Blood Transfusion

Question 1

ABO Blood Group Antigens

Answer 1

ABO gene encodes glycosyltransferase. Glycans added to proteins or lipids on Red Cells. A and B genes code for transferase enzymes. A antigen is N-acetyl-galactosamine. B antigen is galactose. ‘O’ gene is non-functional allele. So A and B are (co-)dominant and O is recessive

Question 2

transfusions…

Answer 2

If blood group A, have antibodies against B
If blood group B, have antibodies against A
If blood group O, have antibodies against A and B
If blood group AB, have no antibodies against A and B

Question 3

igM characteristics

Answer 3

can fix complement and has a high thermal range, also dangerous as it may cause cell lysis

Question 4

outline factors of the RhD blood gorup system (Rhesus antigen)

Answer 4

if you have a deletion in RhD gene and youre given rhd+ blood there will be a formation of aantigens and a reaction

Question 5

what cam anti d cause?

Answer 5

transfussion reactions or haemolytic disease of the newborn

Question 6

what can plasma be made into?

Answer 6

products are: clotting or coag factors, albumin, antibodies

Question 7

what can buffy coat be rpoduced into?

Answer 7

platelets (wc or leucocytes)

Question 8

give the indications for rbc transfusion

Answer 8

To correct severe acute anaemia, which might otherwise cause organ damage
To improve quality of life in patient with otherwise uncorrectable anaemia
To prepare a patient for surgery or speed up recovery
To reverse damage caused by patient’s own red cells - Sickle Cell Disease

Question 9

RBC transfuison

Answer 9

stored at 4 degrees, transfused over 2-4 hrs, 1 unit incriments

Question 10

Platelet transfusion

Answer 10

1 dose platelets (=4 pooled or 1 apheresis donor), increments 20-40.109/L, Stored at ~22oC, shelf life 7 days, Transfuse over 20-30 minutes
Massive haemorrhage, Bone marrow failure, Prophylaxis for surgery, More major surgery

Question 11

lab tests done for plasma componenets

Answer 11

PT, APTT, Fibrinogen.

Question 12

what would a Direct Coombs test look for?

Answer 12

autoimmune haemolytic anaemia, passive anti-D, haemolytic transfusion reactions

Question 13

what would an indirect coombs test look for?

Answer 13

cross matching

Question 14

Haemolytic disease of the newborn (HDN) caused by…

Answer 14

Rh D most immunogenic also c, K, other Rh antigens, Jka, ABO less immunogenic, Positive DAT at birth, anaemia, jaundice

Question 15

how can HDN be prevented?

Answer 15

using prophylactic anti-d (sensitising events, routine 28/40)

Question 16

how can HDN be treated?

Answer 16

Antibody titres, Doppler ultrasound, Intrauterine transfusions

Question 17

what are other available cellular therapies?

Answer 17

Leucapheresis, Bone marrow harvests, Donor lymphocyte infusions, ‘Other banks’ - Bone, milk, tendons, heart valves, faecal, Islet cells, mesenchymal stem cells, Gene therapies.