1. Transfusion Reactions

2. Introduction
Blood transfusion is safe, effective way to correct hematology defects and crucial part of supportive care of some patients
Sometimes unwanted results may occur during or after transfusion
One of these is transfusion reactions 2

3. Transfusion Reactions
They are adverse reactions associated with the transfusion of blood and its components
3% of individuals receiving blood transfusions have a transfusion reaction

4. Transfusion reactions
Non-threatening to fatal (Fatal ~ 1/50000)
Immunological or Non-immunological
May or may not cause RBC destruction
Immediate to delayed
Immediate – rapid onset (<24 hours)
Delayed – >24 Hours,Occur days, weeks,
May involve infectious agents

5. Transfusion Reactions
Most common causes of transfusion related DEATHS:
Improper specimen identification
Improper patient identification
Antibody identification error
Crossmatch procedure error
Most transfusion reactions (not all) are the result of human error.

6. Immediate

7. Immediate Hemolytic Reactions
Most common cause is ABO incompatibility (clerical error)
Red cell destruction due to complement activation by IgM
RBCs hemolysed due to reaction between Abs in recipient (A & B) & Ags on donor’s RBCs
As little as mL can trigger a reaction

8. Symptoms Fever Pain at infusion site Back/chest pain Physical signs
Hypotension
Bleeding
Renal failure
Hemoglobinuria

9. Steps taken if hemolytic reaction is suspected
Stop transfusion
Keep IV line open with physiologic saline
Perform bedside clerical checks
Contacts patient’s physician & blood bank
Return unit, set & attached solutions to Lab
Collect suitable blood samples for evaluation
Microbiological on unit, culture of patient’s blood, Check for DIC, Renal function

10. Treatment Treat hypotension by fluid replacement
Maintenance of renal blood flow
Replacement of depleted coagulation factors
Dialysis in case of renal failure

12. Transfusion of RBCs Allo-Abs
Rarely, patient’s red cells can be hemolyzed by Abs in transfused whole blood or plasma
Caused by anti-A or Anti-B in certain plasma products
Cryoprecipitate
Factor VIII or IX
Positive DAT, Anti-A or Anti-B can be eluted from red cells

13. Transfusion Induced Alloimmunization
Ags are administered during transfusion
In 1st transfusion Induce alloantibodies
This will cause problems in subsequent transfusions
Prior transfusion beneficial in some cases
E.g. renal transplantation is more successful in patients with prior multiple transfusions

14. Pseudo-Hemolytic Reactions
Some transfusions may appear to be immediate HTR, but they are not due to immune RBC destruction
These are called pseudo-hemolytic TR

15. Manifestation
Possible Mechanism
Hemolysis
1- Excessive Infusion pressure
2- Infusion through small pre needles
3- Overheating of donor red cells
4- Infusion of congenitally abnormal red cells
5- Freezing of red cells prior to infusion
6- Infusion of RBCs damaged by microorganisms
Hypotension or Shock
1- Infusion of infected blood products
2- Anaphylactic reactions
Fever
1- Febrile reaction
2- Infusion of infected blood
Hyperbilirubinemia
1- Infusion of large quantities of blood stored for 4-5 weeks
2- Infusion of hemolysed blood

16. Delayed Hemolytic Transfusion Reactions
DHTRs occur at least 24 hrs after transfusion
Mediated by IgG antibodies
Patient previously exposed to RBC antigen and has low antibody titer until exposed again
Cannot be detected in crossmatch
Rh, Kidd, Duffy, and Kell

17. Delayed Hemolytic Transfusion Reactions
Patients have no symptoms
The only indication is a fall in hemoglobin
Diagnosis made by re-crossmatch
DAT is usually positive
Elutions are performed to identify Ab

18. White Cell Reactions Febrile Reactions
Most common, 2% of all transfusions
Caused from HLAs on the WBCs of the donor that react with the recipient antibody
Any component that contains WBCs could cause FNHTRs
Cytokines IL-1, 6,8 and Tnf-alpha generated in stored blood/products.
Determining factor is age of blood products
Leukocytes reduced units may be given
TNF alpha: is a cytokine involved in systemic inflammation and is a member of a group of cytokines that stimulate the acute phase reaction.

19. Pulmonary Infiltrates
Transfusion Related Acute Lung Injury
Can be due to:
Hypervolemia
Donor antibodies that react with the recipient’s granulocytes or vice versa
which cause embolism to blood vessels in lung tissue
Then fluids and proteins leak into alveolar space/ interstitium
The lungs fill with a high-protein fluid
Patient displays acute respiratory insufficiency with x-ray showing pulmonary edema without cardiac failure

20. Graft-versus-Host Disease
Rare but fatal condition that has a 90% mortality rate
May be caused by donor lymphocytes transfused into an immunocompromised recipient
acute graft-versus-host-disease is characterized by selective damage to the liver, skin and mucosa, and the gastrointestinal tract
Any components that contain T-lymphocytes should be irradiated to prevent GVHD

21. Platelet Reactions Post Transfusion Purpura (PTP)
PTP characterized by severe consumptive thrombocytopenia
Typically in women with a history of pregnancy, immunized with Human platelet Specific Alloantigen (HPA)
Thrombocytopenia is self-limiting and lasts for 2-6 weeks
Occur in patients who are negative for HPA-1a

22. Plasma Protein Reactions Anaphylaxis
Cause
Infusion of IgA proteins into Pt with IgA antibodies
IgA deficiency about 1 in 700
Hypotension and bronchospasm
Transfusion should be stopped immediately
IgA deficient patients should be transfused with blood products lacking IgA

23. Urticaria Second most comon type of TR
Characterized by a pruritic rash during or following transfusion
Allergic reactions are IgE mediated. 
These reactions are usually attributed to hypersensitivity to soluble allergens found in the transfused blood component.
Associated with anti-IgA in recipients who are IgA deficient.
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24. Urticaria
If not accompanied by other signs or symptoms, transfusion can be continued
Anti-histamines are given