Exam Revision

Question 1

What types of antibodies are there?

Answer 1

Naturally occuring

Immune

Question 2

Which of the two (naturally occurring or immune) is this:
Present in plasma without any known immunisation
Not present at birth
Ig subtype: IgM
React optimally at 4°C
'Complete'
Examples:
- anti-A
- anti-B
- anti-Lewis
- anti-M
- anti-N

Answer 2

Naturally occuring

Question 3

Which of the two (naturally occurring or immune) is this:
No cross reaction between antigenic structure on naturally occurring substance and antigens on RBCs
Produced following:
- a blood transfusion
- immunisation during pregnancy
- intentional immunisation (exception: as an auto-immune antibody in certain diseases)
Ig subtype - IgG
React optimally at 37°C
‘Incomplete’

Answer 3

Immune

Question 4

Examples of Naturally Occuring Antibodies?

Answer 4

anti-A
anti-B
anti-Lewis
anti-M
anti-N

Question 5

Examples of Immune Antibodies?

Answer 5

anti-Rh
anti-Kell
anti-Duffy
anti-Kidd

Question 6

Universal Donors and Universal Recipients

Answer 6

O - universal donors

AB - universal receivers

Question 7

What do the forward and reverse reactions identify?

Answer 7

Forward - identifies antigens on RBC

Reverse - identifies antibodies in plasma

Question 8

Which antibodies demonstrate dosage?

Answer 8

anti - C, c, E, e
anti - Jka, Jkb
anti - M, S, s
anti - Fya, Fyb

Question 9

Are people with weak D antigen considered Rh(D) pos?

Answer 9

Yes as they have the whole D antigen just with decreased expression

Question 10

Are people with partial D antigen considered Rh(D) pos?

Answer 10

Depends on if they are a donor or recipient
Recipient - Rh(D) neg as will produce anti-D in response to full D antigen
Donor - Rh(D) pos as will cause immunogenic effect in patients who are Rh(D) neg

Question 11

All the Blood Groups and their Antigens

Answer 11

ABO
- A, B, O
Rh
- C, c, D, E, e
Kell
- K, k
Kidd
- Jka, Jkb
Duffy
- Fya, Fyb
MNS
- M, N, S, s, U

Question 12

Which potentiator/enhancement media decreases ζ potential like this:
- by decreasing the ionic strength of the reaction medium therefore increasing antibody uptake during sensitisation?

Answer 12

Low ionic strength saline

Question 13

Which potentiator/enhancement media decreases ζ potential like this:
- increases dielectric constant of the medium

Answer 13

Albumin

Question 14

Which potentiator/enhancement media decreases ζ potential like this:
- by removing sialic acid residues

Answer 14

Enzymes

Question 15

Which potentiator/enhancement media decreases ζ potential like this:
- steric exclusion of water molecules and concentrating antibodies around the RBCs to accelerate antibody binding to RBCs

Answer 15

Polyethylene glycol

Question 16

Write these in Wiener form and phenotype form using Fisher-Race:

1. DCe/dce
2. DCe/DCe
3. DCe/DcE
4. DcE/dce
5. DcE/DcE
6. Dce/dce
7. dce/dce
8. dCe/dce
9. dcE/dce

Answer 16

1. R1r, DCce
2. R1R1, DCe
3. R1R2, DCcEe
4. R2r, DcEe
5. R2R2, DcE
6. R0r, Dce
7. rr, dce
8. r’r, dCce
9. r”r, dcEe

Question 17

What vein is blood collected from for whole blood?

Answer 17

Antecubital vein

Question 18

What are plasma and platelets placed into during apheresis?

Answer 18

Plasma - sodium citrate

Platelets - acid citrate dextrose

Question 19

How much does each unit of transfusion material raise their intended variable?

Answer 19

RBC - increase [Hb] by ~10g/L
Platelets - increase platelets by 20-50 x 10^9/L
Cryoprecipitate - per 5/10kg increases [Fbg] by 0.5-1.0g/L

Question 20

Materials that can be Transfused

Answer 20

RBC
Platelets
Fresh frozen plasma
Cryoprecipitate
Cryoprecipitate depleted plasma

Question 21

What kind of adverse transfusion reaction is this:
1:40k-80k transfusions, fatal in 1:1.8 million transfusions
Occur soon after transfusion starts (minutes to hours)
Usually ABO incompatibilities
e.g. complement-mediated intravascular haemolysis
- complement activation → C3a and C5a release → mast cell activation → histamine and serotonin release
- factor XII activation → bradykinin production → vasodilation and ↑ EC permeability → hypotension
- EC activation and damage → TF exposure → DIC

