Transfusion Medicine Flashcards
Fucosyl Transferase 1 gene
Makes the O or H antigen backbone
On chromosome 19
Glycosyltransferase A vs GTB
A: adds N-acetylgalactosamine, A antigen
B: adds galactose, B antigen
Both on chromosome 9
O blood group is due to lack of…
Both GTA and GTB
Two copies of non functional GTA gene, with delation 261G causing a frameshift mutation
Bombay phenotype
Mutated FUT1
Make antibodies against H antigen
Can only accept blood from other Bombay phenotype
Cannot synthesize A nor B antigens regardless of GTA/GTB genotype
Anti-AB antibodies
Mostly IgM, but also IgG and some IgA
Due to exposure to similar carbohydrates on gut bacteria
When is Rhogam given?
At 28 weeks of gestation
Time of delivery
Any trauma or significant bleeding
How long can 1. RBCs 2. Plasma 3. Platelets 4. Blood stem cells be stored for?
- 42 days: 1-6 degC
- 12 months: below -18 degC
- 7 days - at room temp, rock gently
- Years: -196 degC
Why do blood products need to be leukoreduced?
To get rid of the vast majority of white cells
Don’t want their cytokines or HLA
Transfusion-associated cardiac overload
TACO
Patient with heart failure, if you give them too much too fast their heart cannot handle it and the fluid builds up in lungs and they could die
Causes the most deaths (more common than TRALI)
Transfusion-related acute lung injury
TRALI
Antibodies to HLA
Why you have to use male plasma! No chance that they would have seen foreign HLA
Most fatal transfusion reaction
Forward typing
Is A or B antigen present on a patient’s cells?
Is D antigen present on a patient’s cells?
Reverse typing
Are anti-A or anti-B antibodies present in patient’s serum?
Screen (Indirect antiglobulin test)
To see if the patient has antibodies against the antigens present on the allogenic screen RBCs
Analogous to reverse typing
