The incidence of transfusion-related acute lung injury using active surveillance: A systematic review and meta-analysis

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-related mortality. A concern with passive surveillance to detect transfusion reactions is underreporting. Our aim was to obtain evidence-based estimates of TRALI incidence using meta-analysis of active surveillance studies and to compare these estimates with passive surveillance.

STUDY DESIGN AND METHODS

We performed a systematic review and meta-analysis of studies reporting TRALI rates. A search of Medline and Embase by a research librarian identified studies published between January 1, 1991 and January 20, 2023. Prospective and retrospective observational studies reporting TRALI by blood component (red blood cells [RBCs], platelets, or plasma) were identified and all inpatient and outpatient settings were eligible. Adult and pediatric, as well as general and specific clinical populations, were included. Platelets and plasma must have used at least one modern TRALI donor risk mitigation strategy. A random effects model estimated TRALI incidence by blood component for active and passive surveillance studies and heterogeneity was examined using meta-regression.

RESULTS

Eighty studies were included with approximately 176-million blood components transfused. RBCs had the highest number of studies (n = 66) included, followed by platelets (n = 35) and plasma (n = 34). Pooled TRALI estimates for active surveillance studies were 0.17/10,000 (95% confidence intervals [CI]: 0.03-0.43; I2  = 79%) for RBCs, 0.31/10,000 (95% CI: 0.22-0.42; I2  = <1%) for platelets, and 3.19/10,000 (95% CI: 0.09-10.66; I2  = 86%) for plasma. Studies using passive surveillance ranged from 0.02 to 0.10/10,000 among the various blood components.

DISCUSSION

In summary, these estimates may improve a quantitative understanding of TRALI risk, which is important for clinical decision-making weighing the risks and benefits of transfusion.

Genetic landscape of human neutrophil antigen variants in India from population-scale genomes

Antibodies against human neutrophil antigens (HNAs) play a significant role in various clinical conditions such as neonatal alloimmune neutropenia, transfusion-related acute lung injury, and other nonhemolytic transfusion reactions. This study aims to identify the genotype and allele frequencies of HNAs in the healthy Indian population. Ten genetic variants in four human genes encoding alleles of HNAs class I-V approved by the International Society of Blood Transfusion-Granulocyte Immunobiology Working Party were used in the analysis. Genetic variants from whole genome sequences of 1029 healthy Indian individuals corresponding to HNA alleles were analyzed. The frequencies of the variants were compared with global population datasets using an in-house computational pipeline. In HNA class I, allele frequencies of FCGR3B*01, FCGR3B*02, and FCGR3B*03 encoding HNA-1a, HNA-1b, and HNA-1c were 0.07, 0.8, and 0.13, respectively. HNA class 3 alleles namely SLC44A2*01 (encoding HNA-3a) and SLC44A2*02 (encoding HNA-3b) were found at allele frequencies of 0.78 and 0.22, respectively. The frequencies of ITGAM*01 encoding HNA-4a and ITGAM*02 encoding HNA-4a were 0.95 and 0.05, respectively. Furthermore, allele frequencies of HNA class 5 alleles were 0.32 for ITGAL*01 (encoding HNA-5a) and 0.68 for ITGAL*02 (encoding HNA-5b). Interestingly, it was also found that rs2230433 variant deciding the HNA class 5 alleles, was highly prevalent (78.2%) in the Indian population compared with other global populations. This study presents the first comprehensive report of HNA allele and genotype frequencies in the Indian population using population genome datasets of 1029 individuals. Significant difference was observed in the prevalence of HNA5a and HNA5b in India in comparison to other global populations.

Noncardiogenic pulmonary edema in small animals

OBJECTIVE

To review various types of noncardiogenic pulmonary edema (NCPE) in cats and dogs.

ETIOLOGY

NCPE is an abnormal fluid accumulation in the lung interstitium or alveoli that is not caused by cardiogenic causes or fluid overload. It can be due to changes in vascular permeability, hydrostatic pressure in the pulmonary vasculature, or a combination thereof. Possible causes include inflammatory states within the lung or in remote tissues (acute respiratory distress syndrome [ARDS]), airway obstruction (post-obstructive pulmonary edema), neurologic disease such as head trauma or seizures (neurogenic pulmonary edema), electrocution, after re-expansion of a collapsed lung or after drowning.

DIAGNOSIS

Diagnosis of NCPE is generally based on history, physical examination, and diagnostic imaging. Radiographic findings suggestive of NCPE are interstitial to alveolar pulmonary opacities in the absence of signs of left-sided congestive heart failure or fluid overload such as cardiomegaly or congested pulmonary veins. Computed tomography and edema fluid analysis may aid in the diagnosis, while some forms of NCPE require additional findings to reach a diagnosis.

THERAPY

The goal of therapy for all types of NCPE is to preserve tissue oxygenation and reduce the work of breathing. This may be achieved by removing the inciting cause (eg, airway obstruction) and cage rest in mild cases and supplemental oxygen in moderate cases and may require mechanical ventilation in severe cases.

PROGNOSIS

Prognosis is generally good for most causes of veterinary NCPE except for ARDS, although data are scarce for some etiologies of NCPE.

Human neutrophil antigen-1, -3, -4, and -5 allele and genotype frequencies in the Croatian blood donor population and their clinical significance

OBJECTIVES

Human neutrophil antigens (HNAs) and antibodies play an important role in allo- and autoimmunity associated with immune neutropenia and transfusion reactions. The aim of this study was to determine the HNA-1, -3, -4 and -5 allele and genotype frequencies in the Croatian blood donor population to assess the role of HNA-1, -3, -4, and -5 alleles in the development of neonatal alloimmune neutropenia and antibody-mediated transfusion-related acute lung injury.

