TRALI pathogenesis involves what mechanism?

TRALI pathogenesis involves what mechanism?

• A. Donor anti-HLA antibodies activating recipient neutrophils
• B. Bacterial contamination causing septic shock
• C. IgA deficiency reacting with plasma IgA
• D. Volume overload causing pulmonary edema

Answer: (A)

TRALI pathogenesis is an immune-mediated injury where donor anti-HLA antibodies (and sometimes anti-HNA antibodies) bind to antigens on recipient neutrophils and activate them in the pulmonary microvasculature. This neutrophil activation leads to endothelial injury, capillary leak, and noncardiogenic pulmonary edema. A helpful way to think about it is the two-hit model: the recipient’s inflammatory state primes neutrophils, and the transfused antibodies provide the second hit that triggers their activation in the lungs. This mechanism is distinct from transfusion-related sepsis (bacterial contamination), an IgA-mediated anaphylactic-type reaction, or volume-overload edema (TACO).

TRALI pathogenesis is an immune-mediated injury where donor anti-HLA antibodies (and sometimes anti-HNA antibodies) bind to antigens on recipient neutrophils and activate them in the pulmonary microvasculature. This neutrophil activation leads to endothelial injury, capillary leak, and noncardiogenic pulmonary edema. A helpful way to think about it is the two-hit model: the recipient’s inflammatory state primes neutrophils, and the transfused antibodies provide the second hit that triggers their activation in the lungs. This mechanism is distinct from transfusion-related sepsis (bacterial contamination), an IgA-mediated anaphylactic-type reaction, or volume-overload edema (TACO).