Age of transfused blood in critically ill adults.

BACKGROUND: Fresh red cells may improve outcomes in critically ill patients by enhancing oxygen delivery while minimizing the risks of toxic effects from cellular changes and the accumulation of bioactive materials in blood components during prolonged storage. METHODS: In this multicenter, randomized, blinded trial, we assigned critically ill adults to receive either red cells that had been stored for less than 8 days or standard-issue red cells (the oldest compatible units available in the blood bank). The primary outcome measure was 90-day mortality. RESULTS: Between March 2009 and May 2014, at 64 centers in Canada and Europe, 1211 patients were assigned to receive fresh red cells (fresh-blood group) and 1219 patients were assigned to receive standard-issue red cells (standard-blood group). Red cells were stored a mean (±SD) of 6.1±4.9 days in the fresh-blood group as compared with 22.0±8.4 days in the standard-blood group (P<0.001). At 90 days, 448 patients (37.0%) in the fresh-blood group and 430 patients (35.3%) in the standard-blood group had died (absolute risk difference, 1.7 percentage points; 95% confidence interval [CI], -2.1 to 5.5). In the survival analysis, the hazard ratio for death in the fresh-blood group, as compared with the standard-blood group, was 1.1 (95% CI, 0.9 to 1.2; P=0.38). There were no significant between-group differences in any of the secondary outcomes (major illnesses; duration of respiratory, hemodynamic, or renal support; length of stay in the hospital; and transfusion reactions) or in the subgroup analyses. CONCLUSIONS: Transfusion of fresh red cells, as compared with standard-issue red cells, did not decrease the 90-day mortality among critically ill adults. (Funded by the Canadian Institutes of Health Research and others; Current Controlled Trials number, ISRCTN44878718.).

Effects of red-cell storage duration on patients undergoing cardiac surgery.

BACKGROUND: Some observational studies have reported that transfusion of red-cell units that have been stored for more than 2 to 3 weeks is associated with serious, even fatal, adverse events. Patients undergoing cardiac surgery may be especially vulnerable to the adverse effects of transfusion. METHODS: We conducted a randomized trial at multiple sites from 2010 to 2014. Participants 12 years of age or older who were undergoing complex cardiac surgery and were likely to undergo transfusion of red cells were randomly assigned to receive leukocyte-reduced red cells stored for 10 days or less (shorter-term storage group) or for 21 days or more (longer-term storage group) for all intraoperative and postoperative transfusions. The primary outcome was the change in Multiple Organ Dysfunction Score (MODS; range, 0 to 24, with higher scores indicating more severe organ dysfunction) from the preoperative score to the highest composite score through day 7 or the time of death or discharge. RESULTS: The median storage time of red-cell units provided to the 1098 participants who received red-cell transfusion was 7 days in the shorter-term storage group and 28 days in the longer-term storage group. The mean change in MODS was an increase of 8.5 and 8.7 points, respectively (95% confidence interval for the difference, -0.6 to 0.3; P=0.44). The 7-day mortality was 2.8% in the shorter-term storage group and 2.0% in the longer-term storage group (P=0.43); 28-day mortality was 4.4% and 5.3%, respectively (P=0.57). Adverse events did not differ significantly between groups except that hyperbilirubinemia was more common in the longer-term storage group. CONCLUSIONS: The duration of red-cell storage was not associated with significant differences in the change in MODS. We did not find that the transfusion of red cells stored for 10 days or less was superior to the transfusion of red cells stored for 21 days or more among patients 12 years of age or older who were undergoing complex cardiac surgery. (Funded by the National Heart, Lung, and Blood Institute; RECESS ClinicalTrials.gov number, NCT00991341.).

The role of comparative effectiveness research in transfusion medicine clinical trials: proceedings of a National Heart, Lung, and Blood Institute workshop.

