Transfusions

Question 1

What determines blood type?

Answer 1

The red cell antigens present.

Question 2

What are antigens?

Answer 2

Proteins displayed on cells that can trigger an immune response.

Question 3

Which chromosome is the ABO gene found on?

Answer 3

Chromosome 9.

Question 4

What blood type is seen if 1 ‘A’ gene and 1’O’ gene are combined?

Answer 4

‘A’, as this is dominant over ‘O’.

The same applies if ‘B’ rather than ‘A’ is present.

Question 5

What antigens are expressed in type ‘O’ blood?

Answer 5

None

Question 6

How many ‘O’ genes are required for ‘O’ type blood?

Answer 6

2

Question 7

What is the result of an ‘A’ gene and a ‘B’ gene together?

Answer 7

‘AB’ blood.

Question 8

What antibodies are produced to fight blood antigens?

Answer 8

Those to attack against blood antigens not observed in the phenotype.

Antibodies produced are IgM.

Question 9

What antibodies exist in ‘A’ type blood?

Answer 9

Anti-B antibodies.

Converse also true for ‘B’ blood.

Question 10

What antibodies exist in ‘AB’ type blood?

Answer 10

No antibodies present.

Question 11

What antibodies exist in ‘O’ type blood?

Answer 11

Both anti-A and anti-B antibodies exist.

Question 12

Which individuals can receive type ‘O’ blood?

Answer 12

Anyone, however ‘O’ group individuals can only receive ‘O’ blood.

Question 13

Which individuals can receive type ‘AB’ blood?

Answer 13

Only ‘AB’ individuals, with these individuals capable of receiving any form of blood.

Question 14

What blood groups can receive group ‘A’?

Answer 14

A
AB

The same applies for ‘B’

Question 15

What blood can be given to group ‘A’?

Answer 15

O
A

The same applies for ‘B’.

Question 16

What % of the population are RhD positive?

Answer 16

Around 85%.

Question 17

What blood antibody can cause transfusion reactions and haemolytic disease of the newborn?

Answer 17

Anti-D antibody

This is highly immunogenic.

Question 18

What are the aims of transfusion testing?

Answer 18

Identify ‘ABO’ and RhD grouping of the patient.

Identify any significant RBC antibodies present.

Allow selection of appropriate blood for transfusion.

Question 19

How is ABO grouping determined?

Answer 19

2 steps -
Antisera
Reagent red cells

Will cause agglutination of cells.

Question 20

What is IAT used to diagnose?

Answer 20

Presence of anti-D antibodies

Question 21

When is red cell transfusion indicated?

Answer 21

Symptomatic anaemia with Hb < 70g/L

Major bleeding

Important to also treat the underlying cause.

Question 22

When is platelet transfusion indicated?

Answer 22

Prophylactically in those with bone marrow failure or a very low platelet count

Treatment of bleeding in those with thrombocytopenia

Prophylactically in those with thrombocytopenia undergoing surgery

Question 23

When is fresh frozen plasma (FFP) given?

Answer 23

Bleeding with a coagulopathy (PT >1.5)

Prophylactically prior to surgery in those with a coagulopathy

Massive haemorrhage

Question 24

When should fresh frozen plasma (FFP) not be given?

Answer 24

In the absence of bleeding/a planned procedure - even in the presence of an abnormal coagulation screen.

Question 25

When should observations be taken during a transfusion?

Answer 25

Prior to initiation
15 mins after initiation
60 mins following completion