Transfusion-related acute lung injury (TRALI) following allogeneic stem cell transplant for acute myeloid leukemia

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.

High-resolution CT findings of idiopathic pneumonia syndrome after haematopoietic stem cell transplantation: based on the updated concept of idiopathic pneumonia syndrome by the American Thoracic Society in 2011

Idiopathic pneumonia syndrome (IPS) is an acute lung dysfunction of non-infectious aetiology and a severe complication following haematopoietic stem cell transplantation (HSCT). Recently, the American Thoracic Society (ATS) updated the concept of IPS and extended the concept to a wider range; it defined IPS as "an idiopathic syndrome of pneumopathy after HSCT, with evidence of widespread alveolar injury and in which infectious aetiologies and cardiac dysfunction, acute renal failure, or iatrogenic fluid overload have been excluded." The ATS also categorised the presumed site of primary tissue injury into three patterns (pulmonary parenchyma, vascular endothelium, and airway epithelium), each of which has several entities. Since the therapeutic strategies for IPS are clearly different from those of infectious diseases, and therapeutic delay causes a poor prognosis, radiologists should be aware of some characteristic HRCT findings of IPS, which includes a wide spectrum of entities. In this article, the characteristic HRCT findings of these entities, including acute interstitial pneumonia/acute respiratory distress syndrome, eosinophilic pneumonia, non-cardiogenic capillary leak syndrome, diffuse alveolar haemorrhage, transfusion-related acute lung injury, organising pneumonia, and bronchiolitis obliterans syndrome, are shown.

Transfusion-related acute lung injury; clinical perspectives

Transfusion-related acute lung injury (TRALI) was introduced in 1983 to describe a clinical syndrome seen within 6 h of a plasma-containing blood products transfusion. TRALI is a rare transfusion complication; however, the FDA has suggested that TRALI is the leading cause of transfusion-related mortality. Understanding the pathogenesis of TRALI will facilitate adopting preventive strategies, such as deferring high plasma volume female product donors. This review outlines the clinical features, pathogenesis, treatment, and prevention of TRALI.

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.

An official American Thoracic Society research statement: noninfectious lung injury after hematopoietic stem cell transplantation: idiopathic pneumonia syndrome

RATIONALE

Acute lung dysfunction of noninfectious etiology, known as idiopathic pneumonia syndrome (IPS), is a severe complication following hematopoietic stem cell transplantation (HSCT). Several mouse models have been recently developed to determine the underlying causes of IPS. A cohesive interpretation of experimental data and their relationship to the findings of clinical research studies in humans is needed to better understand the basis for current and future clinical trials for the prevention/treatment of IPS.

OBJECTIVES

Our goal was to perform a comprehensive review of the preclinical (i.e., murine models) and clinical research on IPS.

METHODS

An ATS committee performed PubMed and OVID searches for published, peer-reviewed articles using the keywords "idiopathic pneumonia syndrome" or "lung injury" or "pulmonary complications" AND "bone marrow transplant" or "hematopoietic stem cell transplant." No specific inclusion or exclusion criteria were determined a priori for this review.

MEASUREMENTS AND MAIN RESULTS

Experimental models that reproduce the various patterns of lung injury observed after HSCT have identified that both soluble and cellular inflammatory mediators contribute to the inflammation engendered during the development of IPS. To date, 10 preclinical murine models of the IPS spectrum have been established using various donor and host strain combinations used to study graft-versus-host disease (GVHD). This, as well as the demonstrated T cell dependency of IPS development in these models, supports the concept that the lung is a target of immune-mediated attack after HSCT. The most developed therapeutic strategy for IPS involves blocking TNF signaling with etanercept, which is currently being evaluated in clinical trials.

CONCLUSIONS

IPS remains a frequently fatal complication that limits the broader use of allogeneic HSCT as a successful treatment modality. Faced with the clinical syndrome of IPS, one can categorize the disease entity with the appropriate tools, although cases of unclassifiable IPS will remain. Significant research efforts have resulted in a paradigm shift away from identifying noninfectious lung injury after HSCT solely as an idiopathic clinical syndrome and toward understanding IPS as a process involving aspects of both the adaptive and the innate immune response. Importantly, new laboratory insights are currently being translated to the clinic and will likely prove important to the development of future strategies to prevent or treat this serious disorder.

Neutrophil-specific antigen HNA-2a, NB1 glycoprotein, and CD177

PURPOSE OF REVIEW

Several advances have been made in characterization of the molecule that carries human neutrophil antigen (HNA)-2a, NB1 glycoprotein, the gene that encodes NB1 glycoprotein, CD177, and the role of antibodies to HNA-2a in transfusion reactions.

