Using data collected by the College of American Pathologists (CAP) fetal red blood cells (RBCs) detection surveys from 2014-2019 (24 proficiency testing samples to approximately 50 laboratories using ...flow cytometry and 1000 laboratories using Kleihauer-Betke) where the recommended RhIg dose was calculated from mean reported values with the CAP RhIg Dose Calculator,3 we compared differences in dose calculation. Inherent limitations to using Kleihauer-Betke include lack of standardization, associated labor to perform, and relative imprecision with a coefficient of variation of 30% to 80% as demonstrated in the past 5 years of CAP proficiency testing (2016-2020).4 Advantages include its ease of access, inexpensive cost, and lack of special equipment needed. The risks of RhIg do not exceed risks associated with any other pooled human product, few incidents of viral transmission have been reported in North America, and RhIg is currently manufactured with viral inactivation products.6 Flow cytometry is currently not feasible for many laboratories owing to the need for special equipment and longer duration of turnaround times, which can impact patient care. ...Kleihauer-Betke remains an adequate method for assessing fetal-maternal hemorrhage and RhIg dose.
BACKGROUND
Children are known to be physiologically and biochemically different from adults. However, there are no multi‐institutional studies examining the differences in the frequency, type, and ...severity of transfusion reactions in pediatric versus adult patients. This study aims to characterize differences between pediatric and adult patients regarding adverse responses to transfusions.
STUDY DESIGN AND METHODS
This is a retrospective data analysis of nine children's hospitals and 35 adult hospitals from January 2009 through December 2015. Included were pediatric and adult patients who had a reported reaction to transfusion of any blood component. Rates are reported as per 100,000 transfusions for comparison between pediatric and adult patients.
RESULTS
Pediatric patients had an overall higher reaction rate compared to adults: 538 versus 252 per 100,000 transfusions, notably higher for red blood cell (577 vs. 278 per 100,000; p < 0.001) and platelet (833 vs. 358 per 100,000; p < 0.001) transfusions. Statistically higher rates of allergic reactions, febrile nonhemolytic reactions, and acute hemolytic reactions were observed in pediatric patients. Adults had a higher rate of delayed serologic transfusion reactions, delayed hemolytic transfusion reactions, and transfusion‐associated circulatory overload.
CONCLUSION
Pediatric patients had double the rate of transfusion reactions compared to adults. The nationally reported data on reaction rates are consistent with this study's findings in adults but much lower than the observed rates for pediatric patients. Future studies are needed to address the differences in reaction rates, particularly in allergic and febrile reactions, and to further address blood transfusion practices in the pediatric patient population.
More than 100 million units of blood are collected worldwide each year, yet the indication for red blood cell (RBC) transfusion and the optimal length of RBC storage prior to transfusion are ...uncertain.
To provide recommendations for the target hemoglobin level for RBC transfusion among hospitalized adult patients who are hemodynamically stable and the length of time RBCs should be stored prior to transfusion.
Reference librarians conducted a literature search for randomized clinical trials (RCTs) evaluating hemoglobin thresholds for RBC transfusion (1950-May 2016) and RBC storage duration (1948-May 2016) without language restrictions. The results were summarized using the Grading of Recommendations Assessment, Development and Evaluation method. For RBC transfusion thresholds, 31 RCTs included 12 587 participants and compared restrictive thresholds (transfusion not indicated until the hemoglobin level is 7-8 g/dL) with liberal thresholds (transfusion not indicated until the hemoglobin level is 9-10 g/dL). The summary estimates across trials demonstrated that restrictive RBC transfusion thresholds were not associated with higher rates of adverse clinical outcomes, including 30-day mortality, myocardial infarction, cerebrovascular accident, rebleeding, pneumonia, or thromboembolism. For RBC storage duration, 13 RCTs included 5515 participants randomly allocated to receive fresher blood or standard-issue blood. These RCTs demonstrated that fresher blood did not improve clinical outcomes.
It is good practice to consider the hemoglobin level, the overall clinical context, patient preferences, and alternative therapies when making transfusion decisions regarding an individual patient. Recommendation 1: a restrictive RBC transfusion threshold in which the transfusion is not indicated until the hemoglobin level is 7 g/dL is recommended for hospitalized adult patients who are hemodynamically stable, including critically ill patients, rather than when the hemoglobin level is 10 g/dL (strong recommendation, moderate quality evidence). A restrictive RBC transfusion threshold of 8 g/dL is recommended for patients undergoing orthopedic surgery, cardiac surgery, and those with preexisting cardiovascular disease (strong recommendation, moderate quality evidence). The restrictive transfusion threshold of 7 g/dL is likely comparable with 8 g/dL, but RCT evidence is not available for all patient categories. These recommendations do not apply to patients with acute coronary syndrome, severe thrombocytopenia (patients treated for hematological or oncological reasons who are at risk of bleeding), and chronic transfusion-dependent anemia (not recommended due to insufficient evidence). Recommendation 2: patients, including neonates, should receive RBC units selected at any point within their licensed dating period (standard issue) rather than limiting patients to transfusion of only fresh (storage length: <10 days) RBC units (strong recommendation, moderate quality evidence).
