Download Blood Groups, Blood Typing and Blood Transfusions

BLOOD GROUPS, BLOOD TYPING, BLOOD TRANSFUSIONS AND BLOOD DISORDERS
HISTORY
Experiments with blood transfusions, the transfer of blood or blood components into a person's
blood stream, have been carried out for hundreds of years. Many patients died as a result of this
procedure. It was not until 1901 when the Austrian Karl Landsteiner discovered human blood
groups, that blood transfusions became safer.
Mixing blood from two individuals can lead to blood clumping or agglutination. This can have fatal
consequences. Karl Landsteiner discovered that blood clumping was an immunological reaction
which occurs when the receiver of a blood transfusion has antibodies against the donor blood cells.
Karl Landsteiner's work made it possible to determine blood types and thus paved the way for
blood transfusions to be carried out safely. For this discovery he was awarded the Nobel Prize in
Physiology or Medicine in 1930.
BLOOD GROUPS
The differences in human blood are due to the presence or absence of certain protein molecules
called antigens and antibodies. The antigens are proteins located on the surface of the red blood
cells (RBCs) and are inherited. The antibodies are proteins in the blood plasma that develop
shortly after birth. Individuals have different types and combinations of these molecules. The blood
group you belong to depends on what you have inherited from your parents.
There are more than 20 genetically determined blood group systems known today, but the ABO
and Rh systems are the most important ones used for blood transfusions. Not all blood groups are
compatible with each other. Mixing incompatible blood groups leads to blood clumping or
agglutination, which is dangerous for individuals. Karl Landsteiner was involved in the discovery of
both the ABO and Rh blood groups.
ABO BLOOD GROUPING SYSTEM
According to the ABO blood typing system there are four different kinds of blood types: A, B, AB or
O (null).
If you belong to the blood group A, you have A antigens on the surface of your RBCs and B
antibodies in your blood plasma.
If you belong to the blood group B, you have B antigens on the surface of your RBCs and A
antibodies in your blood plasma.
If you belong to the blood group AB, you have both A and B antigens on the surface of your RBCs
and no A or B antibodies at all in your blood plasma.
If you belong to the blood group O, you have neither A nor B antigens on the surface of your RBCs
but you have both A and B antibodies in your blood plasma.
Rh FACTOR BLOOD GROUPING SYSTEM
Many people also have the Rh factor (protein) on the RBCs surface. This protein was originally
discovered on the blood cells of the Rhesus monkey (hence the name Rh factor). This is also an
antigen and those who have it are called Rh+. Those who do not have it are called Rh-. A person
with Rh- blood does not have Rh antibodies naturally in the blood plasma (as one can have A or B
antibodies, for instance). But a person with Rh- blood can develop Rh antibodies in the blood
plasma if he or she receives blood from a person with Rh+ blood. The donor’s Rh antigens can
trigger the production of Rh antibodies. A person with Rh+ blood can receive blood from a person
with Rh- blood without any problems.
BLOOD GROUP NOTATION
According to above blood grouping systems, you can belong to one of following eight blood
groups:
A Rh+ or A+
B Rh+ or B+
AB Rh+ or AB+
O Rh+ or O+
A Rh- or A-
B Rh- or B-
AB Rh- or AB-
O Rh- or O-
DETERMINATION OF A PERSON’S BLOOD GROUP
A person’s blood group (or blood type) can be determined using the following steps:
1. Three separate blood samples from the same person are mixed with three separate reagents.
Each reagent contains one of the antibodies = A, B or Rh.
2. Observe each mixture and note where agglutination (clumping) has occurred. The
agglutination indicates that the blood has reacted with a certain antibody and therefore is not
compatible with blood containing that kind of antibody. If the blood does not agglutinate, it
indicates that the blood does not have the antigens binding the special antibody in the reagent.
WHAT HAPPENS WHEN BLOOD CLUMPS OR AGGLUTINATES
For a blood transfusion to be successful, ABO and Rh blood groups must be compatible between
the donor blood and the patient blood. If they are not, the RBCs from the donated blood will clump
or agglutinate. The agglutinated RBCs can clog blood vessels and stop the circulation of the blood
to various parts of the body. The agglutinated cells also crack open and the contents leak out in the
body. The RBCs contain hemoglobin which becomes toxic when outside the cell. This can have
fatal consequences for the patient.
The A antigen and the A antibodies can bind to each other in the same way that the B antigens can
bind to the B antibodies. This is what would happen if a B blood person (A antibodies) receives
blood from an A blood person. The RBCs will be linked together, like bunches of grapes, by the
antibodies. As mentioned earlier, this clumping can result in death.
BLOOD TRANSFUSIONS
Of course you can always give A blood to a person with blood group A, B blood to a person with
blood group B and so on. But in extreme cases (when the same blood type is not available) you
can receive blood with another type of blood group, or donate blood to a person with another kind
of blood group.
