The Pathogenic Involvement of Neutrophils in Acute Respiratory Distress Syndrome and Transfusion-Related Acute Lung Injury

The acute respiratory distress syndrome (ARDS) is a serious and common complication of multiple medical and surgical interventions, with sepsis, pneumonia, and aspiration of gastric contents being common risk factors. ARDS develops within 1 week of a known clinical insult or presents with new/worsening respiratory symptoms if the clinical insult is unknown. Approximately 40% of the ARDS cases have a fatal outcome. Transfusion-related acute lung injury (TRALI), on the other hand, is characterized by the occurrence of respiratory distress and acute lung injury, which presents within 6 h after administration of a blood transfusion. In contrast to ARDS, acute lung injury in TRALI is not attributable to another risk factor for acute lung injury. 'Possible TRALI', however, may have a clear temporal relationship to an alternative risk factor for acute lung injury. Risk factors for TRALI include chronic alcohol abuse and systemic inflammation. TRALI is the leading cause of transfusion-related fatalities. There are no specific therapies available for ARDS or TRALI as both have a complex and incompletely understood pathogenesis. Neutrophils (polymorphonuclear leukocytes; PMNs) have been suggested to be key effector cells in the pathogenesis of both syndromes. In the present paper, we summarize the literature with regard to PMN involvement in the pathogenesis of both ARDS and TRALI based on both human data as well as on animal models. The evidence generally supports a strong role for PMNs in both ARDS and TRALI. More research is required to shed light on the pathogenesis of these respiratory syndromes and to more thoroughly establish the nature of the PMN involvement, especially considering the heterogeneous etiologies of ARDS.

Blood transfusion products contain mitochondrial DNA damage-associated molecular patterns: a potential effector of transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is the most frequent and severe complication in patients receiving multiple blood transfusions. Current pathogenic concepts hold that proinflammatory mediators present in transfused blood products are responsible for the initiation of TRALI, but the identity of the critical effector molecules is yet to be determined. We hypothesize that mtDNA damage-associated molecular patterns (DAMPs) are present in blood transfusion products, which may be important in the initiation of TRALI.

METHODS

DNA was extracted from consecutive samples of packed red blood cells, fresh frozen plasma (FFP), and platelets procured from the local blood bank. Quantitative real-time polymerase chain reaction was used to quantify ≈200 bp sequences from the COX1, ND1, ND6, and D-loop regions of the mitochondrial genome.

RESULTS

A range of mtDNA DAMPs were detected in all blood components measured, with FFP displaying the largest variation.

CONCLUSIONS

We conclude that mtDNA DAMPs are present in packed red blood cells, FFP, and platelets. These observations provide proof of the concept that mtDNA DAMPs may be mediators of TRALI. Further studies are needed to test this hypothesis and to determine the origin of mtDNA DAMPs in transfused blood.

Transfusion-Related Acute Lung Injury: The Work of DAMPs

Current notions in immunology hold that not only pathogen-mediated tissue injury but any injury activates the innate immune system. In principle, this evolutionarily highly conserved, rapid first-line defense system responds to pathogen-induced injury with the creation of infectious inflammation, and non-pathogen-induced tissue injury with 'sterile' tissue inflammation. In this review, evidence has been collected in support of the notion that the transfusion-related acute lung injury induces a 'sterile' inflammation in the lung of transfused patients in terms of an acute innate inflammatory disease. The inflammatory response is mediated by the patient's innate immune cells including lung-passing neutrophils and pulmonary endothelial cells, which are equipped with pattern recognition receptors. These receptors are able to sense injury-induced, damage-associated molecular patterns (DAMPs) generated during collection, processing, and storage of blood/blood components. The recognition process leads to activation of these innate cells. A critical role for a protein complex known as the NLRP3 inflammasome has been suggested to be at the center of such a scenario. This complex undergoes an initial 'priming' step mediated by 1 class of DAMPs and then an 'activating' step mediated by another class of DAMPs to activate interleukin-1beta and interleukin-18. These 2 cytokines then promote, via transactivation, the formation of lung inflammation.

