The history of transfusion related acute lung injury: how we got to where we are today

Abstract

Transfusion-related acute lung injury (TRALI) is a serious and acute complication of blood transfusion, manifesting as non-cardiogenic pulmonary edema requiring respiratory support, and often, mechanical ventilation. TRALI typically occurs during or after the transfusion of high plasma volume blood components, but can occur with any blood component in susceptible recipients due to the passive transfusion of donor anti-leukocyte antibodies or biological response modifiers that accumulate in stored blood products. Once the leading cause of transfusion associated mortality, TRALI incidence has declined significantly following the implementation of prevention measures. Broader understanding of the pathogenesis demonstrated that a significant proportion of cases occur consequently to anti-leukocyte antibodies in the plasma of multiparous female donors. Thus, exclusion of these high-risk donors with the use of male-only, never-pregnant female, or antibody-negative tested female donors resulted in a substantial decline of TRALI in participating countries, internationally. Although effective, these measures have not completely eradicated the risk of TRALI, which remains the second leading cause of transfusion-related death. TRALI is not only challenging to differentiate from transfusion-associated circulatory overload (TACO), but continues to go under-reported, altogether highlighting the opportunity for further research into these remaining cases. We provide a review on the evolution of TRALI, including its defining criteria, pathophysiology, mitigation strategies, and promising new therapeutic modalities. TRALI is an excellent example of how improved understanding of a disease process can translate into effective prevention measures through a combination of research and hemovigilance reporting.