The pathogenesis of transfusion-related acute lung injury

Abstract

Transfusion-related acute lung injury (TRALI) is defined clinically as a pulmonary edema occurring within 6 hours after transfusion of blood products. This is a major cause of morbidity and mortality associated with blood transfusion. Its pathophysiology is complex and not fully understood. TRALI is the result of a neutrophil-mediated damage to the pulmonary endothelium. Possible causal agents include alloantibodies against leucocytes and biologically active mediators accumulated in stored blood products. Leucostasis in the recipient’s lung is a predisposing state due to leucocyte priming preceding the activation of neutrophils by blood transfusion leading to lung injury. TRALI is frequent in critical ill patients as they meet several risk factors associated with this injury. This review focuses on the pathogenesis of TRALI based on epidemiologic and experimental published data.