HLA class II antibodies in transfusion-related acute lung injury

Absence of blood donors' anti-SARS-CoV-2 antibodies in pre-storage leukoreduced red blood cell units indicates no role of passive immunity for blood recipients

Transfer of vaccine antibodies (Ab) from donors to recipients after transfusion of packed red blood cells (RBC) is supposed, thus affecting the recipients' response to vaccinations. In this prospective study, SARS-CoV-2 IgG level in donors' serum and RBC supernatant samples was assessed. Among 346 subjects, 280 were referred for hyperimmune plasma donation and 30 for whole blood donations. All units underwent pre-storage filtration, and residual plasma volume was 18±18 mL. The mean total IgG and IgM levels were 171.43 ± 48.79 and 11.43 ± 10.69 mg/dL respectively, with significant reduction after plasma depletion and filtration (IgG 5.86 ± 5.2 and IgM 1.43 ± 3.78, p < 0.05). Anti-COVID-19 Ab were identified in serum of 28/30 (93.5%) blood donors but were absent in all blood units. The mean value of anti-SARS-CoV-2 IgG level in donors' serum samples and in RBC units was 8.80 S/C (range 0.01-23.4) and 0.11 (range 0.01-0.37) S/C, respectively (p<0.05). This study shows deplasmation and leukodepletion of RBC units ensured removal of IgG content and no red blood cell unit was reactive for anti-COVID-19 antibodies even from donors with high serum titre. These findings demonstrate that deplasmated and leukodepleted RBCs are not to be considered blood products containing substantial amounts of immune globulin, and differently from other blood derived-products containing Ab, transfusions with deplasmated and leukodepleted RBCs do not require delayed vaccinations and a revision of current recommendations is requested.

Identifying new safety risk of human serum albumin: a retrospective study of real-world data

Objective: To mine and analyze the adverse reaction signals of human serum albumin (HSA) using the FDA adverse event reporting system (FAERS) database for the safe clinical use of this drug. Methods: Data cleaning and analysis of adverse event reports in the FAERS database for a total of 76 quarters from Q1 2004 to Q4 2022 were performed using the reporting odds ratio (ROR), Medicines and Healthcare Products Regulatory Agency (MHRA), and Bayesian confidence propagation neural network (BCPNN). Gender-differentiated signal detection was used to investigate the gender differences in the occurrence of HSA adverse events. Results: Through a combination of three methods, a total of 535 adverse event reports were identified. These reports involved 1,885 cases of adverse reactions, with respiratory, thoracic, and mediastinal disorders, as well as general disorders and administration site conditions, as the most common. One noteworthy new signal was the occurrence of transfusion-related acute lung injury. Additionally, gender-differentiated signals were present, with females experiencing paraesthesia, hypertension, pulmonary oedema, loss of consciousness, and vomiting. Conclusion: This study has revealed that HSA poses a risk of causing transfusion-related acute lung injury. It has also been observed that adverse reactions, including paraesthesia, hypertension, pulmonary oedema, loss of consciousness, and vomiting, are more prevalent in females. These findings should be taken into account when using HSA in a clinical setting.

Transfusion-Related Acute Lung Injury Caused by HLA-II Antibodies: A Case Report

OBJECTIVE

The aim of this study was to retrospectively analyze the etiology of a case of suspected transfusion-related acute lung injury (TRALI) occurring after blood transfusion.

METHODS

The clinical symptoms, signs, imaging examinations, and laboratory test results of a patient with suspected TRALI after blood transfusion were retrospectively analyzed, and human leukocyte antigen (HLA) genotyping of the patient and HLA antibodies of the plasma donors were performed.

RESULTS

The clinical manifestations of the patient were consistent with those of TRALI after blood transfusion. This TRALI was treated by timely ventilator support. The patient results of high-resolution HLA genotyping were HLA-A* 01:01, 11:01; HLA-B* 15:02, 37:01; HLA-C* 06:02, 08:01; DRB1* 10:01, 12:02; DRB3* 03:01, 03:01; DQA1* 01:05, 06:01; DQB1* 03:01, 05:01; DPA1* 01:03, 02:01; and DPB1* 02:01, 09:01. Of the 6 plasma donors tested, 3 were found to have HLA-II antibodies, which were HLA-DPA1*01:03, HLA-DQB1*03:01, and HLA-DQB1*03:01 antibodies.

CONCLUSION

We described a case of TRALI caused by HLA-DQB1*03:01 antibody and DPA1*01:03 antibody.

