Blood transfusion Flashcards
4 blood groups?
A,B,AB and O
Antibodies in plasma for 4 groups?
A- anti-B
B- anti-A
AB-none
O-anti-A and anti-B
Antigens present on RBC’s for 4 groups?
A- A antigen
B- B antigen
AB- A and B antigens
O- none
How are A and B antigens formed?
By adding sugar residues onto a common glycoprotein and fucose stem (H antigen) on the RBC membrane. Group O only has an H stem
Which genes code for which antigens?
A gene codes for enzyme that adds N-acetyl galactosamine
B gene codes for enzyme which adds galactose
A and B genes are co-dominant while O is recessive
RhD negative and positive?
dd vs DD or Dd genes RhD negative people can make anti-D antibodies after exposure to RhD antigen, IgG class antibodies
2 implications of anti-D antibodies?
- Patient must receive RhD negative blood or risk having delayed haemolytic transfusion reaction
- HDN- haemolytic disease of the newborn. If RhD negative mother has anti-D antibodies and fetus is RhD positive
2 tests for blood transfusions?
ABO and RhD group and Antibody screen tests
Bloop serum cross test to check for agglutination
What diseases are tested for in an infection test?
HIV Hep B Hep C Hep E HTLV Syphilis
1 unit?
WHOLE BLOOD OR BLOOD PRODUCTS DERIVED FROM ONE SINGLE BLOOD DONATION
Storage conditions for RBC’s?
must be kept in a blood fridge at 4±2˚C and can only be kept up to 5 weeks, to prevent bacterial proliferation, which could harm patients.
Storage conditions for FFP?
must be kept frozen, to preserve all the coagulation factors; at room temperature they start to degenerate so lose function within hours.
Storage conditions for platelets?
must be kept at room temperature (22±2˚C) and agitated (on a mechanical rocker), to preserve platelet function– otherwise they don’t work well when transfused