The Role of Complement in Transfusion-Related Acute Lung Injury

Transfusion-related acute lung injury (TRALI) is a life-threatening complication of acute respiratory distress occurring within 6 hours of blood transfusion. TRALI is one of the leading causes of transfusion-related fatalities and specific therapies are unavailable. Neutrophils are recognized as the major pathogenic cells, whereas T regulatory cells and dendritic cells appear to be important for protection against TRALI. The pathogenesis, however, is complex and incompletely understood. It is frequently postulated that the complement system plays an important role in the TRALI pathogenesis. In this article, we assess the evidence regarding the involvement of complement in TRALI from both human and animal studies. We hypothesize about the potential connection between the complement system and neutrophils in TRALI. Additionally, we draw parallels between TRALI and other acute pulmonary disorders of acute lung injury and acute respiratory distress syndrome regarding the involvement of complement. We conclude that, even though a role for complement in the TRALI pathogenesis seems plausible, studies investigating the role of complement in TRALI are remarkably limited in number and also present conflicting findings. Different types of TRALI animal models, diverse experimental conditions, and the composition of the gastrointestinal microbiota may perhaps all be factors which contribute to these discrepancies. More systematic studies are warranted to shed light on the contribution of the complement cascade in TRALI. The underlying clinical condition of the patient, which influences the susceptibility to TRALI, as well as the transfusion factor (antibody-mediated vs non–antibody-mediated), will be important to take into consideration when researching the contribution of complement. This should significantly increase our understanding of the role of complement in TRALI and may potentially result in promising new treatment strategies.

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Studies investigating complement and TRALI are limited in number and present conflicting findings.

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Systematic investigation is needed to better understand the contribution of the complement cascade in TRALI.

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Future studies in this area should consider both the clinical susceptibility of the patient as well as the effect of transfusion factors.

Transfusion in the mechanically ventilated patient

Red blood cell transfusions are a frequent intervention in critically ill patients, including in those who are receiving mechanical ventilation. Both these interventions can impact negatively on lung function with risks of transfusion-related acute lung injury (TRALI) and other forms of acute respiratory distress syndrome (ARDS). The interactions between transfusion, mechanical ventilation, TRALI and ARDS are complex and other patient-related (e.g., presence of sepsis or shock, disease severity, and hypervolemia) or blood product-related (e.g., presence of antibodies or biologically active mediators) factors also play a role. We propose several strategies targeted at these factors that may help limit the risks of associated lung injury in critically ill patients being considered for transfusion.

Transfusion and risk of infection in Canada: Update 2012

Although multiple critical steps are taken to minimize the risk of infection from transfusion of blood or blood products in developed countries, this risk can never be entirely eliminated. In Canada, the risks of noninfectious transfusion reactions, such as transfusion-related acute lung injury and major allergic or anaphylactic reactions, are greater than that of infection. This updated practice point provides an overview of transfusion infection risks in Canada. Infectious agents, systemic conditions, donor and recipient factors, and collection and infusion techniques are considered. Suggestions are offered to improve both system and process, and to help practitioners who are discussing informed consent with patients and parents before administering blood or a blood product.

Evaluation of Platelet Responses in Transfusion-Related Acute Lung Injury (TRALI)

Platelets are versatile cells which are capable of eliciting nonhemostatic immune functions, especially under inflammatory conditions. Depending on the specific setting, platelets may be either protective or pathogenic in acute lung injury and acute respiratory distress syndrome (ARDS). Their role in transfusion-related acute lung injury (TRALI) is less well defined; however, it has been hypothesized that recipient platelets and transfused platelets both play a pathogenic role in TRALI. Overall, despite conflicting findings, it appears that recipient platelets may play a pathogenic role in antibody-mediated TRALI; however, their contribution appears to be limited. It is imperative to first validate the involvement of recipient platelets by standardizing the animal models, methods, reagents, and readouts for lung injury and taking the animal housing environment into consideration. For the involvement of transfused platelets in TRALI, it appears that predominantly lipids such as ceramide in stored platelets are able to induce TRALI in animal models. These studies will also need to be validated, and moreover, the platelet-derived lipid-mediated mechanisms leading to TRALI will need to be investigated.

