Transfusion-related acute lung injury

Morphological and flow-cytometric analysis of haemin-induced human neutrophil activation: implications for transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is associated with vascular endothelial cell injury following neutrophil activation. Recently, it has been suggested that haem-related molecules induce activation of neutrophils and that erythrocyte-derived substances contained in blood preparations are involved in TRALI. We observed the morphological effects and reactive oxygen species (ROS) production of haem-related molecules and investigated the effects of signal transduction inhibitors on haem-induced neutrophil activation.

MATERIALS AND METHODS

The polymorphonuclear cell fraction was isolated and stimulated using a control stimulant, PMA or fMLP, or by haem-related molecules, haemin, ferric citrate, or protoporphyrin IX. After stimulation, neutrophil was analysed using electron microscopy, a flowcytometer (FCM) and confocal laser scanning microscope to determine the fluorescent intensity of aminophenyl fluorescein (to detect ROS).

RESULTS

In FCM analysis, haemin and protoporphyrin IX, both of which have a porphyrin ring, induced ROS production in neutrophils. Ferric citrate, which has no porphyrin ring, did not induce neutrophil activation. Haemin alone induced ROS production at relatively high concentrations, whereas low-level fMLP acted as an agonist in the presence of low concentrations of haemin. Haem-related molecules induced ROS production in neutrophil granules through signal transduction in a way similar to PMA. However, in electron microscopy studies, haemin stimulated neutrophils showed minute process at their surface and did not show the vacuolation observable following stimulation with PMA or fMLP.

DISCUSSION

We suggest that low concentrations of haem-related molecules with porphyrin rings in the presence of other stimulating agent are important for ROS production and possibly the onset of TRALI. The ROS production induced by these molecules is dependent on a signal transduction pathway in a way similar to PMA.

Effects of blood products on inflammatory response in endothelial cells in vitro

BACKGROUND

Transfusing blood products may induce inflammatory reactions within the vascular compartment potentially leading to a systemic inflammatory response. Experiments were designed to assess the inflammatory potential of different blood products in an endothelial cell-based in vitro model and to compare baseline levels of potentially activating substances in transfusion products.

METHODS

The inflammatory response from pre-activated (endotoxin-stimulated) and non-activated endothelial cells as well as neutrophil endothelial transmigration in response to packed red blood cells (PRBC), platelet concentrates (PC) and fresh frozen plasma (FFP) was determined. Baseline inflammatory mediator and lipid concentrations in blood products were evaluated.

RESULTS

Following incubation with all blood products, an increased inflammatory mediator release from endothelial cells was observed. Platelet concentrates, and to a lesser extent also FFP, caused the most pronounced response, which was accentuated in already pre-stimulated endothelial cells. Inflammatory response of endothelial cells as well as blood product-induced migration of neutrophils through the endothelium was in good agreement with the lipid content of the according blood product.

CONCLUSION

Within the group of different blood transfusion products both PC and FFP have a high inflammatory potential with regard to activation of endothelial cells. Inflammation upon blood product exposure is strongly accentuated when endothelial cells are pre-injured. High lipid contents in the respective blood products goes along with an accentuated inflammatory reaction from endothelial cells.

Accumulation of pro-cancer cytokines in the plasma fraction of stored packed red cells

INTRODUCTION

Perioperative blood transfusion has been linked to decreased survival in pancreatic cancer; however, the exact causal mechanism has not been elucidated. Allogeneic transfusions are known to expose patients to foreign cells and lipid mediators. We hypothesize that stored packed red cells (pRBCs) contain pro-cancer cytokines that augment tumor progression. We analyzed the plasma fraction of stored pRBCs for pro-cancer cytokines and evaluated the affect of both storage time and leukocyte reduction on these mediators.

METHODS

Chemiarray™ analysis for pro-cancer cytokines was performed on the acellular plasma fraction of stored leukocyte-reduced (LR) and non-leukocyte-reduced (NLR) pRBCs at day 1 (D.1-fresh) and day 42 (D.42-outdate) of storage. Elevated expression of monocyte chemotactic protein-1 (MCP-1), regulated on activation, normal T cell expressed and secreted (RANTES), angiogenin, tumor necrosis factor-alpha (TNF-α), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF) was found. Specific enzyme-linked immunosorbent assay was performed for each of these factors in LR and NLR blood at D.1, day 28, and D.42. Data were analyzed by ANOVA. A p value ≤ 0.05 was considered significant; N ≥ 4 per group. Migration assays were performed using inhibitors of EGF (gefitinib) and PDGF (imatinib) on murine pancreatic adenocarcinoma cells (Pan02) exposed to D.1 and D.42 LR and NLR plasma. Proliferation assays were performed on Pan02 cells to test the inhibition of PDGF.

RESULTS

MCP-1 levels increased with storage time in LR blood, 86.3 ± 6.3 pg/ml at D.1 vs. 121.2 ± 6.1 pg/ml at D.42 (p = 0.007), and NLR blood, 78.2 ± 7.3 pg/ml at D.1 vs. 647.8 ± 220.7 pg/ml at D.42 (p = 0.02). RANTES levels are lower in LR compared to NLR stored blood, 3.0 ± 1.9 vs. 15.8 ± 0.7 pg/ml at D.42 (p < 0.001), but similar in D.1 blood, 13.8 ± 1.8 pg/ml in LR vs. 12.0 ± 1.6 pg/ml in NLR. Angiogenin levels were different between LR and NLR blood, 0 pg/ml (undetectable) vs. 44.2 ± 3.7 pg/ml (p < 0.001). Storage time did not affect concentration. TNF-α levels were not different between LR and NLR blood, and there was no storage time effect on concentration. EGF and PDGF levels increased with storage time in NLR blood only, 216.4 ± 3.8 pg/ml at D.1 vs. 1,436.4 ± 238.6 pg/ml at D.42 for EGF (p = 0.001), and 61.6 ± 6.0 pg/ml at D.1 vs. 76.5 ± 1.7 pg/ml at D.42 (p = 0.003) for PDGF. Inhibition of EGF reduced migration in Pan02 cells treated with D.42 NLR blood, 245.9 ± 11.2 vs. 164.6 ± 10.6 cells/hpf (p < 0.001). Inhibition of PDGF had no effect on Pan02 migration and reduced cell proliferation in cells treated with D.42 NLR, 181.1 ± 1.5% over control vs. 157.5 ± 2.1% (p < 0.001).

