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* Context.--Substantial variability between different antibody titration methods has been identified since the development and introduction of the uniform procedure in 2008. Objective.--To determine whether more recent methods or techniques decrease interlaboratory and intralaboratory variation measured using proficiency testing. Design.--Proficiency test data for antibody titration between 2014 and 2018 were obtained from the College of American Pathologists. Interlaboratory and intralaboratory variations were compared by analyzing the distribution of titer results by method and phase, comparing the results against the supplier's quality control titer, and by evaluating the distribution of paired titer results when each laboratory received a sample with the same titer twice. Results.--A total of 1337 laboratories participated in the antibody titer proficiency test during the study period. Only 54.1 % (5874 of 10 852) of anti-D and 63.4% (3603 of 5680) of anti-A reported responses were within 1 titer of the supplier's intended result. Review of the agreement between laboratories of the same methodology found that 78.4% (3139 of 4004) for anti-A and 89.0% (9655 of 10 852) of laboratory responses for anti-D fell within 1 titer of the mode response. When provided with 2 consecutive samples of the same titer (anti-D titer: 16), 85% (367 of 434) of laboratories using the uniform procedure and 80% (458 of 576) using the other method reported a titer difference of 1 or less. Conclusions.--Despite advances, interlaboratory and intralaboratory variance for this assay remains high in comparison with the strong reliance on titer results in clinical practice. There needs to be a reevaluation of the role of this test in clinical decision-making. (Arch Pathol Lab Med. 2023;147:1351-1359; doi: 10.5858/arpa.2022-0248-CP), Antibody titration in transfusion medicine is a commonly used clinical assay to detect the strength of reactivity of red cell antibodies present in a patient's plasma. (1) There are a [...]

DescriptionCoronavirus disease 2019 convalescent plasma (CCP) has emerged as a potential treatment of COVID-19. However, meta-analysis data and recommendations are limited. The Association for the Advancement of Blood and Biotherapies (AABB) developed clinical practice guidelines for the appropriate use of CCP.MethodsThese guidelines are based on 2 living systematic reviews of randomized controlled trials (RCTs) evaluating CCP from 1 January 2019 to 26 January 2022. There were 33 RCTs assessing 21 916 participants. The results were summarized using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) method. An expert panel reviewed the data using the GRADE framework to formulate recommendations.Recommendation 1 (outpatient)The AABB suggests CCP transfusion in addition to the usual standard of care for outpatients with COVID-19 who are at high risk for disease progression (weak recommendation, moderate-certainty evidence).Recommendation 2 (inpatient)The AABB recommends against CCP transfusion for unselected hospitalized persons with moderate or severe disease (strong recommendation, high-certainty evidence). This recommendation does not apply to immunosuppressed patients or those who lack antibodies against SARS-CoV-2.Recommendation 3 (inpatient)The AABB suggests CCP transfusion in addition to the usual standard of care for hospitalized patients with COVID-19 who do not have SARS-CoV-2 antibodies detected at admission (weak recommendation, low-certainty evidence).Recommendation 4 (inpatient)The AABB suggests CCP transfusion in addition to the usual standard of care for hospitalized patients with COVID-19 and preexisting immunosuppression (weak recommendation, low-certainty evidence).Recommendation 5 (prophylaxis)The AABB suggests against prophylactic CCP transfusion for uninfected persons with close contact exposure to a person with COVID-19 (weak recommendation, low-certainty evidence).Good clinical practice statementCCP is most effective when transfused with high neutralizing titers to infected patients early after symptom onset.

BackgroundAt the start of the coronavirus disease 2019 (COVID-19) pandemic, widespread blood shortages were anticipated. We sought to determine how hospital blood supply and blood utilization were affected by the first wave of COVID-19.Study design and methodsWeekly red blood cell (RBC) and platelet (PLT) inventory, transfusion, and outdate data were collected from 13 institutions in the United States, Brazil, Canada, and Denmark from March 1st to December 31st of 2020 and 2019. Data from the sites were aligned based on each site's local first peak of COVID-19 cases, and data from 2020 (pandemic year) were compared with data from the corresponding period in 2019 (pre-pandemic baseline).ResultsRBC inventories were 3% lower in 2020 than in 2019 (680 vs. 704, p

BackgroundThe AABB Clinical Transfusion Medicine Committee (CTMC) compiles an annual synopsis of the published literature covering important developments in the field of transfusion medicine (TM), which has been made available as a manuscript published in Transfusion since 2018.MethodsCTMC committee members reviewed original manuscripts including TM-related topics published electronically (ahead) or in print from December 2019 to December 2020. The selection of topics and manuscripts was discussed at committee meetings and chosen based on relevance and originality. Next, committee members worked in pairs to create a synopsis of each topic, which was then reviewed by two additional committee members. The first and senior authors of this manuscript assembled the final manuscript. Although this synopsis is extensive, it is not exhaustive, and some papers may have been excluded or missed.ResultsThe following topics are included: COVID-19 effects on the blood supply and regulatory landscape, COVID convalescent plasma, adult transfusion practices, whole blood, molecular immunohematology, pediatric TM, cellular therapy, and apheresis medicine.ConclusionsThis synopsis provides easy access to relevant topics and may be useful as an educational tool.

