Plasma and lipids from stored packed red blood cells cause acute lung injury in an animal model

Transfusion Related Acute Lung Injury (TRALI): A Single Institution Experience of 15 Years

Transfusion related acute Lung injury (TRALI) though a serious blood transfusion reaction with a fatality rate of 5-25 % presents with acute respiratory distress with hypoxaemia and noncardiac pulmonary oedema within 6 h of transfusion. In non fatal cases, it may resolve within 72 h or earlier. Although reported with an incidence of 1:5000, its true occurrence is rather unknown. Pathogenesis is believed to be related to sequestration and adhesion of neutrophils to the pulmonary capillary endothelium and its activation leading to its destruction and leaks. The patient's underlying condition, anti-neutrophil antibody in the transfused donor plasma and certain lipids that accumulate in routinely stores blood and components are important in its aetiopathogenesis. Patient's predisposing conditions include haematological malignancy, major surgery (especially cardiac), trauma and infections. The more commonly incriminated products include fresh frozen plasma (FFP), platelets (whole blood derived and apheresis), whole blood and Packed RBC. Occasional cases involving cryoprecipitate and Intravenous immunoglobulin (IVig) have also been reported. We present a 15 year single institution experience of TRALI, during which we observed 9 cases among 170,871 transfusions, giving an incidence of 1:19,000. We did not encounter cases of haematological malignancy or cardiac surgery in our TRALI patients. Among the blood products, that could be related to TRALI in our patients included solitary cases receiving cryoprecipitate, IVIg, and recombinant Factor VII apart from platelets and FFP. All patients were treated with oxygen support. Six patients required mechanical ventilation. Off label hydrocortisone was given to all patients. There were no cases of fatality among our patients.

Blood Transfusion and the Risk of Acute Kidney Injury Among Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Background—

Acute kidney injury (AKI) complicating percutaneous coronary intervention (PCI) is associated with adverse clinical outcomes. To date, no studies have evaluated the association of blood transfusion with AKI in patients undergoing PCI.

Methods and Results—

We used a retrospective cohort study of all patients with acute coronary syndrome undergoing PCI from CathPCI Registry (n=1 756 864). The primary outcome was AKI defined as the rise in serum creatinine post procedure ≥0.5 mg/dL or ≥25% above baseline values. AKI developed in 9.0% of study sample. Patients with AKI were older, more often women, and had high prevalence of comorbidities, including diabetes mellitus, hypertension, and advanced stages of chronic kidney disease at baseline. Blood transfusion was utilized in 2.2% of patients. In the overall sample, AKI developed in 35.1% of patients who received transfusion versus 8.4% of patients without transfusion (adjusted odds ratio, 4.87 [4.71–5.04]). In the subgroup of patients who sustained bleeding event and received transfusion, the rate of AKI was significantly increased across all preprocedure hemoglobin levels versus no blood transfusion. Similar findings were seen in the subgroup of patients with no bleeding event.

Conclusions—

Blood transfusion is strongly associated with AKI in patients with acute coronary syndrome undergoing PCI. Further investigation is needed to determine whether a restrictive blood transfusion strategy might improve PCI outcomes by reducing the risk of AKI.

LysoPCs induce Hck- and PKCδ-mediated activation of PKCγ causing p47phox phosphorylation and membrane translocation in neutrophils

Lysophosphatidylcholines (lysoPCs) are effective polymorphonuclear neutrophil (PMN) priming agents implicated in transfusion-related acute lung injury (TRALI). LysoPCs cause ligation of the G2A receptor, cytosolic Ca²⁺ flux, and activation of Hck. We hypothesize that lysoPCs induce Hck-dependent activation of protein kinase C (PKC), resulting in phosphorylation and membrane translocation of 47 kDa phagocyte oxidase protein (p47^phox). PMNs, human or murine, were primed with lysoPCs and were smeared onto slides and examined by digital microscopy or separated into subcellular fractions or whole-cell lysates. Proteins were immunoprecipitated or separated by polyacrylamide gel electrophoresis and immunoblotted for proteins of interest. Wild-type (WT) and PKCγ knockout (KO) mice were used in a 2-event model of TRALI. LysoPCs induced Hck coprecipitation with PKCδ and PKCγ and the PKCδ:PKCγ complex also had a fluorescence resonance energy transfer (FRET)⁺ interaction with lipid rafts and Wiskott-Aldrich syndrome protein family verprolin-homologous protein 2 (WAVE2). PKCγ then coprecipitated with p47^phox Immunoblotting, immunoprecipitation (IP), specific inhibitors, intracellular depletion of PKC isoforms, and PMNs from PKCγ KO mice demonstrated that Hck elicited activation/Tyr phosphorylation (Tyr311 and Tyr525) of PKCδ, which became Thr phosphorylated (Thr507). Activated PKCδ then caused activation of PKCγ, both by Tyr phosphorylation (Τyr514) and Ser phosphorylation, which induced phosphorylation and membrane translocation of p47^phox In PKCγ KO PMNs, lysoPCs induced Hck translocation but did not evidence a FRET⁺ interaction between PKCδ and PKCγ nor prime PMNs. In WT mice, lysoPCs served as the second event in a 2-event in vivo model of TRALI but did not induce TRALI in PKCγ KO mice. We conclude that lysoPCs prime PMNs through Hck-dependent activation of PKCδ, which stimulates PKCγ, resulting in translocation of phosphorylated p47^phox.

