Recurrent transfusion-related acute lung injury

Predicting Acute Respiratory Distress Syndrome in Severe Blunt Trauma: The Utility of Interleukin-18

Background: In trauma, direct pulmonary injury and innate immune response activation primes the lungs for acute respiratory distress syndrome (ARDS). The inflammasome-dependent release of interleukin-18 (IL-18) was recently identified as a key mediator in ARDS pathogenesis, leading us to hypothesize that plasma IL-18 is a diagnostic predictor of ARDS in severe blunt trauma. Patients and Methods: Secondary analysis of the Inflammation and Host Response to Injury database was performed on plasma cytokines collected within 12 hours of severe blunt trauma. Trauma-related cytokines, including IL-18, were compared between patients with and without ARDS and were evaluated for association with ARDS using regression analysis. Threshold cytokine concentrations predictive of ARDS were determined using receiver-operating curve (ROC) analysis. Results: Cytokine analysis of patients without ARDS patients (n = 61) compared with patients with ARDS (n = 19) demonstrated elevated plasma IL-18 concentration in ARDS and IL-18 remained correlated with ARDS on logistic regression after confounder adjustment (p = 0.008). Additionally, ROC analysis revealed IL-18 as a strong ARDS predictor (area under the curve [AUC] = 0.83), with a threshold IL-18 value of 170 pg/mL (Youden index, 0.3). Unlike in patients without ARDS, elevated IL-18 persisted in patients with ARDS during the acute injury phase (p ≤ 0.02). Other trauma-related cytokines did not correlate with ARDS. Conclusions: In severe blunt trauma, IL-18 is a robust predictor of ARDS and remains elevated throughout the acute injury phase. These findings support the use of IL-18 as a key ARDS biomarker, promoting early identification of trauma patients at greater risk of developing ARDS. Timely recognition of ARDS and implementation of advantageous supportive care practices may reduce trauma-related ARDS morbidity and costs.

Transfusion-related Acute Lung Injury in the Perioperative Patient

Transfusion-related acute lung injury is a leading cause of death associated with the use of blood products. Transfusion-related acute lung injury is a diagnosis of exclusion which can be difficult to identify during surgery amid the various physiologic and pathophysiologic changes associated with the perioperative period. As anesthesiologists supervise delivery of a large portion of inpatient prescribed blood products, and since the incidence of transfusion-related acute lung injury in the perioperative patient is higher than in nonsurgical patients, anesthesiologists need to consider transfusion-related acute lung injury in the perioperative setting, identify at-risk patients, recognize early signs of transfusion-related acute lung injury, and have established strategies for its prevention and treatment.

Transfusion-related acute lung injury: critical neutrophil activation by anti-HLA-A2 antibodies for endothelial permeability

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a major complication of hemotherapy that may occur after the transfusion of any blood type component. Several clinical reports have suggested the presence of anti-HLA antibodies in the blood product. This study sought to examine the role of anti-HLA-A2 antibodies in polymorphonuclear neutrophil (PMN) activation and thus in endothelial permeability.

STUDY DESIGN AND METHODS

PMN activation was assessed by both nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) activity and reactive oxygen species (ROS) production. A coculture assay of EA.hy926 endothelial cells with PMNs or differentiated-PLB-985 cells, a model of neutrophil-like cells, was performed to estimate the impact of ROS on endothelial permeability.

RESULTS

Anti-HLA-A2 antibodies significantly increased PMN activation, with subsequent endothelial dysfunction. Phagocyte NADPH oxidase (NOX2) activity was shown to be involved in this process and ROS themselves were demonstrated to induce VE-cadherin cleavage and endothelial permeability.

CONCLUSION

Our data may support the existence of a critical anti-HLA-A2 antibody threshold for PMN activation, with NOX2 activity and subsequent endothelial permeability in the two-hit model of TRALI.

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.

