The incidence of transfusion-related acute lung injury using active surveillance: A systematic review and meta-analysis.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-related mortality. A concern with passive surveillance to detect transfusion reactions is underreporting. Our aim was to obtain evidence-based estimates of TRALI incidence using meta-analysis of active surveillance studies and to compare these estimates with passive surveillance. STUDY DESIGN AND METHODS: We performed a systematic review and meta-analysis of studies reporting TRALI rates. A search of Medline and Embase by a research librarian identified studies published between January 1, 1991 and January 20, 2023. Prospective and retrospective observational studies reporting TRALI by blood component (red blood cells [RBCs], platelets, or plasma) were identified and all inpatient and outpatient settings were eligible. Adult and pediatric, as well as general and specific clinical populations, were included. Platelets and plasma must have used at least one modern TRALI donor risk mitigation strategy. A random effects model estimated TRALI incidence by blood component for active and passive surveillance studies and heterogeneity was examined using meta-regression. RESULTS: Eighty studies were included with approximately 176-million blood components transfused. RBCs had the highest number of studies (n = 66) included, followed by platelets (n = 35) and plasma (n = 34). Pooled TRALI estimates for active surveillance studies were 0.17/10,000 (95% confidence intervals [CI]: 0.03-0.43; I2 = 79%) for RBCs, 0.31/10,000 (95% CI: 0.22-0.42; I2 = <1%) for platelets, and 3.19/10,000 (95% CI: 0.09-10.66; I2 = 86%) for plasma. Studies using passive surveillance ranged from 0.02 to 0.10/10,000 among the various blood components. DISCUSSION: In summary, these estimates may improve a quantitative understanding of TRALI risk, which is important for clinical decision-making weighing the risks and benefits of transfusion.

Meta-analysis of bacterial growth characteristics in platelet components: Refining the inputs of a simulation analysis comparing the relative safety of testing strategies.

BACKGROUND: The relative safety of bacterial risk control strategies for platelets that include culture with or without rapid testing has been compared using simulation analysis. A wide range of bacterial lag and doubling times were included. However, published data on growth rates are available and these data have not been synthesized. We conducted a systematic review and meta-analysis to estimate growth rates and used these estimates to refine a comparative safety analysis of bacterial risk control strategies in the FDA guidance STUDY DESIGN AND METHODS: Data were extracted from published studies on bacterial growth rates in platelet components during storage. These data were used to estimate the practical range of growth rates. This refined the inputs for a simulation model comparing the safety of the testing strategies. RESULTS: In total, 108 growth curves for 11 different aerobic organisms were obtained. Doubling times ranged from 0.8 to 12 h, but the lower 90% range was approximately 1-5 h. The revised comparative safety simulation using the narrower 1-5-h range showed similar rankings to the prior simulation, with 48-h large-volume delayed sampling with 7-day expiration (48C-7) demonstrating the lowest-ranking relative performance at the 103 and 105 colony forming unit (CFU)/mL exposure thresholds. DISCUSSION: This was a two-step study. First, meta-analysis of published data on aerobic bacterial growth rates in stored platelets showed the vast majority of doubling times were 1-5 h. Next, an updated comparative safety simulation yielded similar results to a prior study, with 48C-7 showing the least favorable relative safety performance.

The epidemiology of transfusion-related acute lung injury: A scoping review and analysis.

BACKGROUND: The purpose of this scoping review was to identify available sources of evidence on the epidemiology of transfusion-related acute lung injury (TRALI) and whether meta-analysis on the incidence of TRALI is feasible. TRALI is a serious complication and the second leading cause of death related to blood transfusion. Estimates of the incidence of TRALI would provide a useful benchmark for research to reduce TRALI. STUDY DESIGN AND METHODS: We searched the Medline, EMBASE, and PubMed databases for publications related to the incidence of TRALI and hemovigilance. We included all studies irrespective of language or country. Both full-text articles and conference abstracts were included. Participants of the studies must all have received a blood transfusion. Reviews and case studies were excluded. RESULTS: We identified 427 articles or abstracts to include for review. More than half were abstracts, and the majority were published after 2010. Reported TRALI definitions varied, but only 27.2% of studies reported any definition for TRALI. TRALI rates were reported using different denominators, such as per blood unit (54.1%), patient (34.4%), and transfusion episode (14.8%). Study populations and contexts were mostly general (75.6% and 80.3%, respectively). There was also variation in study design with most being observational (90.6%) and only 13.1% of all studies used modern donor restriction policies. DISCUSSION: There was substantial variation in reporting in studies on TRALI incidence. Meta-analysis of TRALI rates may be feasible in specific circumstances where reporting is clear. Future studies should clearly report key items, such as a TRALI definition.