CONCLUSION

Pro-cancer cytokines that can augment tumor progression were identified in pRBCs. Some of these factors are present in fresh blood. The soluble factors identified herein may represent possible therapeutic targets to offset negative effects of transfusion. These data stress the need for efforts in cancer patients to reduce transfusion requirements if needed.

Red blood cell transfusions worsen the outcomes even in critically ill patients undergoing a restrictive transfusion strategy

CONTEXT AND OBJECTIVE

Anemia and blood transfusions are common in intensive care. This study aimed to evaluate epidemiology and outcomes among critically ill patients under a restrictive transfusion strategy.

DESIGN AND SETTING

Prospective observational cohort study in an intensive care unit (ICU) at a tertiary hospital.

METHODS

All adults admitted to the ICU over a one-year period who remained there for more than 72 hours were included, except those with acute coronary syndrome, ischemic stroke, acute hemorrhage, prior transfusion, pregnant women and Jehovah's Witnesses. The restrictive strategy consisted of transfusion indicated when hemoglobin levels were less than or equal to 7.0 g/dl.

RESULTS

The study enrolled 167 patients; the acute physiology and chronic health evaluation II (APACHE II) score was 28.9 ± 6.5. The baseline hemoglobin level was 10.6 ± 2.2 g/dl and on day 28, it was 8.2 ± 1.3 g/dl (P < 0.001). Transfusions were administered to 35% of the patients. In the transfusion group, 61.1% did not survive, versus 48.6% in the non-transfusion group (P = 0.03). Transfusion was an independent risk factor for mortality (P = 0.011; odds ratio, OR = 2.67; 95% confidence interval, CI = 1.25 to 5.69). ICU stay and hospital stay were longer in the transfusion group: 20.0 (3.0-83.0) versus 8.0 (3.0-63.0) days (P < 0,001); and 24.0 (3.0-140.0) versus 14.0 (3.0-80.0) days (P = 0.002), respectively.

CONCLUSIONS

In critically ill patients, there was a reduction in hemoglobin with increasing length of ICU stay. Moreover, transfusion was associated with worse prognoses.

Transfusion-related Acute Lung Injury: Report of Two Cases

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

Use of Blood Products

Patients in the pediatric intensive care unit (PICU) frequently receive transfusions of blood products. While these therapies are often beneficial, they can be associated with significant, yet often overlooked, risks. Clinical guidelines for blood product transfusions must be well defined in order to prevent misuse of this limited resource. It is important for the intensivist to have a thorough understanding of the indications for specific blood products, and the transfusion needs of particular patient populations.

Blood products and the phases of perianesthesia care-reviewing the implications

Perianesthesia nurses often provide care for patients who have received blood products. Over the years, great advances in the safety and technology around blood products have occurred, yet transfusions are not without risk. Because 50% of blood transfusions are administered in the surgical setting, the perianesthesia nurse must know the indications and potential adverse reactions. The perianesthesia nurse has an important role in supporting appropriate use of blood products, which can be a scarce resource at times. By knowing indications, benefits, and risks of transfusion, the nurse can better advocate for the patient's needs. Additionally, with this knowledge, the nurse is able to support patient education and ensure that consent obtained is informed in nature. In this article, the commonly used blood products, potential adverse reactions, and methods to reduce transfusion errors are being reviewed. Ideally, nurses should be provided a periodic review on blood products and transfusion safety to maintain knowledge, competency, and an acceptable comfort level overall. Ongoing education can be an effective means to expand knowledge of the health care provider and improve patient safety and outcomes.

The pro-inflammatory effects of platelet contamination in plasma and mitigation strategies for avoidance

BACKGROUND AND OBJECTIVES

Plasma and platelet concentrates are disproportionately implicated in transfusion-related acute lung injury (TRALI). Platelet-derived pro-inflammatory mediators, including soluble CD40 ligand (sCD40L), accumulate during storage. We hypothesized that platelet contamination induces sCD40L generation that causes neutrophil [polymorphonuclear leucocyte (PMN)] priming and PMN-mediated cytotoxicity.

MATERIALS AND METHODS

Plasma was untreated, centrifuged (12,500 g) or separated from leucoreduced whole blood (WBLR) prior to freezing. Platelet counts and sCD40L concentrations were measured 1-5 days post-thaw. The plasma was assayed for PMN priming activity and was used in a two-event in vitro model of PMN-mediated human pulmonary microvascular endothelial cell (HMVEC) cytotoxicity.

RESULTS

Untreated plasma contained 42±4·2×10(3)/μl platelets, which generated sCD40L accumulation (1·6-eight-fold vs. controls). Priming activity and HMVEC cytotoxicity were directly proportional to sCD40L concentration. WBLR and centrifugation reduced platelet and sCD40L contamination, abrogating the pro-inflammatory potential.

CONCLUSION

Platelet contamination causes sCD40L accumulation in stored plasma that may contribute to TRALI. Platelet reduction is potentially the first TRALI mitigation effort in plasma manufacturing.

MHC class I-specific antibody binding to nonhematopoietic cells drives complement activation to induce transfusion-related acute lung injury in mice

In a manner partially independent of activating Fcγ receptors, antibody-mediated production of complement component C5a and recruitment of macrophages elicit transfusion-related acute lung injury in mice.

Transfusion-related acute lung injury (TRALI), a form of noncardiogenic pulmonary edema that develops during or within 6 h after a blood transfusion, is the most frequent cause of transfusion-associated death in the United States. Because development of TRALI is associated with donor antibodies (Abs) reactive with recipient major histocompatibility complex (MHC), a mouse model has been studied in which TRALI-like disease is caused by injecting mice with anti–MHC class I monoclonal Ab (mAb). Previous publications with this model have concluded that disease is caused by FcR-dependent activation of neutrophils and platelets, with production of reactive oxygen species that damage pulmonary vascular endothelium. In this study, we confirm the role of reactive oxygen species in the pathogenesis of this mouse model of TRALI and show ultrastructural evidence of pulmonary vascular injury within 5 min of anti–MHC class I mAb injection. However, we demonstrate that disease induction in this model involves macrophages rather than neutrophils or platelets, activation of complement and production of C5a rather than activation of FcγRI, FcγRIII, or FcγRIV, and binding of anti–MHC class I mAb to non-BM–derived cells such as pulmonary vascular endothelium. These observations have important implications for the prevention and treatment of TRALI.

