BB - Transfusion Reactions

Question 1

What are the 4 categories of transfusion reactions?

Answer 1

Immunologic acute
Immunologic delayed
Non-immunologic acute
Non-immunologic delayed

Question 2

What is the most common cause of febrile transfusion reactions? What are some treatments or prevention methods (3)?

Answer 2

White cell reactions

Order washed RBCs
Aspirin or other antipyretics
Blood transfused through a leuko-reduced filter (RBC-LR)

Question 3

Immediate LYTIC reactions are caused by this mechanism… Is cellular destruction extravascular or intravascular?

Answer 3

Antibodies that activate complement (ie ABO antibodies)
-severe, lethal

Intravascular

Question 4

Compared to acute reactions, delayed reactions are usually ___ in severity

Answer 4

Milder/weaker

-may go undetected

Question 5

Antibodies against this antigen, ___, are notorious for falling below detectable levels. As such, they cause this type of transfusion reaction…

Answer 5

Kidd

Immunologic delayed/delayed hemolytic transfusion reaction (DHTR)

Question 6

Delayed reactions cause mostly extravascular or intravascular destruction?

Answer 6

Extravascular

-macrophages engulf antibody-coated RBCs in liver/spleen

Question 7

When a transfusion reaction has occurred, what should we do?

Answer 7

Immediately STOP the transfusion

Notify the lab

Question 8

What 3 steps should the lab do when a transfusion reaction has occurred?

Answer 8

Check for clerical errors

Check for hemolysis

Perform a DAT to check for blood incompatibility

Question 9

If a transfusion reaction is suspected and DAT is positive with anti-IgG on pre and/or post specimens, what should we do next?

Answer 9

Elution, then test to identify the antibody using the eluate

Question 10

IHTR - common antibodies that cause it (4). Which is the most lytic?

Answer 10

anti-A, anti-Kell, anti-Jka and anti-Fya

anti-A most lytic

Question 11

IHTR - extravascular damage is characterized by the formation of…

Answer 11

Antigen-antibody complexes on RBCs

• incomplete complement activation
• damages kidneys

Question 12

Are febrile transfusion reactions hemolytic? Are they a type of immediate or delayed reaction?

Answer 12

No, associated with fever

Immediate = febrile non-hemolytic transfusion reaction (FNHTR)

Question 13

FNHTR - temperature rise for diagnosis? Caused by?

Answer 13

1ºC above baseline of 37C

White cell reactions:
antibodies against donor HLAs

Question 14

What is the term for hives (allergic reaction)?

Answer 14

Urticaria

Question 15

DHTR - are complement proteins activated?

Answer 15

No

Question 16

What is the term for blood in the urine?

Answer 16

Hematuria

Question 17

Rapid intravascular hemolysis can release this into the blood and these 2 things into the urine. What are the clinical terms for each?

Answer 17

Hemoglobinemia - excess hemoglobin in the plasma

Hemoglobinuria - hemoglobin in the urine

Hemosiderinuria - hemosiderin in the urine

Question 18

Immediate non-hemolytic immune transfusion reactions (4)

Answer 18

Febrile non-hemolytic transfusion reaction (FNHTR)
Allergic reactions
Anaphylactic reactions
Transfusion related acute lung injury (TRALI)

Question 19

Immediate non-hemolytic non-immune transfusion reactions (3)

Answer 19

Bacterial contamination
Transfusion-associated circulatory overload (TACO)
Physically or chemically induced transfusion reactions (PCITR)

Question 20

Delayed non-hemolytic immune transfusion reactions (4)

Answer 20

Alloimmunization
Immunosuppression
Post transfusion purpura (PTP)
Transfusion-associated graft-vs-host disease

Question 21

Delayed non-hemolytic non-immune transfusion reactions (2)

Answer 21

Viral contamination

Iron overload