MATERIAL AND METHODS

A total of 371 blood samples from unselected healthy blood donors were analyzed. Samples from all 371 donors were genotyped for HNA-1, samples from 160 donors were genotyped for HNA-3, and samples from 142 donors were genotyped for HNA-4 and HNA-5 using the polymerase chain reaction with sequence-specific primers (PCR-SSP) method.

RESULTS

The frequencies of the FCGR3B*01, FCGR3B*02 and FCGR3B*03 HNA-1 alleles were 0.393, 0.607 and 0.022, and of the SLC44A2*01 and SLC44A2*02 HNA-3 alleles 0.781 and 0.219, respectively. The frequencies of the ITGAM*01 and ITGAM*02 HNA-4 alleles were 0.796 and 0.204, and of the ITGAL*01 and ITGAL*02 HNA-5 alleles 0.718 and 0.282, respectively.

CONCLUSION

These are the first results on the HNA allele and genotype frequencies in the Croatian blood donor population. We observed no deviations from previous reports on Caucasian populations. Determination of the HNA antigen frequencies in the population is important to estimate the risk of alloimmunization to HNA, especially the risk of fetal-maternal incompatibility and alloantibody production by transfusion of the HNA incompatible blood components.

Severe antibody-mediated transfusion-related acute lung injury in an obstetric patient following transfusion of fresh frozen plasma from a non-transfused male blood donor

Transfusion-Related Acute Lung Injury (TRALI) has been associated with neutrophil reacting antibodies in transfused blood products. We report a case of life-threatening TRALI in an obstetric patient triggered by transfusion from a non-transfused male blood donor. A residual risk of TRALI exist, even in a male-only plasma setting.

Reporting transfusion-related acute lung injury cases

BACKGROUND:

Transfusion-related acute lung injury (TRALI) is a rare but potentially fatal complication of blood product transfusion. It is felt worldwide that TRALI is an underrecognized and underreported entity because of lack of awareness.

AIM:

The purpose of this study was to report all cases of TRALI diagnosed in a tertiary care hospital over a 5-year period.

MATERIALS AND METHODS:

This is a retrospective review of all TRALI cases reported from January 2011 to December 2015. All TRALI cases were identified from a manual review of reported transfusion reaction forms. For detailed information of all TRALI cases, medical record charts of patients were reviewed. The record of donors implicated in TRALI cases was derived from blood bank system.

STATISTICAL ANALYSIS USED:

The rate of TRALI cases per 1000 blood products transfused was computed by dividing the transfusion reactions by total number of all blood units transfused.

RESULTS:

Total number of transfusions during the study was 291,041. Six cases of TRALI were reported during this period. Rate of TRALI per 1000 units transfused was 0.02%. The mortality associated with TRALI was 33.3%. TRALI occurred following the transfusion of fresh-frozen plasma in one patient, packed red blood cells in two patients, and a mixture of blood components in three patients. In all cases, the donors were male.

CONCLUSION:

The rate of TRALI reported to our blood bank was found to be 0.02%, which is very low as compared to international data. This is the first comprehensive study on TRALI from the country and a step forward to create awareness about the importance of diagnosing and reporting TRALI.

Leukocyte-Reactive Antibodies in Female Blood Donors: The Austrian Experience

Introduction

Antibody-mediated transfusion-related acute lung injury (TRALI) is caused by antibodies against human leukocyte antigens (HLAs) or human neutrophil antigens (HNAs), and is one of the most serious complications associated with transfusion medicine. Prevention strategies like testing allo-exposed female blood donors have not yet been introduced nationwide in Austria. To assess the need and feasibility of routine leukocyte antibody testing, the prevalence of leukocyte-reactive antibodies in an Austrian female donor population was been determined using classical cell-based methods which were compared with a high-throughput bead-based method.

Methods

Sera from 1,022 female blood donors were screened using a granulocyte aggregation test (GAT) and a white blood cell immunofluorescence test (WIFT) after retesting and specification of positive samples by granulocyte immunofluorescence test (GIFT) and monoclonal antibody-specific immobilization of granulocyte antigens (MAIGA). Potential HLA reactivities were confirmed using the microbeads assay LabScreen^TM Mixed. The results in 142 donor sera and 38 well-defined reference sera were investigated by the microbeads assay LabScreen^TM Multi and compared with classical cell-based methods.

Results

Reactivity with either granulocytes and/or lymphocytes was detected in 79 sera (7.7%), with the majority being HLA-specific. Antibodies against HNA were obtained in 7 samples (0.7%). The aggregating potential of the detected antibodies was observed in 9 cases (0.9%). Most of the leukocyte-reactive antibodies occurred at a donor age of between 35 and 59 years (n = 61). LabScreen Multi showed good agreement (κ = 0.767) for HNA antibody detection by cell-based assays, but double/multiple specificities (100% of 7 anti-HNA-1b sera) as well as false-negative results (40% of 15 HNA-3-specific sera) occurred.

Discussion

Leukocyte-reactive antibody screening is advised in Austrian female donors for safe blood transfusion, including single-donor convalescent plasma treatment of COVID-19 that may be implemented soon. For the introduction of LabScreen Multi, the combination with GAT should be considered to ensure correct anti-HNA-3a detection.

Molecular Genetics of the Human Neutrophil Antigens

BACKGROUND AND OBJECTIVE

Antibodies to human neutrophil antigens (HNAs) have been implicated in transfusion-related acute lung injury and allo- and autoimmune neutropenia. To date, five HNA systems are assigned, and during the last decades enormous efforts have been undertaken to identify the underlying genes and to characterize the antigens. This review of the literature will provide the current genetic, molecular and functional information on HNAs.