Establishing assay cutoffs for HLA antibody screening of apheresis donors

BACKGROUND

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related deaths. Donor HLA antibodies have been implicated in TRALI cases. Blood centers are implementing TRALI risk reduction strategies based on HLA antibody screening of some subpopulations of ever-pregnant apheresis platelet (PLT) donors. However, if screening assay cutoffs are too sensitive, donation loss may adversely impact blood availability.

STUDY DESIGN AND METHODS

Pregnancy history and HLA antibody screening and single-antigen bead data from blood donors in the Retrovirus Epidemiology Donor Study-II Leukocyte Antibody Prevalence Study were evaluated for correlations between assay screening values, HLA antibody titer, and number of HLA antigen specificities. The probabilities of matching a cognate antigen in a recipient were calculated and examined in association with total number of specificities observed and screening values. The relative impact of imposing various screening assay cutoffs or pregnancy stratification was examined in relation to detection of HLA antibody-reactive donations and loss of donors and donations.

RESULTS

We provide evidence that higher HLA antibody screening assay values are associated with maintaining higher screening signals upon dilution and an increased breadth of specificities compared with lower screening values; the latter correlated with an increased risk of a cognate antigen match in potential recipients. Depending on the TRALI risk reduction strategy used, the potential loss of donations ranged between 0.9 and 6.0%.

CONCLUSION

This analysis should enable blood centers to decide upon a TRALI risk reduction strategy for apheresis PLTs that is consistent with how much donation loss the blood center can tolerate.

The Leukocyte Antibody Prevalence Study-II (LAPS-II): a retrospective cohort study of transfusion-related acute lung injury in recipients of high-plasma-volume human leukocyte antigen antibody-positive or -negative components

BACKGROUND

We used a multicenter retrospective cohort study design to evaluate whether human leukocyte antigen (HLA) antibody donor screening would reduce the risk of transfusion-related acute lung injury (TRALI) or possible TRALI.

STUDY DESIGN AND METHODS

In the Leukocyte Antibody Prevalence Study-II (LAPS-II), we evaluated pulmonary outcomes in recipients of 2596 plasma-rich blood components (transfusable plasma and plateletpheresis) sent to participating hospitals; half of the components were collected from anti-HLA-positive donors (study arm) and half from anti-HLA-negative donors (control arm) matched by sex, parity, and blood center. A staged medical record review process was used. Final recipient diagnosis was based on case review by a blinded expert panel of pulmonary or critical care physicians.

RESULTS

TRALI incidence was 0.59% (seven cases) in study arm recipients versus 0.16% (two cases) in control arm recipients for an odds ratio (OR) of 3.6 (95% confidence interval [CI], 0.7-17.4; p = 0.10). For possible TRALI cases (nine study arm, eight control arm), the OR was 1.2 (95% CI, 0.4-3.0; p = 0.81), and for TRALI and possible TRALI aggregated together, it was 1.7 (95% CI, 0.7-3.7; p = 0.24). Transfusion-associated circulatory overload incidence was identical in the two arms (1.17 and 1.22%, respectively; OR, 1.0; p = 1.0).

CONCLUSIONS

TRALI incidence in recipients of anti-HLA-positive components was relatively low for a lookback study (1 in 170) and was higher than in the control arm, but did not reach significance. Based on this trend, the data are consistent with the likelihood that TRALI risk is decreased by selecting high-volume plasma components for transfusion from donors at low risk of having HLA antibodies.

The effect of blood transfusion on pulmonary permeability in cardiac surgery patients: a prospective multicenter cohort study

BACKGROUND

There is an association between blood transfusion and pulmonary complications in cardiac surgery. Mediators of increased pulmonary vascular leakage after transfusion are unknown. We hypothesized that factors may include antibodies or bioactive lipids, which have been implicated in transfusion-related acute lung injury.

STUDY DESIGN AND METHODS

We performed a prospective cohort study in two university hospital intensive care units in the Netherlands. Pulmonary vascular permeability was measured in cardiac surgery patients after receiving no, restrictive (one or two transfusions), or multiple (five or more transfusions) transfusions (n=20 per group). The pulmonary leak index (PLI), using (67) Ga-labeled transferrin, was determined within 3 hours postoperatively. Blood products were screened for bioactive lipid accumulation and the presence of antibodies.

RESULTS

The PLI was elevated in all groups after cardiac surgery. Transfused patients had a higher PLI compared to nontransfused patients (33×10(-3) ± 20×10(-3) vs. 23×10(-3) ± 11×10(-3)/min, p<0.01). The amount of red blood cell (RBC) products, but not of fresh-frozen plasma or platelets, was associated with an increase in PLI (β, 1.6 [0.2-3.0]). Concerning causative factors in the blood product, neither the level of bioactive lipids nor the presence of antibodies was associated with an increase in PLI. Patient factors such as surgery risk and time on cardiopulmonary bypass did not influence the risk of pulmonary leakage after blood transfusion.

CONCLUSIONS

Transfusion in cardiothoracic surgery patients is associated with an increase in pulmonary capillary permeability, an effect that was dose dependent for RBC products. The level of bioactive lipids or the presence of HLA or HNA antibodies in the transfused products were not associated with increased pulmonary capillary permeability.

Many, but not all, outcome studies support exclusion of female plasma from the blood supply

Transfusion-related acute lung injury (TRALI) has been identified as the most common cause of transfusion-related death. Although extensive literature supports restrictions on female-donor plasma to reduce antibody-mediated TRALI, only a few outcome studies have assessed for effects of this change, and some, but not all, have endorsed the policy. A recent report even suggests poorer outcomes in cardiac surgery patients with a shift to male-donor-only plasma, raising concerns that TRALI alone, whether catastrophic or more survivable, is insufficient compared with broader measures, such as short-term mortality or long-term survival, as an end point to assess for overall improvements in patient care.

