BSI 2 Lecture 12: Immunology Flashcards
What must be considered when giving life-saving blood transfusions or transplanted organs?
The antigens expressed on RBCs
How many surface antigens do RBCs possess?
Many, but most are only weakly antigenic and have little medical significance
What are the 2 significant surface antigen groups?
O-A-B groups and Rh groups
What are the two antigens responsible for most transfusion reactions?
A and B
What are A and B composed of?
They are proteins with added sugar groups (glycoproteins)
What determines which antigens your RBCs express?
Genetics
What is Group A?
RBCs express antigen A
What is Group B?
RBCs express antigen B
What is Group AB?
RBCs express both A and B antigens
What is Group O?
RBCs don’t express either antigen
What else does the person possess besides the antigen on their RBCs?
Antibodies to the group or groups they do not express
What antibodies does blood group A possess?
Anti-B
What antibodies does blood group B possess?
Anti-A
What antibodies does blood group AB possess?
Neither anti-A or anti-B
What antibodies does blood group O possess?
Both anti-A and anti-B
Why are people with blood type O called “universal donors”?
Because they can only receive blood from other O blood types, but since they don’t present any antigen, they can donate to anyone
What happens to the production of blood group antibodies throughout life?
At birth it’s about 0. From about 2-8 months is when the antibodies start producing and it reaches a maximum after 8-10. It decreases gradually throughout life.
What type of antibodies are these?
Mostly IgG and IgM
What happens when RBCs come in contact with specific antibodies for the antigen(s) expressed on their surface?
Agglutination, because the antibodies have multiple binding sites that clump RBCs