RECENT FINDINGS

New information on alleles and antigens has been added to nearly each of the five HNA systems. HNA-1d has been added as the antithetical epitope to HNA-1c that is located on the glycoprotein encoded by FCGR3B*02 but not by FCGR3B. FCGR3B*04 and *05 now are included as new alleles. A CD177*787A>T substitution was demonstrated as the main reason for the HNA-2-negative phenotype on neutrophils. The target glycoprotein of HNA-3 antibodies could be identified as choline transporter-like protein 2 (CTL2) encoded by SLC44A2. The conformation sensitive epitope discriminates between arginine and glutamine at position 152 resulting in HNA-3a and HNA-3b. An additional Leu151Phe substitution can impair HNA-3a antibody binding. Recently an alloantibody against HNA-4b which discriminates from HNA-4a by an Arg61His exchange of the glycoprotein encoded by the ITGAM gene was reported in neonatal alloimmune neutropenia. An update of the current HNA nomenclature based on the new findings was provided in 2016 by the ISBT Granulocyte Immunobiology Working Party nomenclature subcommittee.

CONCLUSIONS

The molecular basis of each of the five HNA antigen systems has been decoded during the past decades. This enables reliable molecular typing strategies, antibody detection and specification as well as development of new assays based on recombinant antigens. However, research on HNA alleles, antigens, and antibodies is not finally terminated and also in the future will add new findings.

Granulocyte antibodies in male blood donors: can they trigger transfusion-related acute lung injury?

BACKGROUND

White blood cell-associated antibodies can lead to transfusion-related acute lung injury (TRALI). Female donors with a history of pregnancies have been identified as a main cause for these antibodies. Male or female donors without a history of pregnancy are considered as safe donors.

STUDY DESIGN AND METHODS

Following the identification of two TRALI cases associated with blood products from male donors, we investigated the frequency of granulocyte-specific and human leukocyte antigen (HLA) antibodies in the entire blood donor population using a high throughput automated flow-cytometry-based granulocyte immunofluorescence test (Flow-GIFT). We investigated sera from 14,343 whole blood donors (female, n = 6974, 48.7%; male, n = 7369, 51.3%) using automated Flow-GIFT. Of the female blood donors, 60.4% had a history of pregnancy. Positive sera were retested by the standard granulocyte immunofluorescence test and granulocyte agglutination test. For the detection of HLA Class I and II immunoglobulin G antibodies, we used a commercial screening enzyme-linked immunosorbent assay.

RESULTS

We detected in 924 (21.9%) of the 4212 females with a history of pregnancy antibodies against granulocyte antigens (n = 62, 1.5%), HLA Class I and/or II antigens (n = 864, 20.5%). Notably, in 3.5% (n = 96) of 2762 females without a history of pregnancy and in 2.1% (n = 154) of 7369 males antibodies against granulocyte antigens (n = 13, 0.47% and n = 45, 0.6%), HLA Class I and/or II (n = 83, 3% and n = 109, 1.4%, respectively), were also detected.

CONCLUSION

Human neutrophil antigen antibodies are rare in male and females without a history of pregnancy compared to females with a history of pregnancy, but their relevance is not negligible.

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 risk mitigation: an update

Transfusion-related acute lung injury (TRALI) is a life-threatening complication of transfusion. Greater understanding of the pathophysiology of this syndrome has much improved during the last two decades. Plasma-containing components from female donors with leucocyte antibodies were responsible for the majority of TRALI fatalities before mitigation strategies were implemented. Over the past 15 years, measures to mitigate risk for TRALI have been implemented worldwide and they continued to evolve with time. The AABB requires that all plasma containing components and whole blood for transfusion must be collected from men, women who have not been pregnant, or women who have tested negative for human leucocyte antigen antibodies. Although the incidence of TRALI has decreased following the institution of TRALI mitigation strategies, TRALI is still the most common cause of transfusion-associated death in the United States. In this review, we focus on TRALI risk mitigation strategies. We describe the measures taken by blood collection facilities to reduce the risk of TRALI in the United States, Canada and European countries. We also review the literature for the effectiveness of these measures.

Antibodies to major histocompatibility complex class II antigens directly prime neutrophils and cause acute lung injury in a two-event in vivo rat model

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a significant cause of mortality, especially after transfusions containing antibodies to major histocompatibility complex (MHC) class II antigens. We hypothesize that a first event induces both 1) polymorphonuclear neutrophils (PMNs) to express MHC class II antigens, and 2) activation of the pulmonary endothelium, leading to PMN sequestration, so that the infusion of specific MHC class II antibodies to these antigens causes PMN-mediated acute lung injury (ALI).

STUDY DESIGN AND METHODS

Rats were treated with saline (NS), endotoxin (lipopolysaccharide [LPS]), or cytokines (interferon-γ [IFNγ], macrophage colony-stimulating factor [MCSF], tumor necrosis factor-α [TNFα]); the PMNs were isolated; and the surface expression of the MHC class II antigen OX6 and priming by OX6 antibodies were measured by flow cytometry or priming assays.

RESULTS

A two-event model of ALI was completed with NS, LPS, or IFNγ/MCSF/TNFα (first events) and the infusion of OX6 (second event). Compared with NS incubation, rats treated with either LPS or IFNγ/MCSF/TNFα exhibited OX6 PMN surface expression, OX6 antibodies primed the formyl-methionyl-leucyl phenylalanine (fMLF)-activated respiratory burst, and PMN sequestration was increased. OX6 antibody infusion into LPS-incubated or IFNγ/MCSF/TNFα-incubated rats elicited ALI, the OX6 antibody was present on the PMNs, and PMN depletion abrogated ALI.

CONCLUSION

Proinflammatory first events induce PMN MHC class II surface expression, activation of the pulmonary endothelium, and PMN sequestration such that the infusion of cognate antibodies precipitates TRALI.

HNA antibody-mediated neutrophil aggregation is dependent on serine protease activity

BACKGROUND AND OBJECTIVES

Transfusion-related acute lung injury (TRALI) is often caused by antibodies against human neutrophil alloantigen-2 (HNA-2) and HNA-3a. Neutrophil aggregation is considered as a major cause of TRALI, but little is known about how HNA antibodies initiate this process. We explored mechanisms involved in neutrophil aggregation induced by HNA-2 and HNA-3a antibodies.