Transfusion and Acute Respiratory Distress Syndrome: Clinical Epidemiology, Diagnosis, Management, and Outcomes

Transfusion related acute lung injury (TRALI) is a life-threatening complication of blood product transfusion. It is the leading cause of blood product transfusion related death in the USA. The syndrome is defined by hypoxemic respiratory failure with bilateral infiltrates on chest X-ray in the setting of a blood transfusion and absence of cardiac failure. The exact incidence of TRALI is unknown, but the incidence is higher in the critically ill patient population. Multiple patient and donor related risk factors for TRALI exist, including critically illness, alcohol use, and receiving transfusions with high plasma volumes. Practitioners should have a low index of suspicion for the diagnosis of TRALI, and blood bank reporting is vital to aid in diagnosis and future prevention. Management is primarily supportive care, with supplemental oxygen as the mainstay for therapy. Despite the transient course of TRALI, its morbidity is severe with the majority of patients requiring mechanical ventilation and treatment in the intensive care unit. For patients that survive TRALI, outcomes are promising without residual pulmonary deficits. Prevention strategies over the past 10 years have helped to decrease the incidence of TRALI and have led to increased awareness of this condition in the medical field.

C-reactive protein enhances murine antibody-mediated transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is a syndrome of respiratory distress triggered by blood transfusions and is the leading cause of transfusion-related mortality. TRALI has primarily been attributed to passive infusion of HLA and/or human neutrophil antigen antibodies present in transfused blood products, and predisposing factors such as inflammation are known to be important for TRALI initiation. Because the acute-phase protein C-reactive protein (CRP) is highly upregulated during infections and inflammation and can also enhance antibody-mediated responses such as in vitro phagocytosis, respiratory burst, and in vivo thrombocytopenia, we investigated whether CRP affects murine antibody-mediated TRALI induced by the anti-major histocompatibility complex antibody 34-1-2s. We found that BALB/c mice injected with 34-1-2s or CRP alone were resistant to TRALI, however mice injected with 34-1-2s together with CRP had significantly enhanced lung damage and pulmonary edema. Mechanistically, 34-1-2s injection with CRP resulted in a significant synergistic increase in plasma levels of the neutrophil chemoattractant macrophage inflammatory protein-2 (MIP-2) and pulmonary neutrophil accumulation. Importantly, murine MIP-2 is the functional homolog of human interleukin-8, a known risk factor for human TRALI. These results suggest that elevated in vivo CRP levels, like those observed during infections, may significantly predispose recipients to antibody-mediated TRALI reactions and support the notion that modulating CRP levels is an effective therapeutic strategy to reduce TRALI severity.

Peripheral blood monocyte-derived chemokine blockade prevents murine transfusion-related acute lung injury (TRALI)

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality and can occur with any type of transfusion. TRALI is thought to be primarily mediated by donor antibodies activating recipient neutrophils resulting in pulmonary endothelial damage. Nonetheless, details regarding the interactions between donor antibodies and recipient factors are unknown. A murine antibody-mediated TRALI model was used to elucidate the roles of the F(ab')2 and Fc regions of a TRALI-inducing immunoglobulin G anti-major histocompatibility complex (MHC) class I antibody (34.1.2s). Compared with intact antibody, F(ab')2 fragments significantly increased serum levels of the neutrophil chemoattractant macrophage inflammatory protein 2 (MIP-2); however, pulmonary neutrophil levels were only moderately increased, and no pulmonary edema or mortality occurred. Fc fragments did not modulate any of these parameters. TRALI induction by intact antibody was completely abrogated by in vivo peripheral blood monocyte depletion by gadolinium chloride (GdCl3) or chemokine blockade with a MIP-2 receptor antagonist but was restored upon repletion with purified monocytes. The results suggest a two-step process for antibody-mediated TRALI induction: the first step involves antibody binding its cognate antigen on blood monocytes, which generates MIP-2 chemokine production that is correlated with pulmonary neutrophil recruitment; the second step occurs when antibody-coated monocytes increase Fc-dependent lung damage.

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.

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.

Recipient T lymphocytes modulate the severity of antibody-mediated transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is a serious complication of transfusion and has been ranked as one of the leading causes of transfusion-related fatalities. Nonetheless, many details of the immunopathogenesis of TRALI, particularly with respect to recipient factors are unknown. We used a murine model of antibody-mediated TRALI in an attempt to understand the role that recipient lymphocytes might play in TRALI reactions. Intravenous injection of an IgG2a antimurine major histocompatibility complex class I antibody (34-1-2s) into BALB/c mice induced moderate hypothermia and pulmonary granulocyte accumulation but no pulmonary edema nor mortality. In contrast, 34-1-2s injections into mice with severe combined immunodeficiency caused severe hypothermia, severe pulmonary edema, and approximately 40% mortality indicating a critical role for T and B lymphocytes in suppressing TRALI reactions. Adoptive transfer of purified CD8+ T lymphocytes or CD4+ T cells but not CD19+ B cells into the severe combined immunodeficiency mice alleviated the antibody-induced hypothermia, lung damage, and mortality, suggesting that T lymphocytes were responsible for the protective effect. Taken together, these results suggest that recipient T lymphocytes play a significant role in suppressing antibody-mediated TRALI reactions. They identify a potentially new recipient mechanism that controls the severity of TRALI reactions.