RECENT FINDINGS

NB1 glycoprotein binds to the endothelial cell adhesion molecule, platelet endothelial cell adhesion molecule-1 (PECAM-1), and participates in neutrophil transmigration. The overexpression of neutrophil CD177 mRNA has become a useful, but nonspecific biomarker of myeloproliferative diseases, especially polycythemia vera. CD177 mRNA overexpression is also a biomarker of a subset of patients with essential thrombocythemia who are at increased risk of thromboembolic complications. In patients with myeloproliferative disorders CD177 mRNA overexpression is secondary to a gain-of-function mutation in JAK2, JAK2 V617F. NB1 glycoprotein is co-localized on neutrophil plasma membranes with proteinase 3 and a complex of NB1 glycoprotein and proteinase 3 may initiate the activation of neutrophils by antineutrophil cytoplasmic antibodies in patients with Wegener's granulomatosis. The inadvertent transfusion of antibodies to HNA-2a with blood components frequently causes pulmonary transfusion reactions.

SUMMARY

The expression of CD177 is an important biomarker of myeloproliferative diseases, NB1 glycoprotein is a ligand for PECAM-1 and it may have a role in Wegener's granulomatosis, and antibodies to HNA-2a frequently cause pulmonary transfusion reactions.

The two-event model of transfusion-related acute lung injury

The objective of this review is to present the two-event model of transfusion-related acute lung injury (TRALI), a life-threatening complication of transfusions that has been the most common cause of transfusion-related death over the past 2 yrs in the United States. The two-event model of TRALI, which is identical to the pathogenesis of the acute respiratory distress syndrome (ARDS), is reviewed and contrasted to antibody-mediated TRALI. Laboratory studies, both in vitro and in vivo, are discussed as well as human studies of TRALI. Methods to avoid patient exposure to blood components that may cause TRALI are also discussed.

Transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is a life-threatening adverse event of transfusion, which has an increasing incidence in the United States and is the leading cause of transfusion-related death. TRALI and acute lung injury (ALI) share a common clinical definition except that TRALI is temporally- and mechanistically-related to transfusion of blood or blood components. A number of different models have been proposed to explain the pathogenesis. The first is an antibody-mediated event whereby transfusion of anti-HLA, class I or class II, or anti-granulocyte antibodies into patients whose leukocytes express the cognate antigens. The antibody:antigen interaction causes complement-mediated pulmonary sequestration and activation of neutrophils (PMNs) resulting in TRALI. The second is a two-event model: the first event is the clinical condition of the patient resulting in pulmonary endothelial activation and PMN sequestration, and the second event is the transfusion of a biologic response modifier (including anti-granulocyte antibodies, lipids, and CD40 ligand) that activates these adherent PMNs resulting in endothelial damage, capillary leak, and TRALI. These hypotheses are discussed with respect to animal models and human studies that provide the experimental and clinical relevance. The definition of TRALI, patient predisposition, treatment, prevention and reporting guidelines are also examined.

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.

Transfusion related acute lung injury: a pediatric perspective

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-associated mortality. TRALI occurs in children and adults, but the syndrome has not been reviewed from a pediatric perspective. We reviewed the literature on TRALI from a pediatric perspective. TRALI has been documented in pediatric patients, especially in the setting of hematologic malignancy. Additional TRALI cases have been reported in pediatric patients with a variety of diagnoses. TRALI is likely to be much more common than previously appreciated in the pediatric patient population. TRALI should be considered in the differential diagnosis of all pediatric patients who develop new acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) during or within six hours of a blood product transfusion. When a case of TRALI is suspected, a transfusion reaction report to the blood bank is important to initiate the investigation and identify the implicated donor.

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

Transfusion-related acute lung injury (TRALI) is a life-threatening adverse effect of transfusion that is occurring at increasing incidence in the United States and that, in the past 2 reporting years, has been the leading cause of transfusion-related death. TRALI and acute lung injury (ALI) share a common clinical definition except that TRALI is temporally and mechanistically related to the transfusion of blood/blood components. In prospective studies, 2 patient groups, 1 requiring cardiac surgery and 1 with hematologic malignancies and undergoing induction chemotherapy, were predisposed. Two different etiologies have been proposed. The first is a single antibody-mediated event involving the transfusion of anti-HLA class I and class II or antigranulocyte antibodies into patients whose leukocytes express the cognate antigens. The second is a 2-event model: the first event is the clinical condition of the patient resulting in pulmonary endothelial activation and neutrophil sequestration, and the second event is the transfusion of a biologic response modifier (including lipids or antibodies) that activates these adherent polymorphonuclear leukocytes (PMNs), resulting in endothelial damage, capillary leak, and TRALI. These hypotheses are discussed, as are the animal models and human studies that provide the experimental and clinical relevance. Prevention, treatment, and a proposed definition of TRALI, especially in the context of ALI, are also examined.