MATERIALS AND METHODS

Isolated neutrophils were pretreated with broad-spectrum or specific inhibitors against different cell functions or proteases. Granulocyte agglutination test (GAT) was performed with serially diluted anti-HNA-2 and anti-HNA-3a plasmas or control plasma, and reactivity was evaluated microscopically. Reactive oxygen species (ROS) production in neutrophils was investigated using a lucigenin-based chemiluminescence assay.

RESULTS

HNA-2 and HNA-3a antibody-mediated neutrophil aggregation was inhibited by pretreatment with formaldehyde, iodoacetamide and the serine protease inhibitors Pefabloc-SC, N-p-tosyl-L-phenylalanine chloromethyl ketone (TPCK) and Nα-tosyl-L-lysine chloromethyl ketone hydrochloride (TLCK). In contrast, inhibition of actin polymerization, respiratory burst, cysteine proteases, metalloproteases or aspartic proteases did not affect neutrophil aggregation. Furthermore, HNA-3a antibodies did not directly cause ROS production in neutrophils.

CONCLUSION

Aggregation of neutrophils induced by HNA-2 and HNA-3a antibodies is an active process and depends on trypsin- or chymotrypsin-like serine proteases but is not dependent on the production of ROS. These findings may open new prospects for the pharmacologic prevention of neutrophil-associated acute lung injury.

[Coagulation management in patients with liver disease]

BACKGROUND

End-stage liver disease is associated with complex alterations in hemostasis. Whereas prognosis is essentially affected by life-threatening bleeding complications in some patients, others, especially those with cholestatic liver diseases, suffer from thromboembolic complications. Standard laboratory values (SLVS; prothrombin time, activated partial thrombin time, platelet count) cannot sufficiently reflect the altered balance of pro- and anticoagulatory factors. Moreover, a couple of studies indicated that SLVS are not able to predict bleeding complications in patients with acute liver failure or decompensated liver cirrhosis.

DIAGNOSIS AND THERAPY

Use of bed-side coagulation diagnostics such as thrombelastometry/-graphy, detection of thrombocyte function by multiple electrode aggregometry and selective measurement of single factors allows a targeted and causal therapy of hepatic coagulopathies especially in the context of bleeding complications or surgical interventions. In recent years, coagulation management guided by these new devices has contributed to a reduction in transfusion of allogenic blood products, which may be associated with undesirable side effects.

DISCUSSION

The current review summarizes the complex pathophysiological alterations of hemostasis associated with advanced liver insufficiency and discusses recent upcoming diagnostics and coagulation management in this patient cohort.

Split Blood Products

The last 20 years have seen many advances in transfusion therapy and safety. Blood products are biological products engendering complex interactions with the immune system. Prestorage leukoreduction results in a reduced risk of febrile reactions, CMV transmission, and immune modulation, proving to be safer for patients than non-leuko reduced products.

Simple patient identification issues and clerical error continue to be the primary causes of ABO-incompatible transfusions. Rigorous donor screening as well as serologic and nucleic acid testing for transfusion transmitted infection have brought the blood supply to a very safe level, although transmission of these agents continues to be a problem in underdeveloped countries. Emerging infectious diseases, beyond current laboratory detection capabilities, combined with global travel, pose unknown imminent risks everywhere. We also briefly discuss the current risks of transfusion-transmitted infections.

We review currently available hemostatic blood products, their compositions, and their clinical indications; we mention product modifications currently in development; and we touch upon the hemostatic properties and drawbacks of whole blood, which is currently gaining popularity as an alternative to split blood products. We conclude with an in-depth overview of the risks associated with transfusion, including incompatibility, hemolytic transfusion reactions, transfusion-associated circulatory overload (TACO), and transfusion-related acute lung injury (TRALI).

Spotlight on pathogenesis of TRALI: HNA-3a (CTL2) antibodies

Human neutrophil antigen-3a (HNA-3a) antibodies contained in donor plasma can result in severe, sometimes fatal transfusion-related acute lung injury (TRALI). Recent developments in TRALI secondary to antibodies to HNA-3a antigen span diagnosis, pathophysiology, treatment, and prevention resulting in improved understanding, potential treatments, and mitigation strategies. First, on the molecular level, characterization of HNA-3 antigen has allowed for genotyping methods that clarify population prevalence. Related work has led to generation of multiple antibody detection assays. These assays aid in determining potential populations at risk and potential mitigation strategies. Second, the development of TRALI requires a hit from the patient and from the product. Anti-HNA-3a is one of the product-derived factors and appears to result in TRALI by binding directly to pulmonary endothelium as well as to neutrophils expressing the corresponding antigen. Finally, potential mitigation strategies include red blood cell product filtration to remove anti-HNA-3a as well as other antibodies.

Delicate balance of bleeding and thrombosis in end-stage liver disease and liver transplantation

Liver transplantation in cirrhotic patients is accompanied by severe bleeding. Indeed, the first 100 recipients of liver allografts transplanted by Thomas E. Starzl died mainly by uncontrolled bleeding. Since then, much progress has been made as to the understanding of the pathophysiology and the treatment of hemostatic disorders in cirrhotic patients. The aim of this review is to provide a state-of-the-art overview on recent developments and treatment options for hemostatic disorder in cirrhotic patients. Patients with end-stage-liver disease (ESLD) do not suffer only from procoagulant deficiency; there is also a lack of natural anticoagulants (i.e. proteins C and S) and profibrinolytics. Conventional laboratory methods such as the determination of the international normalized ratio or the activated partial thromboplastin time cannot predict bleeding complications in these patients. Progressive diagnostic techniques reveal that cirrhotic patients have the same capacity to produce thrombin like healthy volunteers. Moreover, cirrhotic patients--and particularly those with primary biliary cirrhosis or primary sclerosing cholangitis-- are at a higher risk for developing thrombosis as compared with healthy controls. Hemostatic alterations are common in cirrhotic patients; they involve both the pro- and the anticoagulant pathways. However, this is a very delicate balance, which may be shifted to either of these pathways by different treatments thereby causing bleeding or thrombosis, respectively.