Comparative effectiveness research (CER) is the study of existing treatments or ways to deliver health care to determine what intervention works best under specific circumstances. CER evaluates evidence from existing studies or generates new evidence, in different populations and under specific conditions in which the treatments are actually used. CER does not embrace one research design over another but compares treatments and variations in practice using methods that are most likely to yield widely generalizable results that are directly relevant to clinical practice. Treatments used in transfusion medicine (TM) are among the most widely used in clinical practice, but are among the least well studied. High-quality evidence is lacking for most transfusion practices, with research efforts hampered by regulatory restrictions and ethical barriers. To begin addressing these issues, the National Heart, Lung, and Blood Institute convened a workshop in June 2011 to address the potential role of CER in the generation of high-quality evidence for TM decision making. Workshop goals were to: 1) evaluate the current landscape of clinical research, 2) review the potential application of CER methods to clinical research, 3) assess potential barriers to the use of CER methodology, 4) determine whether pilot or vanguard studies can be used to facilitate planning of future CER research, and 5) consider the need for and delivery of training in CER methods for researchers.

Clinical trial opportunities in hemostasis and thrombosis: NHBLI State-of-the-Science symposium.

Clinical trials in hemostasis and thrombosis (HT) are needed to guide medical practice and future research. Providing public support for trials that could have the greatest impact on clinical care has been a major challenge. The National Heart, Lung and Blood Institute (NHLBI) convened a State-of-the-Science meeting in Bethesda on September 14th and 15th, 2009 to identify Phase II and III clinical trials in HT that could have critical impact on healthcare. An oversight committee composed of representatives of the NHLBI and three experienced extramural investigators chose chairs of subcommittees representing six broad areas of investigation in adult and pediatric HT. Chairs were charged with identifying important, feasible proposals. Nineteen trial concepts were presented at this public meeting, followed by open commentary from members of an independent external panel chosen to evaluate the trials and from symposium participants from the wider scientific community. Descriptions of two important clinical trial concepts from each of the six subcommittees are provided in the Supporting Information. Phase II-III clinical trials that could have high impact include studies for treatment of venous thromboembolism (TE) in children and in adults, the potential utility of statins in prophylaxis of TE, prophylaxis of adults with severe hemophilia, management of heparin-induced thrombocytopenia (HIT) and of primary immune thrombocytopenia (ITP). The external panel also provided recommendations concerning infrastructure and approach that could improve the conduct of studies including: development of core organizations with expertise in design of clinical trials, biostatistics, and contract development; funding based on output and milestones; and enhanced investment in coordinating centers.

Effect of fresh red blood cell transfusions on clinical outcomes in premature, very low-birth-weight infants: the ARIPI randomized trial.

CONTEXT: Even though red blood cells (RBCs) are lifesaving in neonatal intensive care, transfusing older RBCs may result in higher rates of organ dysfunction, nosocomial infection, and length of hospital stay. OBJECTIVE: To determine if RBCs stored for 7 days or less compared with usual standards decreased rates of major nosocomial infection and organ dysfunction in neonatal intensive care unit patients requiring at least 1 RBC transfusion. DESIGN, SETTING, AND PARTICIPANTS: Double-blind, randomized controlled trial in 377 premature infants with birth weights less than 1250 g admitted to 6 Canadian tertiary neonatal intensive care units between May 2006 and June 2011. INTERVENTION: Patients were randomly assigned to receive transfusion of RBCs stored 7 days or less (n = 188) vs standard-issue RBCs in accordance with standard blood bank practice (n = 189). MAIN OUTCOME MEASURES: The primary outcome was a composite measure of major neonatal morbidities, including necrotizing enterocolitis, retinopathy of prematurity, bronchopulmonary dysplasia, and intraventricular hemorrhage, as well as death. The primary outcome was measured within the entire period of neonatal intensive care unit stay up to 90 days after randomization. The rate of nosocomial infection was a secondary outcome. RESULTS: The mean age of transfused blood was 5.1 (SD, 2.0) days in the fresh RBC group and 14.6 (SD, 8.3) days in the standard group. Among neonates in the fresh RBC group, 99 (52.7%) had the primary outcome compared with 100 (52.9%) in the standard RBC group (relative risk, 1.00; 95% CI, 0.82-1.21). The rate of clinically suspected infection in the fresh RBC group was 77.7% (n = 146) compared with 77.2% (n = 146) in the standard RBC group (relative risk, 1.01; 95% CI, 0.90-1.12), and the rate of positive cultures was 67.5% (n = 127) in the fresh RBC group compared with 64.0% (n = 121) in the standard RBC group (relative risk, 1.06; 95% CI, 0.91-1.22). CONCLUSION: In this trial, the use of fresh RBCs compared with standard blood bank practice did not improve outcomes in premature, very low-birth-weight infants requiring a transfusion. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00326924; Current Controlled Trials Identifier: ISRCTN65939658.

