Haematology 10 - Blood transfusions 2

Question 1

Cut offs for acute and delayed transfusion reaction

Answer 1

<24 hours or >24 hours

Question 2

Types of acute transfusion reaction

Answer 2

ABO incompatibility, allergy, anaphylaxis, bacterial infection, febrile non haemolytic transfusion reaction, TACO and TRALI

Question 3

Types of delayed transfusion reaction

Answer 3

DHTR, Post transfusion purpura, TA GvHD, Infection (viral, malaria, cVJD), Iron overload

Question 4

Immunoglobulins involved in acute and delayed transfusion, respectively and the types of haemolysis

Answer 4

Acute: IgM e.g. anti-A and anti-B –> intravascular haemolysis
Delayed: IgG e.g. anti-Duffy anti-KIdd –> extravascular

Question 5

Most common type of acute transfusion reaction

Answer 5

TACO

Question 6

Outline symptoms of FNHTR, pathophysiology and treatmetn

Answer 6

Fever ~1C raised, chills/rigors
Stop/slow transfusion
Paracetamol
Caused by release of cytokines from white cells during incubation, this is much less common now as most blood products are leucodepleted

Question 7

Allergic transfusion reactions - sx

Answer 7

Urticaria, wheeze

Question 8

Allergic transfusion reactions occur most commonly from transfusion of which blood product?

Answer 8

Plasma (proteins in donor plasma)

Question 9

Tx of allergy

Answer 9

Stop/slow transfusion + IV antihistamines

Question 10

ABO incompatibility sx

Answer 10

acute intravascular haemolysis (IgM mediated)

Question 11

Which blood products most prone to bacterial contamination

Answer 11

Platelets as stored at room temp

Question 12

In which people can anaphylactic acute transfusion reactions be fatal in?

Answer 12

If have IgA deficiency

Question 13

TRALI vs TACO

Answer 13

ARDS Like presentation + fever, no raised JVP/ fluid overload, non-responsive to diuretics

Question 14

TRALI pathophysiology

Answer 14

Anti-WBC antibodies in donor blood, interacts with recipient wBCs –> WBCs aggregate in pulmonary capillaries –> neutrophil activation + lung damage

Question 15

Prevention strategy for TRALI

Answer 15

Use male donors so no HLA antibdoies formed e.g. in pregnancy + people with no previous transfusions

Question 16

Which antibodies associated with delayed transfusion reactions?

Answer 16

Anti-Duffy and anti-Kidd

Question 17

Which people are given CMV-ve blood?

Answer 17

Pregnant women and neonates

Question 18

Post-transfusion purpura - when does it come on and how can it be tretaed?

Answer 18

7-10 days after transfusion

IVIG

Question 19

WHen do pregnant women routinely have their group and screen tests?

Answer 19

Booking visit ~12 weeks and 28 weeks

Question 20

How can foetus be screened for RhD status?

Answer 20

ffDNA sample ~16 weeks

Question 21

How can you monitor foetal anaemia?

Answer 21

MCA doppler USS

Question 22

MOA of anti-D immunoglobulin

Answer 22

Foetal RBCs in maternal circulation coated with anti-D immunoglobulin, cleared by maternal reticuloendothelial system before they can sensitise the mother to produce anti-D immunoglobulin

Question 23

When must anti-D injection be given for it to prevent sensitisation?

Answer 23

within 72 hours of sensitisation event

Question 24

Dose of anti-D if < or >20 weeks

Answer 24

<20: 250 iU

>20: 500 IU

Question 25

Routine anti-D administration doses

Answer 25

either 1500 IU at 28 weeks or 500 IU at 28 weeks and another 500IU at 34 weeks

Question 26

ffDNA technique implemented in 2019

Answer 26

cffDNA testing can be offered to mother's ~16 weeks, if foetus RhD-, non anti-D needed