3.10 Blood Transfusion Flashcards
What antigens will group A blood type patients have on their RBCs, and what antibodies in their plasma?
A antigens
Anti-B antibodies
What antigens will group B blood type patients have on their RBCs, and what antibodies in their plasma?
B antigens
Anti-A antibodies
What antigens will group AB blood type patients have on their RBCs, and what antibodies in their plasma?
A and B antigens
No antibodies
What antigens will group O blood type patients have on their RBCs, and what antibodies in their plasma?
No antigens
Anti-A and anti-B antibodies
Why can AB+ take blood from anyone?
AB people do not have any antibodies in their plasma, so there is nothing to attack the foreign RBCs when they are transfused
How do you cross match a sample of blood for transfusion?
Take a sample of the patient’s serum (contains antibodies) and the donor’s RBCs
If they agglutinate then the samples are incompatible
During blood testing, what infections are tested for?
HIV, HEP B C E, HTLV And Syphillis
Do we test for Creutzfeldt-Jacob Disease?
Yes
Who do we give red cells to?
Patients with anaemia
What RhD group are you if you lack the D antigen?
Negative
Do RhD negative patients have Anti-D antibodies in their plasma?
No, but they can make Anti-D antibodies
How do RhD Negative People make anti D antibodies?
RhD negative mother with an RhD positive baby
Transfusion of RhD positive blood
If a RhD negative patient has a blood transfusion with a RhD positive person, what implications does this have for their future transfusion?
Exposure to D antigen produces anti-D antibodies
Thus next transfusion must be with RhD negative blood to prevent haemolytic transfusion reaction
Haemolysis can cause anaemia, high bilirubin and jaundice
What is haemolytic disease of the newborn?
If a RhD negative mother has an RhD positive first child, anti-D antibodies are produced
If the second child is also RhD positive, anti-D antibodies cross the placenta and cause haemolysis of foetal red blood cells
What can haemolytic disease of the newborn cause?
If severe – hydrops fetails and death before birth
If less severe – high bilirubin thus brain damage, leading to death
Why can Anti-D antibodies cross the placenta?
They are class IgG
How can the formation of Anti-D antibodies in mothers be prevented?
Give them Anti-D Immunoglobins
How does giving the mother Anti-D immunoglobins work to prevent HDN?
Anti-D works by destroying any RhD positive blood in the mother’s circulation, before it can be recognized by the mothers systems and therefore before the mothers own Anti-D antibodies can be made, thus preventing HDN
Which blood component will patients need to replace all their clotting factors which have been depleted during massive bleeding?
Fresh frozen plasma
In an emergency which group of Fresh Frozen Plasma should we give when we do not know their blood group?
AB negative as the plasma will not contain any antibodies
In an emergency, which group of red cells can we give to any patients?
O Negative Blood - this is because O negative Red Cells do not have A or B antigens on the surface of the Red cells which could be attacked by the patients Anti-A Antibodies or Anti-B Antibodies
What gene controls blood group?
The ABO gene
How do genes code for ABO?
Adding a sugar residue to a common glycoprotein and fucose stem (H antigen) on the RBC membrane
What is added to the the common H antigen to make it an A antigen?
N-acetyl galactosamine