A comparison of aprotinin and lysine analogues in high-risk cardiac surgery.

BACKGROUND: Antifibrinolytic agents are commonly used during cardiac surgery to minimize bleeding and to reduce exposure to blood products. We sought to determine whether aprotinin was superior to either tranexamic acid or aminocaproic acid in decreasing massive postoperative bleeding and other clinically important consequences. METHODS: In this multicenter, blinded trial, we randomly assigned 2331 high-risk cardiac surgical patients to one of three groups: 781 received aprotinin, 770 received tranexamic acid, and 780 received aminocaproic acid. The primary outcome was massive postoperative bleeding. Secondary outcomes included death from any cause at 30 days. RESULTS: The trial was terminated early because of a higher rate of death in patients receiving aprotinin. A total of 74 patients (9.5%) in the aprotinin group had massive bleeding, as compared with 93 (12.1%) in the tranexamic acid group and 94 (12.1%) in the aminocaproic acid group (relative risk in the aprotinin group for both comparisons, 0.79; 95% confidence interval [CI], 0.59 to 1.05). At 30 days, the rate of death from any cause was 6.0% in the aprotinin group, as compared with 3.9% in the tranexamic acid group (relative risk, 1.55; 95% CI, 0.99 to 2.42) and 4.0% in the aminocaproic acid group (relative risk, 1.52; 95% CI, 0.98 to 2.36). The relative risk of death in the aprotinin group, as compared with that in both groups receiving lysine analogues, was 1.53 (95% CI, 1.06 to 2.22). CONCLUSIONS: Despite the possibility of a modest reduction in the risk of massive bleeding, the strong and consistent negative mortality trend associated with aprotinin, as compared with the lysine analogues, precludes its use in high-risk cardiac surgery. (Current Controlled Trials number, ISRCTN15166455 [controlled-trials.com].).

Transfusion-related mortality: the ongoing risks of allogeneic blood transfusion and the available strategies for their prevention.

As the risks of allogeneic blood transfusion (ABT)-transmitted viruses were reduced to exceedingly low levels in the US, transfusion-related acute lung injury (TRALI), hemolytic transfusion reactions (HTRs), and transfusion-associated sepsis (TAS) emerged as the leading causes of ABT-related deaths. Since 2004, preventive measures for TRALI and TAS have been implemented, but their implementation remains incomplete. Infectious causes of ABT-related deaths currently account for less than 15% of all transfusion-related mortality, but the possibility remains that a new transfusion-transmitted agent causing a fatal infectious disease may emerge in the future. Aside from these established complications of ABT, randomized controlled trials comparing recipients of non-white blood cell (WBC)-reduced versus WBC-reduced blood components in cardiac surgery have documented increased mortality in association with the use of non-WBC-reduced ABT. ABT-related mortality can thus be further reduced by universally applying the policies of avoiding prospective donors alloimmunized to WBC antigens from donating plasma products, adopting strategies to prevent HTRs, WBC-reducing components transfused to patients undergoing cardiac surgery, reducing exposure to allogeneic donors through conservative transfusion guidelines and avoidance of product pooling, and implementing pathogen-reduction technologies to address the residual risk of TAS as well as the potential risk of the next transfusion-transmitted agent to emerge in the foreseeable future.

A multidisciplinary "think tank": the top 10 clinical trial opportunities in transfusion medicine from the National Heart, Lung, and Blood Institute-sponsored 2009 state-of-the-science symposium.

