Blood Transfer Reactions & Models

Blood Transfer Reactions

Allergic or Anaphylactic Transfusion Reaction

• Type I hypersensitivity reaction against plasma proteins in transfused blood.
• Over exaggerated reaction to a non-harmful antigen.
• IgA-deficient individuals should receive blood products without IgA because they may have anti-IgA antibodies, leading to anaphylaxis if transfused with IgA-containing blood.
• Timing: Minutes to within 3 hours after transfusion.
• Mechanism: Release of preformed inflammatory mediators.
• Symptoms:
  • Similar to typical allergic reactions: fever, reduced blood pressure, fast breathing and pulse.

Acute Hemolytic Transfusion Reaction

• Can occur during transfusion or up to 24 hours after transfusion.
• Involves fever (especially in pediatrics).
• Leads to lysis of blood and release of hemoglobin, potentially causing hemoglobin injury to the kidneys (acute tubular necrosis).
• May result in:
  • Hemoglobinuria, jaundice

Febrile Non-Hemolytic Transfusion Reaction

• Caused by cytokines generated by WBCs during blood product storage.

• Timing: Within 1 to 6 hours of transfusion.

• Involves preformed cytokines.

• Symptoms:

  • Fever, chills, flushing.
  • More common in children.
  • No hemolysis, bilirubin elevation, or jaundice.

Transfusion-Related Acute Lung Injury (TRALI)

• Caused by inflammation of the pulmonary interstitium.
• Timing: Within minutes to 6 hours of transfusion.
• Associated with neutrophils in the transfused blood.
• Chest X-ray findings:
  • Bilateral infiltrates, pulmonary edema (fluid accumulation), low blood glass capacity

Delayed Hemolytic Transfusion Reaction

• Occurs typically after 48 hours of transfusion, usually within 1 to 2 weeks.
• Due to slow destruction by the reticuloendothelial system.
• Response to a foreign antigen on red blood cell surface.
• Presents as extravascular hemolysis.
• May cause:
  • Fever, anemia, elevated bilirubin.

Febrile Non-immunologic Transfusion Reaction

• Generally a simple reaction that may not require treatment.
• Presentation: Fever without jaundice.
• Caused by cytokines released by WBCs; mimics an infectious process.

ABO Incompatibility

• Occurs when the mother is blood type O (has anti-A and anti-B antibodies) and the baby has blood type A or B.
• Maternal antibodies cross the placenta and attack fetal red blood cells.
• Causes both intravascular and extravascular hemolysis.
• Symptoms include jaundice in the sclera and skin and hemoglobinuria.
• IVIG if severe

Additional key points

• Type I hypersensitivity involves IgE against plasma proteins.
• TRALI neutrophils damage lung parenchyma resulting pulmonary edema.
• Delayed hemolytic reaction involves body reacting to antigen on red blood cell surface.
• Febrile nonhemolytic reaction does not require treatment
• Acute hemolytic reactions shows a similar clinical picture to TRALI so pay attention!

Treatments

• Leukoreduction (removal of white blood cells) or washed blood cells can mitigate febrile, non-hemolytic transfusion reactions by reducing cytokine levels.

Practice Questions

• A five-year-old child with chills four hours post-transfusion without jaundice likely has a febrile non-hemolytic transfusion reaction caused by preformed cytokines.
• A 10-year-old boy with a history of chronic transfusions who collapses and becomes hypotensive after a recent transfusion may be experiencing an anaphylactic transfusion reaction. Key is IgA deficiency.
• An anemic Gravida 4 para 4 patient presenting a week after transfusion with fatigue and shortness of breath has a delayed hemolytic transfusion reaction due to patient antibodies against donor red blood cell antigens.