Research in RBC transfusion medicine has significantly advanced the science in recent years and provides high-quality evidence to inform guidelines. A restrictive transfusion threshold is safe in most clinical settings and the current blood banking practices of using standard-issue blood should be continued.
The AABB (formerly, the American Association of Blood Banks) developed this guideline on appropriate use of platelet transfusion in adult patients.
These guidelines are based on a systematic review ...of randomized, clinical trials and observational studies (1900 to September 2014) that reported clinical outcomes on patients receiving prophylactic or therapeutic platelet transfusions. An expert panel reviewed the data and developed recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.
The AABB recommends that platelets should be transfused prophylactically to reduce the risk for spontaneous bleeding in hospitalized adult patients with therapy-induced hypoproliferative thrombocytopenia. The AABB recommends transfusing hospitalized adult patients with a platelet count of 10 × 109 cells/L or less to reduce the risk for spontaneous bleeding. The AABB recommends transfusing up to a single apheresis unit or equivalent. Greater doses are not more effective, and lower doses equal to one half of a standard apheresis unit are equally effective. (Grade: strong recommendation; moderate-quality evidence).
The AABB suggests prophylactic platelet transfusion for patients having elective central venous catheter placement with a platelet count less than 20 × 109 cells/L. (Grade: weak recommendation; low-quality evidence).
The AABB suggests prophylactic platelet transfusion for patients having elective diagnostic lumbar puncture with a platelet count less than 50 × 109 cells/L. (Grade: weak recommendation; very-low-quality evidence).
The AABB suggests prophylactic platelet transfusion for patients having major elective nonneuraxial surgery with a platelet count less than 50 × 109 cells/L. (Grade: weak recommendation; very-low-quality evidence).
The AABB recommends against routine prophylactic platelet transfusion for patients who are nonthrombocytopenic and have cardiac surgery with cardiopulmonary bypass. The AABB suggests platelet transfusion for patients having bypass who exhibit perioperative bleeding with thrombocytopenia and/or evidence of platelet dysfunction. (Grade: weak recommendation; very-low-quality evidence).
The AABB cannot recommend for or against platelet transfusion for patients receiving antiplatelet therapy who have intracranial hemorrhage (traumatic or spontaneous). (Grade: uncertain recommendation; very-low-quality evidence).
Background
Correct classification of transfusion reactions is important not only for effective patient care and donor management but also for accurate tracking of events in hemovigilance systems. We ...compared the ability of a generative artificial intelligence (AI) system to correctly diagnose hypothetical clinical situations as transfusion reactions in comparison to previous studies reporting the accuracy of transfusion medicine (TM) specialists in assessing these cases.
Methods
An AI system was requested to assess 36 case scenarios to provide a diagnosis, severity, and imputability of the transfusion reactions using the CDC National Healthcare Safety Network (NHSN) criteria. Responses were compared to an expert panel's classifications and to the published responses of a panel of TM specialists. Additionally, the AI's responses were compared to the TM specialists' prior attempts to use the TrDDx web‐based algorithm for the five most challenging cases.
Results
The AI's classification accuracy varied widely depending on the NHSN category. The AI accurately classified all transfusion‐associated circulatory overload and transfusion‐related acute lung injury cases, exceeding TM specialists' assessments. Conversely, it did not correctly identify any cases in select NHSN categories such as DSTR. Overall accuracy among all diagnostic categories was 48.7% for AI responses versus 72.1% for prior TM specialist responses (p = 0.005). AI‐generated responses included non‐standard terminology, limited severity assessments, and no imputability determinations.
Discussion
A generative AI system may have a role in helping healthcare providers to consider transfusion reaction categories that might be missed, but caution is advised in applying the AI's output to transfusion reaction classification at present.
Ankylosing spondylitis (AS) is an autoimmune disorder with a strong genetic risk, especially with HLA-B27. Clinical testing for HLA-B27 has been used to help diagnose patients with signs and symptoms ...of AS. Testing methods used by clinical laboratories for HLA-B27 fall into the broad categories of serologic/antibody- or molecular-based methods and have evolved over time. The College of American Pathologists (CAP) offers a proficiency testing survey for HLA-B27.
To analyze HLA-B27 testing trends and their performance in the past decade, using the proficiency testing survey data submitted to CAP.
We analyzed the HLA-B27 CAP proficiency testing data from 2010 to 2020 for the method used, participant concordance, and error rates. Results from case scenarios to understand evolving scientific data around HLA-B27 risk alleles were also analyzed.
