Blood Transfusion Physiology (bj)

Question 1

How are ABO blood groups determined?

Answer 1

ABO gene encodes Glucosyltransferase to produce certain glycans which are added to proteins & lipids on red cells. these are the antigens denoting blood group

Question 2

What surface antigen is A, B & O?

Answer 2

A = N-acetyl-galactosamine
B = Just Galactose
O = No antigen (it's gene is a non-functional allele)

Question 3

How are blood groups inherited?

Answer 3

O is recessive

A & B are dominant

Question 4

How do you decide which blood group to give when giving red cells?

Answer 4

The donor musn’t have any antigens (A or B) that the recipient doesn’t have or the host will attack the donor cells

Question 5

So who can give/receive group A red cells?

Answer 5

A can give to A or AB (as they won’t react to the donor A antigen)

The can only take from A or O

Question 6

Who can give/receive group B red cells?

Answer 6

B can give to B or AB

Can only take from B or O

Question 7

Who can give/receive group O red cells?

Answer 7

Can donate to anyone (as no antigens)

But can’t receive from anyone but O

Question 8

Who can give/receive group AB red cells?

Answer 8

Only donates to AB and can take from anyone

Question 9

The rules for donating fresh frozen plasma are different to red cells. How do blood groups affect FFP donation?

Answer 9

With FFP donor must have all the antigens the recipient has (can also have extra.) But it won’t work if the recipient has antigens not present in the donor

Question 10

So who can give/receive group A FFP?

Answer 10

Group A FFP - can give to A or O

Group A patient - can receive A + AB FFP

Question 11

What blood groups can group B FFP be given to?

What FFP groups can a type B patient receive?

Answer 11

Can give to B or O

Can only receive from B or AB

Question 12

So who can give/receive group AB FFP?

Answer 12

Give to A, B, AB or O (so anyone)

Can receive from AB

Question 13

So who can give/receive group O FFP?

Answer 13

O can only donate to O but they can receive from anyone

Question 14

Other than the ABO blood groups the other main grouping is RhD +ve vs RhD -ve. What’s the danger of RhD?

Answer 14

If RhD -ve people receive RhD +ve blood they will create Anti-D antibodies –> Transfusion reaction

Question 15

How is RhD involved in maternity?

Answer 15

An RhD -ve mother can pass on anti-D antibodies to their newborn.
If they’re RhD +ve the newborn will develop haemolytic disease

Question 16

What do we test a blood donor for before using their blood?

Answer 16

Behavioural screen (sex, age, travel, tattoos etc)
ABO & RhD group testing
Inf screening (HEP B,C,E, HIV & syphilis)