Richard J. Benjamin

Plasma components: properties, differences, and uses

General use of plasma components includes replacement for multiple coagulation factor deficiencies, for treatment of single coagulation factor deficiencies for which a concentrate is unavailable, and as a replacement fluid used in therapeutic plasma exchange for thrombotic thrombocytopenic purpura. Four major products currently transfused are fresh‐frozen plasma (FFP), plasma frozen within 24 hours of phlebotomy (FP24), cryoprecipitate‐poor plasma (CPP), and thawed plasma. FP24, CPP, and thawed plasma contain decreased amounts of labile coagulation factors. Pathogen reduction technology has included solvent/detergent, methylene blue, and ultraviolet light irradiation with psoralen or riboflavin treatment and is available in Europe but not in the United States. Pathogen‐reduced plasma may contain reduced levels of certain coagulant and/or anticoagulant factors compared to FFP. Clinical findings with pathogen‐reduced plasma have provided an impetus to the US Food and Drug Administration to promulgate specific requirements for approval of novel plasma products, some of which may be too burdensome for the industry to readily overcome.

The residual risk of transfusion-related acute lung injury at the American Red Cross (2008-2011): limitations of a predominantly male-donor plasma mitigation strategy

The American Red Cross began preferentially distributing plasma from male donors in 2007 and subsequently observed an 80% decrease in reported cases of transfusion‐related acute lung injury (TRALI) after plasma transfusion. Plasma distributions from male donors now exceed 99% for groups A, B, and O, but only approximately 60% for group AB. We evaluated the ongoing risk of TRALI and the ABO blood group of involved plasma donors.

Bacterial culture of apheresis platelets: a mathematical model of the residual rate of contamination based on unconfirmed positive results

Platelet septic reactions result from low concentrations of bacteria that escape detection by quality‐control BacT/ALERT™ culture testing. We estimate the contamination rate with these bacteria at the time of testing using a mathematical model.

TRALI risk reduction: donor and component management strategies.

Transfusion‐related lung injury (TRALI) occurs in ∼1 in 5,000 transfusions and may cause considerably more morbidity and mortality that is not recognized in clinical practice. Based on the current understanding of the etiology of TRALI, blood centers have implemented or are evaluating various donor and component management strategies in an effort to mitigate the risk of TRALI. Many cases of TRALI are likely caused by antibodies to leukocyte antigens (HLA or HNA) in blood components. Approximately 10 to 20% of female blood donors with a history of pregnancy and 1 to 5% of male blood donors harbor these antibodies. Alternatively, TRALI may be mediated by other bioactive lipids or substances that accumulate during storage and cause a reaction when transfused to susceptible patients. The complex interplay among various donor‐, component‐, and patient‐related factors underlying TRALI guarantees that effective prevention will not be a single or simple intervention but rather will require a multifaceted approach. Perhaps, the most important risk reduction strategy is the effort to ensure appropriate use of blood products and eliminate unnecessary transfusions. Blood collection agencies, however, have more proximate control over donor selection and component management than transfusion practice. AABB has provided some guidance on deferring donors implicated in TRALI and minimizing the preparation of high plasma volume components from donors who have anti‐leukocyte antibodies or are at increased risk of leukocyte alloimmunization. Blood centers have taken various approaches to mitigate the risk of TRALI, and the possible benefit and the inherent limitations of the current strategies will be reviewed. J. Clin. Apheresis 2009.

The International Experience of Bacterial Screen Testing of Platelet Components With an Automated Microbial Detection System: A Need for Consensus Testing and Reporting Guidelines

The BacT/ALERT microbial detection system (bioMerieux, Inc, Durham, NC) is in routine use in many blood centers as a prerelease test for platelet collections. Published reports document wide variation in practices and outcomes. A systematic review of the English literature was performed to describe publications assessing the use of the BacT/ALERT culture system on platelet collections as a routine screen test of more than 10000 platelet components. Sixteen publications report the use of confirmatory testing to substantiate initial positive culture results but use varying nomenclature to classify the results. Preanalytical and analytical variables that may affect the outcomes differ widely between centers. Incomplete description of protocol details complicates comparison between sites. Initial positive culture results range from 539 to 10606 per million (0.054%-1.061%) and confirmed positive from 127 to 1035 per million (0.013%-0.104%) donations. False-negative results determined by outdate culture range from 662 to 2173 per million (0.066%-0.217%) and by septic reactions from 0 to 66 per million (0%-0.007%) collections. Current culture protocols represent pragmatic compromises between optimizing analytical sensitivity and ensuring the timely availability of platelets for clinical needs. Insights into the effect of protocol variations on outcomes are generally restricted to individual sites that implement limited changes to their protocols over time. Platelet manufacturers should reassess the adequacy of their BacT/ALERT screening protocols in light of the growing international experience and provide detailed documentation of all variables that may affect culture outcomes when reporting results. We propose a framework for a standardized nomenclature for reporting of the results of BacT/ALERT screening.

