood collected?
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The cord blood collection process is simple, safe, and painless.
It is usually completed in less than five minutes by your health
care provider. Cord blood collection does not interfere with
delivery and is possible with vaginal or cesarean deliveries.
Your health care provider will use one of two options for cord
blood collection: syringe method or bag method.
◦ Syringe method: a syringe is used to draw blood from the
umbilical cord shortly after the umbilical cord has been cut.
The process is basically the same as drawing blood for a blood
test.
◦ Bag method: the umbilical cord is elevated to cause the blood
to drain into a bag.
The syringe or bag should be pre-labeled with a unique number
that represents your baby. Cord blood may only be collected
during the first 15 minutes following the birth, and should be
processed by the laboratory within 48 hours.
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The Cord Blood Bank is responsible for collection of the blood.
However, the related authorities (delivery doctors, nurses) must
be aware of the mothers’ wish to donate or store Cord Blood
after the birth.
Minutes after a child’s birth and after the umbilical cord is cut,
the placenta and its attached portion of the cord are delivered
With maternal assent to collect the cord blood,
staff move the placenta to an adjacent laboratory, where they
collect the cord blood into a sterile plastic bag, much like those
used for blood transfusion.
Because they collect cord blood from the delivered placenta, no
risk is incurred by mother or child.
explains all aspects of the Program to the mother and requests
her consent to donate the cord blood. Donation of the blood
from a single placenta becomes a unique cord blood unit.
The volume collected varies but usually ranges from 50 to 200
ml (about one-half to one cup).
Storage:
The cord blood is frozen and stored in liquid nitrogen
freezers designed especially for cord blood units.
 The BioArchive is a robotic freezer that controls and
monitors the rate of freezing, then stores the unit in liquid
nitrogen and provides quick access to stored units
 whenever needed, all under computer control and with
complete documentation.
 When a transplant center requests a matched cord blood unit
for a patient, the available inventory of cord blood units is
“searched” for matches to the patient. The best matching unit
(or units) can be selected, reported, confirmed and delivered
rapidly upon request.
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Freezing:
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Each cord blood unit is frozen (one at a time) in an
individual “controlled-rate freezer” module within
the BioArchive™ system. We use a freezing rate
documented to maintain cell viability. A record of
the freezing curve is printed and maintained in the
BioArchive™ computer memory.
Finding a Match
Several studies indicate that cord blood transplants do not
need to be as perfectly HLA-matched to the recipient as
bone marrow transplants do. However, patients have a
better chance to survive and regain health if the cord blood
graft is better matched (6/6 or 5/6) and provides cell doses
of 20 million nucleated cells per kg or more.
 Cord Blood Unit Match Reports: An individual Match
Report gives detailed information about the cord blood
unit, including number of total nucleated and CD34+ cells,
ABO and Rh blood groups and results of other laboratory
tests.
 The match referred to is required between the donor’s and
recipient’s HLA antigens. The closer the match is, the
better is the body’s chance of accepting the new stem cell.
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