Prevalence of leucocyte antibodies in non-transfused male and female platelet apheresis donors

OBJECTIVES

In our study group of Thai PLT apheresis donors, we assessed the prevalence of anti-leucocyte antibodies.

BACKGROUND

Antibodies against human leucocyte antigens (anti-HLA), neutrophil antigens (anti-HNA), and major histocompatibility complex class I related chain A (anti-MICA) in blood products can lead to transfusion-related acute lung injury (TRALI). To reduce the risk of TRALI, some blood centres are implementing strategies based on screening platelet (PLT) apheresis donors for the presence of anti-leucocyte antibodies.

METHODS/MATERIALS

Blood samples were collected from non-transfused individuals, 340 males and 63 females (50 nulliparous and 13 parous). Anti-HLA class I and II and anti-MICA were analysed using the Luminex assay, and anti-HNA-3 was detected using the granulocyte agglutination test.

RESULTS

Anti-HLA was found in 14 of 403 subjects (3.5%). Ten subjects (2.5%) tested positive for HLA class I, 2 (0.5%) for HLA class II, and 2 (0.5%) for both HLA class I and HLA class II. Anti-HLA class I or II were detected in 2 of 13 (15.4%) parous females and only anti-HLA class I was found in 4 (8.0%) nulliparous females. Six of 327 subjects tested (1.8%), all males, were positive for anti-MICA. Anti-HNA-3 was not found in any of the 403 individuals.

CONCLUSIONS

Screening for anti-HLA class I and II should be implemented for Thai PLT apheresis donors. Although immunisation against HNA and MICA seems to be a rare event in Thais, further work is necessary to decide whether our PLT apheresis donors should be screened for HNA and MICA antibodies.

Transfusion-Related Acute Lung Injury During Liver Transplantation: A Scoping Review

Liver transplantation is associated with significant blood loss, often requiring massive blood product transfusion. Transfusion-related acute lung injury (TRALI) is a devastating cause of transfusion-related deaths. While reports have investigated the general incidence of TRALI, the incidence of TRALI specifically following transfusion during liver transplant remains unclear. This scoping review summarizes existing literature regarding TRALI during the liver transplantation perioperative period. Databases were searched for all articles and abstracts reporting on TRALI after liver transplantation. Data collected included number of patients studied, patient characteristics, incidences of TRALI, TRALI characteristics, and patient outcomes. The primary outcome investigated was the incidence of TRALI in the setting of liver transplantation. Thirteen full-text citations were included in this review. The incidence of TRALI post-liver transplant was 0.68% (65 of 9,554). Based on reported transfusion data, patients diagnosed with TRALI received an average of 10.92 ± 10.81 units of packed red blood cells (pRBC), 20.05 ± 15.72 units of fresh frozen plasma, and 5.75 ± 10.00 units of platelets. Common interventions following TRALI diagnosis included mechanical ventilation with positive end-expiratory pressure, inhaled high-flow oxygen, inhaled pulmonary vasodilator, and pharmacologic treatment using pressors or inotropes, corticosteroids, or diuretics. Based on reported mortality data, 26.67% of patients (12 of 45) diagnosed with TRALI died during the postoperative period. This scoping review underscores the importance of better understanding the incidence and presentation of TRALI after liver transplant surgery. The clinical implications of these results warrant the development of identification and management strategies for liver transplant patients at increased risk for developing TRALI.

A consensus redefinition of transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a serious complication of blood transfusion and is among the leading causes of transfusion-related morbidity and mortality in most developed countries. In the past decade, the pathophysiology of this potentially life-threatening syndrome has been increasingly elucidated, large cohort studies have identified associated patient conditions and transfusion risk factors, and preventive strategies have been successfully implemented. These new insights provide a rationale for updating the 2004 consensus definition of TRALI.

STUDY DESIGN AND METHODS

An international expert panel used the Delphi methodology to develop a redefinition of TRALI by modifying and updating the 2004 definition. Additionally, the panel reviewed issues related to TRALI nomenclature, patient conditions associated with acute respiratory distress syndrome (ARDS) and TRALI, TRALI pathophysiology, and standardization of reporting of TRALI cases.

RESULTS

In the redefinition, the term "possible TRALI" has been dropped. The terminology of TRALI Type I (without an ARDS risk factor) and TRALI Type II (with an ARDS risk factor or with mild existing ARDS) is proposed. Cases with an ARDS risk factor that meet ARDS diagnostic criteria and where respiratory deterioration over the 12 hours before transfusion implicates the risk factor as causative should be classified as ARDS. TRALI remains a clinical diagnosis and does not require detection of cognate white blood cell antibodies.

