Haematology 13: Blood Transfusions 1 Flashcards
What happens in Haemolytic disease of the newborn ?
- RhD -ve mother has a RhD positive child and comes into contact with the blood during pregnancy/ or has a RhD +ve blood transfusion.
- The mother now makes anti-D
- The next baby is RhD +ve and this time the anti-D antibodies (IgG) cross the placenta
- This causes a delayed haemolytic reaction
How does indirect antiglobulin technique work to screen blood ?
- Blood recipient’s plasma is put into test tube (contains recipient antibodies)
- Blood donor’s red cells are added to the test tube (has antigens)
- If the recipient has antibodies against the donor’s red cells they will form antigen-antibody complexes
- Coombs antibody is added (anti-human antibody)
- This causes cross linking if immune complexes are present
- if agglutination takes place the blood is not matched
What is the universal donor group for RBC ?
O- (no antigens on cells)
What is the universal donor group for plasma ?
AB (no antibodies in plasma)
Which method of blood transfusion is more acceptable for jehova’s witnesses ?
Cell salvage (collection, filtration and return of blood lost during surgery)
Why do patients with immunosuppression require irradiation of blood products ?
The donor lymphocytes can start reacting to self antigens and mount an immune response
This is known as transfusion associated graft versus host disease (TA-GvHD)
Which immune deficiency causes severe allergic reactions to donor blood plasma ?
IgA deficiency
Name 2 haematological diseases in which platelet transfusion is strongly contraindicated ?
HIT - heparin induced thrombocytopenia
TTP- thrombotic thrombocytopenic purpura
What is prothrombin complex concentrate (PPC) ?
A blood product containing vitamin K dependent clotting factors 10, 9, 7 and 2