BACKGROUND: In September 2009, the National Heart, Lung, and Blood Institute convened the State-of-the-Science Symposium in Transfusion Medicine to identify Phase II and/or III clinical trials that would provide important information to advance transfusion medicine. STUDY DESIGN AND METHODS: Seven multidisciplinary subcommittees developed proposals in the following areas: 1) platelet (PLT) product use, 2) neonatal and/or pediatric transfusion practice, 3) surgical transfusion practice, 4) intensive care unit and/or in trauma transfusion practice, 5) plasma and/or cryoprecipitate product use and therapeutic apheresis practice, 6) red blood cell (RBC) product use and/or blood conservation management, and 7) medical transfusion practice or blood donor studies. The committees consisted of transfusion medicine specialists, hematologists, cardiovascular surgeons, anesthesiologists, neonatologists, critical care physicians, and clinical trial methodologists. Proposals were presented and an external panel evaluated and prioritized each concept for scientific merit, clinical importance, and feasibility. RESULTS: Twenty-four concepts were presented by the subcommittees. Ten concepts addressed four areas deemed most important: 1) PLT transfusion strategies to prevent and/or mitigate bleeding in neonates and patients with hematologic malignancies, 2) RBC transfusion trigger strategies to improve overall outcomes in different patient populations, 3) evaluation of optimal plasma:PLT:RBC ratios in trauma resuscitation, and 4) pathogen inactivation of PLTs to improve PLT transfusion safety. CONCLUSIONS: The proposal themes not only represent inquiries about the indications for transfusion, but also epitomize the lack of consensus when clinical practice lacks a strong evidence base. Ultimately, the purpose of this publication is to provide a "blueprint" of ideas for further development rather than endorse any one specific clinical trial design.

Clinical review: Canadian National Advisory Committee on Blood and Blood Products--Massive transfusion consensus conference 2011: report of the panel.

In June 2011 the Canadian National Advisory Committee on Blood and Blood Products sponsored an international consensus conference on transfusion and trauma. A panel of 10 experts and two external advisors reviewed the current medical literature and information presented at the conference by invited international speakers and attendees. The Consensus Panel addressed six specific questions on the topic of blood transfusion in trauma. The questions focused on: ratio-based blood resuscitation in trauma patients; the impact of survivorship bias in current research conclusions; the value of nonplasma coagulation products; the role of protocols for delivery of urgent transfusion; the merits of traditional laboratory monitoring compared with measures of clot viscoelasticity; and opportunities for future research. Key findings include a lack of evidence to support the use of 1:1:1 blood component ratios as the standard of care, the importance of early use of tranexamic acid, the expected value of an organized response plan, and the recommendation for an integrated approach that includes antifibrinolytics, rapid release of red blood cells, and a foundation ratio of blood components adjusted by results from either traditional coagulation tests or clot viscoelasticity or both. The present report is intended to provide guidance to practitioners, hospitals, and policy-makers.

Research opportunities for pathogen reduction/inactivation of blood components: summary of an NHLBI workshop.

In July 2008, a workshop sponsored by the Division of Blood Diseases and Resources of the National Heart, Lung, and Blood Institute (NHLBI) was convened to identify potential research opportunities that could advance our understanding of both the biologic and the clinical impact of the various available pathogen reduction/inactivation (PR/PI) methods of blood components (platelets [PLTs], red blood cells, and plasma) intended for allogeneic transfusion. These discussions resulted in consensus that, even though several PR/PI technologies have already been licensed and are being used in Europe and elsewhere for PLTs and plasma, concerns about possible side effects, particularly component quality and pulmonary toxicity, have impeded regulatory approval in North America (United States and Canada). Such concerns thus threaten to stall further development of these technologies. As a consequence, the NHLBI workshop participants focused on formulating a series of research-related recommendations to better understand, mitigate, and prevent these adverse effects. Other important issues identified included the need for a single method to inactivate pathogens in whole blood without damaging the various blood components; new ways to monitor the efficacy of treated components, including animal models to screen for safety; a better understanding of the effect of PR/PI-treated products on recipient alloimmunization, tolerance, and immune modulation; understanding the impact of PR/PI on various other noninfectious hazards of transfusion; and establishing methods to evaluate risk-benefit and cost-effectiveness, in particular with reference to emerging pathogens. The working group also discussed issues related to specific blood components, such as improving the process of clinical evaluation, investigating the impact of PR/PI on component storage lesions, understanding mechanisms that reduce component viability, and addressing the underlying resistance to the adoption of PR/PI-treated components. This communication summarizes the opinions of workshop participants on these issues and concludes with a list of areas for possible research that could advance the application of PR/PI methods to enhance the safety of the world's blood supplies.

Proceedings of a Consensus Conference: pathogen inactivation-making decisions about new technologies.

