Exam Revision Flashcards
What types of antibodies are there?
Naturally occuring
Immune
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
Naturally occuring
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’
Immune
Examples of Naturally Occuring Antibodies?
anti-A anti-B anti-Lewis anti-M anti-N
Examples of Immune Antibodies?
anti-Rh
anti-Kell
anti-Duffy
anti-Kidd
Universal Donors and Universal Recipients
O - universal donors
AB - universal receivers
What do the forward and reverse reactions identify?
Forward - identifies antigens on RBC
Reverse - identifies antibodies in plasma
Which antibodies demonstrate dosage?
anti - C, c, E, e
anti - Jka, Jkb
anti - M, S, s
anti - Fya, Fyb
Are people with weak D antigen considered Rh(D) pos?
Yes as they have the whole D antigen just with decreased expression
Are people with partial D antigen considered Rh(D) pos?
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
All the Blood Groups and their Antigens
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
Which potentiator/enhancement media decreases ζ potential like this:
- by decreasing the ionic strength of the reaction medium therefore increasing antibody uptake during sensitisation?
Low ionic strength saline
Which potentiator/enhancement media decreases ζ potential like this:
- increases dielectric constant of the medium
Albumin
Which potentiator/enhancement media decreases ζ potential like this:
- by removing sialic acid residues
Enzymes
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
Polyethylene glycol
Write these in Wiener form and phenotype form using Fisher-Race:
- DCe/dce
- DCe/DCe
- DCe/DcE
- DcE/dce
- DcE/DcE
- Dce/dce
- dce/dce
- dCe/dce
- dcE/dce
- R1r, DCce
- R1R1, DCe
- R1R2, DCcEe
- R2r, DcEe
- R2R2, DcE
- R0r, Dce
- rr, dce
- r’r, dCce
- r”r, dcEe
What vein is blood collected from for whole blood?
Antecubital vein
What are plasma and platelets placed into during apheresis?
Plasma - sodium citrate
Platelets - acid citrate dextrose
How much does each unit of transfusion material raise their intended variable?
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
Materials that can be Transfused
RBC Platelets Fresh frozen plasma Cryoprecipitate Cryoprecipitate depleted plasma
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
Acute haemolytic transfusion reaction
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
`
Delayed haemolytic transfusion reaction
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)
Infection
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
Allergic
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
Transfusion related acute lung injury (TRALI)
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
Transfusion related circulatory overload (TACO)
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
Febrile non-haemolytic transfusion reaction
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
Transfusion associated graft vs host disease
Blood Group Antigens that are Enhanced/Destroyed by Enzyme Treatment
Enhanced: - Rh - Kidd (Jka & Jkb) Destroyed - Duffy (Fya & Fyb) - MNS (M, N, S & s)
Blood Group Antibodies that don’t react with Enzyme Treated Cells
MNS (anti - M, N, S & s)
Duffy (anti - Fya & Fyb)