A national study of plasma use in critical care: clinical indications, dose and effect on prothrombin time

INTRODUCTION

Fresh frozen plasma (FFP) is widely used, but few studies have described patterns of plasma use in critical care. We carried out a multicentre study of coagulopathy in intensive care units (ICUs) and here describe overall FFP utilisation in adult critical care, the indications for transfusions, factors indicating the doses used and the effects of FFP use on coagulation.

METHODS

We conducted a prospective, multicentre, observational study of all patients sequentially admitted to 29 adult UK general ICUs over 8 weeks. Daily data throughout ICU admission were collected concerning coagulation, relevant clinical outcomes (including bleeding), coagulopathy (defined as international normalised ratio (INR) >1.5, or equivalent prothrombin time (PT)), FFP and cryoprecipitate use and indications for transfusion.

RESULTS

Of 1,923 admissions, 12.7% received FFP in the ICU during 404 FFP treatment episodes (1,212 FFP units). Overall, 0.63 FFP units/ICU admission were transfused (0.11 units/ICU day). Reasons for FFP transfusion were bleeding (48%), preprocedural prophylaxis (15%) and prophylaxis without planned procedure (36%). Overall, the median FFP dose was 10.8 ml kg⁻¹, but doses varied widely (first to third quartile, 7.2 to 14.4 ml kg⁻¹). Thirty-one percent of FFP treatments were to patients without PT prolongation, and 41% were to patients without recorded bleeding and only mildly deranged INR (<2.5). Higher volumes of FFP were administered when the indication was bleeding (median doses: bleeding 11.1 ml kg⁻¹, preprocedural prophylaxis 9.8 ml kg⁻¹, prophylaxis without procedure 8.9 ml kg⁻¹; P = 0.009 across groups) and when the pretransfusion INR was higher (ranging from median dose 8.9 ml kg⁻¹ at INR ≤ 1.5 to 15.7 ml kg⁻¹ at INR >3; P < 0.001 across ranges). Regression analyses suggested bleeding was the strongest predictor of higher FFP dose. Pretransfusion INR was more frequently normal when the transfusion indication was bleeding. Overall, posttransfusion corrections of INR were consistently small unless the pretransfusion INR was >2.5, but administration during bleeding was associated with greater INR corrections.

CONCLUSIONS

There is wide variation in FFP use by ICU clinicians, and a high proportion of current FFP transfusions are of unproven clinical benefit. Better evidence from clinical trials could significantly alter patterns of use and modify current treatment costs.

The effect of FFP:RBC ratio on morbidity and mortality in trauma patients based on transfusion prediction score

BACKGROUND AND OBJECTIVES

The empiric use of a high plasma to packed red-blood-cell [fresh frozen plasma:red-blood-cells (FFP:RBC)] ratio in trauma resuscitation for patients with massive bleeding has become well accepted without clear or objective indications. Increased plasma transfusion is associated with worse outcome in some patient populations. While previous studies analyse only patients who received a massive transfusion, this study analyses those that are at risk to receive a massive transfusion, based on the trauma-associated severe haemorrhage (TASH) score, to objectively determine which patients after severe trauma would benefit or have increased complications by the use of a high FFP:RBC ratio.

METHODS

Multicentre retrospective study from the Trauma Registry of the German Trauma Society. Multivariate logistic regression and statistical risk adjustments utilized in analyses.

RESULTS

A high ratio of FFP:RBC in the ≥15 TASH group was independently associated with survival, with an odds ratio of 2·5 (1·6-4·0), while the <15 TASH group was associated with increased multi-organ failure, 47% vs. 38%, (P<0·005).

CONCLUSIONS

A predictive model of massive transfusion upon admission might be able to rapidly identify which severe trauma patients would benefit or have increased complications from the immediate application of a high ratio of FFP:RBCs. This study helps to identify the appropriate population for a prospective, interventional trial.

Results of HLA antibody testing using ELISA vs the fluorescent bead method and retrospective review of data for recipients of packed RBCs and platelets from male HLA-immunized donors

We reviewed HLA antibody testing results using an enzyme-linked immunosorbent assay (ELISA) for all male blood donors at our institution during a 3.5-month period to look for HLA immunization. Confirmatory testing of 33 blood samples positive for HLA class I and/or II antibodies was performed using the fluorescent bead method. A retrospective review of recipients of packed RBCs and platelets processed from these 33 HLA-immunized male donors were conducted to identify transfusion-related acute lung injury and cognate antigens. The agreement rates between the methods for HLA class I and II antibodies were 21% (7/33) and 6% (2/33), respectively. We noted HLA antibodies in the male donors corresponding to cognate antigens in 2 recipients of packed RBCs and in 3 recipients of platelets. Of 8 donors positive for HLA antibodies, 5 did not have a history of blood transfusion. We conclude that ELISA was too sensitive and had a high false-positive rate for the detection of HLA class II antibodies.

Variceal bleeding: consensus meeting report from the Brazilian Society of Hepatology

In the last decades, several improvements in the management of variceal bleeding have resulted in a significant decrease in morbidity and mortality of patients with cirrhosis and bleeding varices. Progress in the multidisciplinary approach to these patients has led to a better management of this disease by critical care physicians, hepatologists, gastroenterologists, endoscopists, radiologists and surgeons. In this respect, the Brazilian Society of Hepatology has, recently, sponsored a consensus meeting in order to draw evidence-based recommendations on the management of these difficult-to-treat subjects. An organizing committee comprised of four people was elected by the Governing Board and was responsible to invite 27 researchers from distinct regions of the country to make a systematic review of the subject and to present topics related to variceal bleeding, including prevention, diagnosis, management and treatment, according to evidence-based medicine. After the meeting, all participants met together for discussion of the topics and the elaboration of the aforementioned recommendations. The organizing committee was responsible for writing the final document. The meeting was held at Salvador, May 6th, 2009 and the present manuscript is the summary of the systematic review that was presented during the meeting, organized in topics, followed by the recommendations of the Brazilian Society of Hepatology.