The significance of relative dose intensity in adjuvant chemotherapy of pancreatic ductal adenocarcinoma-including the analysis of clinicopathological factors influencing relative dose intensity

Recently, it has been reported that the relative dose intensity (RDI) of adjuvant chemotherapy (AC) influences survival in various cancers, but there are very few reports about RDI in pancreatic ductal adenocarcinoma (PDAC). The optimal timing for initiation of AC for PDAC also remains unknown. The aim of this study was to identify the significance of RDI and the time interval between surgery and initiation of AC on survival of patients with PDAC. Clinicopathological factors that affect RDI were also investigated.A total of 311 consecutive PDAC patients who underwent curative resection between May 2005 and January 2015 were enrolled. Patients who underwent neoadjuvant chemoradiation, had UICC stage IV disease, or had early recurrences within 6 months were excluded, and the remaining 168 cases were analyzed.Patients with RDIs ≥80% (n = 79) showed significantly better overall survival (OS) compared to patients with RDIs <80% (n = 55) (median survival time (MST): 45.6 months, 26.0 months, P < 0.001). Patients with no AC (n = 34) showed the worst OS (MST: 20.8 months). Whether the AC was initiated earlier or later than 8 weeks after surgery did not influence survival, either in patients with RDIs ≥80% (P = 0.79) or in those with <80% (P = 0.73). Patients in the S-1 monotherapy group (n = 49) showed significantly better OS than patients in the gemcitabine monotherapy group (n = 51) (MST: 95.0 months, 26.0 months, respectively; P = 0.001). Univariate analysis conducted after adjusting for the chemotherapeutic drug used identified several prognostic factors; male gender (P = 0.01), intraoperative blood transfusion (P = 0.005), lymph node metastasis (P = 0.03), and postoperative WBC count (P = 0.03). Multivariate analysis identified intra-plus postoperative blood transfusion (P = 0.002) and high postoperative platelet-to-lymphocyte ratios (PLR) (P = 0.04) as independent predictors of poor RDI.Efforts to maintain RDI had a greater impact on survival than the struggle to start AC early after surgery. Intra-plus postoperative blood transfusion and a high postoperative PLR could be predictive markers of reduced RDI in AC of PDAC patients. Avoidance of perioperative blood transfusions where possible and nutritional support during the perioperative period could maintain adequate RDI and may lead to improved long-term outcome.

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.

Metabolic pathways that correlate with post-transfusion circulation of stored murine red blood cells

Transfusion of red blood cells is a very common inpatient procedure, with more than 1 in 70 people in the USA receiving a red blood cell transfusion annually. However, stored red blood cells are a non-uniform product, based upon donor-to-donor variation in red blood cell storage biology. While thousands of biological parameters change in red blood cells over storage, it has remained unclear which changes correlate with function of the red blood cells, as opposed to being co-incidental changes. In the current report, a murine model of red blood cell storage/transfusion is applied across 13 genetically distinct mouse strains and combined with high resolution metabolomics to identify metabolic changes that correlated with red blood cell circulation post storage. Oxidation in general, and peroxidation of lipids in particular, emerged as changes that correlated with extreme statistical significance, including generation of dicarboxylic acids and monohydroxy fatty acids. In addition, differences in anti-oxidant pathways known to regulate oxidative stress on lipid membranes were identified. Finally, metabolites were identified that differed at the time the blood was harvested, and predict how the red blood cells perform after storage, allowing the potential to screen donors at time of collection. Together, these findings map out a new landscape in understanding metabolic changes during red blood cell storage as they relate to red blood cell circulation.

Molecular mechanisms of erythrocyte aging

Anemia and hemorrhagic shock are leading causes of morbidity and mortality worldwide, and transfusion of human blood products is the ideal treatment for these conditions. As human erythrocytes age during storage in blood banks they undergo many biochemical and structural changes, termed the red blood cell 'storage lesion'. Specifically, ATP and pH levels decrease as metabolic end products, oxidative stress, cytokines, and cell-free hemoglobin increase. Also, membrane proteins and lipids undergo conformational and organizational changes that result in membrane loss, viscoelastic changes and microparticle formation. As a result, transfusion of aged blood is associated with a host of adverse consequences such as decreased tissue perfusion, increased risk of infection, and increased mortality. This review summarizes current research detailing the known parts of the erythrocyte storage lesion and their physiologic consequences.

Postoperative complications of spine surgery

A variety of surgical approaches are available for the treatment of spine diseases. Complications can arise intraoperatively, in the immediate postoperative period, or in a delayed fashion. These complications may lead to severe or even permanent morbidity if left unrecognized and untreated [1-4]. Here we review a range of complications in the early postoperative period from more benign complications such as postoperative nausea and vomiting (PONV) to more feared complications leading to permanent loss of neurological function or death [5]. Perioperative pain management is covered in a separate review (Chapter 8).

A Clinical Trial to Detect Subclinical Transfusion-induced Lung Injury during Surgery

BACKGROUND

Transfusion-related acute lung injury incidence remains the leading cause of posttransfusion mortality. The etiology may be related to leukocyte antibodies or biologically active compounds in transfused plasma, injuring susceptible recipient's lungs. The authors have hypothesized that transfusion could have less severe effects that are not always appreciated clinically and have shown subtly decreased pulmonary oxygen gas transfer in healthy volunteers after transfusion of fresh and 21-day stored erythrocytes. In this study, the authors tested the same hypothesis in surgical patients.

METHODS

Ninety-one patients undergoing elective major spine surgery with anticipated need for erythrocyte transfusion were randomly allocated to receive their first transfusion of erythrocytes as cell salvage (CS), washed stored, or unwashed stored. Clinicians were not blinded to group assignment. Pulmonary gas transfer and mechanics were measured 5 min before and 30 min after erythrocyte transfusion.