CONCLUSIONS

Clinicians should report all cases of posttransfusion pulmonary edema to the transfusion service so that further investigation can allow for classification of such cases as TRALI (Type I or Type II), ARDS, transfusion-associated circulatory overload (TACO), or TRALI or TACO cannot distinguish or an alternate diagnosis.

Severe Transfusion-related Acute Lung Injury in the Intensive Care Unit Secondary to Transfusion of Fresh Frozen Plasma

Transfusion-related acute lung injury (TRALI) is a life-threatening complication of transfusion of blood products. A case of severe TRALI secondary to infusion of fresh frozen plasma in the intensive care unit is discussed. Additionally, the aetiology and pathogenesis of this relatively under-diagnosed and under-reported clinical entity is reviewed. It is our conclusion that proper diagnosis and reporting is necessary for prompt and appropriate treatment of the patient and to prevent additional reactions in other patients.

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

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

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.

T regulatory cells and dendritic cells protect against transfusion-related acute lung injury via IL-10

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related fatalities and is characterized by acute respiratory distress following blood transfusion. Donor antibodies are frequently involved; however, the pathogenesis and protective mechanisms in the recipient are poorly understood, and specific therapies are lacking. Using newly developed murine TRALI models based on injection of anti-major histocompatibility complex class I antibodies, we found CD4⁺CD25⁺FoxP3⁺ T regulatory cells (Tregs) and CD11c⁺ dendritic cells (DCs) to be critical effectors that protect against TRALI. Treg or DC depletion in vivo resulted in aggravated antibody-mediated acute lung injury within 90 minutes with 60% mortality upon DC depletion. In addition, resistance to antibody-mediated TRALI was associated with increased interleukin-10 (IL-10) levels, and IL-10 levels were found to be decreased in mice suffering from TRALI. Importantly, IL-10 injection completely prevented and rescued the development of TRALI in mice and may prove to be a promising new therapeutic approach for alleviating lung injury in this serious complication of transfusion.

Evaluation of a new microbeads assay for granulocyte antibody detection

BACKGROUND

To reduce the risk of transfusion-associated acute lung injury (TRALI), a high number of plasma donors were tested for human leukocyte antigen (HLA) and human neutrophil antigen (HNA) antibodies. For HNA antibody detection, the gold standard is a combination of the granulocyte immunofluorescence test (GIFT) and the granulocyte agglutination test (GAT). However, these tests are not suitable for a high-throughput of samples.

STUDY DESIGN AND METHODS

To evaluate the new generation of the LABScreen MULTI assay (One Lambda, Inc.), which has special new beads for all the known HNA specificities, including HNA-3a, 97 sera samples containing well-defined HNA antibodies were used. For background testing, we used 91 samples from plasma donors previously identified by GAT, GIFT, and the monoclonal antibody-specific immobilization of granulocyte antigens (MAIGA) assay.

RESULTS

Compared with previous tests, the new LABScreen MULTI assay was highly specific for the HNA-1a, HNA-1b, HNA-2, and HNA-3a antibody specificities required to prevent TRALI. Ninety-eight percent of the HNA-1a, HNA-1b, and HNA-2 antibodies could be detected as true positive; and 90% of the HNA-3a antibodies were recognized correctly as positive. False-positive reactions were identified in 5.5% of samples that previously tested negative.

CONCLUSION

The detection of HNA-3a antibody specificities could be integrated into the new LABScreen MULTI assay; however, we detected only 90%. In addition, we detected further HNA antibodies, such as HNA-1c, HNA-1d, and some HNA-3b and HNA-4a antibodies. The new generation of LABScreen MULTI is a great step toward feasible high-throughput testing for HNA antibodies. Nevertheless, GIFT and GAT remain the gold-standard methods for the differentiation of rare and currently unknown HNA specificities.

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.

The Epidemiology of Transfusion-related Acute Lung Injury Varies According to the Applied Definition of Lung Injury Onset Time

RATIONALE

Research that applies an unreliable definition for transfusion-related acute lung injury (TRALI) may draw false conclusions about its risk factors and biology. The effectiveness of preventive strategies may decrease as a consequence. However, the reliability of the consensus TRALI definition is unknown.

OBJECTIVES

To prospectively study the effect of applying two plausible definitions of acute respiratory distress syndrome onset time on TRALI epidemiology.