Generation of neutrophil priming activity by cell-containing blood components treated with pathogen reduction technology and stored in platelet additive solutions

BACKGROUND

Storage of cell-containing blood components such as platelet concentrates (PCs) and red blood cells (RBCs) results in generation of biologically active compounds, many of which may be associated with adverse transfusion events. Priming of the neutrophil oxidase activity is a common characteristic of many of the biologically active compounds found in stored blood. We evaluated the priming activity of pathogen reduction technology (PRT)-treated PCs stored in plasma or platelet additive solution (PAS) and PRT-treated RBCs.

STUDY DESIGN AND METHODS

PCs were collected with Trima or Amicus equipment and were PRT treated with the Mirasol PRT system or the Intercept Blood System. Some units were gamma irradiated. Products were stored in 100% plasma or 35% plasma plus PAS. RBCs were washed and PRT treated before storage. Samples were removed throughout storage and priming of the oxidase activity was measured.

RESULTS

Platelets collected on Trima or Amicus equipment and stored in plasma or PAS demonstrated increasing priming activity during 5 to 7 days of storage. Gamma irradiation, but not PRT treatment with either technology, further enhanced this priming activity. Supernatants of RBCs stored for 42 days induced priming in untreated controls, but not in washed or Mirasol PRT-treated test products.

CONCLUSION

Production of oxidase priming activity increased during storage in all blood products. No significant differences were associated with the collection method, storage in PAS, or PRT treatment. The generation of biologically active compounds, which may serve as an etiology for adverse events, appears to be independent of these processes for collection, storage, and pathogen reduction.

Morbidity after paediatric cardiac surgery assessed with usage of medicines: a population-based registry study

OBJECTIVE

To examine the overall morbidity of patients who underwent surgery for congenital cardiac defect during childhood.

BACKGROUND

A congenital cardiac defect treated with surgery is seldom totally cured. The incidence of residua, sequelae, and comorbidity is quite high. The morbidity has not been thoroughly examined.

METHODS AND PATIENTS

Medication was used as an indicator of morbidity. Data from the Finnish Research Registry of Paediatric Cardiac Surgery were linked to data from the medication registry of Finland's Social Insurance Institution. This study includes 5116 patients with a mean age of 33.5 (ranged from 14.7 to 64.8) years, who had undergone surgery for congenital cardiac defect between 1953 and 1989. The use of medicines among patients in 2004 was compared with 10232 age- and sex-matched control subjects.

RESULTS

The overall use of medicines was frequent; 62% of patients and 53% of controls had purchased at least one prescribed medicine (risk ratio: 1.2, 95% confidence interval: 1.1-1.2). The number of patients using cardiovascular medicines (17%) and anti-thrombotic agents (5%) was higher than that of control subjects (risk ratio: 2.2 and 8.4). In addition, the patients needed medicinal care for epilepsy (3%), asthma (7%), and psychiatric diseases (10%) more often than did controls (risk ratio: 2.2, 1.5, and 1.3, respectively).

CONCLUSION

Patients operated on for congenital cardiac defect had more chronic diseases and used more medicines than did controls.

Enhancement of endothelial permeability by coculture with peripheral blood mononuclear cells in the presence of HLA Class II antibody that was associated with transfusion-related acute lung injury

BACKGROUND

HLA Class II antibody-initiated activation of monocytes possessing the corresponding antigen is thought to participate in the pathogenesis of transfusion-related acute lung injury (TRALI). Pulmonary edema, a hallmark of TRALI, is caused by increasing vascular permeability.

STUDY DESIGN AND METHODS

To investigate the contribution of HLA Class II antibody and monocytes to the development of pulmonary edema in TRALI, we studied whether the permeability of human lung microvascular endothelial cells (HMVECs) could be enhanced by coculturing HMVECs with peripheral blood mononuclear cells (PBMNCs) in the presence of HLA Class II antibody-containing plasma, which was implicated in TRALI (anti-HLA-DR plasma). In addition, similar experiments were performed with human umbilical vein endothelial cells (HUVECs). The endothelial permeability to fluoresceinated dextran, which was added from the start of coculture, was measured.

RESULTS

The coculture of HMVECs or HUVECs with PBMNCs in the presence of anti-HLA-DR plasma resulted in the increase of endothelial permeability in the corresponding antigen-antibody-dependent manner. CV-3988, a platelet-activating factor (PAF) receptor antagonist, almost completely suppressed the increase in endothelial permeability. Neutralizing antibodies to tumor necrosis factor (TNF)-α alone and simultaneous addition of the antibodies to TNF-α and interleukin (IL)-1β to the coculture partially suppressed the permeability increase of HMVECs and HUVECs, respectively.

CONCLUSIONS

HLA Class II antibody and monocytes in the corresponding antigen-antibody combination caused the enhancement of endothelial permeability. PAF, TNF-α, and/or IL-1β might be involved in the endothelial permeability increase. HLA Class II antibody-initiated monocyte activation could lead to the development of pulmonary edema in TRALI.

Acquired von Willebrand syndrome after continuous-flow mechanical device support contributes to a high prevalence of bleeding during long-term support and at the time of transplantation

OBJECTIVES

The objective of the study was to determine the prevalence of bleeding during continuous-flow left ventricular assist device support and to identify potential mechanisms for those bleeding events.

BACKGROUND

Bleeding is frequently reported with continuous-flow left ventricular assist devices and may result from anticoagulation coupled with bleeding diathesis such as acquired von Willebrand syndrome. Accordingly, the prevalence of coagulation abnormalities including laboratory assessment for von Willebrand syndrome, bleeding events during device support, and at heart transplantation were evaluated.

METHODS

A retrospective study in all HeartMate II (HM II) (Thoratec Corp., Pleasanton, California) patients who underwent implantation between April 1, 2004, and August 1, 2009, was performed. Bleeding was defined as the need for transfusion >7 days after device insertion of 1 U of packed red blood cells. Transfusion at heart transplantation was compared with that in HeartMate XVE patients.