RESULTS

The primary outcome variable, gas transfer, as assessed by change of PaO2/FIO2, with erythrocyte transfusion was not significant in any group (mean ± SD; CS: 9 ± 59; washed: 10 ± 26; and unwashed: 15 ± 1) and did not differ among groups (P = 0.92). Pulmonary dead space (VD/VT) decreased with CS transfusion (-0.01 ± 0.04; P = 0.034) but did not change with other erythrocytes; the change from before to after erythrocyte transfusion did not differ among groups (-0.01 to +0.01; P = 0.28).

CONCLUSIONS

The authors did not find impaired gas exchange as assessed by PaO2/FIO2 with transfused erythrocytes that did or did not contain nonautologous plasma. This clinical trial did not support the hypothesis of erythrocyte transfusion-induced gas exchange deficit that had been found in healthy volunteers.

The association between platelet transfusion and idiopathic pneumonia syndrome is unaffected by platelet product type

BACKGROUND

Methods used to produce platelet (PLT) components, pooling of PLT-rich plasma (PRP-PLT) and apheresis (AP-PLT), may variably contribute to the pathogenesis and severity of idiopathic pneumonia syndrome (IPS).

STUDY DESIGN AND METHODS

We performed a retrospective cohort study of 906 allogeneic hematopoietic cell transplant recipients to examine associations between PLT product type and risks of developing IPS and dying after IPS onset. Proportional hazards models included separate terms for the sum of all PLT transfusions and the sum of PRP-PLT units received in the 3 or 7 days before IPS onset. Similarly constructed models analyzed the outcome of time to death after IPS onset. All analyses were adjusted for known IPS risk factors.

RESULTS

Patients received a median of three PRP-PLT transfusions (interquartile range [IQR], 0-6) and five AP-PLT transfusions (IQR, 1-13) while at risk for IPS. Seventy-five patients (8%) developed IPS by Posttransplant Day 120. The proportion of PRP-PLT transfusions was not associated with risk of developing IPS (3-day hazard ratio [HR] 0.98, 95% CI 0.74-1.29, p = 0.86; 7-day HR 1.00, 95% CI 0.86-1.15, p = 0.95) or dying after IPS onset (3-day HR 0.99, 95% CI 0.75-1.31, p = 0.97; 7-day HR 0.98, 95% CI 0.78-1.12, p = 0.47).

CONCLUSION

The association between PLT transfusions and risk of developing IPS or dying after IPS onset does not differ according to PLT product type. Further research is required to identify potentially modifiable steps in PLT component production that contribute to IPS.

Can Transfusions be Eliminated in Major Abdominal Surgery? Analysis of a Vive-Year Experience of Blood Conservation in Patients Undergoing Pancreaticoduodenectomy

Pancreaticoduodenectomy (PD) has historically required perioperative blood transfusion in 40 to 60 per cent of cases. Growing data suggest that transfusions may be deleterious in the surgical patient. We recently initiated a minimal transfusion approach to PD consisting of limited postoperative blood draws, early iron supplementation, changes in surgical technique, and elimination of hemoglobin transfusion triggers. Predictors of perioperative transfusion were analyzed in 130 consecutive patients undergoing PD by a single surgeon between 2008 and 2013, divided into two eras with 65 patients each. Patients in each era were similar with respect to age, comorbidities, American Society of Anesthesiologists class, body mass index, and diagnosis. The transfusion rate for the entire group was 22 per cent. Nonsignificant predictors of perioperative transfusion include American Society of Anesthesiologists class ≥3 ( P = 0.41), vascular resections ( P = 0.56), body mass index ≥30 ( P = 0.72), and intraoperative blood loss ( P = 0.89). Significant predictors of transfusion include PD performed in Era 1 as well as preoperative hemoglobin levels <10 g/dL. In Era 1, 38 per cent of patients required transfusion compared with 6 per cent in Era 2 ( P < 0.01). Shorter length of stay and a trend toward decreased pancreatic fistulae were seen in Era 2. Transfusions can be almost completely eliminated in PD and this may contribute to improved outcomes.

Transfusion-related alloimmune neutropenia with no pulmonary complications: one donor-five cases

BACKGROUND

Neutrophil alloantibodies are well-known triggers of transfusion-related acute lung injury (TRALI) and also cause immune neutropenia. Alloimmune neutropenia due to transfusion is an isolated phenomenon that is only rarely identified. Its incidence is specified in the literature as being less than one in 10,000 transfused plasma-containing units. We expect that this phenomenon is underreported.

STUDY DESIGN AND METHODS

We observed five cases of alloimmune neutropenia with no respiratory complications with only one case initially reported as a suspected transfusion reaction. The other four cases were detected in the course of the subsequent lookback investigation.

RESULTS

The first case was reported as a potential transfusion reaction when a female patient showed a decrease in the white blood cell count after a platelet (PLT) transfusion. Examinations of the donor blood revealed an antibody against the human neutrophil antigen HNA-1b; the recipient was typed HNA-1b positive and HNA-1a negative. After examining the blood counts of other patients who previously received PLT concentrates from the same donor, we identified four other patients with an unreported decrease in the leukocyte and/or granulocyte count of more than approximately 50% after transfusion.

CONCLUSION

HNA antibodies are generally regarded as potential triggers of TRALI. Here we describe an HNA antibody that reproducibly caused transfusion-related neutropenia only without pulmonary complications. Factors predisposing patients to TRALI development are widely discussed. Our case suggests that antibody characteristics are also relevant in the development of TRALI. Current measures to prevent TRALI should also prevent transfusion-related alloimmune neutropenia.