METHODS

We studied 316 adults admitted to the intensive care unit and transfused red blood cells within 24 hours of blunt trauma. We identified patients with acute respiratory distress syndrome, and defined acute respiratory distress syndrome onset time two ways: (1) the time at which the first radiographic or oxygenation criterion was met, and (2) the time both criteria were met. We categorized two corresponding groups of TRALI cases transfused in the 6 hours before acute respiratory distress syndrome onset. We used Cohen's kappa to measure agreement between the TRALI cases and implicated blood components identified by the two acute respiratory distress syndrome onset time definitions. In a nested case-control study, we examined potential risk factors for each group of TRALI cases, including demographics, injury severity, and characteristics of blood components transfused in the 6 hours before acute respiratory distress syndrome onset.

MEASUREMENTS AND MAIN RESULTS

Forty-two of 113 patients with acute respiratory distress syndrome were TRALI cases per the first acute respiratory distress syndrome onset time definition and 63 per the second definition. There was slight agreement between the two groups of TRALI cases (κ = 0.16; 95% confidence interval, -0.01 to 0.33) and between the implicated blood components (κ = 0.15, 95% confidence interval, 0.11-0.20). Age, Injury Severity Score, high plasma-volume components, and transfused plasma volume were risk factors for TRALI when applying the second acute respiratory distress syndrome onset time definition but not when applying the first definition.

CONCLUSIONS

The epidemiology of TRALI varies when applying two plausible definitions of acute respiratory distress syndrome onset time to severely injured trauma patients. A TRALI definition that standardizes acute respiratory distress syndrome onset time might improve reliability and align efforts to understand epidemiology, biology, and prevention.

Accumulation of CD62P during storage of apheresis platelet concentrates and the role of CD62P in transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-associated morbidity and mortality. Activated platelets have important roles in TRALI and CD62P was identified to be an important indicator of platelet activation. However, the precise roles of CD62P in TRALI have remained elusive. The present study assessed CD62P accumulation during storage of apheresis platelet concentrates (A‑Plts) and established a mouse model of TRALI to further investigate the roles of CD62P in TRALI. The results showed that the CD62P concentration in A‑Plts was increased with the storage time. Mice were treated with monoclonal major histocompatibility complex (MHC)‑1 antibody to induce TRALI. The murine model of TRALI was successfully established as evidenced by pulmonary oedema, accompanied by decreased clearance of bronchoalveolar lavage fluid (BALF), increased pulmonary and systemic inflammation, elevated lung myeloperoxidase (MPO) activity as well as increased pulmonary and systemic coagulation in the TRALI group compared with those in the control group. To further determine the role of CD62P in TRALI, mice were treated with anti‑CD62P antibody to knockdown CD62P in vivo. It was found that pulmonary oedema, BALF clearance, pulmonary and systemic inflammation, MPO activity as well as pulmonary and systemic coagulation were decreased in the TRALI + anti‑CD62P antibody group compared with those in the TRALI + isotype antibody group. The present study supported the notion that CD62P is involved in mediating TRALI and may provide an important molecular basis for enhancing the clinical safety and effectiveness of platelet transfusion.

Antibody-mediated transfusion-related acute lung injury; from discovery to prevention

Transfusion-related acute lung injury (TRALI), a syndrome of respiratory distress caused by blood transfusion, is the leading cause of transfusion-related mortality. The majority of TRALI cases have been related to passive infusion of human leucocyte antigen (HLA) and human neutrophil antigen (HNA) antibodies in donor blood. In vitro, ex vivo and in vivo animal models have provided insight in TRALI pathogenesis. The various classes of antibodies implicated in TRALI appear to have different pathophysiological mechanisms for the induction of TRALI involving endothelial cells, neutrophils, monocytes and, as very recently has been discovered, lymphocytes. The HLA and HNA-antibodies are found mainly in blood from multiparous women as they have become sensitized during pregnancy. The incidence of TRALI has decreased rapidly following the introduction of a male-only strategy for plasma donation. This review focuses on pre-clinical and clinical studies investigating the pathophysiology of antibody-mediated TRALI.

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).