Boom or bust? Estimating blood demand and supply as the baby boomers age

O n January 1, 2011, the first-born of the baby boomer generation celebrated their 65th birthday. The social and economic impact caused by the aging and retirement of those born between 1946 and 1964 has long been debated and is now upon us. For the blood banking industry in the United States, little has been discussed publicly with even less preparation for the coming changes. US blood centers appear oblivious to the possible effect of shifting demographics and are poorly prepared to forecast long-term blood demands, raising the specter of future blood shortages even as the industry wallows presently in an apparent glut of blood. While the National Blood Collection and Utilization Survey (NBCUS) has proven a powerful tool to track blood donation, and the US Census Bureau has mapped and predicted the effects of demographic changes well into the future, inadequate information on the demographics of blood use in our hospitals and those factors that influence utilization has left us without the tools we need to inform policy. In this setting, the report of Greinacher and coworkers sounds a warning bell. In the small German federal state of Mecklenburg-Pomerania with a population of 1,707,266 inhabitants, the authors were able to track the vast majority of hospital transfusions and blood bank donation records for a 1-year period (2005). These were used to integrate ageand gender-specific transfusion rates with well-established population demographics to predict the influence of population changes on the relative blood supply. The process was validated by utilizing 1997 transfusion data from one hospital to predict blood demand and supply in 2007. Remarkable accuracy was demonstrated, with a difference of only 226 red blood cell (RBC) units (1.2%) from that actually used. In this former East German state, marked population changes followed the fall of the Berlin Wall and are predicted to continue into the future. Birth rates have fallen precipitously and young people often migrate elsewhere to follow financial opportunities, while the postwar generation ages and is expected to live longer than their parents. Overall the population is predicted to decline by 8.3% by 2020, but disproportionately: the potential blood donor group aged 18 to 68 years may decline by 16.1% while the patient group 65 years and older that received approximately 62.1% of RBC transfusions in 2005 is predicted to grow by 26.4%. Assuming no changes in donation patterns and medical indications for blood use, these opposing forces are predicted to yield a 47% shortfall in the blood supply by 2020, representing a major challenge to blood providers and their hospital users. This study has weaknesses: Age-specific blood use was estimated using data from major hospitals that represent only 80.5% of distributed products. It is possible, but unlikely, that transfusions occurring outside the hospital environment would show differing demographics. It is also based on only a single year of data, which may be subject to peculiarities. Finally, a study of this nature cannot account for new technologies, blood management strategies, or world events (e.g., global recession) that may affect supply and demand. Nevertheless, it is clear that population demographics provide a powerful baseline on which to build future plans for the blood supply and that the need for such planning is critical. Other countries show similar population dynamics to those described in Germany. Indeed a number of major economies, including Japan, Hong Kong, South Korea, Italy, Spain, and many other European countries have inverted population pyramids that bode poorly for the future blood supply, with dramatically increasing aged groups and diminishing young donor pools. Interventions to increase the blood supply and decrease blood utilization are needed sooner rather than later. How do these data reflect the US situation? Population demographic predictions are readily available, calculated from the 2000 census that will soon be updated with 2010 data. The threat is real: the US population is expected to swell by approximately 10% over the next 10 years; however, the major donor population (aged 16-64) will increase by only 5.2%, while those 65 years and older will increase 36.2% from 40.2 million to 54.8 million. The 65 years and older age group will shift from 13.0 to 16.1% of the total population, an absolute 3.1% increase, dramatic indeed if this group uses the majority of the blood supply (Fig. 1). Unfortunately, little US age-specific blood use data are available. Early work performed in a limited setting in Olmsted County, Minnesota, in 1989 through 1992, suggested that 53.3% of RBC units were transfused into patients older than 65 years at a time when the incident rates of RBC transfusion were approximately 48.7 units/1000 inhabitants. The findings of Greinacher and colleagues that 62.1% of RBC were transfused into this TRANSFUSION 2011;51:670-673.

Seasonal temperature variation and the rate of donor deferral for low hematocrit in the American Red Cross

BACKGROUND: Hematocrit (Hct) values in healthy adult populations exhibit seasonal variation, with the lowest values occurring in the summer. The extent to which environmental temperature contributes to the seasonal trend in deferral rates for unacceptable Hct in the American Red Cross was further analyzed.

Contemporary issues in transfusion medicine informatics

The Transfusion Medicine Service (TMS) covers diverse clinical and laboratory-based services that must be delivered with accuracy, efficiency and reliability. TMS oversight is shared by multiple regulatory agencies that cover product manufacturing and validation standards geared toward patient safety. These demands present significant informatics challenges. Over the past few decades, TMS information systems have improved to better handle blood product manufacturing, inventory, delivery, tracking and documentation. Audit trails and access to electronic databases have greatly facilitated product traceability and biovigilance efforts. Modern blood bank computing has enabled novel applications such as the electronic crossmatch, kiosk-based blood product delivery systems, and self-administered computerized blood donor interview and eligibility determination. With increasing use of barcoding technology, there has been a marked improvement in patient and specimen identification. Moreover, the emergence of national and international labeling standards such as ISBT 128 have facilitated the availability, movement and tracking of blood products across national and international boundaries. TMS has only recently begun to leverage the electronic medical record to address quality issues in transfusion practice and promote standardized documentation within institutions. With improved technology, future growth is expected in blood bank automation and product labeling with applications such as radio frequency identification devices. This article reviews several of these key informatics issues relevant to the contemporary practice of TMS.

Clostridium perfringens in apheresis platelets: an unusual contaminant underscores the importance of clinical vigilance for septic transfusion reactions (CME).

Posttransfusion sepsis is typically caused by aerobic bacteria in apheresis platelets (PLTs) that escape detection by routine quality control cultures performed on every donation before components are distributed. We report the first case to implicate an anaerobic isolate, Clostridium perfringens, in apheresis PLTs and investigate its detection in vitro by approved tests.

Tracking TRALI in target populations

A prospective, case-controlled study in cardiac surgery reveals a high incidence (2.4%) of TRALI despite the introduction of plasma from male donors, indicating a need for additional interventions in susceptible populations.