Bacterial culture time to detection in platelet components: An evidence synthesis and estimation of detection failures.

BACKGROUND: Non-pathogen reduction platelet bacterial risk control strategies in the US FDA guidance include at least one culture. Almost all of these strategies have a culture hold time of ≥12 h. Studies have reported time to detection (TTD) of bacterial cultures inoculated with bacteria from contaminated platelets, but these data and estimates of risk associated with detection failures have not been synthesized. METHODS: We performed a literature search to identify studies reporting TTD for samples obtained from spiked platelet components. Using extracted data, regression analysis was used to estimate TTD for culture bottles at different inoculum sizes. Detection failures were defined as events in which contaminated components are transfused to a patient. We then used published data on time of transfusion (ToT) to estimate the risk of detection failures in practice. RESULTS: The search identified 1427 studies, of which 16 were included for analysis. TTD data were available for 16 different organisms, including 14 in aerobic cultures and 11 in anaerobic cultures. For inocula of 1 colony forming unit (CFU), the average TTD for aerobic organisms was 19.2 h while it was 24.9 h in anaerobic organisms, but there was substantial overall variation. A hold time of 12 versus 24 h had minimal effect for most organisms. CONCLUSION: TTD variation occurs between bacterial species and within a particular species. Under typical inventory management, the relative contribution of culture detection failures is much smaller than the residual risk from sampling failures. Increasing the hold period beyond 12 h has limited value.

Current advances in 2022: A critical review of selected topics by the Association for the Advancement of Blood and Biotherapies (AABB) Clinical Transfusion Medicine Committee.

BACKGROUND: The Association for the Advancement of Blood and Biotherapies Clinical Transfusion Medicine Committee (CTMC) composes a summary of new and important advances in transfusion medicine (TM) on an annual basis. Since 2018, this has been assembled into a manuscript and published in Transfusion. STUDY DESIGN AND METHODS: CTMC members selected original manuscripts relevant to TM that were published electronically and/or in print during calendar year 2022. Papers were selected based on perceived importance and/or originality. References for selected papers were made available to CTMC members to provide feedback. Members were also encouraged to identify papers that may have been omitted initially. They then worked in groups of two to three to write a summary for each new publication within their broader topic. Each topic summary was then reviewed and edited by two separate committee members. The final manuscript was assembled by the first and senior authors. While this review is extensive, it is not a systematic review and some publications considered important by readers may have been excluded. RESULTS: For calendar year 2022, summaries of key publications were assembled for the following broader topics within TM: blood component therapy; infectious diseases, blood donor testing, and collections; patient blood management; immunohematology and genomics; hemostasis; hemoglobinopathies; apheresis and cell therapy; pediatrics; and health care disparities, diversity, equity, and inclusion. DISCUSSION: This Committee Report reviews and summarizes important publications and advances in TM published during calendar year 2022, and maybe a useful educational tool.

Clinical Practice Guidelines From the Association for the Advancement of Blood and Biotherapies (AABB): COVID-19 Convalescent Plasma.

DESCRIPTION: Coronavirus 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. METHODS: These 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 STATEMENT: CCP is most effective when transfused with high neutralizing titers to infected patients early after symptom onset.

Red Blood Cell Transfusion: 2023 AABB International Guidelines.