Experimental prestorage filtration removes antibodies and decreases lipids in RBC supernatants mitigating TRALI in vivo

Transfusion-related acute lung injury (TRALI) remains a significant cause of transfusion-related mortality with red cell transfusion. We hypothesize that prestorage filtration may reduce proinflammatory activity in the red blood cell (RBC) supernatant and prevent TRALI. Filters were manufactured for both small volumes and RBC units. Plasma containing antibodies to human lymphocyte antigen (HLA)-A2 or human neutrophil antigen (HNA)-3a was filtered, and immunoglobulins and specific HNA-3a and HLA-2a neutrophil (PMN) priming activity were measured. Antibodies to OX27 were added to plasma, and filtration was evaluated in a 2-event animal model of TRALI. RBC units from 31 donors known to have antibodies against HLA antigens and from 16 antibody-negative controls were filtered. Furthermore, 4 RBC units were drawn and underwent standard leukoreduction. Immunoglobulins, HLA antibodies, PMN priming activity, and the ability to induce TRALI in an animal model were measured. Small-volume filtration of plasma removed >96% of IgG, antibodies to HLA-A2 and HNA-3a, and their respective priming activity, as well as mitigating antibody-mediated in vivo TRALI. In RBC units, experimental filtration removed antibodies to HLA antigens and inhibited the accumulation of lipid priming activity and lipid-mediated TRALI. We conclude that filtration removes proinflammatory activity and the ability to induce TRALI from RBCs and may represent a TRALI mitigation step.

Transfusion-related acute lung injury: advances in understanding the role of proinflammatory mediators in its genesis

Transfusion-related acute lung injury (TRALI) is the most common cause of serious morbidity and mortality due to hemotherapy. The pathogenesis is the result of two events: the first related to the recipient's clinical condition, predisposing to acute lung injury (ALI) through neutrophil or polymorphonuclear leukocyte sequestration, and the second being the infusion of antibodies or mediators that activate these adherent polymorphonuclear neutrophils, resulting in endothelial damage, capillary leak and ALI. TRALI is most prevalent in the critically ill, although many of these cases are termed ALI. Although mitigation strategies, such as the use of male-only plasma, have decreased the number of TRALI cases and deaths, TRALI still occurs. This review will detail the pathophysiology of TRALI, provide insight into newer areas of research and critically assess current practices to mitigate TRALI and improve transfusion safety.

[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.

Transfusion-related acute lung injury: a clinical review

Three decades ago, transfusion-related acute lung injury (TRALI) was considered a rare complication of transfusion medicine. Nowadays, the US Food and Drug Administration acknowledge the syndrome as the leading cause of transfusion-related mortality. Understanding of the pathogenesis of TRALI has resulted in the design of preventive strategies from a blood-bank perspective. A major breakthrough in efforts to reduce the incidence of TRALI has been to exclude female donors of products with high plasma volume, resulting in a decrease of roughly two-thirds in incidence. However, this strategy has not completely eradicated the complication. In the past few years, research has identified patient-related risk factors for the onset of TRALI, which have empowered physicians to take an individualised approach to patients who need transfusion.

Ninety-six suspected transfusion related acute lung injury cases: Investigation findings and clinical outcome

Transfusion related acute lung injury (TRALI) is one of the complications of blood transfusion and can result in major morbidity or mortality. The diagnosis depends upon the application of strict clinical criteria defining acute lung injury (ALI) and a temporal relationship to blood transfusion. We present the clinical and immunogenetic findings of 96 suspected TRALI cases investigated between 1996 and 2004. During this time period the national haemovigilance scheme (UK) defined TRALI as a reaction occurring either during or within 24 h of blood transfusion. Using clinical, laboratory and post mortem evidence, 64/96 cases could be defined as TRALI in our series. Sensitive techniques were employed to screen for HLA class I, class II and granulocyte specific antibodies in donor serum. Donor derived antibodies were detected in 58/64 (90%) of cases. Recipient derived DNA or cells were not always available but incompatibility was confirmed by the presence of the cognate antigen on recipient leucocytes or by crossmatching in 47/64 (73%) of cases. Cases referred prior to 2001 were not tested for HLA class II antibodies. By applying strict clinical criteria and using sensitive techniques a white blood cell antibody mediated immunological pathophysiology can be implicated in the majority TRALI cases.

The association between red blood cell and platelet transfusion and subsequently developing idiopathic pneumonia syndrome after hematopoietic stem cell transplantation

BACKGROUND

Blood transfusions are common during hematopoietic stem cell transplantation (HSCT) and may contribute to lung injury.