Antibody-based flow cytometry is the most common method, though it has decreased from 60% in 2010 to 52% in 2020, with a corresponding increase in molecular methods. Among the molecular methods, real-time polymerase chain reaction has increased from 2% to 15%. Flow cytometry had the highest error rate (5.33%), and sequence-specific oligonucleotide (0%) is the most accurate (0%). Results of case scenarios demonstrated that most participants understood that allele-level HLA-B27 typing results inform clinical interpretation, for example HLA-B*27:06 is not associated with AS.
These data demonstrated the changing trends for HLA-B27 testing during the past decade. HLA-B27 allelic typing provides a better understanding of AS association. This is possible by testing for the second field with methods like next-generation sequencing.
BACKGROUND
Transfusion‐related acute lung injury (TRALI) is a serious complication of blood transfusion and is among the leading causes of transfusion‐related morbidity and mortality in most ...developed countries. In the past decade, the pathophysiology of this potentially life‐threatening syndrome has been increasingly elucidated, large cohort studies have identified associated patient conditions and transfusion risk factors, and preventive strategies have been successfully implemented. These new insights provide a rationale for updating the 2004 consensus definition of TRALI.
STUDY DESIGN AND METHODS
An international expert panel used the Delphi methodology to develop a redefinition of TRALI by modifying and updating the 2004 definition. Additionally, the panel reviewed issues related to TRALI nomenclature, patient conditions associated with acute respiratory distress syndrome (ARDS) and TRALI, TRALI pathophysiology, and standardization of reporting of TRALI cases.
RESULTS
In the redefinition, the term “possible TRALI” has been dropped. The terminology of TRALI Type I (without an ARDS risk factor) and TRALI Type II (with an ARDS risk factor or with mild existing ARDS) is proposed. Cases with an ARDS risk factor that meet ARDS diagnostic criteria and where respiratory deterioration over the 12 hours before transfusion implicates the risk factor as causative should be classified as ARDS. TRALI remains a clinical diagnosis and does not require detection of cognate white blood cell antibodies.
CONCLUSIONS
Clinicians should report all cases of posttransfusion pulmonary edema to the transfusion service so that further investigation can allow for classification of such cases as TRALI (Type I or Type II), ARDS, transfusion‐associated circulatory overload (TACO), or TRALI or TACO cannot distinguish or an alternate diagnosis.
Although approximately 85 million units of red blood cells (RBCs) are transfused annually worldwide, transfusion practices vary widely. The AABB (formerly, the American Association of Blood Banks) ...developed this guideline to provide clinical recommendations about hemoglobin concentration thresholds and other clinical variables that trigger RBC transfusions in hemodynamically stable adults and children.
These guidelines are based on a systematic review of randomized clinical trials evaluating transfusion thresholds. We performed a literature search from 1950 to February 2011 with no language restrictions. We examined the proportion of patients who received any RBC transfusion and the number of RBC units transfused to describe the effect of restrictive transfusion strategies on RBC use. To determine the clinical consequences of restrictive transfusion strategies, we examined overall mortality, nonfatal myocardial infarction, cardiac events, pulmonary edema, stroke, thromboembolism, renal failure, infection, hemorrhage, mental confusion, functional recovery, and length of hospital stay. RECOMMENDATION 1: The AABB recommends adhering to a restrictive transfusion strategy (7 to 8 g/dL) in hospitalized, stable patients (Grade: strong recommendation; high-quality evidence). RECOMMENDATION 2: The AABB suggests adhering to a restrictive strategy in hospitalized patients with preexisting cardiovascular disease and considering transfusion for patients with symptoms or a hemoglobin level of 8 g/dL or less (Grade: weak recommendation; moderate-quality evidence). RECOMMENDATION 3: The AABB cannot recommend for or against a liberal or restrictive transfusion threshold for hospitalized, hemodynamically stable patients with the acute coronary syndrome (Grade: uncertain recommendation; very low-quality evidence). RECOMMENDATION 4: The AABB suggests that transfusion decisions be influenced by symptoms as well as hemoglobin concentration (Grade: weak recommendation; low-quality evidence).
Allogeneic platelets collected for transfusion treated with pathogen reduction technology (PRT), which has been available in some countries for more than a decade, are now increasingly available in ...the United States (US). The implementation of PRT-treated platelets, also known as pathogen-reduced platelets (PRPs), has been spurred by the need to further decrease the risk of sepsis associated with bacterial contamination coupled with the potential of this technology to reduce the risk of infections due to already recognized, new, and emerging infectious agents. This article will review available PRP products, examine their benefits, highlight unresolved questions surrounding this technology, and summarize pivotal research studies that have compared transfusion outcomes (largely in adult patients) for PRPs with non-PRT-treated conventional platelets (CPs). In addition, studies describing the use of PRPs in pediatric patients and work done on the association between PRPs and HLA alloimmunization are discussed. As new data emerge, it is critical to re-evaluate the risks and benefits of existing PRPs and newer technologies and reassess the financial implications of adopting PRPs to guide our decision-making process for the implementation of transfusing PRPs.
PDF