Transfusion-Related Acute Lung Injury (TRALI) in two Thalassaemia Patients Caused by the Same Multiparous Blood Donor

We report two separate episodes of transfusion-related acute lung injury (TRALI) in two thalassaemia patients who received red blood cell transfusions from the same multiparous donor. Both cases had the same symptomatology and occurred within 60 minutes of transfusion. The patients presented dyspnoea, sweating, fatigue, dizziness, fever, and sense of losing consciousness. The chest x-ray showed a pulmonary oedema-like picture with both lungs filled with fluid. The patients were treated in the intensive therapy unit. They were weaned off the ventilator and discharged following hospitalization 7 and 9 days respectively. The TRALI syndrome was diagnosed to be associated with HLA-specific donor antibodies against mismatched HLA-antigens of the transfused patients. Haemovigilance improvements are essential for reducing the morbidity and mortality in transfused patients. Blood from multiparous donors should be tested for the presence of IgG HLA-Class I and -Class II antibodies before being transfused in thalassaemia and other chronically transfused patients.

Transfusion-related acute lung injury in a COVID-19-positive convalescent plasma recipient: a case report

We present a case of transfusion-related acute lung injury as a complication of convalescent plasma transfusion in a patient who presented with COVID-19-related severe acute respiratory syndrome. Despite treatment with tocilizumab, remdesivir, and intravenous steroids, worsening dyspnea prompted adjunctive treatment with convalescent plasma. Two hours after completion of the plasma transfusion, the patient developed hypoxia-induced cardiac arrest secondary to transfusion-related acute lung injury. This case sheds light on life-threatening transfusion reactions and emphasizes the need to investigate post-transfusion monitoring protocols as well as the possible role of surveillance equipment.

Transfusion-associated hypoxemia in pediatric patients with solid tumors after autologous peripheral blood stem cell transplantation

BACKGROUND

Although several types of transfusion-related adverse reactions (TRARs) have been reported, one of the most important involves respiratory features during and after blood transfusion. Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are the most severe adverse events following blood transfusion, whereas transfusion-associated dyspnea　(TAD) is a less severe respiratory distress. However, there exists little evidence of these factors in pediatric populations.

CASE REPORT

Here, two cases of atypical TRARs with respiratory features, in pediatric patients with solid tumors, appearing after transfusion of platelet concentrate following autologous peripheral blood stem cell transplantation are reported. Both patients developed mild hypoxemia during PC transfusion, which continued for approximately 2 weeks. Chest radiography in either patient did not reveal any abnormalities that are included in the criteria of either TRALI or TACO. Both patients recovered following oxygen administration.

CONCLUSION

This complication of TRARs with respiratory features may occur more frequently in pediatric populations than realized because it may be under-recognized or under-reported. Accumulation of additional cases, including non-typical cases, is necessary to fully understand the pathology of TRARs, correctly classify these reactions, and improve care of patients receiving blood transfusions.

Possible roles of platelets in liver transplantation: regeneration and cancer recurrence

When tissue injury results in breakage, platelets are not only involved in plug formation and wound sealing, but they also play an important role throughout the tissue recovery process. Specifically, platelets accumulate at the site of injury and release a large number of biologically active mediators at injury sites, which initiate or modulate damaged tissue regeneration. Moreover, extensive experimental evidence has elucidated the involvement of platelets in tumor growth and metastasis. As such, this mini-review aimed to highlight the relatively lesser known functions of platelets.