STUDY DESIGN AND METHODS

This study examined the associations between red blood cell (RBC) and platelet (PLT) transfusions and idiopathic pneumonia syndrome (IPS) among 914 individuals who underwent myeloablative allogeneic HSCT between 1997 and 2001. Patients received allogeneic blood transfusions at their physicians' discretion. RBCs, PLTs, and a composite of "other" transfusions were quantified as the sum of units received each 7-day period from 6 days before transplant until IPS onset, death, or Posttransplant Day 120. RBC and PLT transfusions were modeled as separate time-varying exposures in proportional hazards models adjusted for IPS risk factors (age, baseline disease, irradiation dose) and other transfusions. Timing of PLT transfusion relative to myeloid engraftment and PLT ABO blood group (match vs. mismatch) were included as potential interaction terms.

RESULTS

Patients received a median of 9 PLT and 10 RBC units. There were 77 IPS cases (8.4%). Each additional PLT unit transfused in the prior week was associated with 16% higher IPS risk (hazard ratio, 1.16; 95% confidence interval, 1.09-1.23; p < 0.001). Recent RBC and PLT transfusions were each significantly associated with greater risk of IPS when examined without the other; only PLT transfusions retained significance when both exposures were included in the model. The PLT association was not modified by engraftment or ABO mismatch.

CONCLUSION

PLT transfusions are associated with greater risk of IPS after myeloablative HSCT. RBCs may also contribute; however, these findings need confirmation.

Approach of using established and new laboratory tests to more comprehensively investigate noninfectious and nonhemolytic transfusion reactions--along with the experience in Japan

BACKGROUND AND OBJECTIVES

Noninfectious and nonhaemolytic transfusion reactions are the most common type of transfusion reactions. Several new tests have been made, helping diagnosis and understanding of their pathogenesis. This manuscript provides a review of the literature on currently available tests in association with the approach in Japan.

MATERIALS & METHODS

Primarily by using key words, more than 100 pertinent articles in the Medline database were identified and reviewed.

RESULTS

Numbers of laboratory tests are available including those for plasma protein levels, plasma protein antibodies, leucocyte and platelet antibodies, serum N-terminal-pro-brain natriuretic peptide levels, serum tryptase levels and genetic microchimerism. Cross-match tests, such as basophil activation test and neutrophil activation test, are also available to determine a causal relationship between the reaction and transfusion.

CONCLUSIONS

Several tests should help to confirm diagnosis and determine causal relationship between adverse reactions and transfusion and to gain an insight into the mechanism of the reaction in some cases, although some of the recently developed tests have not been completely validated.

Pulmonary complications of transfused blood components

Three transfusion complications are responsible for the majority of the morbidity and mortality in hospitalized patients. This article discusses the respiratory complications associated with these pathophysiologic processes, including definitions, diagnosis, mechanism, incidence, risk factors, clinical management, and strategies for prevention. It also explores how different patient populations and different blood components differentially affect the risk of these deadly transfusion complications. Lastly, the article discusses how health care providers can risk stratify individual patients or patient populations to determine whether a given transfusion is more likely to benefit or harm the patient based on the transfusion indication, risk, and expected result.

Therapeutic options for transfusion related acute lung injury; the potential of the G2A receptor

Priming of polymorphonuclear leukocytes (PMNs) enhances their adhesion to endothelium, the release of their granule content and their production of reactive oxygen species. These effects are etiological in transfusion related acute lung injury (TRALI) and many clinically important mediators of TRALI prime PMNs. A priming activity that develops over time in stored blood products has been shown to be due to the accumulation of lysophospatidylcholines (lyso-PCs) and has been found to be related clinically to TRALI. Lyso- PCs prime PMNs activating the G2A receptor and several inhibitors of this receptor, which could potentially be therapeutic in TRALI, have been identified. Recent work has described early steps in the signaling from the G2A receptor which has revealed potential targets for novel antagonists of lyso-PC mediated priming via G2A. Additionally, characterization of the process by which lyso-PCs are generated in stored blood products could allow development of inhibitors and additive solutions to block their formation in the first place.

Transfusion reactions: newer concepts on the pathophysiology, incidence, treatment, and prevention of transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. TRALI presents as acute lung injury (ALI) within 6 hours after blood product transfusion. Diagnosing TRALI requires a high index of suspicion, and the exclusion of circulatory overload or other causes of ALI. The pathophysiology of TRALI is incompletely understood, but in part involves transfusion of certain anti-neutrophil antibodies, anti-HLA antibodies, or other bioactive substances, into susceptible recipients. Recent studies have identified both recipient and transfusion risk factors for the development of TRALI. This article describes these TRALI risk factors, as well as diagnosis, treatment and prevention strategies.

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.