Freeze-dried plasma at the point of injury: from concept to doctrine

While early plasma transfusion for the treatment of patients with ongoing major hemorrhage is widely accepted as part of the standard of care in the hospital setting, logistic constraints have limited its use in the out-of-hospital setting. Freeze-dried plasma (FDP), which can be stored at ambient temperatures, enables early treatment in the out-of-hospital setting. Point-of-injury plasma transfusion entails several significant advantages over currently used resuscitation fluids, including the avoidance of dilutional coagulopathy, by minimizing the need for crystalloid infusion, beneficial effects on endothelial function, physiological pH level, and better maintenance of intravascular volume compared with crystalloid-based solutions. The Israel Defense Forces Medical Corps policy is that plasma is the resuscitation fluid of choice for selected, severely wounded patients and has thus included FDP as part of its armamentarium for use at the point of injury by advanced life savers, across the entire military. We describe the clinical rationale behind the use of FDP at the point-of-injury, the drafting of the administration protocol now being used by Israel Defense Forces advanced life support providers, the process of procurement and distribution, and preliminary data describing the first casualties treated with FDP at the point of injury. It is our hope that others will be able to learn from our experience, thus improving trauma casualty care around the world.

[Transfusion-related acute lung injury]

Transfusion-related acute lung injury (TRALI) developed into the leading cause of transfusion-related morbidity and mortality after the first description by Popovsky et al. approximately three decades ago. It was the most frequent reason for transfusion-related fatalities worldwide before implementation of risk minimization strategies by donor selection. Plasma-rich blood products, such as fresh frozen plasma and apheresis platelets seem to be the leading triggers of TRALI. Hypoxemia and development of pulmonary edema within 6 h of transfusion are the diagnostic criteria for TRALI. The differentiation between cardiac failure and other transfusion-related lung injuries, such astransfusion-associated circulatory overload ( TACO) is difficult and causal treatment is not available. Therapy is based on supportive measures, such as oxygen insufflationor mechanical ventilation. The exactly pathogenesis is still unknown but the most propagated hypothesis is the two-event-model. Neutrophils are primed by the underlying condition, e.g. sepsis or trauma during the first event and these primed neutrophils are activated by transfused leukoagglutinating antibodies (immunogen) or bioreactive mediators (non-immunogen) during the second-event. Transfusion of leukoagglutinating antibodies from female donors with one or more previous pregnancies is the most frequent reason. No more TRALI fatalities were reported after implementation of the donor selection in Germany in 2009.

Human neutrophil antigen-3a antibodies induce neutrophil aggregation in a plasma-free medium

BACKGROUND

Antibodies against the human neutrophil alloantigen-3a (HNA-3a) are involved in severe cases of transfusion-related acute lung injury (TRALI), but the susceptibility of patients towards HNA-3a antibody differs largely. HNA-3a antibodies induce granulocyte aggregation. However, it is unresolved whether plasma proteins are required for granulocyte aggregation.

MATERIALS AND METHODS

We investigated whether HNA-3a-antibody-induced aggregation of polymorphonuclear cells is dependent on plasma factors by using and modifying the granulocyte agglutination test (GAT).

RESULTS

Polymorphonuclear cells homozygous for HNA-3a did not aggregate when incubated with HNA-3a antibodies in a plasma-protein-free GAT setup. When the GAT was performed using polymorphonuclear cells re-suspended in phosphate-buffered saline containing proteins, HNA-3-mediated aggregation was observed. Moreover, using Tween® 20 for blocking the plates, reconstituted the granulocyte aggregation in a protein-free medium. This indicates that granulocyte aggregation probably occurs by direct granulocyte-granulocyte interaction(s) or is mediated by substances released by neutrophils after activation.

DISCUSSION

Granulocyte aggregation induced by HNA-3a antibodies does not require human plasma proteins. Interindividual variability in the response to HNA-3a antibodies does not depend on differences in patient's plasma proteins.

Transfusion-related lung injury in children: a case series and review of the literature

BACKGROUND

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. The majority of the literature involves adult patients. The main objective of this study was to characterize the demographic features, clinical presentation, patient outcomes, and antibody profiles of TRALI patients reported to the Canadian Blood Service (CBS) and to assess similarities and differences between adult and pediatric TRALI cases.

STUDY DESIGN AND METHODS

A retrospective review of cases of TRALI submitted to the CBS from 2001 to 2011 was performed. Information collected included recipient demographics, event details, blood component transfused, morbidity and mortality data, and donor antibody results.

RESULTS

A total of 284 cases of definite, possible, or probable TRALI were reported. Six percent (n = 17) occurred in children. There were no significant differences between pediatric or adult patients with TRALI. Most of the children who presented with TRALI were either teenagers or less than 1 year of age. The incident rate of reported TRALI cases in Canada per 100,000 red blood cell transfusions was estimated at 5.58 for children and 3.75 for adults.

CONCLUSIONS

This study is the largest case series of reported TRALI cases in children. Crude modeling suggests that the incidence of TRALI in children is similar to that of adults. Although the numbers are small, there do not appear to be differences in presentation or outcome between adults and children with TRALI. TRALI is associated with significant morbidity and mortality and pediatricians need to consider this diagnosis in children who experience respiratory distress after transfusions.