* Context.--Modern RHD genotyping can be used to determine when patients with serologic weak D phenotypes have RHD gene variants at risk for anti-D alloimmunization. However, serologic testing, RhD interpretations, and laboratory management of these patients are quite variable. Objective.--To obtain interlaboratory comparisons of serologic testing, RhD interpretations, Rh immune globulin (RhIG) management, fetomaternal hemorrhage testing, and RHD genotyping for weak D-reactive specimens. Design.--We devised an educational exercise in which 81 transfusion services supporting obstetrics performed tube-method RhD typing on 2 unknown red blood cell challenge specimens identified as (1) maternal and (2) newborn. Both specimens were from the same weak D-reactive donor. The exercise revealed how participants responded to these different clinical situations. Results.--Of reporting laboratories, 14% (11 of 80) obtained discrepant immediate-spin reactions on the 2 specimens. Nine different reporting terms were used to interpret weak D-reactive maternal RhD types to obstetricians. In laboratories obtaining negative maternal immediate-spin reactions, 28% (16 of 57) performed unwarranted antiglobulin testing, sometimes leading to recommendations against giving RhIG. To screen for excess fetomaternal hemorrhage after a weak D-reactive newborn, 47% (34 of 73) of reporting laboratories would have employed a contraindicated fetal rosette test, risking false-negative results and inadequate RhIG coverage. Sixty percent (44 of 73) of laboratories would obtain RHD genotyping in some or all cases. Conclusions.--For obstetric and neonatal patients with serologic weak D phenotypes, we found several critical problems in transfusion service laboratory practices. We provide recommendations for appropriate testing, consistent immunohematologic terminology, and RHD genotype-guided management of Rh immune globulin therapy and RBC transfusions., In the United States and Canada, 0.06% to 2.2% of patients have red blood cells (RBCs) that type weakly reactive for RhD, termed 'serologic weak D phenotype.' (1-6) In past [...]

This document is a systematic review that discusses the challenges and inconsistencies in diagnosing cold agglutinins (CA), which are IgM autoantibodies that can cause hemolysis. The review aims to inform future research on the diagnostic investigation and interpretation of CA by describing serological techniques and cut-offs for diagnosing cold agglutinin disease (CAD) or cold agglutinin syndrome (CAS). The authors conducted a literature search and included 56 articles in their analysis, which revealed a lack of standardized definitions and thresholds for diagnosing clinically significant CA. The document provides a summary of various studies and case series related to cold agglutinins (CA), examining different aspects such as the number of participants with CA, the underlying clinical diseases studied, and the definition of CA. It presents a range of perspectives and findings from different studies, providing valuable information for researchers and library patrons interested in understanding CA. The article discusses the lack of consistency in defining the characteristics of cold agglutinin disease (CAD) in autoimmune hemolytic anemia (AIHA). The most commonly used laboratory test for diagnosing CAD is the direct antiglobulin test (DAT), which detects complement deposition on red blood cells. However, the clinical utility of DAT testing and the interpretation of results are variable. CA titers, which reflect the concentration and avidity of cold agglutinins, are also widely used but do not always correlate with disease severity. The determination of thermal amplitude [Extracted from the article]

* Context.--ABO mistransfusions are rare and potentially fatal events. Protocols are required by regulatory agencies to minimize this risk to patients, but how these are applied in the context of massive transfusion protocols (MTPs) is not specifically defined. Objective.--To evaluate the approaches used by transfusion services for switching from universally compatible to patient ABO type-specific blood components during massive hemorrhage. Design.--We added 1 supplemental multiple-choice question to address the study objective to the 2019 College of American Pathologists proficiency test J-survey (J-A 2019). We also reviewed the available literature regarding this topic. Results.--A total of 881 laboratories responded to the supplemental question. Approximately 80% (704 of 881) reported a policy for ABO-type switching during an MTP. Policies varied considerably between responding laboratories, but most (384 of 704, 55%) required 2 ABO types to match before switching from universal to recipient-specific blood components. Additional safety measures used in a minority of these protocols included reaction strength criteria (103 of 704, 15%), on-call medical director approval (41 0f 704, 5.8%), universal red cell unit number limits (12 of 704, 1.7%), or the presence of a mixed field (3 of 704, 0.4%). Conclusions.--This survey reveals that significant heterogeneity exists regarding the available approaches for ABO-type switching during an MTP. Specific expert guidance regarding this issue is very limited, and best practices have not yet been established or rigorously investigated., In the United States, many hospitals have now adopted massive transfusion protocols (MTPs) to ensure that patients with life-threatening hemorrhage receive red cells and plasma in a safe, timely, evidence-based, [...]

Context.--The Kleihauer-Betke (KB) test is validated for estimating the dose of Rh immune globulin needed for Rh-negative pregnant females. However, some clinicians are also ordering the test for Rh-positive women. The degree to which this practice occurs is unknown. Objective.--To evaluate the number of laboratories that perform the KB test on Rh-positive pregnant women, and to establish current ordering practices for this indication. Design.--We added 9 supplemental questions regarding KB test use for fetomaternal hemorrhage to the 2016 College of American Pathologists proficiency test survey. We also reviewed the available literature regarding the diagnostic utility of the KB test for Rh-positive women. Results.--A total of 1578 surveys were evaluated and revealed that 52% (824) of respondents perform these tests for Rh-positive women, and more than 50% (440 of 819; 53.7%) of these laboratories report that the results for Rh-positive women are treated as important or very important. Conclusions.--The KB test is commonly used for Rh-positive women, and the information obtained from the test is considered as urgent and important. However, the available literature in support of this practice is still nonconclusive. doi: 10.5858/arpa.2018-0523-CP, In the United States, nearly all (96.0%) quantitative assays for fetal red blood cells in maternal circulation are performed using several commercially marketed kits for an acid-elution assay, also known [...]