Transfusion-related acute lung injury secondary to biologically active mediators

Mechanistic Understanding of Lung Inflammation: Recent Advances and Emerging Techniques

Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury characterized by an acute inflammatory response in the lung parenchyma. Hence, it is considered as the most appropriate clinical syndrome to study pathogenic mechanisms of lung inflammation. ARDS is associated with increased morbidity and mortality in the intensive care unit (ICU), while no effective pharmacological treatment exists. It is very important therefore to fully characterize the underlying pathobiology and the related mechanisms, in order to develop novel therapeutic approaches. In vivo and in vitro models are important pre-clinical tools in biological and medical research in the mechanistic and pathological understanding of the majority of diseases. In this review, we will present data from selected experimental models of lung injury/acute lung inflammation, which have been based on clinical disorders that can lead to the development of ARDS and related inflammatory lung processes in humans, including ventilation-induced lung injury (VILI), sepsis, ischemia/reperfusion, smoke, acid aspiration, radiation, transfusion-related acute lung injury (TRALI), influenza, Streptococcus (S.) pneumoniae and coronaviruses infection. Data from the corresponding clinical conditions will also be presented. The mechanisms related to lung inflammation that will be covered are oxidative stress, neutrophil extracellular traps, mitogen-activated protein kinase (MAPK) pathways, surfactant, and water and ion channels. Finally, we will present a brief overview of emerging techniques in the field of omics research that have been applied to ARDS research, encompassing genomics, transcriptomics, proteomics, and metabolomics, which may recognize factors to help stratify ICU patients at risk, predict their prognosis, and possibly, serve as more specific therapeutic targets.

Packed blood cells stored in AS-5 become proinflammatory during storage

BACKGROUND

Studies have shown that packed blood cells (PBCs) stored in AS-1 (Adsol, Baxter) and AS-3 (Nutricel, Medsep Corp.) accumulate proinflammatory substances, which may contribute to increased complications from allogeneic blood transfusion. This study assessed whether supernates from PBCs stored in AS-5 (Optisol, Terumo Corp.) prime neutrophils (PMNs), activate platelets (PLTs), and accumulate proinflammatory cytokines and PMN granule constituents.

STUDY DESIGN AND METHODS

PBC units were prepared in AS-5 from nonleukoreduced (NLR) and leukoreduced (LR) whole-blood units and stored at 4 degrees C. Supernates from samples of PBCs collected at various storage times were analyzed by multiplex enzyme-linked immunosorbent assay for proinflammatory cytokines and myeloperoxidase (MPO) and were incubated with type-matched blood, which was assessed by flow cytometry for expression of CD11b on PMNs, CD62P on PLTs, and formation of PMN-PLT aggregates.

RESULTS

Supernates from NLR PBCs stored for at least 14 days elevated CD11b expression on PMNs and the number of PMN-PLT aggregates compared to supernates from collection day PBCs. The magnitude of these effects correlated with storage age. Supernates from LR PBCs did not elicit these responses. Expression of CD62P on PLTs was not affected by supernates from either NLR or LR PBCs. Levels of interleukin (IL)-1beta, IL-6, IL-8, IL-18, NAP-2, MCP-1, RANTES, and MPO were elevated in supernates from 28- and 42-day NLR units. Tumor necrosis factor alpha and MIP-1alpha did not increase, and cytokine levels in LR PBC units did not increase.

CONCLUSION

Units of NLR PBCs stored in AS-5 become increasingly proinflammatory as a function of storage time. Leukoreduction prevents this change.

Fatal transfusion related acute lung injury following coronary artery by-pass surgery: a case report

Background

Transfusion related acute lung injury (TRALI) is a potentially fatal Acute Lung Injury following transfusion of blood components. Hypotheses implicate donor-derived anti-human leukocyte antigen or granulocyte antibodies reacting with recipients' leukocytes, releasing inflammatory mediators. Lack of agreement on underlying cellular and molecular mechanisms renders improving transfusion safety difficult and expensive.

Case Presentation

Literature search has not revealed any case of TRALI from Pakistan. We report the case of fatal TRALI in a 68 year old male who received blood products after coronary artery by-pass surgery.

Conclusion

This article aims to create awareness about this complication and suggests that post transfusion cardiopulmonary instability should alert to the possibility of TRALI.

Effects of leukoreduced blood on acute lung injury after trauma: a randomized controlled trial

OBJECTIVE

The requirement for a blood transfusion after trauma is associated with an increased risk of acute lung injury. Residual leukocytes contaminating red cells are potential mediators of this syndrome. The goal of this trial was to test our hypothesis that prestorage leukoreduction of blood would reduce rates of posttraumatic lung injury.

DESIGN

Double blind, randomized, controlled clinical trial.

SETTING

University-affiliated level I trauma center in King County, Seattle, WA.

PATIENTS

Two hundred sixty-eight injured patients requiring red blood cell transfusion within 24 hrs of injury.

INTERVENTIONS

Prestorage leukoreduced vs. standard allogeneic blood transfusions.