Answer 21

Acute haemolytic transfusion reaction

Question 22

What kind of adverse transfusion reaction is this:
Occurs in 1:2.5k-11k transfusions
Haemolysis occurring > 24 hrs after transfusion
Extravascular haemolysis in RE system
After secondary exposure to antigen
- aby “missed” on pre transfusion screen
Anti-Jka, Rh, Kell, Duffy antibodies
Haemolysis is usually not fatal
- Hb doesn’t rise to expected level, fever, jaundice, haemoglobinuria
`

Answer 22

Delayed haemolytic transfusion reaction

Question 23

What kind of adverse transfusion reaction is this:
Bacterial, viral, parasitic bacterial risk – 1:75k (platelets) to 1:500k (RBCs)
Symptoms
- fever, chills, vomiting, hypotension, dyspnoea, tachycardia, shock, renal failure, DIC
Bacterial sources
- donor (skin or bacteraemia)
- contamination during component preparation (inc water bath)

Answer 23

Infection

Question 24

What kind of adverse transfusion reaction is this:
Range from mild (1:100) to severe (1:20k-50k)
Symptoms:
- urticaria (hives), erythema, itching, hypotension, nausea, vomiting, diarrhoea, respiratory distress
Can be fatal
Due to:
- hypersensitivity to allergens or plasma proteins in donor unit
- IgA ↓ patients with anti-IgA antibody

Answer 24

Allergic

Question 25

What kind of adverse transfusion reaction is this: Occurs in ~1:10k transfusions, the major cause of transfusion-related fatality Symptoms begin within 2-6 hours of transfusion completion Fever, chills, respiratory problems, hypotension, hypoxemia, → respiratory failure Pathophysiology - aby’s in donor plasma bind to HLA/HNA’s on recipients’ granulocytes → granulocyte activation - → basement membrane destruction - → increased permeability of the pulmonary circulation - → leakage of high-protein fluid into the lungs - → pulmonary oedema

Answer 25

Transfusion related acute lung injury (TRALI)

Question 26

What kind of adverse transfusion reaction is this: Occurs in < 1% of transfusions Dyspnoea (shortness of breath), orthopnea (shortness of breath when lying down), cyanosis, tachycardia, pulmonary oedema, hypertension within 1-2 hrs of transfusion Elderly, paediatric, and anaemic patients Often confused with TRALI - patients with TRALI rarely have hypertension - different findings on chest X-ray - distended neck veins and peripheral oedema in TACO Treatment - O2, diuretics Prevention - administer transfusion slowly

Answer 26

Transfusion related circulatory overload (TACO)

Question 27

What kind of adverse transfusion reaction is this: Occurs in 0.1-1% of transfusions (esp platelets) Symptoms - unexpected temp. increase shortly after transfusion, chills, ↑ respiration, headache Similar presentation to TRALI, sepsis, HTR - FNHTR if these have been ruled out Pathophysiology - cytokine release from donor leukocytes - anti-HLA/HNA aby’s in recipient plasma binding to and activating leukocytes in donor units Treatment - acetaminophen Prevention - leukodepletion

Answer 27

Febrile non-haemolytic transfusion reaction

Question 28

What kind of adverse transfusion reaction is this: Very rare Symptoms - rash, fever, liver dysfunction, GI symptoms with recent transfusion history Pathogenesis - immunocompetent T lymphocytes in donor product are transfused into shared HLA (i.e. family) or immunocompromised recipient - donor T-lymphocytes engraft and proliferate in recipient BM - recipient HLA class II and/or minor histocompatibility Ag’s are presented to donor T-lymphocytes → activation - cytokine release and cytolytic activity Diagnosis - HLA typing Results in bone marrow aplasia, usually fatal

Answer 28

Transfusion associated graft vs host disease

Question 29

Blood Group Antigens that are Enhanced/Destroyed by Enzyme Treatment

Answer 29

``` Enhanced: - Rh - Kidd (Jka & Jkb) Destroyed - Duffy (Fya & Fyb) - MNS (M, N, S & s) ```

Question 30

Blood Group Antibodies that don't react with Enzyme Treated Cells

Answer 30

MNS (anti - M, N, S & s) | Duffy (anti - Fya & Fyb)