Pathology consultation on transfusion-related acute lung injury (TRALI)

Transfusion-related acute lung injury (TRALI) is a serious condition characterized by respiratory distress, hypoxia, and bilateral pulmonary infiltrates, which occur within 6 hours of transfusion. Several theories have been proposed to explain the underlying pathologic mechanisms of TRALI. Immune-mediated TRALI accounts for over 80% of reported cases and is mediated by donor antibodies to HLAs and/or human neutrophil antigens (HNA). Immune-mediated TRALI is most commonly associated with donor plasma transfusion or other blood products from multiparous women, which has led many countries to reduce or exclude women from donating high-volume plasma products. This policy change has resulted in a decrease in the incidence of TRALI and highlighted the importance of nonimmune-mediated TRALI, which is thought to be caused by bioreactive lipids and other biologic response modifiers that accumulate during storage of blood products. When TRALI is suspected, clinical consultation with a transfusion medicine specialist helps differentiate it from other transfusion reactions with similar characteristics.

Adverse effects of plasma transfusion

Plasma utilization has increased over the past two decades, and there is a growing concern that many plasma transfusions are inappropriate. Plasma transfusion is not without risk, and certain complications are more likely with plasma than other blood components. Clinical and laboratory investigations of the patients suffering reactions after infusion of fresh-frozen plasma (FFP) define the etiology and pathogenesis of the panoply of adverse effects. We review here the pathogenesis, diagnosis, and management of the risks associated with plasma transfusion. Risks commonly associated with FFP include: 1) transfusion-related acute lung injury, 2) transfusion-associated circulatory overload, and 3) allergic and/or anaphylactic reactions. Other less common risks include 1) transmission of infections, 2) febrile nonhemolytic transfusion reactions, 3) red blood cell alloimmunization, and 4) hemolytic transfusion reactions. The effects of pathogen inactivation or reduction methods on these risks are also discussed. Fortunately, a majority of the adverse effects are not lethal and are adequately treated in clinical practice.

The frequencies of human neutrophil alloantigens among the Japanese population

Human neutrophil antigens (HNAs) play an important role in a variety of clinical conditions including immune-mediated neutropenia, non-hemolytic transfusion reactions, and transfusion-related acute lung injury. The aim of this study was to investigate the frequency distribution of HNAs-1 to -5 among the Japanese population. We analyzed samples from 570 healthy Japanese by molecular and serologic techniques to estimate the gene frequencies of HNAs-1 to -5. DNA samples were obtained and typed for the HNA-1 (n = 523), -3 (n = 570), -4 (n = 570), and -5 (n = 508), by molecular techniques. The HNA-1 genotype was determined by using a commercial polymerase chain reaction-reverse sequence-specific oligonucleotide probes (PCR-rSSOP) kit. The HNA-3 to -5 genotypes were determined by the PCR-sequence specific primer (PCR-SSP), previously described, with a small modification. The HNA-2a phenotype was determined in 301 donors by granulocyte immunofluorescence test. In Japanese, the gene frequencies of HNA-1a, -1b, and -1c were 0.623, 0.377, and 0.000, respectively. The frequency of HNA-2a phenotype was 0.987, and the gene frequencies of HNA-3a and -3b were 0.654 and 0.346, respectively. HNA-4a and -4b were found at 1.000 and 0.000, respectively, and HNA-5a and -5b at 0.840 and 0.160, respectively. We describe, for the first time, the frequencies of all HNAs (HNA-1 to -5) among the Japanese population. This study will be helpful for the prediction of the risk of alloimmunization to HNA, especially to determine the risk of HNA alloantibody production by transfusion of HNA incompatible blood and feto-maternal incompatibility.

Blood donors implicated in transfusion-related acute lung injury with patient-specific HLA antibodies are more broadly sensitized to HLA antigens compared to other blood donors

BACKGROUND

The prevalence of HLA antibodies in randomly surveyed blood donors was compared to the prevalence of antibody in donors who were associated with transfusion-related acute lung injury (TRALI) cases reported to Canadian Blood Services (CBS).

STUDY DESIGN AND METHODS

Current operating procedure mandates that the CBS TRALI Medical Review Group (TMRG) refer possible TRALI cases to the (CBS) Platelet Immunology Laboratory for investigation. Donor samples from these TRALI cases were screened for HLA antibodies. In parallel, a survey was conducted to screen serum samples from blood donors who were not associated in TRALI cases. A comparison analysis of HLA antibody profiles in the two groups of donors was performed.

RESULTS

We studied 121 TRALI-associated donors (TDs) who were recalled in a total of 44 cases reported to CBS and classified by TMRG. We also studied 149 survey donors (SDs) who were deferred for donation for varied reasons and consented to participate in a survey for HLA antibody screening. Twenty-two percent of SDs and 50.4% of TDs tested positive for HLA antibodies. In addition, TDs who were implicated in TRALI demonstrated broader sensitization and higher level of quantitative HLA antibody compared to nonimplicated TDs and SDs.

CONCLUSION

Patient-specific Class I and II HLA antibodies are directly related to the risk of TRALI. Moreover, it supports the concept that HLA antibody strength is directly related to the risk of TRALI when the HLA antibody is patient specific; however, no clear cutoff as defined by mean fluorescence intensity is evident.

Transfusion-related acute lung injury: a preventable syndrome?

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related morbidity and mortality. Recent insights into the pathophysiology of TRALI have led to various preventive strategies. Strategies in donor management range from antibody testing of sensitized donors to the deferral of female plasma donors altogether. However, knowledge on the efficacy of measures to reduce TRALI is limited. In addition, the various measures may lead to a substantial loss of donors, hampering steady blood supply. Thereby, consensus among countries and blood-collecting facilities regarding the optimal strategy to prevent TRALI is lacking. In this review, the advantages and disadvantages of various preventive measures to prevent TRALI are discussed, related to both patient factors as well as blood component-processing strategies, including transfusion policy, donor management and practices of preparation and storage conditions of blood components.