RESULTS

Seventy-nine HM II devices were implanted. Anticoagulation included warfarin in 68.3%, aspirin in 55.7%, and dipyridamole in 58.2% of the patients. Of the patients, 44.3% had bleeding episodes at 112 ± 183 days after left ventricular assist device implantation, with 50% experiencing an event within 2 months. Gastrointestinal bleeding was the most frequent event. At the index event, the international normalized ratio averaged 1.67 ± 0.53, and the platelet count was 237 ± 119 × 10(9)/l. Comparison of the transfusion requirements at heart transplantation of 35 HM II patients with 62 HeartMate XVE patients demonstrated twice the transfusion requirements in HM II patients (packed red blood cells, 6.3 ± 0.8 U vs. 3.8 ± 0.5 U; platelets, 12.5 ± 5.4 U vs. 8.6 ± 6.4 U; fresh frozen plasma, 9.6 ± 4.9 U vs. 4.9 ± 3.6 U; and cryoprecipitate, 4.3 ± 3.6 U vs. 2.2 ± 3.5 U; p < 0.05 for all). High molecular weight von Willebrand factor multimers were measured in 31 HM II patients and were reduced in all patients; 18 of these 31 (58%) patients had bleeding.

CONCLUSIONS

Patients with the HM II had a high incidence of bleeding events during device support and at heart transplantation. All HM II patients had reduced high molecular weight von Willebrand factor multimers. The role of these abnormalities in the high incidence of bleeding deserves further investigation. Furthermore, alterations in anticoagulation should be considered during device support and before surgery in patients supported with the HM II.

Acute lung injury during antithymocyte globulin therapy for aplastic anemia

The case of a 33-year-old man with aplastic anemia who experienced recurrent episodes of hypoxemia and pulmonary infiltrates during infusions of antithymocyte globulin (ATG) is described. With the use of high-dose corticosteroids, the patient's original episodes resolved, and were subsequently prevented before additional administrations of ATG. Rare reports of an association between ATG and acute lung injury are found in the literature, but this is the first report of successful steroid-supported re-exposure. Although the mechanism of ATG-related acute lung injury remains uncertain, it may be parallel to the mechanism of transfusion-related acute lung injury because the pathogenesis of the latter relies, in part, on antileukocyte antibodies. ATG-related toxicity should be included in the differential diagnosis of new, infusion-associated pulmonary infiltrates, and corticosteroids may be a useful therapeutic consideration in the management.

Cardiovascular sex differences influencing microvascular exchange

The vital role of the cardiovascular (CV) system is maintenance of body functions via the matching of exchange to tissue metabolic demand. Sex-specific differences in the regulatory mechanisms of CV function and the metabolic requirements of men and women, respectively, have been identified and appreciated. This review focuses on sex differences of parameters influencing exchange at the point of union between blood and tissue, the microvasculature. Microvascular architecture, blood pressure (hydrostatic and oncotic), and vascular permeability, therefore, are discussed in the specific context of sex in health and disorders. It is notable that when sex differences exist, they are generally subtle but significant. In the aggregate, though, they can give rise to profoundly different phenotypes. The postulated mechanisms responsible for sex differences are attributed to genomics, epigenetics, and sex hormones. Depending on specific circumstances, the effect of the combined factors can range from insignificant to lethal. Identifying and understanding key signalling mechanisms bridging genomics/sex hormones and microvascular exchange properties within the scope of this review holds significant promise for sex-specific prevention and treatment of vascular barrier dysfunction.

Safety of cardiac surgery without blood transfusion: a retrospective study in Jehovah's Witness patients

The aim of this retrospective study was to compare the utilisation of blood products and outcomes following cardiac surgery for 123 Jehovah's Witnesses and 4219 non-Jehovah's Witness patient controls. The study took place over a 7-year period at the Amphia Hospital in Breda, the Netherlands. A specific protocol was used in the management of Jehovah's Witness patients, while the control group received blood without restriction according to their needs. Patients' characteristics were comparable in both groups. Pre-operatively, the mean (SD) Euro Score was higher in the Jehovah's Witness group (3.2 (2.6) vs 2.7 (2.5), respectively; p < 0.02). Pre-operative haemoglobin concentration was higher in the Jehovah's Witness group (8.9 (0.7) vs 8.6 (0.9) g.dl(-1), respectively; p < 0.001). The total cardiopulmonary bypass time did not differ between groups. The requirement for allogenic blood transfusion was 0% in the Jehovah's Witness group compared to 65% in the control group. Postoperatively, there was a lower incidence of Q-wave myocardial infarction (2 (1.8%) vs 323 (7.7%), respectively; p < 0.02), and non Q-wave infarction (11 (9.8%) vs 559 (13.2%), respectively; p < 0.02) in the Jehovah's Witness group compared with controls. Mean (SD) length of stay in the intensive care unit (2.3 (3.2) vs 2.6 (4.2) days; p = 0.26), re-admission rate to the intensive care unit (5 (4.5%) vs 114 (2.7%); p = 0.163), and mortality (3 (2.7%) vs 65 (1.5%); p = 0.59), did not differ between the Jehovah's Witness and control groups, respectively.

Blood still kills: six strategies to further reduce allogeneic blood transfusion-related mortality

After reviewing the relative frequency of the causes of allogeneic blood transfusion-related mortality in the United States today, we present 6 possible strategies for further reducing such transfusion-related mortality. These are (1) avoidance of unnecessary transfusions through the use of evidence-based transfusion guidelines, to reduce potentially fatal (infectious as well as noninfectious) transfusion complications; (2) reduction in the risk of transfusion-related acute lung injury in recipients of platelet transfusions through the use of single-donor platelets collected from male donors, or female donors without a history of pregnancy or who have been shown not to have white blood cell (WBC) antibodies; (3) prevention of hemolytic transfusion reactions through the augmentation of patient identification procedures by the addition of information technologies, as well as through the prevention of additional red blood cell alloantibody formation in patients who are likely to need multiple transfusions in the future; (4) avoidance of pooled blood products (such as pooled whole blood-derived platelets) to reduce the risk of transmission of emerging transfusion-transmitted infections (TTIs) and the residual risk from known TTIs (especially transfusion-associated sepsis [TAS]); (5) WBC reduction of cellular blood components administered in cardiac surgery to prevent the poorly understood increased mortality seen in cardiac surgery patients in association with the receipt of non-WBC-reduced (compared with WBC-reduced) transfusion; and (6) pathogen reduction of platelet and plasma components to prevent the transfusion transmission of most emerging, potentially fatal TTIs and the residual risk of known TTIs (especially TAS).