Donor characteristics do not influence transfusion-related acute lung injury incidence in a secondary analysis of two case-control studies

OBJECTIVE

To investigate the relation between donor characteristics and TRALI incidence.

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a potentially fatal complication of transfusion. In pre-clinical studies and several clinical studies, TRALI has been related to loss of product quality during red blood cell (RBC) storage, called the "storage lesion". Donor characteristics, as for example age, genetics and life style choices influence this "storage lesion". We hypothesized that donor sex, age and blood type is related to TRALI incidence.

METHODS/MATERIALS

We performed a secondary analysis of two cohort studies, designed to identify TRALI risk factors by matching TRALI patients to transfused controls. We obtained donor sex, age and blood type from the Dutch Blood Bank Sanquin and investigated TRALI incidence in patients who were exposed to a certain donor characteristic. We used Kruskal-Wallis testing to compare the number of transfused products and Chi² testing to compare proportions of TRALI patients and transfused control.

RESULTS

After implementation of the male-donor only plasma strategy, patients received more transfusion products from male donors. However, we did not detect a relation between TRALI incidence and donor sex. Both TRALI patients and transfused controls received mainly products from donors over 41 years old, but donor age did not influence TRALI risk. Donor blood type, the transfusion of blood type-compatible and blood type-matched products also had no influence on TRALI incidence.

CONCLUSION

We conclude that in two cohorts of TRALI patients, donor age, donor sex and donor blood type are unrelated to TRALI.

Plasma Inclusive Resuscitation Is Not Associated With Transfusion-Related Acute Lung Injury Under Updated Guidelines

INTRODUCTION

Plasma inclusive resuscitation (PIR) uses fresh frozen plasma as an adjunct to crystalloid in the management of burn shock and has potential benefits over other colloids. Yet, safety concerns for transfusion-related acute lung injury (TRALI) exist. The aim of this study evaluated the association between TRALI and PIR in a cohort of severely burn-injured patients using the updated Canadian Blood Services Consensus definitions.

METHODS

Burn-injured patients requiring PIR at a burn center from 2018 to 2022 were retrospectively reviewed. To assess for TRALI, data related to acute hypoxemia, bilateral pulmonary edema, left atrial hypertension, and changes to respiratory status up to 6 h after PIR were recorded. To identify other risks and benefits associated with PIR timing, resuscitative volumes and outcomes were compared between early (0-8 h) and late PIR (8-24 h) initiation.

RESULTS

Of the 88 patients included for study, no patient developed TRALI type I or II under the updated definitions. Early (n = 39) compared to late PIR (n = 49) was associated with a higher percent total body surface area (TBSA, 36.3%, 26.0%, P = 0.01). The predicted 24-h volume was higher for early PIR (10.1 L, 6.3 L, P = 0.049), but the observed 24-h volume (cc/kg/%TBSA) was not significantly different (5.2, 5.3, P = 0.62).

CONCLUSIONS

In a cohort of severely burn-injured patients undergoing PIR, no patient developed TRALI type I or type II under the updated Canadian Blood Services Consensus definitions. Earlier use of PIR was not associated with higher resuscitative volumes despite higher TBSA. Further studies are necessary to better ascertain the potential risks and benefits associated with PIR.

Patient Blood Management, Anemia, and Transfusion Optimization Across Surgical Specialties

Patient blood management (PBM) is a systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood and minimizing allogenic transfusion need and risk. According to the PBM approach, the goals of perioperative anemia management include early diagnosis, targeted treatment, blood conservation, restrictive transfusion except in cases of acute and massive hemorrhage, and ongoing quality assurance and research efforts to advance overall blood health.