Synthesis, toxicity study and anti-inflammatory effect of MHTP, a new tetrahydroisoquinoline alkaloid

The alkaloid 2-methoxy-4-(7-methoxy-1,2,3,4-tetrahydroisoquinolin-1-yl)phenol (MHTP) was synthesized to prospect new compounds with therapeutic properties. Thus, the goal of this study was to evaluate the MHTP anti-inflammatory effect by in vivo and in vitro assays. The MHTP toxicity was analyzed. We found that MHTP pre-treatment (2.5-10 mg/kg) showed antiedematogenic effect (p < 0.05) in carrageenan-induced paw edema by inhibiting the PGE2 action independently of mast cell degranulation or histamine activity. MHTP also diminished (p < 0.01) total leukocyte migration in 41.5% into peritoneal cavity during carrageenan-induced peritonitis, reducing polymorphonuclear cells (PMNs) (59.6%) and proteins levels (29.4%). MHTP in an experimental model of acute lung injury inhibited (p < 0.001) total inflammatory cell migration into the lungs and PMNs in 58% and 67.5%, respectively. Additionally, MHTP did not present cytotoxicity at concentrations of 10, 25 or 50 μM but decreased (p < 0.001) the NO production in 24%, 47% and 39%, respectively. The alkaloid also reduced (p < 0.001, in lipopolysaccharide (LPS)-stimulated macrophages (1 μg/mL), IL-1β, IL-6 and IL-10 levels in 35.7%, 31.0% and 33.4%, respectively. The results obtained in this study allow us to conclude that the inedited synthetic alkaloid, MHTP has anti-inflammatory effect by inhibiting PGE2 function as well as inhibiting inflammatory cell migration to the inflamed site and attenuated the acute lung injury disease by inhibiting the migration of neutrophil to the lung. However, further studies will be carried out to demonstrate the mechanisms of action of the molecule and explore its potential as a future drug to treat inflammatory processes.

Established and theoretical factors to consider in assessing the red cell storage lesion

The collection and storage of red blood cells (RBCs) is a logistical necessity to provide sufficient blood products. However, RBC storage is an unnatural state, resulting in complicated biological changes, referred to collectively as the "storage lesion." Specifics of the storage lesion have been studied for decades, including alterations to cellular properties, morphology, molecular biology of carbohydrates, proteins and lipids, and basic metabolism. Recently, mass spectrometry-based "omics" technology has been applied to the RBC storage lesion, resulting in many new observations, the initial effects of which are more information than understanding. Meanwhile, clinical research on RBC transfusion is considering both the efficacy and also the potential untoward effects of transfusing stored RBCs of different ages and storage conditions. The myriad biological changes that have now been observed during the storage lesion have been extensively reviewed elsewhere. This article focuses rather on an analysis of our current understanding of the biological effects of different elements of the storage lesion, in the context of evolving new clinical understanding. A synopsis is presented of both established and theoretical considerations of the RBC storage lesion and ongoing efforts to create a safer and more efficacious product.

Transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is defined as the onset or the worsening of respiratory distress within 6  h of the transfusion of a plasma-containing blood component. It is currently considered to be one of the leading causes of severe posttransfusion morbidity and acute mortality in countries with a high development index. Understanding of the pathogenesis of TRALI has resulted in the development of preventive measures that have contributed to reducing its incidence. Early recognition of the clinical symptoms allow the clinician to identify the syndrome and to undertake therapeutic measures that may reduce the morbidity and mortality associated with this complication.

Red blood cell storage lesion

OBJECTIVE

To summarize current understanding of the mechanisms responsible for changes occurring during red blood cell (RBC) storage, collectively known as the storage lesion, and to review the biological and clinical consequences of increasing storage time of RBCs.

DATA SOURCES

Human and veterinary clinical studies, experimental animal model studies, and reviews of the RBC storage lesion with no date restrictions.

HUMAN DATA SYNTHESIS

Experimental studies have characterized the evolution of human RBC and supernatant changes that occur during storage and form the basis for concern about the potential for harm from long-term storage of RBCs. Although 4 randomized controlled trials of varying sizes failed to find an association between RBC storage time and negative clinical outcomes, a recent meta-analysis and numerous observational clinical studies have demonstrated that transfusion of old versus fresh stored RBCs is associated with an increased risk of morbidity and mortality, particularly among trauma victims and cardiac surgery patients. Potential clinical consequences of RBC transfusion following development of the storage lesion include risk of organ dysfunction, organ failure, infections, and death.

VETERINARY DATA SYNTHESIS

Experimental animal models have contributed to the evidence supporting adverse consequences of the RBC storage lesion. Studies on relevant RBC storage issues such as the effect of different preservative solutions and leukoreduction have been completed. Transfusion with RBCs stored for 42 days increases mortality in dogs with experimental sepsis.

CONCLUSION

Storage of RBCs induces progressive biochemical, biomechanical, and immunologic changes that affect red cell viability, deformability, oxygen carrying capacity, microcirculatory flow, and recipient response. Most reports in the human and veterinary literature support the concept that there are deleterious effects of the RBC storage lesion, but additional studies with improved experimental design are needed to identify compelling reasons to modify current blood banking and transfusion practices.

Perioperative blood transfusion is associated with decreased survival in patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma: a multi-institutional study

INTRODUCTION

In this multi-institutional study of patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma, we sought to identify factors associated with perioperative transfusion requirement as well as the association between blood transfusion and perioperative and oncologic outcomes.