Reduction of Fresh Frozen Plasma Requirements by Perioperative Point-of-Care Coagulation Management with Early Calculated Goal-Directed Therapy

BACKGROUND: Massive bleeding and transfusion of packed red blood cells (PRBC), fresh frozen plasma (FFP) and platelets are associated with increased morbidity, mortality and costs. PATIENTS AND METHODS: We analysed the transfusion requirements after implementation of point-of-care (POC) coagulation management algorithms based on early, calculated, goal-directed therapy with fibrinogen concentrate and prothrombin complex concentrate (PCC) in different perioperative settings (trauma surgery, visceral and transplant surgery (VTS), cardiovascular surgery (CVS) and general and surgical intensive care medicine) at 3 different hospitals (AUVA Trauma Centre Salzburg, University Hospital Innsbruck and University Hospital Essen) in 2 different countries (Austria and Germany). RESULTS: In all institutions, the implementation of POC coagulation management algorithms was associated with a reduction in the transfusion requirements for FFP by about 90% (Salzburg 94%, Innsbruck 88% and Essen 93%). Furthermore, PRBC transfusion was reduced by 8.4-62%. The incidence of intraoperative massive transfusion (≥10 U PRBC) could be more than halved in VTS and CVS (2.56 vs. 0.88%; p < 0.0001 and 2.50 vs. 1.06%; p = 0.0007, respectively). Platelet transfusion could be reduced by 21-72%, except in CVS where it increased by 115% due to a 5-fold increase in patients with dual antiplatelet therapy (2.7 vs. 13.7%; p < 0.0001). CONCLUSIONS: The implementation of perioperative POC coagulation management algorithms based on early, calculated, goal-directed therapy with fibrinogen concentrate and PCC is associated with a reduction in the transfusion requirements for FFP, PRBC and platelets as well as with a reduced incidence of massive transfusion. Thus, the limited blood resources can be used more efficiently.

Implementation and outcomes of a transfusion-related acute lung injury surveillance programme and study of HLA/HNA alloimmunisation in blood donors

BACKGROUND

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-associated mortality. Antibodies against human leucocyte antigens (HLA) and human neutrophil antigens (HNA) are often detected in the implicated donors. We investigated the incidence and aetiology of TRALI in Lombardy. Moreover, we determined the rate of HLA and HNA alloimmunisation and the HNA genotype in a cohort of local blood donors.

MATERIALS AND METHODS

During a 2-year observational study in eight blood transfusion services, suspected TRALI cases were collected and characterised by means of HLA and HNA antibody screening of implicated donors, donor/recipient cross-matching and HLA/HNA molecular typing. In addition, 406 Italian donors were evaluated for alloimmunisation and in 102 of them HNA gene frequencies were determined.

RESULTS

Eleven cases were referred to the central laboratory, of whom three were diagnosed as having TRALI, seven as having possible TRALI and one as having transfusion-associated circulatory overload. Seven TRALI cases were immune-mediated whereas in three we did not find either alloantibodies in implicated donors or a positive reaction in the cross-match. The most frequently implicated blood component was red blood cells (in 5 males and in 1 female), whereas four cases of TRALI were associated with transfusion of fresh-frozen plasma (in 3 females and in 1 male). The frequency of reported TRALI/possible TRALI cases was 1:82,000 for red blood cells and 1:22,500 for fresh-frozen plasma. No cases were observed for platelets. Overall, the frequency of HLA or HNA alloimmunisation in blood donors was 29% for females and 7% for males. The latter could be related, at least in part, to natural antibodies. HNA gene frequencies showed that HNA-1b is more frequent than HNA-1a in our sample of donors.

DISCUSSION

The recently adopted national policy to prevent TRALI, i.e. using only plasma donated by males, would have had a positive impact in our setting.

Fresh and stored red blood cell transfusion equivalently induce subclinical pulmonary gas exchange deficit in normal humans

BACKGROUND

Transfusion can cause severe acute lung injury, although most transfusions do not seem to induce complications. We tested the hypothesis that transfusion can cause mild pulmonary dysfunction that has not been noticed clinically and is not sufficiently severe to fit the definition of transfusion-related acute lung injury.

METHODS

We studied 35 healthy, normal volunteers who donated 1 U of blood 4 weeks and another 3 weeks before 2 study days separated by 1 week. On study days, 2 U of blood were withdrawn while maintaining isovolemia, followed by transfusion with either the volunteer's autologous fresh red blood cells (RBCs) removed 2 hours earlier or their autologous stored RBCs (random order). The following week, each volunteer was studied again, transfused with the RBCs of the other storage duration. The primary outcome variable was the change in alveolar to arterial difference in oxygen partial pressure (AaDo(2)) from before to 60 minutes after transfusion with fresh or older RBCs.

RESULTS

Fresh RBCs and RBCs stored for 24.5 days equally (P = 0.85) caused an increase of AaDo(2) (fresh: 2.8 mm Hg [95% confidence interval: 0.8-4.8; P = 0.007]; stored: 3.0 mm Hg [1.4-4.7; P = 0.0006]). Concentrations of all measured cytokines, except for interleukin-10 (P = 0.15), were less in stored leukoreduced (LR) than stored non-LR packed RBCs; however, vascular endothelial growth factor was the only measured in vivo cytokine that increased more after transfusion with LR than non-LR stored packed RBCs. Vascular endothelial growth factor was the only cytokine tested with in vivo concentrations that correlated with AaDo(2).

CONCLUSION

RBC transfusion causes subtle pulmonary dysfunction, as evidenced by impaired gas exchange for oxygen, supporting our hypothesis that lung impairment after transfusion includes a wide spectrum of physiologic derangements and may not require an existing state of altered physiology. These data do not support the hypothesis that transfusion of RBCs stored for >21 days is more injurious than that of fresh RBCs.

The role of HLA antibodies in allogeneic SCT: is the 'type-and-screen' strategy necessary not only for blood type but also for HLA?