Phenotyping and Genotyping of HNA: Prevalence, Risk of Alloimmunization, and HNA Incompatibilities in Indians

Background

Antibodies to human neutrophil alloantigens (HNA) are involved in the pathophysiology of several clinical conditions including transfusion-related acute lung injury (TRALI), alloimmune and autoimmune neutropenia, and febrile nonhemolytic transfusion reactions leading to neutropenia. The cognate antigens are polymorphic structures expressed on several glycoproteins on the neutrophils, i.e., antigens HNA-1a, -1b, -1c, and -1d on Fc-γ-receptor IIIb; HNA-2 on CD177; HNA-3a and -3b on choline transporter-like protein 2; HNA-4a and -4b on CD11b/αM subunit of the αMβ2-integrin (CD11b/CD18, Mac-1, CR3); and HNA-5a and -5b on αL-subunit (CD11a) of the αLβ2 integrin (CD11a/CD18), leukocyte function associated molecule (LFA)-1. Currently, there is a lacuna of diagnostic methods for detection of HNA in India. This study aimed to determine the HNA frequencies in Indians, estimate the risk of alloimmunization, and prepare typed neutrophil panels, which can be used to detect HNA antibodies in neutropenia cases.

Material and Methods

EDTA blood samples were collected from random 1,054 blood donors. HNA-2 was phenotyped on fresh EDTA samples using FITC labelled monoclonal anti-CD177 by flowcytometry. HNA-1 (FCGR3B) genotyping was carried out by DNA sequencing and PCR-RFLP. Antigens of HNA-3 (SLC44A2) and HNA-5 (ITGAL) were genotyped by PCR-RFLP using TaqαI and Bsp1286I restriction enzymes, respectively, while HNA-4 (ITGAM) was genotyped by PCR-SSP.

Results

Allele frequencies of FCGR3B*01, FCGR3B*02, and FCGR3B*03 were found to be 0.433, 0.444, and 0.087, respectively. FCGR3B*01+*02+*03- was the most common genotype (33.78%). Ten individuals showed deficiency of FCGR3B individuals, while 23 showed hyperexpression, i.e., FCGR3B*01+*02+*03+. FCGR3B*04and *05 occurred with a frequency of 0.002 and 0.024. HNA-2 was found to be a high frequency antigen occurring in 98.8% population. Four percent individuals showed atypical expression of CD177 on their neutrophils. Allele frequencies of SLC44A2*01 and SLC44A2*02were 0.812 and 0.188, respectively, and that of ITGAM*01, ITGAM*02, ITGAL*01, and ITGAL*02 were 0.9546, 0.0454, 0.2372, and 0.7628, respectively.

Conclusion

This is the first study in India to report the frequencies of HNA among blood donors. Typed neutrophil panels identified in the present study will enable us to investigate suspected cases of immune neutropenia in future.

Key features of the underlying pathophysiology of Transfusion-related acute lung injury

INTRODUCTION

Transfusion-related acute lung injury (TRALI) remains a leading cause of blood transfusion associated mortality, particularly in the intensive care unit. TRALI is underrecognized, underreported and lacks specific biomarkers and clinical therapies.

AREAS COVERED

In this review, the focus will be on the key pathophysiological features of TRALI. This will include the latest insights into the critical importance of complement (in contrast to Fcγ-receptors; FcγRs) as a driver of TRALI, and the role of recipient immune cells such as neutrophils and macrophages, and also the contribution of the pulmonary endothelium.

EXPERT OPINION

Increased efforts are needed to stimulate active reporting of TRALI cases. More research into the immuno-cellular pathophysiology of TRALI is required, including the role of the pulmonary endothelium. Heterogeneity in the underlying clinical condition and the different transfusion triggers should be taken into consideration. This will aid in the search for novel biomarkers and therapeutic modalities. At the moment, the most promising potential therapeutic strategies appear to be administration of interleukin (IL)-10, inhibition of complement activation and blockade of Osteopontin (OPN). Follow-up investigations are, however, highly warranted which should pave the way for multicenter international clinical trials, in order to battle the mortality due to TRALI.