Importance: Red blood cell transfusion is a common medical intervention with benefits and harms. Objective: To provide recommendations for use of red blood cell transfusion in adults and children. Evidence Review: Standards for trustworthy guidelines were followed, including using Grading of Recommendations Assessment, Development and Evaluation methods, managing conflicts of interest, and making values and preferences explicit. Evidence from systematic reviews of randomized controlled trials was reviewed. Findings: For adults, 45 randomized controlled trials with 20 599 participants compared restrictive hemoglobin-based transfusion thresholds, typically 7 to 8 g/dL, with liberal transfusion thresholds of 9 to 10 g/dL. For pediatric patients, 7 randomized controlled trials with 2730 participants compared a variety of restrictive and liberal transfusion thresholds. For most patient populations, results provided moderate quality evidence that restrictive transfusion thresholds did not adversely affect patient-important outcomes. Recommendation 1: for hospitalized adult patients who are hemodynamically stable, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). In accordance with the restrictive strategy threshold used in most trials, clinicians may choose a threshold of 7.5 g/dL for patients undergoing cardiac surgery and 8 g/dL for those undergoing orthopedic surgery or those with preexisting cardiovascular disease. Recommendation 2: for hospitalized adult patients with hematologic and oncologic disorders, the panel suggests a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (conditional recommendations, low certainty evidence). Recommendation 3: for critically ill children and those at risk of critical illness who are hemodynamically stable and without a hemoglobinopathy, cyanotic cardiac condition, or severe hypoxemia, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). Recommendation 4: for hemodynamically stable children with congenital heart disease, the international panel suggests a transfusion threshold that is based on the cardiac abnormality and stage of surgical repair: 7 g/dL (biventricular repair), 9 g/dL (single-ventricle palliation), or 7 to 9 g/dL (uncorrected congenital heart disease) (conditional recommendation, low certainty evidence). Conclusions and Relevance: It is good practice to consider overall clinical context and alternative therapies to transfusion when making transfusion decisions about an individual patient.

Current advances in transfusion medicine 2021: A critical review of selected topics by the AABB Clinical Transfusion Medicine Committee.

BACKGROUND: Each year the AABB Clinical Transfusion Medicine Committee (CTMC) procures a synopsis highlighting new, important, and clinically relevant studies in the field of transfusion medicine (TM). This has been made available as a publication in Transfusion since 2018. METHODS: CTMC members reviewed and identified original manuscripts covering TM-related topics published electronically (ahead-of-print) or in print from December 2020 to December 2021. Selection of publications was discussed at committee meetings and chosen based on perceived relevance and originality. Next, committee members worked in pairs to create a synopsis of each topic, which was then reviewed by additional committee members. The first and senior authors assembled the final manuscript. Although this synopsis is extensive, it is not exhaustive, and some articles may have been excluded or missed. RESULTS: The following topics are included: blood products; convalescent plasma; donor collections and testing; hemoglobinopathies; immunohematology and genomics; hemostasis; patient blood management; pediatrics; therapeutic apheresis; and cell therapy. CONCLUSIONS: This synopsis highlights and summarizes recent key developments in TM and may be useful for educational purposes.

How do I implement an outpatient program for the administration of convalescent plasma for COVID-19?

Convalescent plasma, collected from donors who have recovered from a pathogen of interest, has been used to treat infectious diseases, particularly in times of outbreak, when alternative therapies were unavailable. The COVID-19 pandemic revived interest in the use of convalescent plasma. Large observational studies and clinical trials that were executed during the pandemic provided insight into how to use convalescent plasma, whereby high levels of antibodies against the pathogen of interest and administration early within the time course of the disease are critical for optimal therapeutic effect. Several studies have shown outpatient administration of COVID-19 convalescent plasma (CCP) to be both safe and effective, preventing clinical progression in patients when administered within the first week of COVID-19. The United States Food and Drug Administration expanded its emergency use authorization (EUA) to allow for the administration of CCP in an outpatient setting in December 2021, at least for immunocompromised patients or those on immunosuppressive therapy. Outpatient transfusion of CCP and infusion of monoclonal antibody therapies for a highly transmissible infectious disease introduces nuanced challenges related to infection prevention. Drawing on our experiences with the clinical and research use of CCP, we describe the logistical considerations and workflow spanning procurement of qualified products, infrastructure, staffing, transfusion, and associated management of adverse events. The purpose of this description is to facilitate the efforts of others intent on establishing outpatient transfusion programs for CCP and other antibody-based therapies.

The impact of the sample time of secondary bacterial culture on the risk of exposure to contaminated platelet components: A mathematical analysis.