The role of HLA antibodies in SCT has drawn increasing attention because of the significantly increased number of patients who receive HLA-mismatched SCT, including cord blood transplantation, haploidentical SCT and unrelated SCT. Technical advancements in the methods of HLA Ab testing have realized rapid, accurate and objective identification, as well as quantification of specific HLA antibodies. Recent clinical studies have suggested that the presence of donor-specific HLA antibodies (DSA) in patients is associated with graft failure in HLA-mismatched SCT when the above-listed stem cell sources are used and results in different impacts. Of note, most of the 'HLA-matched' unrelated SCT actually involve HLA mismatches in HLA-DP and the presence of antibodies against this locus has been reported to be associated with graft failure. Thus, HLA Ab should be examined as a work-up for all patients who undergo SCT from 'alternative donors.' The simplest route for preventing HLA Ab-mediated graft failure in Ab-positive patients is to avoid donors who possess the target Ag of HLA antibodies. If SCT from such donors must be performed, treatment for DSA before SCT may improve the chances of successful donor engraftment.

The pro-inflammatory effects of platelet contamination in plasma and mitigation strategies for avoidance

BACKGROUND AND OBJECTIVES

Plasma and platelet concentrates are disproportionately implicated in transfusion-related acute lung injury (TRALI). Platelet-derived pro-inflammatory mediators, including soluble CD40 ligand (sCD40L), accumulate during storage. We hypothesized that platelet contamination induces sCD40L generation that causes neutrophil [polymorphonuclear leucocyte (PMN)] priming and PMN-mediated cytotoxicity.

MATERIALS AND METHODS

Plasma was untreated, centrifuged (12,500 g) or separated from leucoreduced whole blood (WBLR) prior to freezing. Platelet counts and sCD40L concentrations were measured 1-5 days post-thaw. The plasma was assayed for PMN priming activity and was used in a two-event in vitro model of PMN-mediated human pulmonary microvascular endothelial cell (HMVEC) cytotoxicity.

RESULTS

Untreated plasma contained 42±4·2×10(3)/μl platelets, which generated sCD40L accumulation (1·6-eight-fold vs. controls). Priming activity and HMVEC cytotoxicity were directly proportional to sCD40L concentration. WBLR and centrifugation reduced platelet and sCD40L contamination, abrogating the pro-inflammatory potential.

CONCLUSION

Platelet contamination causes sCD40L accumulation in stored plasma that may contribute to TRALI. Platelet reduction is potentially the first TRALI mitigation effort in plasma manufacturing.

TRALI-new challenges for histocompatibility and immunogenetics in transfusion medicine

Antibodies against human leukocyte antigens (HLAs) have long been associated with transfusion-related acute lung injury (TRALI). In contrast to febrile transfusion reactions and refractoriness to platelet transfusions in immunized patients, the causative antibodies in TRALI are present in the transfused blood component, i.e. they are formed by the blood donor and not by the recipient. Consequently, blood components with high plasma volume are particularly associated with TRALI. In addition to antibodies against HLAs, antibodies directed against human neutrophil antigens (HNAs) present in the plasma of predominantly multiparous female blood donors can induce severe TRALI reactions. Especially, antibodies to HLA class II and HNA-3a antigens can induce severe or even fatal ALI in critically ill patients. Over the last decade, the clinical importance of TRALI as major cause for severe transfusion-related morbidities has led to the establishment of new guidelines aimed at preventing this condition, including routine testing for HLA and -HNA antibodies for plasma donors with a history of allogeneic sensitization. This, in turn, poses new challenges for close collaboration between blood transfusion centers and histocompatibility and immunogenetics laboratories, for sensitive and specific detection of the relevant antibodies.

Benefit of transfusion-related acute lung injury risk-minimization measures--German haemovigilance data (2006-2010)

OBJECTIVE

Based on the frequency of immune-mediated and non-immune-mediated transfusion-related acute lung injury (TRALI), the effect of risk-minimization measures was evaluated during a period of 5 years (2006-2010). Risk-minimization measures were implemented in 2008/2009, consisting of exclusion of female donors with a history of pregnancy or exclusion of female donors with human leucocyte antigen (HLA)/human neutrophil alloantigen (HNA) antibodies.

METHODS

TRALI was confirmed according to the criteria of the International Haemovigilance Network. Based upon the results of donor testing of white-blood-cell antibodies (WBC-Ab) against HLA or HNAs, confirmed cases were classified as immune- or non-immune-mediated TRALI. Reporting rates were calculated on the basis of the annually transfused blood components, and pre- and post-implementation periods were compared.

RESULTS

In total, 60 immune-mediated (75%) and 20 non-immune-mediated (25%) TRALI reactions were confirmed. A total of 68 (64 women and four men) donors were involved: seven red-blood-cell concentrates donors (13%), six platelet concentrate donors (10%), and 48 fresh frozen plasma (FFP) donors (77%). The reporting rate of immune-mediated TRALI caused by FFP decreased continuously; from 12·71 per million units in 2006/2007 to 6·81 per million units in 2008/2009 and no case in 2010.

CONCLUSION

The comparison of the pre- and the post-implementation period demonstrated a significantly reduced risk of TRALI events comparing 2006/2007 with 2010 (P-value: <0·01). Furthermore, no case of TRALI-induced fatality occurred after the implementation of risk-minimization measures.

[The immunological conflict in the transfusion-related acute lung injury or TRALI]

Despite its underrated incidence, transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related morbidity and mortality worldwide. The pulmonary edema in TRALI occurs in the course of the transfusion of apheresis products or erythrocyte concentrates. Its pathogenesis is attributed to the infusion of donor antibodies that recognize leucocyte antigens in the transfused host, with subsequent sequestration of leucocytes in the pulmonary vessels. It is also associated with the passive transfer of lipids and other biological response modifiers that accumulate during the storage or processing of blood components. The innate immunity and inflammatory kinins are key components. The knowledge of its etiopathogenesis must come into play for improving prevention and diagnosis and for application of adapted care of the patient.