Transfusion-related acute lung injury: Current understanding and preventive strategies

Transfusion-related acute lung injury (TRALI) is the most serious complication of transfusion medicine. TRALI is defined as the onset of acute hypoxia within 6 hours of a blood transfusion in the absence of hydrostatic pulmonary oedema. The past decades have resulted in a better understanding of the pathogenesis of this potentially life-threating syndrome. The present notion is that the onset of TRALI follows a threshold model in which both patient and transfusion factors are essential. The transfusion factors can be divided into immune and non-immune mediated TRALI. Immune-mediated TRALI is caused by the passive transfer of human neutrophil antibodies (HNA) or human leukocyte antibodies (HLA) present in the blood product reacting with a matching antigen in the recipient. Non-immune mediated TRALI is caused by the transfusion of stored cell-containing blood products. Although the mechanisms behind immune-mediated TRALI are reasonably well understood, this is not the case for non-immune mediated TRALI. The increased understanding of pathways involved in the onset of immune-mediated TRALI has led to the design of preventive strategies. Preventive strategies are aimed at reducing the risk to exposure of HLA and HNA to the recipient of the transfusion. These strategies include exclusion of "at risk" donors and pooling of high plasma volume products and have shown to reduce the TRALI incidence effectively. This review discusses the current understanding of TRALI and preventive strategies available.

Impact of a transfusion-related acute lung injury reduction strategy on apheresis platelet collections

BACKGROUND

Most blood centers in the US have implemented transfusion-related acute lung injury (TRALI) mitigation strategies for apheresis platelet (AP) donations based on theoretical impact of donor loss. The aim of this study is to determine the actual impact of a TRALI mitigation strategy in a US blood center.

STUDY DESIGN AND METHODS

Daily collection events and resulting products were retrospectively obtained before and after implementation of a TRALI reduction strategy (HLA antibody testing female AP donors four or more pregnancies) for comparison. The retention rate of reassigned donors was determined by reviewing whole blood (WB) and/or apheresis red blood cell (AR) donations post reassignment. Data were obtained to compare donor frequency and split rate from reassigned (historical data) and new AP donors.

RESULTS

Mean daily collections (27.7 vs. 30.0) and total products (12,211 vs. 12,957) were significantly higher after implementation, but the number of products/collection event was lower (1.49 vs. 1.40). Mean collections/donor/year (4.0 vs. 1.8) and split rate (36% vs. 27%) were historically higher for reassigned (n = 45) versus new AP donors (n = 1,090). Seventy-three of 112 donors (65%) testing positive for HLA antibodies returned for WB or AR donations, 31 of 45 (69%) active AP donors returned.

CONCLUSIONS

Donor loss may not be adequate to estimate impact on AP inventory, as donation characteristics may differ between new donors and those reassigned. We show successful implementation of a TRALI mitigation strategy by increasing collection goals and AP donor recruitment efforts beyond donor loss. Retaining the majority of reassigned donors is feasible.

Intravenous immunoglobulin prevents murine antibody-mediated acute lung injury at the level of neutrophil reactive oxygen species (ROS) production

Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-associated mortality that can occur with any type of transfusion and is thought to be primarily due to donor antibodies activating pulmonary neutrophils in recipients. Recently, a large prospective case controlled clinical study of cardiac surgery patients demonstrated that despite implementation of male donors, a high incidence of TRALI still occurred and suggested a need for additional interventions in susceptible patient populations. To examine if intravenous immunoglobulin (IVIg) may be effective, a murine model of antibody-mediated acute lung injury that approximates human TRALI was examined. When BALB/c mice were injected with the anti-major histocompatibility complex class I antibody 34-1-2s, mild shock (reduced rectal temperature) and respiratory distress (dyspnea) were observed and pre-treatment of the mice with 2 g/kg IVIg completely prevented these symptoms. To determine IVIg's usefulness to affect severe lung damage, SCID mice, previously shown to be hypersensitive to 34-1-2s were used. SCID mice treated with 34-1-2s underwent severe shock, lung damage (increased wet/dry ratios) and 40% mortality within 2 hours. Treatment with 2 g/kg IVIg 18 hours before 34-1-2s administration completely protected the mice from all adverse events. Treatment with IVIg after symptoms began also reduced lung damage and mortality. While the prophylactic IVIg administration did not affect 34-1-2s-induced pulmonary neutrophil accumulation, bone marrow-derived neutrophils from the IVIg-treated mice displayed no spontaneous ROS production nor could they be stimulated in vitro with fMLP or 34-1-2s. These results suggest that IVIg prevents murine antibody-mediated acute lung injury at the level of neutrophil ROS production and thus, alleviating tissue damage.

