Transfusion Reactions Flashcards by Tatjana Obias

Acute Hemolytic Rxn Causes

ABO incompatibility = complement binding to C9 = IVH

Rare:
- pre-formed Ab in recipient
- no Ab screen/ unmatched blood (emergency)
- low frequency antigen (Cw, V, Kpa - Ab screen will be falsely neg)
- Kidd, Kell, Rh Ab

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Time of Immediate Hemolytic Rxn

First 15 minutes of transfusion

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Blood products associated to Immediate Hemolytic Rxn

RBC
plasma
platelets (less severe)

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Immediate Hemolytic Rxn Symptoms

fever/ chills
chest pain/ shortness of breath
angioedema; “vessels swelling”
DIC

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Causes of Febrile Non-Hemolytic Rxns

cytokines in platelet products
HLA (white blood cell) antibodies in patient reacts with donor WBCs

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Time of Febrile Non-hemolytic Reactions

2-4 hours from start of transfusion

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Treatment of Febrile Non-hemolytic Rxns

acetominophen

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Prevention of Febrile Non-hemolytic Rxns

pre-storage leukoreduction
washing products to remove contaminants

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Cause and Effect of Mild Allergic Reactions

Patient’s IgE Ab reacts with allergen in donor PLASMA (food, protein, preservative)
Ab binds mast cells = release granular contents (histamine) = urticarial and pruritis
BP and RESPIRATORY UNAFFECTED, with mild tachycardia

urticarial = hives
pruritis = itching
tachycardia = increased HR

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Time of Mild Allergic Rxns

1-45 min from start of transfusion

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Treatment/ Prevention of Mild Allergic Rxns

anti-histamines
restart transfusion more slowly
pre-treat with anti-histamines
washing to remove contaminants

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Another name for Mild Allergic Rxns

Urticarial Rxns

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Cause of Anaphylactic Allergic Rxns

donor IgA is the “antigen” !
recipient is IgA deficient and makes an anti-IgA from previous transfusions
can be an allergen ie. peanuts (rare)
more severe patient IgE = mast cell degranulation

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Time of Anaphylactic Allergic Rxns

WITHIN MINUTES (1-15 min) of start of transfusion
can start as mild and progresses

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Symptoms of Anaphylactic Allergic Rxns

urticaria, pruritis, dyspnea, low BP, hypoxemia, smooth muscle contractions (GI and respiratory), vasodilation

urticaria = hives
pruritis = itching
dyspnea = shortness of breath

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Treatment for Anaphylactic Allergic Rxns

epinephrine
antihistamine
corticosteroids (anti-inflammatory)

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Prevention of Anaphylactic Allergic Rxns

request IgA deficient products
wash products to remove IgA
prepare drugs
transfuse with MD supervision

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Cause of Bacteriogenic Rxns

bacteria in PLATELETS and BLOOD products:
- normal skin flora
- transient bacteremia in donor (dental bleeding)
- contamination during processing
- improper temp storage

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List bacteria that can cause bacteriogenic rxns

E. coli
Pseudomonas
Yersinia enterocolitica

Time of Bacteriogenic Rxns

Variable:
- minutes if toxins are present
- several days if low microbial count

Symptoms of Bacteriogenic Rxns

fever, chills
low BP
tachycardia
DIC

Treatment of Bacteriogenic Rxns

Broad spectrum antibiotics
Blood culture the donor product (aerobic/ anaerobic) to ID

Cause of Delayed Hemolytic Reaction

Ab formation to non-ABO Ag (Rh, Kell, Duffy, Kidd, Ss) on BLOOD products
EVH; Ab binds donor cells and removed by spleen

Timing of Delayed Hemolytic Rxns

2-14 days post-transfusion
due to secondary exposure

Symptoms of Delayed Hemolytic Rxns

- fever, chills - malaise - jaundice - no symptoms at all malaise = discomfort

Treatment of Delayed Hemolytic Rxns

NONE - monitor Hb, bilirubin, LD, haptoglobin

A post- transfusion investigation takes into account... (3)

1. type of products transfused 2. signs and symptoms 3. serological results from a post-transfusion sample

when are patient vital signs taken? (HR, BP, temp)

- before transfusion - 15 mins after start - end of transfusion

In the first 15 mins, transfusion is slow and patient is monitored for any signs/ symptoms of reaction. What must be done if a reaction occurs ?

- STOP transfusion, but maintain IV line, and run saline - notify attending physician immediately - document vital signs and symptoms - bedside clerical check with the product tag/vs patient (2 identifiers) - notify blood bank - return unused product, along with post-transfusion specimen (EDTA) to blood bank NOTE: even minor reactions must be reported ie. resolved within 20 mins

Positive post-transfusion __ is significant ! Why?

Positive post-transfusion DAT is significant ! - it can indicate DELAYED transfusion rxn; depending on time of investigation, DAT may be only indicator

List other rare causes of positive post-transfusion DAT (3)

- passive antibody - IVIg that binds non-specifically to RBC - donor is already DAT pos

T or F: Rh binds complement

FALSE; Rh DOES NOT bind complement NOTE: (Rh)ude MeaN (Du)des don't give out complements

Why does complement only bind in vivo?

because in vitro, EDTA chelates Ca 2+ and Mg 2+

indicators of IVH

- visible hemolysis (plasma Hb) - hemoglobinuria (due to increased Hb) - decreased haptoglobin (bc it is complexed) - increased LDH

indicators of EVH

- increased bilirubin - increased LDH - decreased haptoglobin (bc it is complexed)/ OR unaffected - decreased Hb

List steps to a transfusion rxn investigation (8)

1. Clerical check 2. Review symptoms (documented on tag) 3. NOTE: - product transfused - time of transfusion to symptoms (week ago = not febrile; minutes = severe allergic) - volume transfused 4. Check for visible hemolysis on post-transfusion sample 5. Serological tests (ABO Rh, Ab screen, DAT, XM) 6. Non-serological tests (bilirubin, Hb, LDH, haptoglobin)

Which products will NOT cause a delayed hemolytic rxn ?

plasma and platelets

In the event of a transfusion rxn, what tests do we run on a pre-transfusion sample ? (4)

1. clerical check 2. ABO Rh 3. AbScr 4. Serological XM

In the event of a transfusion rxn, what tests do we run on a post-transfusion sample ? (6)

1. clerical check 2. check for visible hemolysis 3. ABO Rh 4. Abscr 5. DAT 6. serological XM

In the event of a transfusion rxn, what tests do we run on the donor segment ? (3)

1. clerical check 2. ABO Rh 3. Ag type for any Ab detected in the pre- or post-Ab screen

Serious transfusion rxns will involve a consultation with __.

Serious transfusion rxns will involve a consultation with the pathologist.

What happens to existing allocated units that showed transfusion rxn ?

They are quarantined until permission is given to release

Describe Delayed Hemolytic Rxn Workup

1. Ab ID if AbScr = pos 2. Elution on DAT pos cells 3. Ag type donor segment; DO NOT TYPE DONOR (transfused within 3 months) 4. Update records 5. Serological XM with suspect donors 6. Serological XM Ag neg donors for next transfusion if collection still valid (96 hrs)

What would cause a positive DAT on a post-transfusion sample ?

- ABO incompatible cells = immediate hemolytic run - Mild allergic + severe anaphylactic rxn - Autoimmune hemolytic (warm/ cold) anemia - Drug-induced hemolytic anemia - HDFN

If a patient has a delayed hemolytic rxn, why might the DAT = negative ?

All donor cells have been destroyed due to EVH before post-transfusion sample is collected