Week 1 - intro and blood groups Flashcards
when was the first successful human transfusion given
1818 by Dr James Bundell
when was transfusion considered risky & led to many deaths
1818-1845
who described ABO groups
Karl Landsteiner in 1901
what is an antigen
blood grouping systems that stimulate an immune response on the membranes of red cells
what is an antibody
proteins occurring in body fluids which are produced in response to the introduction of a foreign antigen
what is agglutination
when the red cells are joined together by the cross linking of antibody molecules they become agglutinated
how is agglutination used in the labs?
to determine what blood group antigens are present on the red cells and what red cell antibodies are present in the plasma
what is the most significant blood group system
ABO blood group system
what is Landsteiner’s law?
Antibodies are always present in a healthy persons plasma against antigens not present on their red cells
which antigens have a high frequency from ABO groups in the general population
A and/or B antigens
(~55% of pop)
What is ABO blood group systems capable of producing?
intravascular haemolysis
What are serious transfusion reactions caused by?
ABO incompatibility
How are A and B antigens formed?
The A and B genes add a different terminal carbohydrate molecule to the H antigen converting it to A or B antigen.
This is done via the enzyme products of the A and B genes
A transferase adds N-acetyl-D-galactosamine to H
B transferase adds D-galactose to H
How is the O antigen formed?
The O gene does not produce a functional transferase so the H antigen is left unchanged.
what are immunodominant sugars
the different carbohydrates added by the A, B or H transferases as it forms the antigenic part of the molecule
What blood group is the universal red cell donor
Group O
What blood group is the universal red cell recipient?
Group AB
What is the universal PLASMA donor?
Group AB
What is the universal PLASMA recipient?
Group O
What are some characteristics of ABO antibodies?
They are naturally acquired
full strength achieved by 5 years and declines in old age
Describe forward/front/cell group?
When one’s red cells react against monoclonal anti A and anti B to identify the antigens on the person’s cells
Describe reverse/back/serum group?
When the patient’s collected plasma reacts against A1 and B red cells to identify ABO antibody specificities.
Learn about ABO grouping
What is a common cause of the loss of ABO antigens ?
Myeloid leukaemia