The transfusion will work if the person who is going to receive blood has a blood group that doesn't
have any antibodies against the donor blood's antigens. But if a person who is going to receive
blood has antibodies matching the donor blood's antigens, the RBCs in the donated blood should
clump. Fortunately, the antibodies in the donated blood become diluted in the recipient’s blood if
the transfusion is done slowly. Slow transfusion usually avoids serious consequences. This is why
certain donor blood types can be given to more than one blood type recipient when an exact match
is not available. This is demonstrated in the chart below.
Blood Group
Antigens
Antibodies
Can give blood to
Can receive blood from
AB
A and B
None
AB
AB, A, B, O
A
A
B
A and AB
A and O
B
B
A
B and AB
B and O
O
None
A and B
AB, A, B, O
O
RED BLOOD CELL DISORDERS
Anemia
Anemia (uh-NEE-me-eh) is a condition in which a person’s blood has a lower than normal number
of RBCs, or the RBCs don’t have enough hemoglobin. As a result, people with anemia feel tired,
along with other symptoms, because their bodies are not receiving enough oxygen. Remember
that oxygen is required for cellular respiration (formation of ATP for energy). Without ATP,
normal chemical reactions that keep the cell functioning properly do not occur. In severe or
prolonged cases of anemia, the lack of oxygen in the blood can cause serious and sometimes fatal
damage to the heart and other organs of the body.
Poor nutrition may contribute to inadequate red blood cell production, especially deficiencies in iron
and certain types of vitamin B. When an increased production of RBCs is necessary, such as
during pregnancy or after an episode of bleeding, these nutrients are even more critical. Iron and
vitamin B supplements are often prescribed to prevent anemia.
Iron Deficiency Anemia
Iron Deficiency Anemia is the most common cause of anemia in the United States. It occurs when
the body either has depleted all iron stores or is unable to use the iron available to make adequate
amounts of hemoglobin. For Americans, however, lack of dietary iron is rarely the sole cause of
this anemia. Usually, people have blood loss as well. Young women are at particular risk, because
of monthly blood loss with menstruation. Up to 10 percent of women in their reproductive years
have iron deficiency, and, in about half of those cases, it is severe enough to cause anemia.
Pregnant women also are at risk, which is why prenatal vitamins containing extra iron are
recommended during pregnancy.
Iron-deficiency anemia is less common in men and in postmenopausal women in the United
States. Low iron levels in these groups is a warning that abnormal bleeding could be occurring due
to undiagnosed medical conditions such as ulcer disease or colon cancer. The highest amounts of
iron are found in meat, spinach, raisins, lentils and enriched flour. Iron is absorbed most efficiently,
however, from red meat which is why pre-menopausal women who don't eat much meat are at
particular risk for iron-deficiency anemia. Other factors also contribute to how much iron is
absorbed in the body. Vitamin C enhances the absorption of iron from the intestine, so if you
combine foods with iron and vitamin C, you will increase the amount of iron absorbed. Citrus fruits
are well-known for their vitamin C content, but many vegetables are also a good source of vitamin
C, such as tomatoes, cauliflower, broccoli and potatoes.
Vitamin B12 Deficiency / Pernicious Anemia
A vitamin B12 deficiency produces unusually large RBCs with a shortened life span. Older
Americans may have B12 blood levels that are below the optimal range even when there is no
anemia. This usually is due to an inability to absorb vitamin B12 rather than a dietary deficiency,
although strict vegetarians are at risk because vitamin B12 is found only in animal products. Another
cause of vitamin B12 deficiency is pernicious anemia, an autoimmune disease in which the immune
system attacks the specialized stomach cells that produce a protein called intrinsic factor. This
protein is essential to the absorption of vitamin B12 from food. Vitamin B12 deficiency also can
develop as a complication of gastrointestinal surgery and certain diseases of the intestine,
preventing adequate absorption. Good sources of vitamin B12 include liver, tuna, cottage cheese,
yogurt and eggs. Most standard multivitamin supplements also provide the recommended daily
allowance of vitamin B12.
Aplastic Anemia
Aplastic Anemia is a rare, potentially fatal disease in which the bone marrow doesn't make enough
blood cells. People with aplastic anemia have low levels of all three types of blood cells. In aplastic
anemia, something either destroys the stem cells located in the bone marrow or drastically
changes the environment of the bone marrow so that the stem cells can't develop properly. Several
factors can cause this problem, such as exposure to radiation (radiation sickness), chemotherapy,
environmental toxins (insecticides), some medications, and certain viral infections, including viral
hepatitis, HIV and infectious mononucleosis (Epstein-Barr viral infection).
WHITE BLOOD CELL DISORDER
Leukemia
Leukemia is a form of cancer that affects the body's blood-making system, including the lymphatic
system and bone marrow. Leukemia is either acute (coming on suddenly) or chronic (lasting a
long time).
In acute leukemia, immature blood cells reproduce quickly in the bone marrow, where they
eventually crowd out healthy cells. When present in high numbers, these immature, abnormal cells
sometimes can spread to other organs, causing damage.
Acute lymphoid leukemia
Acute lymphoid leukemia occurs when lymphoid stem cells reach the lymphoblast stage without
developing into normal blood cells. These abnormal cells crowd out healthy blood cells. They can
collect in the lymph nodes and cause swelling.