METHODS

The surgical databases across six high-volume institutions were analyzed to identify patients who underwent pancreaticoduodenectomy for pancreatic adenocarcinoma from 2005 to 2010. For statistical analyses, patients were then stratified by transfusion volume according to whether they received 0, 1-2, or >2 units of packed red blood cells.

RESULTS

Among 697 patients identified, 42 % required blood transfusion. Twenty-three percent received 1-2 units, and 19 % received >2 units. Factors associated with an increased transfusion requirement included older age, heart disease, diabetes, longer operative time, higher blood loss, tumor size, and non-R0 margin status (all p < 0.05). The median disease-free survival (13.8 vs. 18.3 months, p = 0.02) and overall survival (14.0 vs. 21.0 months, p < 0.0001) durations of transfused patients were shorter than those of transfusion-free patients. Multivariate modeling identified intraoperative transfusion of >2 units (hazard ratio, 1.92, p = 0.009) and postoperative transfusions as independent factors associated with decreased disease-free survival.

CONCLUSIONS

This multi-institutional study represents the largest series to date analyzing the effects of perioperative blood transfusion on patient outcomes following pancreaticoduodenectomy for pancreatic adenocarcinoma. While blood transfusion was not associated with increased rate of infectious complications, allogeneic blood transfusion did confer a negative impact on disease-free and overall survival.

Analysis of leucocyte antibodies, cytokines, lysophospholipids and cell microparticles in blood components implicated in post-transfusion reactions with dyspnoea

BACKGROUND AND OBJECTIVES

Post-transfusion reactions with dyspnoea (PTR) are major causes of morbidity and death after blood transfusion. Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are most dangerous, while transfusion-associated dyspnoea (TAD) is a milder respiratory distress. We investigated blood components for immune and non-immune factors implicated in PTR.

MATERIAL AND METHODS

We analysed 464 blood components (RBCs, PLTs, L-PLTs, FFP) transfused to 271 patients with PTR. Blood components were evaluated for 1/antileucocyte antibodies, 2/cytokines: IL-1β, IL-6, IL-8, TNF-α, sCD40L, 3/lysophosphatidylcholines (LysoPCs), 4/microparticles (MPs) shed from plateletes (PMPs), erythrocytes (EMPs) and leucocytes (LMPs).

RESULTS

Anti-HLA class I/II antibodies or granulocyte-reactive anti-HLA antibodies were detected in 18.2% of blood components (RBC and FFP) transfused to TRALI and in 0.5% of FFP transfused to TAD cases. Cytokines and LysoPCs concentrations in blood components transfused to PTR patients did not exceed those in blood components transfused to patients with no PTR. Only EMPs percentage in RBCs transfused to patients with TRALI was significantly higher (P < 0.05) than in RBCs transfused to patients with no PTR.

CONCLUSION

Immune character of PTR was confirmed mainly in 1/5 TRALI cases. Among non-immune factors, only MPs released from stored RBCs are suggested as potential mediators of TRALI. Our results require further observations in a more numerous and better defined group of patients.

Platelets release mitochondria serving as substrate for bactericidal group IIA-secreted phospholipase A2 to promote inflammation

Mitochondrial DNA (mtDNA) is a highly potent inflammatory trigger and is reportedly found outside the cells in blood in various pathologies. Platelets are abundant in blood where they promote hemostasis. Although lacking a nucleus, platelets contain functional mitochondria. On activation, platelets produce extracellular vesicles known as microparticles. We hypothesized that activated platelets could also release their mitochondria. We show that activated platelets release respiratory-competent mitochondria, both within membrane-encapsulated microparticles and as free organelles. Extracellular mitochondria are found in platelet concentrates used for transfusion and are present at higher levels in those that induced acute reactions (febrile nonhemolytic reactions, skin manifestations, and cardiovascular events) in transfused patients. We establish that the mitochondrion is an endogenous substrate of secreted phospholipase A2 IIA (sPLA2-IIA), a phospholipase otherwise specific for bacteria, likely reflecting the ancestral proteobacteria origin of mitochondria. The hydrolysis of the mitochondrial membrane by sPLA2-IIA yields inflammatory mediators (ie, lysophospholipids, fatty acids, and mtDNA) that promote leukocyte activation. Two-photon microscopy in live transfused animals revealed that extracellular mitochondria interact with neutrophils in vivo, triggering neutrophil adhesion to the endothelial wall. Our findings identify extracellular mitochondria, produced by platelets, at the midpoint of a potent mechanism leading to inflammatory responses.

Novel swine model of transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a life-threatening complication of blood transfusion. Antibodies against human leukocyte antigens in donors' plasma are the major causes of TRALI. Several animal models of TRALI have been developed, and the mechanism underlying TRALI development has been extensively investigated using rodent models. Although sheep models of nonimmune TRALI have been developed, large-animal models of antibody-mediated TRALI are not yet available.

STUDY DESIGN AND METHODS

To develop a swine model of TRALI, male Clawn strain miniature pigs were used. A monoclonal antibody (MoAb) against swine leukocyte antigens (SLAs) Class I (4G8, 0.3 or 1.0 mg/kg body weight [BW]) and a control antibody (1.0 mg/kg BW) were injected into the peripheral vein after priming with or without 1 μg/kg BW lipopolysaccharide (LPS; n = 3 each). Lung injury was assessed using PaO2 /FiO2 (P/F) ratio and by chest X-ray imaging. Histopathologic analysis was also conducted.

RESULTS

Lung injury could be induced by injecting 4G8 at an amount of 1.0 mg/kg BW, after LPS. The P/F ratio 90 minutes after the administration of 4G8 significantly decreased (p < 0.05). Bilateral infiltration was shown in chest X-ray imaging. Lung injury was confirmed by histopathologic analysis.