MEASUREMENTS AND MAIN RESULTS

We compared the incidence of acute lung injury and acute respiratory distress syndrome at early (< or = 72 hrs) and late (> 72 hrs) time points after injury. In a subset, we compared plasma levels of surfactant protein-D and von Willebrand factor antigen between intervention arms. Rates of acute lung injury (relative risk [RR] 1.06, 95% confidence interval [CI] .69-1.640) and acute respiratory distress syndrome (RR .96, 95% CI 0.48-1.91) were not statistically different between intervention arms early after injury. Similarly, no statistically significant effect of leukoreduced transfusion on rates of acute lung injury (RR .88, 95% CI .54-1.44) or acute respiratory distress syndrome (RR .95, 95% CI .58-1.57) was observed to occur late after injury. There was no significant difference in the number of ventilator-free days or in other ventilator parameters between intervention arms. No statistically significant effect of leukoreduced blood on plasma levels of surfactant protein-D or von Willebrand factor antigen was identified.

CONCLUSIONS

Prestorage leukoreduction had no effect on the incidence or timing of lung injury or on plasma measures of systemic alveolar and endothelial inflammation in a population of trauma patients requiring transfusion. The relationship between transfusion and lung injury is not obviously explained by mechanistic pathways involving the presence of transfused leukocytes.

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.

Massive transfusion as a risk factor for acute lung injury: Association or causation?

One of the most common clinical sequelae of massive transfusion is acute lung injury. In virtually all clinical settings, there is a very strong relationship between transfusion and acute lung injury that remains even after adjusting for potential confounders. Whether the association between transfusion and acute lung injury in these settings is a result of residual confounding or actually reflects a causal relationship is unknown. However, there are several potential mechanisms by which massive transfusion might predispose to lung injury: a) cognate antigen-antibody interactions (classic transfusion-associated lung injury); b) activation of nonspecific immunity through soluble mediators present in transfused blood; c) an increased risk of infection through transfusion-associated immunomodulation leading to sepsis and sepsis-induced lung injury; and d) volume overload in the face of increased permeability of the alveolar capillary membrane. Elucidating the precise causal mechanism operative in patients receiving massive transfusion has more than academic importance; it has direct implications for transfusion policy and practice.

Transfusion-related acute lung injury

PURPOSE OF REVIEW

Transfusion-related acute lung injury is an uncommon complication of blood transfusion typically manifested by shortness of breath, fever, and hypotension. Transfusion-related acute lung injury is an important cause of transfusion-related morbidity and mortality.

RECENT FINDINGS

Much about the pathogenesis, treatment, and prevention of transfusion-related acute lung injury is poorly understood or is controversial. There is increasing recognition that transfusion-related acute lung injury is an important clinical syndrome, causing most transfusion-related deaths.

SUMMARY

In this report, what is known about transfusion-related acute lung injury is summarized with particular emphasis on recent studies. Some of the areas in which knowledge and/or consensus are currently lacking are identified.

Transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is an uncommon complication of allogeneic blood transfusion manifested typically by shortness of breath, fever, and hypotension. It has been estimated to occur in 0.04% to 0.16% per patient transfused. TRALI has been identified as an important cause of transfusion-related morbidity and mortality. Despite the increasing recognition that TRALI represents an important clinical syndrome, much about the pathogenesis, treatment, and prevention of TRALI is poorly understood or is controversial. In this report, what is known about TRALI is summarized and some of the areas in which knowledge and/or consensus are currently lacking are identified.

16. Immunologic lung disease

This review summarizes the recent advances regarding pathogenesis, diagnosis, and treatment of immunological diseases of the lung. Rather than attempt a comprehensive analysis, we have focused on selected diseases that are of particular relevance to the practicing physician, and the material has been organized according to the dominant immunologic mechanisms underlying the disease. Because of the redundancy that characterizes the mammalian immune repertoire, this system of classification inevitably produces overlap but facilitates acquisition of what is otherwise a disparate collection of facts. The principal lung immunologic mechanisms are most broadly classified as innate or adaptive immune processes. Innate immunity includes neutrophils and complement that are important in diseases, such as pneumonia and the acute respiratory distress syndrome. Adaptive immunity involves T and B cells capable of recognizing discrete antigens. T(H)1- and T(H)2-dependent adaptive immune responses underlie some of the most common and important of lung diseases, including tuberculosis and asthma, respectively. Other important immunopathologic processes include granulomatous inflammation that characterizes sarcoidosis and Churg-Strauss vasculitis, and autoimmunity, which is characteristic of antiglomerular basement membrane disease and others.

TRALI: correlation of antigen-antibody and monocyte activation in donor-recipient pairs

BACKGROUND

TRALI may be a severe reaction associated with transfusion of plasma-containing blood components. TRALI has usually been associated with antibodies against granulocytes and HLA class I antigens, but more recently with antibodies against HLA class II and monocytes. TRALI cases were investigated to determine correlation between antigen and antibody. Additionally, activation of monocytes by TRALI serums was studied.

STUDY DESIGN AND METHODS

Sixteen cases of TRALI were investigated. All patients were typed for HLA antigens. Implicated donors were screened for HLA antigens and antibodies against granulocytes and monocytes. In 6 cases, recipient monocyte activation was measured in vitro after incubation with TRALI and control serums. In four cases, monocyte activation was measured after incubation of TRALI serums against a panel of monocytes of known HLA antigen type.

RESULTS

In 14 of the 16 cases (87.5%), antigen-antibody correlation was identified. TRALI monocytes, incubated with implicated TRALI serum (n = 6), expressed significantly greater cytokine and tissue factor (p < 0.05, repeated-measures ANOVA) than controls. Panel monocytes incubated with TRALI serum showed increased expression of cytokine and/or tissue factor when corresponding antigen was present.

CONCLUSION

In most cases of TRALI, a correlation between antigen and antibody can be identified. Activation of monocytes and their subsequent release of cytokines may play a role in the pathogenesis of TRALI.