Acute myeloid leukemia
Acute myeloid leukemia occurs when myeloid stem cells reach the myeloblast stage and
reproduce without developing into normal blood cells. Immature myeloblast cells crowd the bone
marrow and do not develop into healthy normal blood cells. This leads to anemia (not having
enough RBCs), bleeding and bruising (due to a lack of platelets), and frequent infections because
there are not enough protective white blood cells.
Chronic leukemia
Chronic leukemia may be lymphoid or myeloid but occurs when the body produces too many blood
cells that have developed part way (as far as myelocytes or lymphocytes) but often cannot function
like mature blood cells. Chronic leukemia usually develops more slowly and is a less dramatic
illness than acute leukemia.
PLATELET DISORDER
Thrombocytopenia
Thrombocytopenia is the medical term for a low blood platelet count. Platelets (thrombocytes) play
an important role in blood clotting. They stop blood loss by clumping together at the site of a blood
vessel injury and forming plugs in vessel holes. If for any reason your blood platelet count falls
below normal, this is called thrombocytopenia. Complications may range from none at all to severe
bleeding.
Most people have more than 150,000 platelets per microliter of blood. Anyone with fewer platelets
has some degree of thrombocytopenia. The risk of bleeding increases as the platelet count
decreases, so people with less than 10,000 platelets per microliter of blood are at high risk of
severe bleeding.
BLOOD CLOTTING PROTEIN DISORDER
Hemophilia
Hemophilia is a rare, inherited bleeding disorder in which your blood doesn’t clot normally. If you
have hemophilia, you may bleed for a longer time than others after an injury. You also may bleed
internally, especially in your knees, ankles, and elbows. This bleeding can damage your organs or
tissues and, sometimes, be fatal.
People born with hemophilia have little to none of a protein needed for normal blood clotting. The
protein is called a clotting factor. There are several types of clotting factors, and they work together
with platelets to help the blood clot.
When blood vessels are injured, clotting factors help the platelets stick together to plug cuts and
breaks at the site of the injury to stop the bleeding. Without clotting factors, normal blood clotting
can’t take place. Sometimes people with hemophilia need injections of a clotting factor or factors to
stop bleeding. Hemophilia can be mild, moderate, or severe, depending on how much clotting
factor is in the blood
QUESTIONS TO ACCOMPANY BLOOD GROUPS, TYPES, TRANSFUSIONS AND DISORDERS
1.
Define agglutination: ________________________________________________________
2.
Name the person that discovered there are human blood groups and the year he was
awarded the Nobel Prize for his discovery. ______________________________________
3 A. Antigens and antibodies belong to the category or organic compounds named _________.
B. Antigens are located ___________________ while antibodies are located ______________.
C.(Antigens / Antibodies) are inherited characteristics while (antigens / antibodies) form shortly
after you are born.
4 A. Name the three proteins that may be found on the surface of human RBCs. ______________
B. Name the two proteins that may form in human plasma shortly after birth. _______________
5.
Complete the following chart for each blood type listed. If proteins are absent use an O.
BLOOD TYPE
ANTIGENS PRESENT
ANTIBODIES PRESENT
A+
BAB +
O+
O6.
List two reasons why blood agglutination is dangerous to the human body.
__________________________________________________________________________
__________________________________________________________________________
7.
Why can type O blood be given to all four blood types even though it contains both A and B
antibodies? ________________________________________________________________
8.
List two causes of anemia and explain why anemic persons are always tired. ____________
__________________________________________________________________________
__________________________________________________________________________
9.
Why is oxygen necessary to keep body organs healthy? _____________________________
__________________________________________________________________________
10 A. In iron deficiency anemia, what vitamin deficiency may contribute to the condition and why?
__________________________________________________________________________
B. How is the iron used? ________________________________________________________
11 A. What happens to your RBCs if you do not take in enough vitamin B12 through diet? ________
__________________________________________________________________________
B. Explain the difference between Pernicious Anemia and dietary vitamin B12 deficiency. ______
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
OVER 
12 A. List two reasons (not factors) why stem cells in the bone marrow malfunction in Aplastic
Anemia. ___________________________________________________________________
B. Name the types of blood cells that are affected by Aplastic Anemia. ____________________
13 A. What is the difference between acute and chronic Leukemia? _________________________
__________________________________________________________________________
B. In Acute Lymphoid Leukemia, do the immature cells crowd out the healthy cells? _________
Where else can they collect and what does this cause? ______________________________
C.In Acute Myeloid Leukemia, do the immature cells crowd out the healthy cells? ___________
Why can chronic anemia be a side effect of this condition? ___________________________
14 A. What is Thrombocytopenia? ___________________________________________________
B. Explain how the platelets function during the formation of a clot? ______________________
__________________________________________________________________________
15 A. If a person has Hemophilia, what is lacking in her/his blood? __________________________
B. How does your answer to 15 A help the platelets? __________________________________
__________________________________________________________________________
C.What determines if a person has mild, moderate or severe Hemophilia? _________________
__________________________________________________________________________