Transfusion-related acute lung injury. Eur J Anaesthesiol. 2014;31:345-350. [PMID: 24892308 DOI: 10.1097/eja.0000000000000015]

Transfusion-Related Acute Lung Injury: from Mechanistic Insights to Therapeutic Strategies

Transfusion-related acute lung injury (TRALI) is a potentially lethal complication of blood transfusions, characterized by the rapid onset of pulmonary edema and hypoxemia within six hours post-transfusion. As one of the primary causes of transfusion-related mortality, TRALI carries a significant mortality rate of 6-12%. However, effective treatment strategies for TRALI are currently lacking, underscoring the urgent need for a comprehensive and in-depth understanding of its pathogenesis. This comprehensive review provides an updated and detailed analysis of the current landscape of TRALI, including its clinical presentation, pathogenetic hypotheses, animal models, cellular mechanisms, signaling pathways, and potential therapeutic targets. By highlighting the critical roles of these pathways and therapies, this review offers valuable insights to inform the development of preventative and therapeutic strategies and to guide future research efforts aimed at addressing this life-threatening condition.

Clinical Characteristics and Outcomes of Acute Lung Injury Caused by Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma: A Retrospective Cohort Study from a Single Institution in China

Background

Acute lung injury (ALI) is a rare but life-threatening pulmonary complication of transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). The aim of this study was to characterize the common risk factors, clinical features, imaging findings, treatments, and outcomes of acute lung injury caused by TACE.

Methods

A retrospective study was performed on all TACE-associated ALI cases that were diagnosed at authors' hospital from January 2015 to June 2018.

Results

The study included 14 ALI cases where the mean age of patients was 60.9 ± 11.7 years (range 41-82 years), with a mean onset time of 2.4 ± 1.6 d after TACE. Of the 14 patients, 8 patients (57.1%) developed acute respiratory distress syndrome (ARDS). 7 patients (50%) had underlying chronic respiratory disease and hepatic arteriovenous fistula was detected in 6 patients (42.6%), both of which were significantly higher than control group (P < 0.05). Dyspnea (92.9%) was the most common symptoms. Pleural effusion (64.3%), diffuse pulmonary infiltration (42.9%), and accumulation of Lipiodol in lung field (42.9%) were frequent radiologic abnormalities. 11 patients (78.6%) achieved remission after treatment, and the 30-day mortality rate was approximately 21.4%. Patient's median survival time after the development of ALI was merely 4.3 months, which was obviously worse than control group (4.3 months vs. 13.5 months, P < 0.05).

Conclusion

This study illustrates that TACE-associated ALI is a rare pulmonary complication with a high mortality rate. We infer that pulmonary Lipiodol embolization might be one of the main causes of TACE-associated ALI. Thus, HCC patients who are at high risk should be closely evaluated and monitored during TACE to avoid such potentially fatal complication.

M1-polarized alveolar macrophages are crucial in a mouse model of transfusion-related acute lung injury

BACKGROUND

The pathogenesis of transfusion-related acute lung injury (TRALI) progress is incompletely understood, and specific therapies for TRALI are lacking. Alveolar macrophages (AMs) are critical for initiation and resolution of lung inflammation. However, the role of AMs in the pathogenesis of TRALI-associated lung failure is poorly understood.

STUDY DESIGN AND METHODS

Mouse model for in vivo imaging of interleukin (IL)-6 activation in AMs was established by intratracheal instillation of a lentiviral vector carrying the luciferase reporter gene. The TRALI mouse model was produced by intraperitoneal lipopolysaccharide plus intravenous major histocompatibility complex Class I monoclonal antibody treatment. We focused on the changes in AMs in the lung during TRALI and examined whether targeting AMs is an effective strategy to alleviate this condition.

