Transfusion-Related Acute Lung Injury (TRALI): Current Clinical and Pathophysiologic Considerations

Transfusion-related acute lung injury (TRALI) is a rare transfusion reaction presenting as respiratory distress during or after transfusion of blood products. TRALI varies in severity, and mortality is not uncommon. TRALI reactions have equal gender distributions and can occur in all age groups. All blood products, except albumin, have been implicated in TRALI reactions. TRALI presents as acute respiratory compromise occurring in temporal proximity to a transfusion of a blood product. Other causes of acute lung injury should be excluded in order to definitively diagnose TRALI. Clinically and pathologically, TRALI mimics acute respiratory distress syndrome (ARDS), with neutrophil-derived inflammatory chemokines and cytokines believed to be involved in the pathogenesis of both entities. Anti-HLA and anti-neutrophil antibodies have been implicated in some cases of TRALI. Treatment for TRALI is supportive; prevention is important. It is suspected that TRALI is both underdiagnosed and underreported. One of the difficulties in the evaluation of potential TRALI reactions is, until recently, the lack of diagnostic criteria. A group of transfusion medicine experts, the American–European Consensus Conference (AECC), recently met and developed diagnostic criteria of TRALI, as well as recommendations for management of donors to prevent future TRALI reactions. In light of the AECC consensus recommendations, we report an incident of TRALI in an oncology patient as an example of the potential severity of the lung disease and the clinical and laboratory evaluation of the patient. We also review the literature on this important complication of blood transfusion that internists may encounter.