Transfusion-Related Acute Lung Injury — A Review

Transfusion-related acute lung injury (TRALI), a type of non-cardiogenic pulmonary oedema related to blood transfusion, is gaining prominence as a common adverse event related to blood transfusions in hospitals. Various mechanisms have been postulated to cause TRALI including both antibody-related and non-immune mechanisms. Although transfusion of all types of blood components have been implicated, by far the commonest product related to TRALI was, until recently, fresh frozen plasma, especially that obtained from female donors. However the use of male-only plasma donation in the UK has resulted in an increased observance of TRALI with platelet and red cell transfusions. The diagnosis of this condition is primarily one of exclusion of other causes of pulmonary oedema, with specialist laboratory tests performed to support the diagnosis. The management of TRALI is early diagnosis and good supportive care with, occasionally, ventilatory support. An increased awareness of this complication among intensive care physicians is desirable to prevent one of the commonest and most frequently under-recognised transfusion-related adverse events of the present day.

Transfusion related acute lung injury presenting with acute dyspnoea: a case report

Introduction

Transfusion-related acute lung injury is emerging as a common cause of transfusion-related adverse events. However, awareness about this entity in the medical fraternity is low and it, consequently, remains a very under-reported and often an under-diagnosed complication of transfusion therapy.

Case presentation

We report a case of a 46-year old woman who developed acute respiratory and hemodynamic instability following a single unit blood transfusion in the postoperative period. Investigation results were non-specific and a diagnosis of transfusion-related acute lung injury was made after excluding other possible causes of acute lung injury. She responded to symptomatic management with ventilatory and vasopressor support and recovered completely over the next 72 hours.

Conclusion

The diagnosis of transfusion-related acute lung injury relies on excluding other causes of acute pulmonary edema following transfusion, such as sepsis, volume overload, and cardiogenic pulmonary edema. All plasma containing blood products have been implicated in transfusion-related acute lung injury, with the majority being linked to whole blood, packed red blood cells, platelets, and fresh-frozen plasma. The pathogenesis of transfusion-related acute lung injury may be explained by a "two-hit" hypothesis, involving priming of the inflammatory machinery and then activation of this primed mechanism. Treatment is supportive, with prognosis being substantially better than for most other causes of acute lung injury.

Recurrent transfusion-related acute lung injury after a two-year interval

Transfusion-related acute lung injury (TRALI) is a life-threatening complication of blood transfusion. The epidemiology and pathogenesis of TRALI are not well established. A Medline literature search shows only rare reports of recurrent TRALI, all occurring soon after the first episodes. We report a case of recurrent TRALI after a 2-year interval. A patient developed TRALI after transfusion of 4 units of fresh frozen plasma for gastrointestinal bleeding due to oesophageal varices in September 2002. The patient required mechanical ventilation but recovered completely. Two years later, in October 2004, the patient experienced a second episode of TRALI during liver transplantation for hepatitis C virus /alcoholic cirrhosis. Again, the patient recovered after ventilator support. Laboratory investigation of the first TRALI episode (2002) showed antibodies against class II human leukocyte antigens (HLA) in three female donors. Laboratory investigation of the second episode (2004) showed anti-DR52 (HLA class II) antibodies in one female donor matching the DR-52 HLA class II antigen in the recipient. TRALI can rarely recur. Consideration of future blood needs for patients experiencing recurrent TRALI should include preventive measures against further TRALI reactions, such as blood from male donors or blood less than 14 days old.

Transfusion-related acute lung injury: a literature review

Transfusion-related acute lung injury (TRALI) is a serious and potentially fatal complication of transfusion of blood and blood components. TRALI is under-diagnosed and under-reported because of a lack of awareness. A number of models have been proposed to explain the pathogenesis of TRALI: an antibody mediated model; a two-event biologically active mediator model; and a combined model. TRALI can occur with any type of blood product and can occur with as little as one unit. Its presentation is similar to other forms of acute lung injury and management is predominantly supportive. The main strategy in combating TRALI is prevention both through manipulation of the donor pool and through clinical strategies directed at reducing transfusion of blood products including, but not limited to, evidence-based lower transfusion thresholds. This article presents a review of TRALI and addresses the definition, pathology, pathogenesis, clinical manifestations, treatment and prevention of the syndrome.