Transfusion-related respiratory complications in intensive care: A diagnosis challenge

Transfusion-related respiratory complications can be challenging to diagnose especially in mechanically-ventilated patients in the intensive care unit (ICU) due to the concurrent respiratory symptoms associated with the patients' primary diagnoses. In this narrative review, transfusion-related respiratory complications, including transfusion-associated dyspnea (TAD), transfusion-related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), and transfusion-related allergic reaction (TRAR), are briefly presented in light of the recent consensus or experts' definitions; and the diagnosis issues for ICU patients are discussed. Acute respiratory failure occurring during, or within 6 to 24hours, of transfusion might be a transfusion-related respiratory complication. The recent updated definitions for TRALI and TACO should assist clinicians to differentiate between possible diagnoses. The issues for ICU clinicians are first to recognize the acute respiratory deterioration and the possible causality between the deterioration and blood transfusion and secondly to make the proper diagnosis. This remains challenging for mechanically-ventilated patients. Clinical assessment to identify ICU patients at particular risk of transfusion-related respiratory complications and non-invasive investigation tools could be beneficial and may help to remind clinicians to be alert to the link between transfusion and worsening of respiratory symptoms in these vulnerable critically ill patients.

Targeting mast cell activation alleviates anti-MHC I antibody and LPS-induced TRALI in mice by pharmacologically blocking the TLR3 and MAPK pathway

Transfusion-related lung injury (TRALI) poses a significant risk following blood transfusion and remains the primary cause of transfusion-related morbidity and mortality, primarily driven by the activation of immune cells through anti-major histocompatibility complex class I (anti-MHC I) antibody. However, it remains to be defined how immune microenvironmental cue contributes to TRALI. Here, we uncover that activated mast cells within the immune microenvironment promote lung inflammation and injury in antibody-mediated TRALI, both in vitro and in vivo. This was demonstrated by co-culturing lipopolysaccharide (LPS)-pretreated mast cell line with anti-MHC I antibody and establishing a "two-hit" TRALI mouse model through intratracheal injection of LPS followed by tail-vein injection of anti-MHC I antibody. Importantly, mast cell-deficient KitW-sh/W-sh mice exhibited markedly reduced lung inflammation and injury responses in antibody-mediated TRALI compared with wild-type mice. Mechanistically, activation of toll-like receptor 3 (TLR3)/mitogen-activated protein kinase (MAPK) signaling pathway in mast cells contributes to the enhanced production of proinflammatory factors. These excessive proinflammatory factors produced by activated mast cells contribute to lung inflammation and injury in antibody-mediated TRALI. Pharmacologically targeting the TLR3/MAPK pathway to inhibit mast cell activation normalizes the proinflammatory microenvironment and alleviates lung inflammation and injury in the preclinical TRALI mouse model. Overall, we find that activation of mast cells via the TLR3/MAPK pathway contributes to lung inflammation and injury in antibody-mediated TRALI, providing novel insights into its underlying mechanisms. Furthermore, targeting activated mast cells and the associated pathway offers potential therapeutic strategies for antibody-mediated TRALI.

[Practical blood transfusion and adverse transfusion reactions]

Blood transfusion, which has been conducted as a basic medical procedure since 17th century, is a supportive therapy to compensate loss of each blood component. All blood materials are donated, and alive and subject to decay, type-dependent for transfusion, vary in quality, may induce severe adverse reactions, such as anaphylaxis, and may transmit infectious agents. Therefore, not only the scientific and clinical decisions but also ethical considerations should be focused on for their use. All blood products are determined as "Products Derived from Specific Organism" by the Pharmaceutical and Medical Devices Law in Japan. Of note, blood management systems are different among countries; the Japanese Red Cross Society is a unique organization that collects and manufactures blood products under supervision of the Japanese Government. It establishes a hemovigilant system by which it collects all the information concerning transfusion-related adverse events and provides them to the responsible transfusion service staff of each hospital. Physicians should check all the information from the Japanese Red Cross and refer both the "Guidelines for Blood Transfusion" and "Guidelines for the Usage of Blood Products" by the Ministry of Health, Labor and Welfare for transfusion practice.