Risk factors and outcome of transfusion-related acute lung injury in the critically ill: a nested case-control study

OBJECTIVES

To determine the incidence, risk factors, and outcome of transfusion-related acute lung injury in a cohort of critically ill patients.

DESIGN

In a retrospective cohort study, patients with transfusion-related acute lung injury were identified using the consensus criteria of acute lung injury within 6 hrs after transfusion. Inclusion criterion was a length of intensive care unit admission >48 hrs. Patients developing transfusion-related acute lung injury were matched (on age, sex, and admission diagnosis) to transfused control subjects and patients developing acute lung injury from another origin.

SETTING

Tertiary referral hospital.

PATIENTS

All first-admitted patients from November 1, 2004, until October 1, 2007, to the intensive care unit.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 5208 admitted patients, 2024 patients had a length of stay >48 hrs, of whom 109 were suspected transfusion-related acute lung injury cases. Compared with transfused control subjects, risk factors for transfusion-related acute lung injury were emergency cardiac surgery (odds ratio, 17.6 [1.8-168.5]), hematologic malignancy (odds ratio, 13.1 [2.7-63.8]), massive transfusion (odds ratio, 4.5 [2.1-9.8]), sepsis (odds ratio, 2.5 [1.2-5.2]), mechanical ventilation (odds ratio, 3.0 [1.3-7.1], and high Acute Physiology and Chronic Health Evaluation II score (odds ratio, 1.1 [1.0-1.1]; p < .03 for all). The volume of platelets and plasma transfused was associated with transfusion-related acute lung injury in the univariate analysis. However, this association disappeared in the multivariate analysis. Compared with acute lung injury control subjects, risk factors for transfusion-related acute lung injury were sepsis (odds ratio, 2.4 [1.1-5.3]) and high Acute Physiology and Chronic Health Evaluation II score (odds ratio, 1.1 [1.0-1.1]), whereas pneumonia (odds ratio, 0.4 [0.2-0.7]) was a negative predictive factor. Patients with transfusion-related acute lung injury had a longer duration of mechanical ventilation compared with transfused control subjects and acute lung injury control subjects (231 [138-472] vs. 71 [46-163] and 70 [42-121] hrs, p < .001). Also, 90-day survival of patients with transfusion-related acute lung injury was lower compared with transfused control subjects and acute lung injury control subjects (53% vs. 75% and 83%, p < .02).

CONCLUSIONS

Transfusion-related acute lung injury is common in critically ill patients. Transfusion-related acute lung injury may contribute to an adverse outcome associated with transfusion. This study identifies transfusion-related acute lung injury risk factors, which may aid in assessing the risks and benefits of transfusion in critically ill patients.

Why implement universal leukoreduction?

The improvement of transfusion medicine technology is an ongoing process primarily directed at increasing the safety of allogeneic blood component transfusions for recipients. Over the years, relatively little attention had been paid to the leukocytes present in the various blood components. The availability of leukocyte removal (leukoreduction) techniques for blood components is associated with a considerable improvement in various clinical outcomes. These include a reduction in the frequency and severity of febrile transfusion reactions, reduced cytomegalovirus transfusion-transmission risk, the reduced incidence of alloimmune platelet refractoriness, a possible reduction in the risk of transfusion-associated variant Creutzfeldt-Jakob disease transmission, as well as reducing the overall risk of both recipient mortality and organ dysfunction, particularly in cardiac surgery patients and possibly in other categories of patients. Internationally, 19 countries have implemented universal leukocyte reduction (ULR) as part of their blood safety policy. The main reason for not implementing ULR in those countries that have not appears to be primarily concerns over costs. Nonetheless, the available international experience supports the concept that ULR is a process that results in improved safety of allogeneic blood components.

Clinical impact of blood storage lesions

Recent reports suggest that transfusion of old red blood cell (RBC) units (>2 weeks) was associated with increased risks of postoperative complications and higher mortality rate caught public attention (Yap et al., Ann Thorac Surg 2008; 86:554-559 and Koch et al., 2008; 358:1229-1239). This rekindled the decades old discussion regarding the impact of RBC aging and storage lesions in patient care. The objectives of this review are to provide readers with an overview of the process of banking RBC that may have an impact on its quality, the reported clinical impact of storage lesions, the consequences of transfusing new RBC units only to the nation's blood supply and potential solutions that may improve the feasibility of blood banks to issue new blood units only.

Transfusion-related acute lung injury

Transfusion-related acute lung injury is a clinical syndrome that occurs within 6 hours of transfusion. It is the leading cause of transfusion-related mortality. It presents with shortness of breath, acute pulmonary edema, fever, hypotension, or hypertension followed by hypotension. Treatment consists of respiratory support and fluid administration to support blood pressure. A majority of cases are associated with antibodies to white blood cells in the blood donor. Blood centers in the United States are currently taking measures to reduce the risk of transfusion-related acute lung injury from blood components.

Efficacy and Safety Profile of Solvent/Detergent Plasma in the Treatment of Acute Thrombotic Thrombocytopenic Purpura: A Single-Center Experience

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a rare clinical disorder which was associated with poor prognosis for a long time. The outcome has been improved by the consistent introduction of thera-peutic plasma exchange (TPE) as standard treatment of TTP. PATIENTS AND METHODS: We describe our experience in the use of solvent/detergent-treated plasma (SDP) for TPE in TTP. We retrospectively analyzed acute TTP epi-sodes in 8 patients (mean age = 27 years, range 18-44 years) treated with TPE using SDP with regard to tolerability and efficacy. RESULTS: All 8 patients were positive for anti-ADAMTS-13 antibody. Seven out of 8 had a se-vere ADAMTS-13 deficiency. All patients responded rapidly to SDP TPE with an increase in platelet count to above 150 x 10(9)/l. Hemolytic anemia disappeared over the treatment period. Approximately 2,000 l SDP were used for more than 500 treatments. Treatment with SDP was well tolerated; none of the patients experienced an adverse drug reaction after exposure to SDP. No major complications occurred even after multiple TPE. CONCLUSION: Our investigations suggest that TPE using SDP as replacement fluid is an effective treatment for TTP. The data described also indicate that SDP might offer the benefit of reducing adverse drug reactions.