Transfusion-Related Acute Lung Injury (TRALI): Current Clinical and Pathophysiologic Considerations

Transfusion-related acute lung injury (TRALI) is a rare transfusion reaction presenting as respiratory distress during or after transfusion of blood products. TRALI varies in severity, and mortality is not uncommon. TRALI reactions have equal gender distributions and can occur in all age groups. All blood products, except albumin, have been implicated in TRALI reactions. TRALI presents as acute respiratory compromise occurring in temporal proximity to a transfusion of a blood product. Other causes of acute lung injury should be excluded in order to definitively diagnose TRALI. Clinically and pathologically, TRALI mimics acute respiratory distress syndrome (ARDS), with neutrophil-derived inflammatory chemokines and cytokines believed to be involved in the pathogenesis of both entities. Anti-HLA and anti-neutrophil antibodies have been implicated in some cases of TRALI. Treatment for TRALI is supportive; prevention is important. It is suspected that TRALI is both underdiagnosed and underreported. One of the difficulties in the evaluation of potential TRALI reactions is, until recently, the lack of diagnostic criteria. A group of transfusion medicine experts, the American-European Consensus Conference (AECC), recently met and developed diagnostic criteria of TRALI, as well as recommendations for management of donors to prevent future TRALI reactions. In light of the AECC consensus recommendations, we report an incident of TRALI in an oncology patient as an example of the potential severity of the lung disease and the clinical and laboratory evaluation of the patient. We also review the literature on this important complication of blood transfusion that internists may encounter.

Blood donor and component management strategies to prevent transfusion-related acute lung injury (TRALI)

OBJECTIVE

Discuss the pros and cons of using donor and blood product-management strategies to prevent transfusion-related acute lung injury (TRALI).

DATA SOURCE

A review of the literature was performed.

RESULTS

Despite therapeutic advances in pulmonary and critical care medicine, TRALI is now considered to be one of the leading causes of transfusion-associated mortality, and thus determining how to prevent TRALI is extremely important. Donor and product-management strategies to prevent this life-threatening condition have been suggested, but because of gaps in our understanding of TRALI, blood-bankers do not know how beneficial these interventions will be, nor the amount of potential harm-such as decreasing the availability of blood-that could arise if they were implemented. This article discusses the advantages and disadvantages of the various preventive measures that have been described in the literature.

CONCLUSIONS

Preventing TRALI poses a difficult challenge for blood-banking experts, because it is unknown which measures will be effective in decreasing the incidence of TRALI and which could have significant drawbacks. Only additional research into TRALI prevention will provide the answers on how to best protect patients from this potentially fatal reaction.

Massive Blood Loss and Transfusion in Obstetrics and Gynecology

Massive perioperative or periparturitional bleeding occasionally occurs in obstetric and gynecologic patients. Placenta previa, uterine atony, and ectopic pregnancy are just a few examples of many conditions that could predispose patients to significant blood loss. Therefore, it is important for physicians specializing in obstetrics and gynecology to be proficient in managing episodes of massive hemorrhage and the practice of the most commonly used blood components. We review and update the management of massive hemorrhage for obstetrics and gynecologic patients. In addition, we explore blood component therapy, its risks and benefits.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians Learning.

OBJECTIVES

After completion of this article, the reader should be able to explain the necessity of being proficient in managing episodes of massive hemorrhage, list the indications for use of various blood components, and summarize the risks and benefits of blood component therapy.

Transfusion-related acute lung injury

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Understanding the Consequences of Transfusion-Related Acute Lung Injury

Although the blood supply has become safer with regard to transmission of infectious agents, attention should continue to focus on understanding and eliminating the other serious risks associated with transfusion. Transfusion-related acute lung injury (TRALI) is one such risk, only recently becoming recognized as an important and potentially preventable clinical syndrome. Strategies for prevention of TRALI, however, must rely on knowledge regarding its etiology and diagnosis, and significant gaps in our understanding of the syndrome currently exist. This review summarizes what is known and unknown about the incidence, severity, etiology, diagnosis, and prevention of TRALI and the potential consequences of these knowledge gaps.