Platelets play a dual role in the pathophysiology of transfusion-related acute lung injury

Platelets are increasingly recognized as key regulators of inflammatory and immune responses, through their interaction with endothelium and immune cells. Therefore they might have a role in transfusion-related acute lung injury (TRALI), in which endothelial cells and neutrophils are the key players. In this study, by a classic TRALI animal model, combining a custom-designed system for intravital confocal microscopy of pulmonary microvasculature and a platelet tracking technique, we found that thrombin-activated platelets transfusion aggravated TRALI while resting platelets transfusion alleviated TRALI. Promoting endogenous platelets activation also aggravated TRALI while inhibiting endogenous platelets activation alleviated TRALI. Activated platelets interfered with the stability of endothelial barrier function while resting platelets modulated the activation of neutrophils. Anti-thrombin could alleviate TRALI, which was not reproduced upon anti-GPIIbIIIa or anti-P-selectin In conclusion, platelets might play a dual role (protective and pathogenic) in TRALI, the balance between the two roles is highly dependent on whether platelets are activated by thrombin or not. This might explain the conflicting results of previous researches studying the contribution of platelets in TRALI by platelet depletion technology, in which the induction of TRALI and the condition of animals were different, hence the state of platelets during TRALI was different. Moreover, anti-platelet-activation (such as anti-thrombin) might be a better approach than anti-activated-platelets (such as anti-P-selectin) to search for potential therapies in TRALI. Considering the involvement of thrombin-activated platelets in TRALI, anti-thrombin might be needed when blood component transfusion is performed.

Transfusion-related acute lung injury and treatment with high-flow oxygen therapy in a pediatric patient: a case report

Transfusion-Related Acute Lung Injury (TRALI) is an immune-inflammatory lung pathology that manifests within the first 6-72 hours after administration of blood products. However, due to reduced awareness of TRALI, it continues to be an underreported and often underdiagnosed complication of transfusion therapy. We report a case of a 6-year-old girl with myelodysplastic syndrome and TRALI developed in the first hour after platelet transfusion. Diagnosis of TRALI is based on the exclusion of etiologic factors such as volume overload and cardiogenic pulmonary edema following transfusion. Symptoms responded to high-flow oxygen therapy, so intubation was not attempted and full recovery was achieved.

Adverse effects of microparticles on transfusion of stored red blood cell concentrates

BACKGROUND

Systemic and pulmonary coagulopathy and inflammation are important characteristics of transfusion-related acute lung injury (TRALI). Whether microparticles that accumulate in transfused red blood cell concentrates (RBCs) have proinflammatory and procoagulant potential and contribute to adverse reactions of RBC transfusions is unclear.

AIM

To investigate the ability of microparticles in stored RBCs to promote thrombin generation and induce human pulmonary microvascular endothelial cell (HMVEC) activation and damage.

METHODS

The number and size of microparticles were determined by flow cytometric and nanoparticle tracking analyses, respectively. Thrombin generation and the intrinsic coagulation pathway were assayed by a calibrated automated thrombogram and by measuring activated partial thromboplastin time (aPTT), respectively. The expression of ICAM-1 and the release of cytokines by endothelial cells were detected by flow cytometric analyses. HMVEC damage was assessed by incubating lipopolysaccharide-activated endothelial cells with MP-primed polymorphonuclear neutrophils (PMNs).

RESULTS

The size of the microparticles in the RBC supernatant was approximately 100-300 nm. Microparticles promoted thrombin generation in a dose-dependent manner and the aPTT was shortened. Depleting microparticles from the supernatant of RBCs stored for 35 days by either filtration or centrifugation significantly decreased the promotion of thrombin generation. The expression of ICAM-1 on HMVECs was increased significantly by incubation with isolated microparticles. Furthermore, microparticles induced the release of interleukin-6 (IL-6) and interleukin-8 (IL-8) from HMVECs. Microparticles induced lipopolysaccharide-activated HMVEC damage by priming PMNs, but this effect was prevented by inhibiting the PMNs respiratory burst with apocynin.

