Are we underestimating reverse TRALI?

[Platelet Concentrates - Indication, Informed Consent, Transfusion and Adverse Events]

Transfusion of platelet concentrates (PC) can be a life-saving measure in case of severe thrombocytopenia or thrombocytopathy, particularly in bleeding patients. Although acaryote, platelets are involved in several important functions including immunomodulation, but their most important function is in primary and secondary haemostasis. In this German review, apheresis and whole blood derived PC are compared and indications as well as transfusion triggers and dosage of PC are discussed. Apart from emergencies, transfusion of PC can only occur after informed consent. Therefore, the treating physician should be aware of the potential adverse events and their prophylaxis in order to best advise the patient. Eight of the most prevalent and/or clinically severe adverse events following PC transfusion and their handling and prevention are discussed. In addition, practical aspects of PC transfusion are depicted as well as the treating physician's choice of the appropriate PC including a flowchart for refractory patients.

Transfusion-Related acute lung injury (TRALI) caused by antibodies to HLA-DRB1* 07:01 and HLA-DQB1*02:02: A case report

Transfusion-related acute lung injury (TRALI) is characterized by non-cardiogenic pulmonary edema and acute hypoxemia. There are few reports of HLA-II antibodies causing TRALI in China.

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.

Mechanism of TLR4 mediated immune effect in transfusion-induced acute lung injury based on Slit2/Robo4 signaling pathway

BACKGROUND

Transfusion-related acute lung injury (TRALI) is the infusion of blood or blood system.

OBJECTIVE

To explore the mechanism of TLR4-mediated T cell immune effect in TRALI.

METHODS

In this animal study, a mouse model of LPS-induced TRALI was established. Sixty adult C57/BL6 mice (wild-type, WT) were randomly divided into 5 groups: 1) normal WT type, 2) LPS control group of WT type lipopolysaccharide, 3) WT type TRALI group (LPS + MHC-I mAb), 4) (TLR4 antibody) lipopolysaccharide LPS control group, 5) (TLR4 antibody) TRALI group (LPS + MHC-I mAb). Mice were injected with LPS (0.1 mg/kg) and MHC-I mAb (2 mg/kg) into the tail vein. H&E staining was performed to detect pathological features. The myeloperoxidase (MPO) activity and the level of inflammatory cytokines in lung tissue homogenate supernatant were measured. Blood, spleen single-cell suspension, and bronchoalveolar lavage fluid were collected to detect the ratio of Treg and Th17 cells by flow cytometry. RT-PCR and WB were used to detect mRNA or protein expression.

RESULTS

TLR4 mAb treatment alleviated the pathogenesis of LPS-induced TRALI in vivo, the MPO activity, and the level of proinflammatory factors in lung tissues. TLR4 exerted its function by changing of Treg/Th17 ratio via the SLIT2/ROBO4 signaling pathway and downregulating CDH5 and SETSIP.

CONCLUSION

TLR4 mediates immune response in the LPS-induced TRALI model through the SLIT2/ROBO4 signaling pathway.

Adverse transfusion reactions and what we can do

INTRODUCTION

Transfusions of blood and blood components have inherent risks and the ensuing adverse reactions. It is very important to understand the adverse reactions of blood transfusion comprehensively for ensuring the safety of any future transfusions.

AREAS COVERED

According to the time of onset, adverse reactions of blood transfusion are divided into immediate and delayed transfusion reactions. In acute transfusion reactions, timely identification and immediate cessation of transfusion is critical. Vigilance is required to distinguish delayed responses or reactions that present nonspecific signs and symptoms. In this review, we present the progress of mechanism, clinical characteristics and management of commonly encountered transfusion reactions.

EXPERT OPINION

The incidence of many transfusion-related adverse events is decreasing, but threats to transfusion safety are always emerging. It is particularly important for clinicians and blood transfusion staff to recognize the causes, symptoms, and treatment methods of adverse blood transfusion reactions to improve the safety. In the future, at-risk patients will be better identified and can benefit from more closely matched blood components.

Transfusion of target antigens to preimmunized recipients: a new mechanism in transfusion-related acute lung injury

The recipients’ preformed alloantibodies may initiate TRALI reaction in recipients transfused with soluble antigen.

The antibody interaction with absorbed antigen on ECs leads to endothelial barrier dysfunction and lung injury.

Transfusion-related lung injury (TRALI) is a serious side effect of blood transfusion. Exclusion of antibody carriers from the donor pool has significantly decreased the number of cases, but TRALI remains the leading cause of transfusion-related morbidity and mortality in industrialized countries. Here, we show that proteins released from donor cells during processing of blood components are capable of inducing a new type of reverse TRALI when transfused to preimmunized recipients. First, we show that soluble neutrophil surface protein CD177 in complex with proteinase 3 (sCD177/PR3) is not only present in human plasma but also in packed red blood cell (PRBC) supernatant. Filtration or storage enhances the concentration of sCD177/PR3 in PRBCs. Second, we show that sCD177/PR3 specifically binds to PECAM-1 on stimulated (but not on unstimulated) endothelial cells (ECs). Third, we provide evidence that the sCD177/PR3/PECAM-1 complex is functional. In the presence of monoclonal or human antibodies against CD177 or PR3, ECs produce reactive oxygen species and become apoptotic. Albumin flux through an EC monolayer increases significantly whenever antibodies and the cognate antigens are present. Finally, we describe a clinical case in which anti-CD177 present in a transfusion recipient precipitated TRALI after the transfusion of CD177-positive, but not CD177-negative, PRBCs. In conclusion, we introduce a new TRALI mechanism based on the specific binding of transfused, soluble antigens to activated ECs in preimmunized recipients. We suggest that further studies and clinical work-up of TRALI should also include antibody investigation of the recipient.

A possible case of recipient anti-neutrophil and anti-human leukocyte antigen antibody-mediated fatal reverse transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a transfusion complication often mediated by recipient exposure to plasma from donors with human leukocyte antigen (HLA) and human neutrophil antigen (HNA) antibodies. Recipient anti-donor HLA or HNA antibodies have rarely been implicated.

STUDY DESIGN AND METHODS

Herein, we describe a case of fatal TRALI mediated by recipient anti-HLA and anti-HNA antibodies. Cognate antibody-antigen match was confirmed with serologic and molecular assays.

RESULTS

A 69-year-old G5P5 female with no prior transfusion history and metastatic cholangiocarcinoma with thromboembolic complications presented with heart failure and dyspnea. She was transfused 15 ml of a unit of Fy^a -negative red blood cells and subsequently developed acute onset dyspnea, hypoxemia, hypotension, and fever. Clinical investigations revealed bilateral infiltrates on chest X-ray and cognate recipient HLA and HNA antibodies to donor antigens. The patient died of acute respiratory failure within 24 h of transfusion. In total, the patient had Fy^a , HLA Class I, HNA, and human platelet antigen (HPA) alloantibodies. The 63-year-old female donor had detectable HLA class II antibodies (recipient class II genotype unavailable).

CONCLUSION

The pathophysiology of TRALI has traditionally been ascribed to underlying conditions that put the recipient at risk in combination with donor biological response modifiers. This case illustrates alternative pathogenic mediators including alloantibodies to donor HLA and HNA. Additional studies to determine the contribution and frequency of recipient alloantibodies in TRALI may inform future mitigation strategies to further reduce the incidence of TRALI, particularly in female transfusion recipients.