Optimal use of blood in trauma patients

Injury is rapidly becoming the leading cause of death worldwide, and uncontrolled hemorrhage is the leading cause of potentially preventable death. In addition to crystalloid and/or colloid based resuscitation, severely injured trauma patients are routinely transfused RBCs, plasma, platelets, and in some centers either cryoprecipitate or fibrinogen concentrates or whole blood. Optimal timing and quantity of these products in the treatment of hypothermic, coagulopathic and acidotic trauma patients is unclear. The immediate availability of these components is important, as most hemorrhagic deaths occur within the first 3-6h of patient arrival. While there are strongly held opinions and longstanding traditions in their use, there are little data within which to logically guide resuscitation therapy. Many current recommendations are based on euvolemic elective surgery patients and incorporate laboratory data parameters not widely available in the first few minutes after patient arrival. Finally, blood components themselves have evolved over the last 30 years, with great attention paid to product safety and inventory management, yet there are surprisingly limited clinical outcome data describing the long term effects of these changes, or how the components have improved clinical outcomes compared to whole blood therapy. When focused on survival of the rapidly bleeding trauma patient, it is unclear if current component therapy is equivalent to whole blood transfusion. In fact data from the current war in Iraq and Afghanistan suggest otherwise. All of these factors have contributed to the current situation, whereby blood component therapy is highly variable and not driven by long term patient outcomes. This review will address the issues raised above and describe recent trauma patient outcome data utilizing predetermined plasma:platelet:RBC transfusion ratios and an ongoing prospective observational trauma transfusion study.

Regulation of inflammation by Rac2 in immune complex-mediated acute lung injury

Acute lung injury (ALI) is an inflammatory disorder associated with recruitment and activation of neutrophils in lungs. Rac2, a member of the Rho GTPase subfamily, is an essential regulator of neutrophil degranulation, superoxide release, and chemotaxis. Here, we hypothesized that Rac2 is important in mediating lung injury. Using a model of IgG immune complex-mediated ALI, we showed that injury was attenuated in rac2(-/-) mice compared with wild-type (WT) mice undergoing ALI, with significant decreases in alveolar leukocyte numbers, vascular leakage, and the inflammatory mediators, myeloperoxidase (MPO) and matrix metalloproteinases (MMPs). Reduced injury in rac2(-/-) mice was not associated with diminished cytokine and chemokine production, since bronchoalveolar lavage (BAL) levels of IL-17, TNF, CCL3, CXCL1, and CXCL2 were similarly increased in WT and rac2(-/-) mice with ALI compared with sham-treated mice (no ALI). BAL levels of MMP-2 and MMP-9 were significantly decreased in the airways of rac2(-/-) mice with ALI. Immunohistochemical analysis revealed that MMP-2 and MMP-9 expression was evident in alveolar macrophages and interstitial neutrophils in WT ALI. In contrast, MMP-positive cells were less prominent in rac2(-/-) mice with ALI. Chimeric mice showed that Rac2-mediated lung injury was dependent on hematopoietic cells derived from bone marrow. We propose that lung injury in response to immune complex deposition is dependent on Rac2 in alveolar macrophages and neutrophils.

The role of neutrophils in the pathogenesis of transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is the major cause of transfusion related morbidity and mortality, world wide. Efforts to reduce or eliminate this serious complication of blood transfusion are hampered by an incomplete understanding of its pathogenesis. Currently, TRALI is thought to be mediated by donor alloantibodies directed against host leukocytes or the result of 2 distinct clinical events. For both proposed mechanisms, the neutrophil is the key effector cell. This article reviews TRALI pathophysiology, explores the role of the neutrophil, details practical information for appropriate diagnosis and promotes further studies into the pathogenesis of TRALI.

Role of extracellular adenosine in acute lung injury

Acute lung injury (ALI) is a lung disease characterized by pulmonary edema and severe hypoxia. The past decade hosted a search for endogenous mechanisms controlling lung inflammation and pulmonary edema during ALI. As such, recent evidence indicates extracellular adenosine in orchestrating the resolution of pulmonary edema and inflammation during ALI.

Mirasol Pathogen Reduction Technology treatment does not affect acute lung injury in a two-event in vivo model caused by stored blood components

INTRODUCTION

Mirasol Pathogen Reduction Technology (PRT) treatment uses riboflavin and UV light to inactivate pathogens in blood components. Neutrophil [polymorphonuclear cells (PMN)] priming activity accumulates during routine storage of cellular blood components, and this activity has been implicated in transfusion-related acute lung injury (TRALI). We hypothesize that PRT-treatment of blood components affects the priming activity generated during storage of packed RBCs (PRBCs) or platelet concentrates (PCs), which can elicit ALI in vivo.

METHODS

Plasma, PRBCs and PCs were isolated from healthy donor's whole blood or by apheresis. Half of a collected unit was treated with PRT treatment and the remainder was left as an unmodified control. Supernatant was collected during storage of PCs and PRBCs and assayed for PMN priming activity and used as the second event in a two-event in vivo model of TRALI.

RESULTS

PRT treatment did not induce priming activity in plasma or affect the priming activity generated during storage of PCs or PRBCs as compared with the unmodified controls. The supernatants from stored, but not fresh, PCs and PRBCs did cause ALI as the second event in a two-event animal model of TRALI, which was unaffected by PRT treatment. We conclude that the PRT treatment does not induce priming activity in plasma nor does it affect the priming activity generated during storage of PCs or PRBCs or their ability to cause ALI as the second event in a two-event in vivo model of TRALI. Moreover, the amount of priming activity in TRIMA-isolated PCs was significantly less than SPECTRA-isolated PCs.