CONCLUSION

Microparticles in stored RBCs promote thrombin generation, HMVEC activation and damage which may be involved in TRALI development.

Descriptions of acute transfusion reactions in the teaching hospitals of kermanshah university of medical sciences, iran

BACKGROUND

Transfusion services rely on transfusion reaction reporting to provide patient care and protect the blood supply. Unnecessary discontinuation of blood is a major wastage of scarce blood, as well as man, hours and funds. The aim of the present study was to describe the main characteristics of acute transfusion reactions reported in the 4 hospital of Kermanshah University of Medical Sciences (KUMS), Kermanshah, Iran.

MATERIAL AND METHODS

The study was carried out at 4 teaching hospital of Kermanshah University of Medical Sciences, Kermanshah, Iran, over18 months from April 2010. All adult patients on admission in the hospitals who required blood transfusion and had establish diagnosis and consented were included in the study.

RESULTS

In the year 2010 until 2012, a total of 6238 units of blood components were transfused. A total of 59 (0.94%) cases of transfusion reaction were reported within this 3 years period. The commonest were allergic reactions which presented with various skin manifestations such as urticarial, rashes and pruritus (49.2%), followed by increase in body temperature of > 1°C from baseline which was reported as febrile non-hemolytic transfusion reaction (37.2%). pain at the transfusion site (6.8%) and hypotension (6.8%).

CONCLUSION

It is important that each transfusion of blood components to be monitor carefully. Many transfusion reactions are not recognized, because signs and symptoms mimic other clinical conditions. Any unexpected symptoms in a transfusion recipient should at least be considered as a possible transfusion reaction and be evaluated. Prompt recognition and treatment of acute transfusion reaction are crucial and would help in decreasing transfusion related morbidity and mortality, but prevention is preferable.

Polymorphonuclear neutrophil activation by Src phosphorylation contributes to HLA-A2 antibody-induced transfusion-related acute lung injury

Human leukocyte antigen (HLA)-A2 antibody contributes to the pathogenesis of transfusion-related acute lung injury (TRALI) via polymorphonuclear neutrophil (PMN) activation, but the signaling pathways involved this process remain largely undefined. In this study, we sought to study the signaling pathways involved in the pathogenesis of HLA-A2-induced TRALI. Lipopolysaccharide (LPS), and the plasma from the HLA-A2 antibody-positive donors were utilized to establish a rat model of TRALI. Human pulmonary endothelial cells (HPMECs) were in vitro co-cultured with HLA-A2 antibody-treated PMNs and then treated with LPS to induce a cytotoxicity model. The effects of HLA-A2 antibody on HPMEC injury were evaluated in this model. Besides, dasatinib was used to block the Src phosphorylation to explore whether Src involved in the TRALI or HPMEC injury induced by HLA-A2 antibody. The HLA-A2 antibody plus LPS induced TRALI and stimulated PMN activation in rats. HLA-A2 antibody-induced TRALI could be attenuated via depletion of PMN. HLA-A2 antibody activated NF-κB and NLRP3 inflammasome. In addition, HLA-A2 antibody aggravated the HPMEC injuries and the release of PMN surfaces makers, but dasatinib treatment reversed this effect, indicating that HLA-A2 antibody activated PMNs and exacerbated TRALI by stimulating phosphorylation of Src followed by activation of NF-κB and NLRP3 inflammasome, which was validated in vivo. In summary, HLA-A2 induced PMNs by activating NF-κB/NLRP3 inflammasome via phosphorylated-Src elevation, thereby exacerbating TRALI. This study highlights promising target for the treatment of antibody-mediated TRALI.