CONCLUSION

Lung injury in pigs was successfully induced by anti-SLA MoAb. Priming with LPS is a prerequisite for inducing lung injury and the amount of the antibody is a critical condition.

Storage of Red Blood Cells and Transfusion-Related Acute Lung Injury

Transfusion-related acute lung injury (TRALI) is a major complication post-transfusion. A consensus definition of TRALI has been recently established to improve diagnosis but the pathogenesis of TRALI is yet to be understood. Although the antibody-mediated two-hit model of TRALI is the classical narrative, increasing evidence of the probable implications of prolonged storage of blood provides novel mechanisms towards storage lesion- the potentially injurious cellular and biochemical changes that occur in stored red blood cells. Red blood cell-derived lipids and micro vesicles may have been playing an important role in the development of TRALI. This article will provide a brief overview of the current understanding of TRALI and then discuss the implications and the potential mechanisms by which stored red blood cells may lead to TRALI.

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.

Platelet Vascular Endothelial Growth Factor is a Potential Mediator of Transfusion-Related Acute Lung Injury

Objective

The occurrence of non-hemolytic transfusion reactions is highest with platelet and plasma administration. Some of these reactions are characterized by endothelial leak, especially transfusion related acute lung injury (TRALI). Elevated concentrations of inflammatory mediators secreted by contaminating leukocytes during blood product storage may contribute to such reactions, but platelet-secreted mediators may also contribute. We hypothesized that platelet storage leads to accumulation of the endothelial permeability mediator vascular endothelial growth factor (VEGF), and that intravascular administration of exogenous VEGF leads to extensive binding to its lung receptors.

Methods

Single donor, leukocyte-reduced apheresis platelet units were sampled over 5 days of storage. VEGF protein content of the centrifuged supernatant was determined by ELISA, and the potential contribution of VEGF from contaminating leukocytes was quantified. Isolated-perfused rat lungs were used to study the uptake of radiolabeled VEGF administered intravascularly, and the effect of unlabeled VEGF on lung leak.

Results

There was a time-dependent release of VEGF into the plasma fraction of the platelet concentrates (62 ± 9 pg/ml on day one, 149 ± 23 pg/ml on day 5; mean ± SEM, p<0.01, n=8) and a contribution by contaminating leukocytes was excluded. Exogenous 125I-VEGF bound avidly and specifically to the lung vasculature, and unlabeled VEGF in the lung perfusate caused vascular leak.

Conclusion

Rising concentrations of VEGF occur during storage of single donor platelet concentrates due to platelet secretion or disintegration, but not due to leukocyte contamination. Exogenous VEGF at these concentrations rapidly binds to its receptors in the lung vessels. At higher VEGF concentrations, VEGF causes vascular leak in uninjured lungs. These data provide further evidence that VEGF may contribute to the increased lung permeability seen in TRALI associated with platelet products.

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.

Erythrocyte-derived microvesicles amplify systemic inflammation by thrombin-dependent activation of complement

OBJECTIVE

Transfusion of aged blood has been associated with increased morbidity and mortality in critically ill patients. During storage, erythrocytes release increasing numbers of microvesicles (red blood cell-derived microvesicles [RBC-MV]). We hypothesized that RBC-MV mediate some of the deleterious effects of aged blood transfusions.

APPROACH AND RESULTS

We established a murine transfusion model using RBC-MV purified from aged mouse erythrocytes. Injection of RBC-MV into healthy mice had no effect. However, they aggravated pulmonary leukocyte sequestration and peripheral blood leukopenia induced by lipopolysaccharides. Lipopolysaccharide-induced proinflammatory cytokines were significantly increased in plasma after RBC-MV injection. These effects were not seen in C5aR-deficient mice. In vitro, RBC-MV bound C3 fragments after incubation with plasma but failed to bind immunoglobulins, C1q, or mannose-binding lectin. Preventing thrombin generation inhibited complement activation in vitro and in vivo and reversed the proinflammatory effects of RBC-MV in lipopolysaccharide-primed mice. Finally, the RBC-MV-induced phenotype was recapitulated using phosphatidylserine-expressing liposomes, suggesting that surface expression of phosphatidylserine by RBC-MV was mechanistically involved.

CONCLUSIONS

These results point toward a thrombin-dependent mechanism of complement activation by RBC-MV independent of the classical, lectin, or alternative pathway. Besides identifying RBC-MV as potential mediators of transfusion-related morbidity, our findings may be relevant for other inflammatory disorders involving intravascular microvesicle release, for example, sickle cell disease or thrombotic microangiopathy.

[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.

Interactions of cardiopulmonary bypass and erythrocyte transfusion in the pathogenesis of pulmonary dysfunction in Swine

BACKGROUND

Allogeneic erythrocyte transfusion in cardiac surgical patients is associated with a fourfold increase in pulmonary complications. Our understanding of the processes underlying these observations is poor and there is no experimental model of transfusion-related acute lung injury that shows homology to cardiac surgical patients. Our objective was to develop a novel swine recovery model to determine how two clinical risk factors, allogenic erythrocyte transfusion and cardiopulmonary bypass, interact in the genesis of postcardiac surgery acute lung injury.

METHODS

Thirty-six pigs were infused with allogeneic 14- or 42-day-old erythrocytes or they underwent cardiopulmonary bypass with or without transfusion of 42-day erythrocyte. Controls received saline. All pigs were recovered and assessed for pulmonary dysfunction, inflammation, and endothelial activation at 24 h.