MEASUREMENTS AND MAIN RESULTS

We confirmed that TRALI progress is accompanied by IL-6 activation in AMs. Further study showed that AMs undergo M1 activation during TRALI progress. AM depletion protected mice from TRALI, and transfusion of M1-polarized AMs into 34-1-2 s-treated mice elevated acute lung injury, indicating that the severity of TRALI was able to be ameliorated by targeting AM polarization. Next, we showed that α₁ -antitrypsin (AAT) expression improved lung injury by modulating the production of IL-6 in AMs and decreased polarization of AMs toward the M1 phenotype.

CONCLUSIONS

M1-polarized AMs are crucial in a mouse model of TRALI, and AAT may serve as a future treatment for TRALI by regulating the polarization of AMs.

Ten years of TRALI mitigation: measuring our progress

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-associated mortality for which multiple mitigation strategies have been implemented over the past decade. However, product-specific TRALI rates have not been reported longitudinally and may help refine additional mitigation strategies.

STUDY DESIGN AND METHODS

This retrospective multicenter study included analysis of TRALI rates from 2007 through 2017. Numerators included definite or probable TRALI reports from five blood centers serving nine states in the United States. Denominators were components distributed from participating centers. Rates were calculated as per 100,000 components distributed (p < 0.05 significant).

RESULTS

One hundred four TRALI cases were reported from 10,012,707 components distributed (TRALI rate of 1.04 per 100,000 components). The TRALI rate was 2.25 for female versus 1.08 for male donated components (p < .001). The TRALI rate declined from 2.88 in 2007 to 0.60 in 2017. From 2007 to 2013, there was a significantly higher TRALI rate associated with female versus male plasma (33.85 vs. 1.59; p < 0.001) and RBCs (1.97 vs. 1.15; p = 0.03). From 2014 through 2017, after implementation of mitigation strategies, a significantly higher TRALI rate only from female-donated plateletpheresis continued to be observed (2.98 vs. 0.75; p = 0.04).

CONCLUSION

Although the TRALI rates have substantially decreased secondary to multiple strategies over the past decade, a residual risk remains, particularly with female-donated plateletpheresis products. Additional tools that may further mitigate TRALI incidence include the use of buffy coat pooled platelets suspended in male donor plasma or platelet additive solution due to the lower amounts of residual plasma.

The contribution of red blood cell transfusion to neonatal morbidity and mortality

Anaemia of prematurity will affect 90% of all very preterm infants, resulting in at least one red blood cell (RBC) transfusion. A significant proportion of preterm infants require multiple transfusions over the course of hospital admission. Growing evidence supports an association between transfusion exposure and adverse neonatal outcomes. In adults, transfusion-associated sepsis, transfusion-related acute lung injury and haemolytic reactions are the leading causes of transfusion-related morbidity and mortality; however, these are seldom recognised in newborns. The association between transfusion and adverse outcomes remains inconclusive. However, the evidence from preclinical studies demonstrates that RBC products can directly modulate immune cell function, a pathway termed transfusion-related immunomodulation (TRIM), which may provide a mechanism linking transfusion exposure with neonatal morbidities. Finally, we discuss the impact of TRIM on transfusion medicine, how we may address these issues and the emerging areas of research aimed at improving the safety of transfusions in this vulnerable population.

Slit2/Robo4 signaling pathway modulates endothelial hyper-permeability in a two-event in vitro model of transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) remains the leading cause of transfusion-related mortality. Endothelium semipermeable barrier function plays a critical role in the pathophysiology of transfusion-related acute lung injury (TRALI). Recently, Roundabout protein 4 (Robo4), interaction with its ligand Slit 2, was appreciated as a modulator of endothelial permeability and integrity. However, not much is known about the role of Slit2/Robo4 signaling pathway in the pathophysiology of TRALI. In this study, the TRALI model was performed by the "two-event" model of polymorphonuclear neutrophils (PMN)-mediated pulmonary microvascular endothelial cells (PMVECs) damage. We investigated the expression of Slit2/Robo4 and VE-cadherin and examined the pulmonary endothelial hyper-permeability in TRALI model. We found that the expression of Slit2/Robo4 and VE-cadherin were significantly decreased in a time-dependent manner, whereas the PMVECs permeability was gradually increased over time in TRALI model. Moreover, the treatment with Slit2-N, an active fragment of Slit2, increased the expression of Slit2/Robo4 and VE-cadherin to protect PMVECs from PMN-mediated pulmonary endothelial hyper-permeability. These results indicate that targeting Slit2/Robo4 signaling pathway may modulate the permeability as well as protect the integrity of endothelial barrier. In addition, Slit2-N appears to be a promising candidate for developing novel therapies against TRALI.