Significant progress has been made in reducing the risk of pathogen transmission to transfusion recipients. Nonetheless, there remains a continuing risk of transmission of viruses, bacteria, protozoa, and prions to recipients. These include many of the viruses for which specific screening tests exist as well as pathogens for which testing is currently not being done, including various species of bacteria, babesiosis, variant Creutzfeld-Jacob disease, hepatitis A virus, human herpes virus 8, chikungunya virus, Chagas disease, and malaria. Pathogen inactivation (PI) technologies potentially provide an additional way to protect the blood supply from emerging agents and also provide additional protection against both known and as-yet-unidentified agents. However, the impact of PI on product quality and recipient safety remains to be determined. The purpose of this consensus conference was to bring together international experts in an effort to consider the following issues with respect to PI: implementation criteria; licensing requirements; blood service and clinical issues; risk management issues; cost-benefit impact; and research requirements. These proceedings are provided to make available to the transfusion medicine community the considerable amount of important information presented at this consensus conference.

Transfusion-related immunomodulation (TRIM): an update.

Allogeneic blood transfusion (ABT)-related immunomodulation (TRIM) encompasses the laboratory immune aberrations that occur after ABT and their established or purported clinical effects. TRIM is a real biologic phenomenon resulting in at least one established beneficial clinical effect in humans, but the existence of deleterious clinical TRIM effects has not yet been confirmed. Initially, TRIM encompassed effects attributable to ABT by immunomodulatory mechanisms (e.g., cancer recurrence, postoperative infection, or virus activation). More recently, TRIM has also included effects attributable to ABT by pro-inflammatory mechanisms (e.g., multiple-organ failure or mortality). TRIM effects may be mediated by: (1) allogeneic mononuclear cells; (2) white-blood-cell (WBC)-derived soluble mediators; and/or (3) soluble HLA peptides circulating in allogeneic plasma. This review categorizes the available randomized controlled trials based on the inference(s) that they permit about possible mediator(s) of TRIM, and examines the strength of the evidence available for relying on WBC reduction or autologous transfusion to prevent TRIM effects.

Avoiding transfusions in children undergoing cardiac surgery: a meta-analysis of randomized trials of aprotinin.

Aprotinin, a potent antifibrinolytic drug, reduces the proportion of adults who receive blood transfusions during cardiac surgery, although the effect in children remains unclear. We performed a systematic review of the literature to identify all English language, randomized controlled trials of aprotinin involving children undergoing corrective or palliative cardiac surgery with cardiopulmonary bypass. All studies were assessed for methodological quality, and sources of heterogeneity were examined. We measured the effect of aprotinin on the proportion of children transfused, the volume of blood transfused, and the volume of chest tube drainage. Twelve trials enrolling 626 eligible children met the inclusion criteria. Aprotinin reduced the proportion of children who received red blood cell or whole blood transfusions during cardiac surgery by 33% (relative risk = 0.67; 95% confidence interval, 0.51 to 0.89). Aprotinin did not have a significant effect on the volume of blood transfused or on the amount of postoperative chest tube drainage. Most of the studies were of poor methodological quality and predefined transfusion triggers were infrequently used. Overall, aprotinin reduced the proportion of children who received blood transfusion during cardiac surgery with cardiopulmonary bypass. Further high-quality trials with clinically important outcomes may be warranted before aprotinin can be routinely recommended in this population.

Proceedings of a consensus conference: towards an understanding of TRALI.

Transfusion-related acute lung injury is a relatively uncommon transfusion-associated adverse effect occurring during or soon after an allogeneic blood transfusion. Transfusion-related acute lung injury is a complex syndrome that has many manifestations and has only recently been identified to be an important cause of transfusion-associated morbidity and mortality. But despite its increasing recognition, much about the pathogenesis, treatment, and prevention is poorly understood and often controversial. The purpose of this consensus conference was to bring together international experts in an effort to try to standardize a case definition, which could be used to enhance future understanding of transfusion-related acute lung injury including its epidemiology, pathogenesis, management, prevention, and research. These proceedings are being provided with a view to making available to the transfusion medicine community the considerable amount of important information presented at this consensus conference by the invited international panel of experts.

Bacterial detection of platelets: current problems and possible resolutions.