Transfusion-related Acute Lung Injury: Report of Two Cases

Transfusion-related acute lung injury (TRALI) is a severe life-threatening complication of blood transfusion, characterized by acute lung injury developing within 2–6 h of transfusion. However, TRALI is difficult to diagnose, and the initial report or suspicion of TRALI depends on close collaboration between clinical departments and transfusion centres. A total of 17 adverse post-transfusion reactions were reported to the Blood Centre of the University Hospital Ostrava as suspected TRALI between 2005 and 2010. We report two cases of serious TRALI with different pathogenetic mechanisms.

Transfusion-related acute lung injury: incidence and risk factors

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. To determine TRALI incidence by prospective, active surveillance and to identify risk factors by a case-control study, 2 academic medical centers enrolled 89 cases and 164 transfused controls. Recipient risk factors identified by multivariate analysis were higher IL-8 levels, liver surgery, chronic alcohol abuse, shock, higher peak airway pressure while being mechanically ventilated, current smoking, and positive fluid balance. Transfusion risk factors were receipt of plasma or whole blood from female donors (odds ratio = 4.5, 95% confidence interval [CI], 1.85-11.2, P = .001), volume of HLA class II antibody with normalized background ratio more than 27.5 (OR = 1.92/100 mL, 95% CI, 1.08-3.4, P = .03), and volume of anti-human neutrophil antigen positive by granulocyte immunofluoresence test (OR = 1.71/100 mL, 95% CI, 1.18-2.5, P = .004). Little or no risk was associated with older red blood cell units, noncognate or weak cognate class II antibody, or class I antibody. Reduced transfusion of plasma from female donors was concurrent with reduced TRALI incidence: 2.57 (95% CI, 1.72-3.86) in 2006 versus 0.81 (95% CI, 0.44-1.49) in 2009 per 10 000 transfused units (P = .002). The identified risk factors provide potential targets for reducing residual TRALI.

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.

Detection of granulocyte antibodies using simultaneous analysis of specific granulocyte antibodies assay (SASGA)

OBJECTIVE

Granulocyte-associated antibodies can cause several clinical granulocytopenic disorders. The monoclonal-antibody-specific immobilization of granulocyte antigens (MAIGA) is currently used as the standard assay to specify these antibodies. Here we describe an assay for specific analysis of granulocyte antibodies (SASGA) which is able to simultaneously detect and specify granulocyte IgG- and IgM-antibodies using flow cytometry.

METHODS

Bead populations with distinct fluorescence intensities were used as solid phase for immobilization of mAb. Typed granulocytes were incubated with human sera and a mix of three distinct mouse monoclonal antibodies against specific granulocyte antigens (for example CD16, CD11a, HLA class I). After cell lysis and incubation of lysate with beads, goat antibodies against human IgG and IgM antibodies were added. Seventy-one frozen sera of donors and patients previously implicated in transfusion reactions and various underlying disorders were analysed for specific granulocyte-binding antibodies using MAIGA and SASGA.

RESULTS

The SASGA assay was able to simultaneously detect granulocyte-specific antibodies for different glycoproteins. Overall, the results of MAIGA and SASGA were concordant in 92·9%. 5 sera containing anti-HNA-1b (n=2) and -HLA class I (n=3) were not detected by MAIGA, but were recognized by the SASGA. In serial dilution tests with sera containing anti-HNA-1a, -1b, -2a and HLA class I, the SASGA assay detected the antibodies at higher dilutions than MAIGA.

CONCLUSION

The SASGA assay permits reliable detection of specific granulocyte antibodies. Six distinct antibodies can be simultaneously determined. This method will potentially open the way to investigations on additional specific antibodies as it facilitates laboratory diagnosis.

Experimental models of transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is defined clinically as acute lung injury occurring within six hours of the transfusion of any blood product. It is the leading cause of transfusion-related death in the United States, but under-recognition and diagnostic uncertainty have limited clinical research to smaller case control studies. In this review we discuss the contribution of experimental models to the understanding of TRALI pathophysiology and potential therapeutic approaches. Experimental models suggest that TRALI occurs when a host, with a primed immune system, is exposed to an activating agent such as anti-leukocyte antibody or a biologic response modifier such as lysophosphatidylcholines. Recent work has suggested a critical role for platelets in antibody-based experimental models and identified potential therapeutic strategies for TRALI.