RESULTS

Transfusion of stored allogeneic erythrocytes in pigs compared with sham caused pulmonary dysfunction characterized by reduced lung compliance (mean difference -3.36 [95% CI, -5.31 to -1.42] ml/cm H2O), an increase in protein levels in bronchoalveolar lavage fluid, histological lung injury inflammation, and endothelial activation. Transfusion of blood stored for up to 42 days resulted in greater protein levels in bronchoalveolar lavage fluid, macrophage infiltration, platelet activation, and depletion of T-lymphocytes in recipient lungs versus 14-day-old blood. Transfusion interacted with cardiopulmonary bypass to increase lung injury in the absence of platelet activation.

CONCLUSIONS

In this novel large animal model of allogeneic erythrocyte transfusion, pulmonary dysfunction occurs in the absence of any priming event, is increased when combined with other inflammatory stimuli, and is mediated by monocyte activation and T-lymphocyte depletion.

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.

Impact of immunoreactive substances contained in apheresis platelet concentrate on postoperative respiratory function in surgical patients receiving platelet transfusion: a prospective cohort study

OBJECTIVES

To construct an alternative policy for the donor selection of platelet concentrate (PC), a clinical study exploring the features of lung injury following PC administration is needed.

BACKGROUND

Although a male-donor-only policy for plasma products appears to have efficiently reduced transfusion-related acute lung injury (TRALI), this policy may not be applied to PC because of supply shortages.

METHODS AND MATERIALS

We prospectively examined pulmonary function after the transfusion of PC in informed surgical patients treated at a tertiary university hospital in Japan. The contributions of immunoreactive substances contained in the PC to respiratory function after PC transfusion was then statistically examined.

RESULTS

Eighty-six patients (56 men, 30 women) were enrolled in the analysis. Fifty-four cases experienced respiratory failure (PaO2 /FiO2 <300 mmHg) after transfusion. Five cases were diagnosed as possible TRALI based on permeability pulmonary oedema, while 23 cases were diagnosed as transfusion-associated circulatory overload (TACO) based on chest radiograph findings. A multivariate logistic regression analysis identified the presence of anti-granulocyte antibody as a significant predictor of possible TRALI [P = 0.023; odds ratio (OR), 13.0; 95% confidence interval (CI), 1.4-118.3]. Meanwhile, anti-leukocyte antibody class II was identified as a significant independent predictor of TACO (P = 0.010; OR, 18.4; 95% CI, 2.0-170.1).

CONCLUSIONS

Our data suggest that antibodies contained in PC may contribute to the deterioration of respiratory function after PC transfusion, although the diagnoses of TACO and TRALI may have overlapped among the patients with pulmonary distress in this cohort.

Resuscitation with aged blood exacerbates liver injury in a hemorrhagic rat model

OBJECTIVE

Blood loss and transfusion are frequent among patients undergoing liver surgery. Concerns have been raised about the safety and efficacy of transfusing stored blood. The influence of transfusing fresh vs. stored blood on the liver has not been studied to date. We tested the hypothesis that transfusion of stored, but not fresh blood, adversely affects liver outcome in vivo following acute hemorrhage. Additionally, possible mechanisms linking adverse liver outcome with increased storage duration were evaluated.

DESIGN

Prospective, controlled, animal study.

SETTING

University research laboratory.

SUBJECTS

Adult male Sprague-Dawley rats

INTERVENTIONS

Anesthetized rats were randomized to control, hemorrhagic and shock group (acute bleeding; HSG), or hemorrhagic and blood resuscitation groups (BR) (with fresh blood [BR-d0], blood stored for 4 [BR-d4] or 7 [BR-d7] days, or packed RBCs stored for 7 days [packed RBC-d7]).

MEASUREMENTS AND MAIN RESULTS

Administration of blood or packed RBC stored for 7 days exacerbated liver injury as reflected by liver necrosis and enhanced apoptosis (p < 0.001). Functional MRI analysis of the liver demonstrated significant improvement in liver perfusion with fresh blood (% change in functional MRI signal intensity due to hyperoxia was 16% ± 3% in BR-d0 vs. 4% ± 3% in hemorrhagic group, p < 0.001) but not with stored blood (12% ± 2% and 9% ± 5% for BR-d4 and BR-d7, respectively). Analysis of stored blood showed reduction in RBC deformability at 7 days of storage, reflecting a five-fold increase in the number of undeformable cells.

CONCLUSION

Liver injury is exacerbated by the transfusion of stored blood, primarily due to the change in the rheological properties of RBC. This data call for clinical studies in patients undergoing liver resection or transplantation.

Relationship between red cell storage duration and outcomes in adults receiving red cell transfusions: a systematic review

INTRODUCTION

The duration of red blood cell (RBC) storage before transfusion may alter RBC function and supernatant and, therefore, influence the incidence of complications or even mortality.

METHODS

A MEDLINE search from 1983 to December 2012 was performed to identify studies reporting age of transfused RBCs and mortality or morbidity in adult patients.

RESULTS

Fifty-five studies were identified; most were single-center (93%) and retrospective (64%), with only a few, small randomized studies (eight studies, 14.5%). The numbers of subjects included ranged from eight to 364,037. Morbidity outcomes included hospital and intensive care unit (ICU) length of stay (LOS), infections, multiple organ failure, microcirculatory alterations, cancer recurrence, thrombosis, bleeding, vasospasm after subarachnoid hemorrhage, and cognitive dysfunction. Overall, half of the studies showed no deleterious effects of aged compared to fresh blood on any endpoint. Eleven of twenty-two (50%) studies reported no increased mortality, three of nine (33%) showed no increased LOS with older RBCs and eight of twelve (66%) studies showed no increased risks of organ failure. Ten of eighteen (55%) studies showed increased infections with transfusion of older RBCs. The considerable heterogeneity among studies and numerous methodological flaws precluded a formal meta-analysis.