Smoking fewer than 20 cigarettes per day and remaining abstinent for more than 12 hours reduces carboxyhemoglobin levels in packed red blood cells for transfusion

Background

The prevalence of smokers among blood donors and the effect of smoking on the quality of donated blood have not been extensively explored. In the present study, we determined the prevalence of smoker donors in a large blood bank in Southern Brazil and evaluated the quality of packed red blood cells (RBCs) from these donors through recommended quality control tests and measurement of carboxyhemoglobin (COHb) levels. We then assessed the influence of smoking habits and abstinence before donation on these parameters.

Material and methods

An observational study was conducted to determine the prevalence of smoking donors, while a prospective cohort study compared conventional hematological and serological parameters and COHb levels at 0, 15, and 30 days after donation in RBCs donated by smokers (N = 31) and nonsmokers (N = 31) and their association with smoking habits and abstinence before donation.

Results

Of 14,428 blood donations received in 1 year, 5.9% were provided by smokers. Storage over time slightly altered some quality parameters, such as hematocrit, hemoglobin, hemolysis, and COHb levels, in RBC packs. COHb levels were higher in RBC packs from smokers (8%) than from non-smokers (2%), and increased as a function of the number of cigarettes smoked daily and time elapsed since the last cigarette smoked before donation. Lower levels were found in RBC packs from donors who smoked fewer than 20 cigarettes per day or remained abstinent for more than 12h before giving blood.

Conclusion

Although cigarette smoke had no significant effect on blood quality parameters such as hematocrit, hemoglobin, or hemolysis, it quadrupled COHb levels in packed RBCs. Abstinence from smoking for more than 12h or smoking fewer than 20 cigarettes daily helped decrease COHb levels.

Implications

Given the increasing prevalence of tobacco use worldwide, we suggest blood banks recommend 12h of tobacco abstinence before donation and analyze COHb levels in donated blood as an approach to reduce risk for high-risk recipients.

Platelet transfusion increases risk for acute respiratory distress syndrome in non-massively transfused blunt trauma patients

PURPOSE

While damage control resuscitation is known to confer a survival advantage in severely injured patients, high-ratio blood component therapy should be initiated only in carefully selected trauma patients, due to the morbidity associated with blood product use. With this project, we aim to identify the effect of platelet transfusion in non-massively transfused bluntly injured patients.

METHODS

The Glue Grant database was retrospectively queried and severely injured blunt trauma patients who underwent non-massive transfusion were identified. Patients were divided into quartiles depending on platelet volume they were transfused in the first 48 h. Outcomes of interest included mortality; ventilator, Intensive Care Unit (ICU) and hospital length of stay (LOS); infectious and non-infectious complications. Multivariable regression models were fitted for these outcomes, controlling for age, pre-existing comorbidities, injury severity, acute physiologic derangement, neurologic injury burden, and other fluid and blood product resuscitation.

RESULTS

There was no difference in mortality, LOS, or the incidence of multi-organ failure and infectious complications. However, patients receiving ≥ 250 mL of platelets were more likely to develop acute respiratory distress syndrome (ARDS) compared to those who received < 250 mL [odds ratio 1.91 (95% CI 1.10-3.33, p = 0.022)].

