TACO and TRALI: biology, risk factors, and prevention strategies

Abstract

Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are the leading causes of transfusion-related morbidity and mortality. These adverse events are characterized by acute pulmonary edema within 6 hours of a blood transfusion and have historically been difficult to study due to underrecognition and nonspecific diagnostic criteria. However, in the past decade, in vivo models and clinical studies utilizing active surveillance have advanced our understanding of their epidemiology and pathogenesis. With the adoption of mitigation strategies and patient blood management, the incidence of TRALI and TACO has decreased. Continued research to prevent and treat these severe cardiopulmonary events is focused on both the blood component and the transfusion recipient.

Figure 1.

TRALI cases by blood component type after implementation of a male donor plasma mitigation strategy. TRALI cases classified in the American Red Cross hemovigilance program are expressed per million distributed components for transfusions involving only a single component type. The black stacked bars are reported fatalities. Lines show 95% confidence intervals (95% CIs) for the overall TRALI rates (fatal and nonfatal cases). OR, odds ratio; PLT, platelet. Reprinted from Eder et al with permission.

Figure 2.

TRALI suppression in CD4+ T cell–depleted mice with murine IL-10 administration. (A) Decreased lung wet/dry (W/D) weight ratios of CD4+ T cell–depleted C57BL/6 mice infused with 34-1-2s/AF6-88.5.5.3 and treated prophylactically with murine IL-10 administration (45 mg/kg intravenously). (B) Lung W/D weight ratios of CD4+ T cell–depleted C57BL/6 mice infused with 34-1-2s/AF6-88.5.5.3 and treated therapeutically 15 minutes later with or without murine IL-10 administration (45 mg/kg intravenously) after onset of TRALI (at least a 2° drop in rectal temperature 10 minutes after TRALI antibody injection). Comparisons in both panels were analyzed with one-tailed unpaired t test. Each dot represents 1 mouse, and error bars represent standard deviation. *P < .05; ****P <. 0001. PBS, phosphate-buffered saline. Reprinted from Kapur et al with permission.