The greatest transfusion-transmitted disease risk facing a transfusion recipient is that of bacterial sepsis. The prevalence of bacterial contamination in platelets and red blood cells is approximately 1 in 3,000 units transfused. The available data indicate that transfusion-associated sepsis develops after 1 in 25,000 platelet transfusions and 1 in 250,000 red blood cell transfusions. One of the most widely used strategies for decreasing bacterial sepsis risk is bacterial detection. A roundtable meeting of experts was convened during the XXVIII Annual Congress of the International Society of Blood Transfusion (Edinburgh, UK, July 2004) to provide a forum for experts to share their experiences in the routine bacterial detection of platelet products. This article summarizes the presentations, discussions, and recommendations of the panel. The data presented indicate that some of the current bacterial screening technology is useful for blocking the issuance of platelet units that contain relatively high levels of contaminating bacteria. Platelet units are usually released based on a test-negative status, which often become test-positive only upon longer storage. These data thus suggest that bacterial screening may not prevent all transfusion-transmitted bacterial infections. Two transfusion-transmitted case reports further highlighted the limitation of the routine bacterial screening of platelet products. It was felt that newer technologies, such as pathogen inactivation, may represent a more reliable process, with a higher level of safety. The panel thus recommended that the Transfusion Medicine community may need to change its thinking (paradigm) about bacterial detection, toward the possibility of the pathogen inactivation of blood products, to deal with the bacterial contamination issue. It was suggested, where permitted by regulatory agencies, that blood centers should consider adopting first-generation pathogen inactivation systems as a more effective approach to reducing the risk of transfusion-associated sepsis than some of the approaches currently available.

Protecting the blood supply from emerging pathogens: the role of pathogen inactivation.

Although the risk of infection by blood transfusion is relatively low, breakthrough infections still occur, Transfusion-related fatalities caused by infections continue to be reported, and blood is not tested for many potentially dangerous pathogens. The current paradigm for increasing the safety of the blood supply is the development and implementation of laboratory screening methods and restrictive donor criteria. When considering the large number of known pathogens and the fact that pathogens continue to emerge, it is clear that the utility of new tests and donor restrictions will continue to be a challenge when considering the cost of developing and implementing new screening assays, the loss of potential donors, and the risk of testing errors. Despite improving the safety of blood components, testing remains a reactive approach to blood safety. The contaminating organisms must be identified before sensitive tests can be developed. In contrast, pathogen inactivation is a proactive strategy designed to inactivate a pathogen before it enters the blood supply. Almost all pathogen inactivation technologies target nucleic acids, allowing for the inactivation of a variety of nucleic acid-containing pathogens within plasma, platelets, or red blood cells thus providing the potential to reduce transfusion-transmitted diseases. However, widespread use of a pathogen inactivation technology can only be realized when proven safe and efficacious and not cost-prohibitive.

Transfusion-related acute lung injury.

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

Improving the bacteriological safety of platelet transfusions.

Despite the increased application of aseptic techniques for blood collection and the preparation of platelet concentrates, morbidity and mortality arising from the transfusion of bacterially contaminated allogeneic platelet products persist. This problem exists because stored platelet concentrates represent a nearly ideal growth medium for bacteria and because they are stored at temperatures (22 degrees +/- 2 degrees C) that facilitate bacterial growth. The presence of bacteria in blood components including platelets has been a problem for many decades and currently is the most common microbiological cause of transfusion-associated morbidity and mortality. A variety of strategies have been devised and/or proposed in an attempt to try to reduce the risk of transfusion-associated sepsis. These include pretransfusion bacterial detection, efforts to reduce the likelihood of bacterial contamination, the optimization of blood product processing and storage, reducing recipient exposure, and the introduction of pathogen inactivation methodology. With regard to doing bacterial detection, a number of automated detection systems have become available to test for contaminated platelet components, but their utility to some extent is restricted by the time they take to indicate the presence of bacteria and/or their lack of sensitivity to detect initially low bacterial loads. A variety of other approaches has been shown to reduce the risk of bacterial contamination and include filtration to remove leukocytes and bacteria, diversion of the initial aliquot of blood during donation, and improved donor skin disinfection. Platelet pathogen inactivation methods under investigation include the addition of L-carnitine, gamma-irradiation, riboflavin plus UVA irradiation, and amotosalen HCl plus UVA irradiation. The latter process is licensed for clinical use with platelets in some countries in Europe. All of these approaches, either collectively or individually, hold considerable promise that the prevalence of adverse events associated with bacteria in platelet products will decline significantly in the very foreseeable future.