Syndrome de détresse respiratoire aiguë post-transfusionnel : une pathologie méconnue

Transfusion related acute lung injury (TRALI) is a rare but potentially severe complication of blood transfusion, manifested by pulmonary oedema, fever and hypotension. The signs and symptoms are often attributed to other clinical aspects of a patient's condition, and therefore, TRALI may go unrecognised. It has been estimated to be the third cause of transfusion related mortality, so it should be better diagnosed. Cases are related to multiple blood units, such as white blood cells, red blood cells, fresh frozen plasma, platelets or intravenous immunoglobulins. Physiopathology of TRALI is poorly understood, and still controversial. It is often due to an immunological conflict between transfused plasma antibodies and recipients' blood cells. These antibodies are either HLA (class I or II) or granulocyte-specific. They appear to act as mediators, which result in granulocytes aggregation, activation and micro vascular pulmonary injury. Lipids or cytokines in blood units are also involved as TRALI priming agents. Diagnosis is based on antibody screening in blood components and on specific-antigen detection in the recipient. The screening of anti-HLA or anti-granulocytes is recommended as part of prevention for female donors who had been pregnant. Preventative measures should also include leucoreduction and measures to decrease the amount of priming agents in blood components. In this article, we summarise what is known about TRALI, and we focus attention on unanswered questions and controversial issues related to TRALI.

Transfusion-related acute lung injury: a review

Transfusion-related acute lung injury (TRALI) is an underreported complication of transfusion therapy, and it is the third most common cause of transfusion-associated death. TRALI is defined as noncardiogenic pulmonary edema temporally related to transfusion therapy. The diagnosis of TRALI relies on excluding other diagnoses such as sepsis, volume overload, and cardiogenic pulmonary edema. Supportive diagnostic evidence includes identifying neutrophil or human leukocyte antigen (HLA) antibodies in the donor or recipient plasma. All plasma-containing blood products have been implicated in TRALI, with the majority of cases linked to whole blood, packed RBCs, platelets, and fresh-frozen plasma. The pathogenesis of TRALI may be explained by a "two-hit" hypothesis, with the first "hit" being a predisposing inflammatory condition commonly present in the operating room or ICU. The second hit may involve the passive transfer of neutrophil or HLA antibodies from the donor or the transfusion of biologically active lipids from older, cellular blood products. Treatment is supportive, with a prognosis substantially better than most causes of clinical acute lung injury.

TRALI after the infusion of marrow cells in a patient with acute lymphoblastic leukemia

BACKGROUND

TRALI is one of the most serious, life-threatening complications after blood transfusion. Antibodies against neutrophils or HLA molecules from the donor are thought to be the primary causative agents. Rarely, antibodies in the recipient may react with transfused neutrophils and initiate the same events, which raises the possibility that TRALI may also occur in an allogeneic PBPC transplantation setting.

CASE REPORT

A 30-year-old Japanese man with acute lymphoblastic leukemia developed TRALI immediately after the infusion of marrow cells from an unrelated donor. The infusion was suspended, and he gradually improved after receiving steroids and oxygen support. The next day, the remaining cells, which were separated to MNCs, were infused with no reactions. He then recovered over 5 days without the use of mechanical ventilation.

RESULTS

Laboratory evaluation disclosed the presence of antibodies to neutrophils in his sera sampled after transplantation, but not in the donor's marrow graft. Hence, antibodies to neutrophils in the recipient may have reacted with neutrophils in the graft and contributed to the development of TRALI.

CONCLUSION

This is the first reported case of TRALI after allogeneic BMT. TRALI should be recognized as a rare but serious complication in allogeneic hematopoietic stem cell transplantation.

Transfusion-related acute lung injury

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

Investigating transfusion-related acute lung injury (TRALI)

AIM

Transfusion-related acute lung injury (TRALI) can be a life-threatening transfusion complication and should be considered whenever respiratory distress occurs during a transfusion. Management of donors implicated in TRALI is a n important haemovigilance responsibility for blood services. To enable this, it is imperative to develop an effective strategy for investigating TRALI. The present paper describes an effective approach.

