Blood groups and transfusions Flashcards
What is the life span of red blood cells?
120 days
What are main antigens on RBC?
ABO
Rhesus
What percentage has blood groups? Antibodies?
A dominant- 40% anti-B antibodies
B dominant- 12% anti-A antibodies
AB- 3% universal acceptor no antibodies
O- 45% universal donor no antigens but both
anti-A and anti-B antibodies
What is the universal acceptor?
AB- no antibodies
What is the universal donor?
O- no antigens
- both anti-A and anti-B antibodies
What are ABO antigens made from?
Carbohydrates
Where is IgM antibody made?
Spleen
What antibody can’t cross placenta?
IgM can’t cross placenta
Rhesus (IgG) can cross placenta
Blood type A will have what antigens?
What antibodies?
A
Anti B antibodies (attack B)
Blood type AB will have what antigens?
A, B
What anti anti-bodies will A,B have?
None
What anti-anti bodies will O have
A,B
What blood can receive if you are type A?
A,O
What type of blood can you recieve if B blood?
B,O
What blood can AB blood recieve?
A,B,AB,O
Universal acceptor
What blood can O receive?
O
Universal donor
https://www.youtube.com/watch?v=Amn2EWTY2Lk
https://www.youtube.com/watch?v=Amn2EWTY2Lk
If rhesus negative
Create D antibodies
Can’t receive positive blood
Need negative blood
What is rhesus antigen?
Series C, D, E
D/d most important
D- dominant- null gene so no protein
- no affect
What percentage of population are rhesus negative?
15%
What is rhesus disease?
Haemolytic disease of foetus and new born
(HDFN)
Explain rhesus disease?
Mother’s antibodies attack baby’s erythrocytes
If Mother is D but father gives rhesus D positive baby.
Baby’s rhesus D positive antigens cross placenta- mother make rhesus D antibodies that destroy RBCs of the baby
Baby becomes anaemic
Treatment of rhesus?
Anti-D immunoglobulin injections
Prevents mother making own anti-D immunoglobulins
Mother has already developed anti-D antibodies previous pregnancies- harder to use injection
Antenatal screening during pregnancy
Test for rhesus antigens in pregnant women Prevent sensitisation by giving anti-D to D negative mothers.
Exposure Rhesus D positive antigens?
1) Women rhesus negative (dd)
2) Get exposed foetal rhesus positive (DD/Dd)
antigens
3) Make IgG anti-D
4) Anti-D IgG crosses placenta and haemolytic
babies RBCs
5) Result in in-utero death, still-birth, brain
damage, deafness, and blindness
6) Requires in-utero blood transfusion