CONCLUSIONS

In this systematic review, we could find no definitive argument to support the superiority of fresh over older RBCs for transfusion.

Neutrophils release extracellular DNA traps during storage of red blood cell units

BACKGROUND

Blood transfusion is associated with an increased risk of organ damage, infection, and alloimmunity. Neutrophil extracellular traps (NETs) are extracellular chromatin fibers decorated with neutrophil granular proteins that have been linked to cytotoxicity, thrombosis, and autoimmunity. We questioned whether neutrophils in blood products release NETs during storage and thus could contribute to adverse reactions from blood transfusions.

STUDY DESIGN AND METHODS

We analyzed supernatants and blood smears of human red blood cell (RBC) units that either were or were not leukoreduced before storage for markers of NETs.

RESULTS

We identified extracellular DNA, which was associated with histones and myeloperoxidase, a marker of neutrophil granules, in supernatants and blood smears of nonleukoreduced RBC units. These markers of NETs were absent in leukoreduced RBC units. Importantly, NETs passed through blood transfusion filters and could therefore potentially be infused into patients.

CONCLUSIONS

Our studies indicate that NETs are liberated during storage of nonleukoreduced RBC units. Future studies should address whether NETs in RBC units could potentially contribute to transfusion-associated complications.

Inhibition of lysophosphatidic acid increase by prestorage whole blood leukoreduction in autologous CPDA-1 whole blood

BACKGROUND

Lysophosphatidylcholine (LPC) has been implicated in the onset of transfusion-related acute lung injury (TRALI). In plasma, LPC is converted to lysophosphatidic acid (LPA) by autotaxin (ATX). The effect of leukoreduction in the accumulation of these bioactive lipids and ATX in human autologous blood has not been fully investigated.

STUDY DESIGN AND METHODS

The accumulation of choline-containing phospholipids (LPC, sphingomyelin [SM], and phosphatidylcholine [PC]), LPA, and ATX during the storage of autologous blood and the changes caused by leukoreduction were investigated. A total of 26 orthopedic patients were enrolled. Autologous blood was collected as whole blood and, after leukoreduction, preserved refrigerated until use. Prestorage leukoreduced (LR) and non-LR autologous blood samples were analyzed. The time-dependent changes and the effect of the filtration were compared.

RESULTS

A time-dependent and significant increase in the levels of LPA was observed in both non-LR and LR samples. The concentration of LPA was significantly reduced in LR compared to non-LR samples. The concentration of LPC was higher in LR compared to non-LR samples. The levels of PC, SM, and ATX were not affected by either the storage period or the leukoreduction.

CONCLUSIONS

Leukoreduction of autologous whole blood effectively reduced the accumulation of LPA. On the other hand, prestorage leukoreduction resulted in an increased concentration of LPC, without significantly affecting ATX. Further studies are necessary to confirm the role of LPA in the pathogenesis of adverse effects of blood transfusion, especially TRALI.

Innate immune activation after transfusion of stored red blood cells

The transfusion of red blood cells (RBCs), although necessary for treatment of anemia and blood loss, has also been linked to increased morbidity and mortality. RBCs stored for longer durations and transfused in larger volumes are often cited as contributory to adverse outcomes. The potential mechanisms underlying deleterious effects of RBC transfusion are just beginning to be elucidated. In this narrative review, we explore the hypothesis that prolonged RBC storage results in elaboration of substances which may function as danger associated molecular pattern molecules that activate the innate immune system with consequences unfavorable to healthy homeostasis. The nature of these chemical mediators and the biological responses to them offers insight into the mechanisms of these pathological responses. Three major areas of activation of the innate immune apparatus by stored RBCs have been tentatively identified: RBC hemolysis, recipient neutrophil priming, and reactive oxygen species production. The possible mechanisms by which each might perturb the innate immune response are reviewed in a search for potential novel pathways through which transfusion can lead to an altered inflammatory response.

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.

Hemoglobin-based oxygen carrier mitigates transfusion-mediated pancreas cancer progression

BACKGROUND

Perioperative blood transfusion in pancreatic cancer patients is linked to decreased survival; however, a causal mechanism has not been determined. Previously we have shown that the plasma fraction of stored packed red blood cells (pRBCs) promotes pancreas cancer progression and associated morbidity. We hypothesize these untoward effects will be mitigated by use of a hemoglobin-based oxygen carrier (HBOC).

METHODS

Cytokines and growth factors were measured in the plasma fraction from stored pRBCs and in an HBOC via cytokine array followed by formal enzyme-linked immunosorbent assay (ELISA). In an immunocompetent murine model, pancreas cancer progression was determined in vivo by bioluminescence, tumor weight, and number of metastases.

RESULTS

Elevated levels of epidermal growth factor (EGF), platelet-derived growth factor BB (PDGF-BB), and regulated upon activation, normal T cell expressed and secreted (RANTES) were present in the plasma fraction of stored pRBCs, but were not found in the HBOC. Intravenous delivery of plasma fraction to mice with pancreatic cancer resulted in increased bioluminescence activity compared with mice that received HBOC. Metastatic events and pancreatic primary tumor weights were significantly higher in animals receiving plasma fraction from stored pRBCs compared with animals receiving HBOC.

CONCLUSIONS

Intravenous receipt of the acellular plasma fraction of stored pRBCs promotes pancreatic cancer progression in an immunocompetent mouse model. These untoward events are mitigated by use of an HBOC.