Sunday, September 4, 2011

Dengue special: Transfusion-related acute lung injury (TRALI)

Transfusion of even one unit of a plasma-containing blood product sometimes causes ALI/ARDS (1,2).
What can cause TRALI: Fresh frozen plasma, platelet, and packed red blood cell transfusions? 

Definition: New ALI occurring during or within six hours after a transfusion. 

Pathogenesis: A "two-event" hypothesis holds that recipient granulocytes are primed, either by transfused active substances or by virtue of the patient's underlying clinical condition. Preformed anti-leukocyte antibodies contained in the transfusion product then "activate" these functionally hyperactive granulocytes.

Which donors: Anti-leukocyte antibodies are more likely to be found in blood donated by multiparous women due to sensitization to fetal antigens during pregnancy.

When to suspect: Whenever dyspnea, hypoxemia, and pulmonary infiltrates occur during or within six hours after transfusion of any plasma-containing blood product.

Differential diagnosis
• Transfusion-associated circulatory overload
• Hemolytic transfusion reaction
• Anaphylaxis of IgA-containing products to a IgA deficiency recipient

Management: Is supportive (mechanical ventilation, supplemental oxygen, diuretics when volume overload is present). Clinical improvement will occur spontaneously as lung injury resolves.
Action: Individuals who have developed TRALI should receive no further plasma-containing blood products from the implicated donor.

Prevention
1. Take plasma products only from male donors
2. Screen previously-pregnant and previously-transfused apheresis donors for HLA antibodies
3. Start testing for the detection of white blood cell antibodies

References:
1. Bux J, Sachs UJ. The pathogenesis of transfusion-related acute lung injury (TRALI). Br J Haematol 2007; 136:788.
2. Khan H, Belsher J, Yilmaz M, et al. Fresh-frozen plasma and platelet transfusions are associated with development of acute lung injury in critically ill medical patients. Chest 2007; 131:1308.


No comments:

Post a Comment