CONCLUSIONS

Pre-emptive platelet transfusion should be avoided in non-massively transfused blunt injury victims in the absence of true or functional thrombocytopenia, as it increases risk for ARDS with no survival benefit.

Transfusion practices and infectious risks

Transfusion-transmitted infections remain among the most-feared complications of allogeneic blood transfusion. Thanks to several strategies including donor screening and deferral, blood testing and pathogen inactivation, their risks have reached all-time low levels, particularly in developed nations. Nonetheless, new and emerging infections remain a threat that is likely to exacerbate in the coming years with continued globalization and climate change. More effective strategies of pathogen inactivation and more vigilant horizon screening are hoped to abate the risk. Additionally, allogeneic transfusion has repeatedly been shown to be associated with worsening of outcomes in patients, including the documented increased risk of infections (often nosocomial) in recipients of transfusions. The underlying mechanism is likely to be related to immunosuppressive effects of allogeneic blood, iron content, and bacterial contamination. This issue is best addressed by more judicious and evidence-based use of allogeneic blood components to ensure the potential benefits outweigh the risks.

Hemoglobin optimization and transfusion strategies in patients undergoing cardiac surgery

Although red blood cells (RBCs) transfusion is sometimes associated with adverse reactions, anemia could also lead to increased morbidity and mortality in high-risk patients. For these reasons, the definition of perioperative strategies that aims to detect and treat preoperative anemia, prevent excessive blood loss, and define “optimal” transfusion algorithms is crucial. Although the treatment with preoperative iron and erythropoietin has been recommended in some specific conditions, several controversies exist regarding the benefit-to-risk balance associated with these treatments. Further studies are needed to better define the indications, dosage, and route of administration for preoperative iron with or without erythropoietin supplementation. Although restrictive transfusion strategies in patients undergoing cardiac surgery have been shown to effectively reduce the incidence and the amount of RBCs transfusion without increase in side effects, some high-risk patients (e.g., symptomatic acute coronary syndrome) could benefit from higher hemoglobin concentrations. Despite all efforts made last decade, a significant amount of work remains to be done to improve hemoglobin optimization and transfusion strategies in patients undergoing cardiac surgery.

Blood transfusion and 30-day readmission rate in adult patients hospitalized with sickle cell disease crisis

BACKGROUND

Sickle cell disease (SCD) patients hospitalized with vasoocclusive pain crisis tend to have prolonged length of stay (LOS) and high 30-day readmission rates. We investigated the associations of demographic characteristics, comorbidities, and blood transfusion during hospitalization with these outcomes.

STUDY DESIGN AND METHODS

Repeated regression analysis was used to analyze 39,324 admissions of 4348 adults with sickle cell crisis from 2007 to 2012 in the Truven Health MarketScan Medicaid Databases.

RESULTS

The mean (95% range) LOS was 5.9 (1.0-19.0) days and the 30-day readmission rate was 39.6% (95% confidence interval [CI], 39.1%-40.0%). Older age; chronic cardiopulmonary, renal, or liver disease; and sepsis were associated with both longer LOS and greater 30-day readmission rate. Female sex, iron overload, acute chest syndrome, acute renal failure, and stroke were additional predictors of longer LOS. Simple red blood cell transfusion was administered in 31.8% of the admissions, and these patients tended to have more severe disease (chronic cardiopulmonary or kidney disease, acute chest syndrome, acute kidney or liver failure, sepsis). Nevertheless, transfusion was associated with a reduced estimated odds ratio (OR) of inpatient mortality of 0.75 (95% CI, 0.57-0.99) and a decreased OR of 30-day readmission of 0.78 (95% CI, 0.73-0.83).

CONCLUSION

Our findings point to blood transfusion as a potential means to reduce the 30-day readmission rate among Medicaid patients hospitalized with sickle cell crisis. There is a need for a prospective study to examine the potential benefit and safety of simple blood transfusion for this purpose.