Blood Groups and Transfusion Flashcards
What is present on the surface of red blood cells to determine ABO blood grouping?
Sugar (glycoprotein)
What is present on the surface of red blood cells to determine Rhesus blood grouping?
Protein
What is the role of ABO antibodies?
These are IgM antibodies that an individual has to antigens on the surface of red blood cells that are non-self i.e. if an individual is Group A, they will have IgM antibodies for B-type antigens on RBCs.
These antibodies are also known as cold-acting as they can bind to antigens at room temperature
What antibodies will someone with Group A blood have?
Anti-B IgM antibodies
What antibodies will someone with Group AB blood have?
No IgM antibodies
What antibodies will someone with Group B blood have?
Anti-A IgM antibodies
What antibodies will someone with Group O blood have?
IgM antibodies to both a and b types
What genotype would give rise to the group A blood phenotype?
AA/AO
What genotype would give rise to the group B blood phenotype?
BB/BO
What genotype would give rise to the group AB blood phenotype?
AB (codominance)
What genotype would give rise to the group O blood phenotype?
OO
What are the three inherited antigens that are important in Rhesus blood grouping?
C/c, D/d (d represents no rhesus factor), E/e and these are inherited as a triplet
What is haemolytic disease of the newborn (HDN)?
If a mother is Rhesus negative (d) carries a child that is Rhesus positive (D) then on the first pregnancy they will develop antibodies to Rhesus factor in an immune response, but complications don’t occur. However, if a second pregnancy occurs with a child that is Rhesus positive, the mother’s immune system will illicit an immediate immune attack on the foetal red blood cells which can lead to still-birth or severe brain damage in the foetus.
What are alloantibodies?
A type of antibody produced by an individual in response to antigens that are not present on their own cells ordinarily
What are autoantibodies?
Antibodies which react with antigens that are present on a person’s own cells
What happens when antibodies bind to antigens on structures?
They perform an agglutination function whereby the red blood cells with non-self antigens are pooled together which makes it easier for the complex to be engulfed by macrophages
What are the four main types of blood transfusion possible?
Red cells, platelets, fresh frozen plasma and clotting factors.
What is meant by ‘whole blood transfusion’?
This is where the blood is collected directly from a donor into an anticoagulant and administered to a patient
What is a ‘red cell transfusion’
This is where blood is taken from a donor and most of the plasma is removed
What is a ‘red cell in additive solution’ transfusion?
This is a blood unit where most of the plasma, white cells and platelets are removed
What is a ‘leukocyte-depleted red cell’ transfusion?
This is a blood unit where almost 100% of all of the white cells in a simple are removed
What form of blood transfusion would be given to a leukaemia patient
Leukocyte-depleted red cell transplant
If an individual is Rhesus positive (D) what kind of blood can they receive?
Rhesus positive or negative blood, as they do not facilitate an immune reaction
If an individual is Rhesus negative (d) what kind of blood can they receive?
Rhesus negative only, they will stimulate an immune reaction to Rhesus positive blood
What are the disadvantanges of red blood cell transfusion?
Infection transmission, allo immunisation risk (could compromise future transfusion effectiveness), incompatibility, iron-overload and danger of circulatory overload
When may platelets be administered to a patient?
If they have a disorder of platelet function, bone marrow failure or bypass surgery
What are the three forms of plasma that can be collected from a donor?
Fresh frozen plasma (whole), cryoprecipitate and albumin
When would fresh frozen plasma be administered to a patient?
This form of plasma still retains functional clotting factors and therefore can be administered in those with bleeding disorders such as haemophilia
When would cryoprecipitate (plasma) be administered to a patient?
This form of plasma is high in certain clotting factors but low in others, and is most commonly used in the treatment of low fibrinogen levels
When would albumin (plasma) be administered to a patient?
This form of plasma has been heat-sterilised and fractionated so are blood group antigens are destroyed and therefore it can be used solely to replace plasma albumin to maintain oncotic pressure
Why does plasma transfusion have to be matched to blood groups?
Plasma contains clotting factors and antibodies, and therefore if an individual is blood group A but they are given the plasma of someone who is blood group O, the plasma will contain antibodies to their blood group and lead to rejection.
What kind of fresh frozen plasma can be given to someone who is Rhesus positive?
Plasma is unaffected by Rhesus factor so it doesn’t matter
What kind of fresh frozen plasma can be given to someone with blood group A?
Plasma from A or AB donor
What kind of fresh frozen plasma can be given to someone with blood group B?
Plasma from B or AB donor
What kind of fresh frozen plasma can be given to someone with blood group AB?
Plasma from AB donor
What kind of fresh frozen plasma can be given to someone with blood group O?
Plasma from A, B, AB or O donor (any)
What is a major indicator to stop transfusion?
Rapid temperature spike >40 degrees as this is indicative of intravascular haemolysis
What are the signs and symptoms of a transfusion reaction?
Symptoms: restlessness, flushing, anxiety, abdominal pain, nausea, vomiting
Signs: fever, hypotension, haemoglobinuria, oozing from venipuncture site
How is an acute transfusion reaction treated?
Stop transfusion promptly! Administer IV saline to control hypotension, administer frusemide (loop diuretic) to maintain renal perfusion if there is low urinary output and treat any resultant disseminated intravascular coagulation