METHODS

Cases of suspected TRALI we re referred to the Platelet and Granulocyte Immunobiology Laboratory at the Australian Red Cross Blood Service-Queensland; a reference neutrophil testing service. Recipient and donor samples were tested for the presence of leucocyte antibodies. Where possible, compatibility testing was performed between donor and recipient samples.

RESULTS

From March 1999 to June 2001 , leucocyte antibodies directed against neutrophil-specific or human leucocyte antigens (HIA) were detected in at least one donor in seven of the nine cases investigated. Incompatibility with patient antigens (HNA-2a, non-specific HLA and HLA B5, B16, B35) was confirmed by cross matching in three cases.

CONCLUSION

TRALI is a serious non-infectious hazard of transfusion that must be reported and investigated promptly. Prompt investigations allow appropriate management of implicated donations and donors so as to minimize the incidence of TRALI. Therefore, the role of clinicians in reporting such cases and the hospital blood banks in collecting appropriate samples is critical. We suggest that hospital blood banks retain transfused donation units for at least 24 h after transfusion to expedite TRALI investigations. Due to the specialized nature of investigation, it is necessary to direct such investigations to specialist reference neutrophil testing services. In cases where the recipient has the leucocyte antibody, the use of white cell filters in future transfusions should be beneficial, because there is little evidence to substantiate the use of phenotyped blood products.

Acute Respiratory Distress Syndrome in Blunt Trauma: Identification of Independent Risk Factors

Acute respiratory distress syndrome (ARDS) is a major contributor to morbidity and mortality in trauma patients. Although many injuries and conditions are believed to be associated with ARDS independent risk factors in trauma patients and their relative importance in development of the syndrome are undefined. The aim of this project is to identify independent risk factors for the development of ARDS in blunt trauma patients and to examine the contributions of each factor to ARDS development. Patients with ARDS were identified from the registry of a Level I trauma center over a 4.5-year period. Records were reviewed for demographics, injury characteristics, transfusion requirements, and hospital course. Variables examined included age >65 years, Injury Severity Score (ISS) >25, hypotension on admission (systolic blood pressure <90), significant metabolic acidosis (base deficit <-5.0), severe brain injury as shown by a Glasgow Coma Scale score (GCS) <8 on admission, 24-hour transfusion requirement >10 units packed red blood cells, pulmonary contusion (PC), femur fracture, and major infection (pneumonia, empyema, or intraabdominal abscess). Both univariate and stepwise logistic regression were used to identify independent risk factors, and receiver operating characteristic curve (ROC) analysis was used to determine the relative contribution of each risk factor. A total of 4397 patients having sustained blunt trauma were admitted to the intensive care unit and survived >24 hours between October 1995 and May 2000. Of these patients 200 (4.5%) developed ARDS. All studied variables were significantly associated with ARDS in univariate analyses. Stepwise logistic regression, however, demonstrated age >65 years, ISS >25, hypotension on admission, 24-hour transfusion requirement >10 units, and pulmonary contusion as independent risk factors, whereas admission metabolic acidosis, femur fracture, infection, and severe brain injury were not. Using a model based on the logistic regression equation derived yields better than 80 per cent discrimination in ARDS patients. The risk factors providing the greatest contribution to ARDS development were ISS >25 (ROC area 0.72) and PC (ROC area 0.68) followed by large transfusion requirement (ROC area 0.56), admission hypotension (ROC area 0.57), and age >65 (ROC area 0.54). Independent risk factors for ARDS in blunt trauma include ISS >25, PC, age >65 years, hypotension on admission, and 24-hour transfusion requirement >10 units but not admission metabolic acidosis, femur fracture, infection, or severe brain injury. Assessment of these variables allows accurate estimate of risk in the majority of cases, and the most potent contributors to the predictive value of the model are ISS >25 and PC. Improvement in understanding of which patients are actually at risk may allow for advances in treatment as well as prevention in the future.

Breathlessness and blood: a combustible combination

Pulmonary complications are increasingly recognized as serous hazards of transfusion. The evidence suggests that transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are underrecognized. Both present with dyspnea but other signs and symptoms assist in determining the proper diagnosis. Males and females are equally affected. Morbidity is significant with both complications and in the case of TRALI, the mortality is in the range of 6-10%. Although the clinical descriptions of both entities are well established, the clinical profile of the at-risk population for both TRALI and TACO is not well understood. Because early intervention can reduce morbidity, it is important that clinicians recognize these disorders and apply appropriate treatment.