BACKGROUND: The US Food and Drug Administration (FDA) issued a guidance for bacterial risk control strategies for platelet components in September 2019 that includes strategies using secondary bacterial culture (SBC). While an SBC likely increases safety, the optimal timing of the SBC is unknown. Our aim was to develop a model to provide insight into the best time for SBC sampling. STUDY DESIGN AND METHODS: We developed a mathematical model based on the conditional probability of a bacterial contamination event. The model evaluates the impact of secondary culture sampling time over a range of bacterial contamination scenarios (lag and doubling times), with the primary outcome being the optimal secondary sampling time and the associated risk. RESULTS: Residual risk of exposure decreased with increasing inoculum size, later sampling times for primary culture, and using higher thresholds of exposure (in colony-forming units per milliliter). Given a level of exposure, the optimal sampling time for secondary culture depended on the timing of primary culture and on the expiration time. In general, the optimal sampling time for secondary culture was approximately halfway between the time of primary culture and the expiration time. CONCLUSION: Our model supports that the FDA guidance is quite reasonable and that sampling earlier in the specified secondary culture windows may be most optimal for safety.

Current advances in transfusion medicine 2020: A critical review of selected topics by the AABB Clinical Transfusion Medicine Committee.

BACKGROUND: The 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. METHODS: CTMC 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. RESULTS: The 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. CONCLUSIONS: This synopsis provides easy access to relevant topics and may be useful as an educational tool.

The incremental benefit of anaerobic culture for controlling bacterial risk in platelets: a systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: Septic transfusion reactions are a principal cause of transfusion-related mortality. The frequency of detectable bacterial contamination is greater in platelets compared to other blood components because platelets are stored at room temperature. Most strategies outlined in the September 2019 FDA guidance require both aerobic culture (AC) and anaerobic culture (AnC) testing. We performed a systematic review and meta-analysis in an effort to provide the best available estimate of the effectiveness of AnC. MATERIALS AND METHODS: Our analysis was performed according to published guidelines. Broad and context-specific meta-analyses of bacterial detection rates in platelets by AnC were performed to assess the practical effectiveness of AnC as a risk control measure. RESULTS: Seven studies with a total of 1 767 014 tested platelet components were included for analysis. With exclusion of positives due to Cutibacterium/Propionibacterium species and redundancy due to AC results, AnC detected 0·06 contamination events per thousand (EPT) components tested, twofold lower than the AC (0·12 EPT). CONCLUSION: Excluding Cutibacterium/Propionibacterium species, AnC detects occasional bacterial contamination events that are not detected by AC (~1 in 17 000 platelet components).

Residual bacterial detection rates after primary culture as determined by secondary culture and rapid testing in platelet components: A systematic review and meta-analysis.

BACKGROUND: Primary culture alone was a bacterial risk control strategy intended to facilitate interdiction of contaminated platelets (PLTs). A September 2019 FDA guidance includes secondary testing options to enhance safety. Our objective was to use meta-analysis to determine residual contamination risk after primary culture using secondary culture and rapid testing. STUDY DESIGN AND METHODS: A December 2019 literature search identified articles on PLT bacterial detection rates using primary culture and a secondary testing method. We used meta-analysis to estimate secondary testing detection rates after a negative primary culture. We evaluated collection method, sample volume, sample time, and study date as potential sources of heterogeneity. RESULTS: The search identified 6102 articles; 16 were included for meta-analysis. Of these, 12 used culture and five used rapid testing as a secondary testing method. Meta-analysis was based on a total of 103 968 components tested by secondary culture and 114 697 by rapid testing. The residual detection rate using secondary culture (DRSC ) was 0.93 (95% CI, 0.24-0.6) per 1000 components, while residual detection rate using rapid testing (DRRT ) was 0.09 (95% CI, 0.01-0.25) per 1000 components. Primary culture detection rate was the only statistically significant source of heterogeneity. CONCLUSION: We evaluated bacterial detection rates after primary culture using rapid testing and secondary culture. These results provide a lower and upper bound on real-world residual clinical risk because these methods are designed to detect high-level exposures or any level of exposure, respectively. Rapid testing may miss some harmful exposures and secondary culture may identify some clinically insignificant exposures.

Bacterial contamination rate of platelet components by primary culture: a systematic review and meta-analysis.

BACKGROUND: Platelets have the highest bacterial contamination risk of all blood components, and septic transfusion reactions remain a problem. A good estimate of contamination rates could provide information about residual risk and inform optimal testing strategies. We performed a systematic review and meta-analysis of platelet contamination rates by primary culture. STUDY DESIGN AND METHODS: A literature search in December 2019 identified articles on platelet contamination rates using primary culture. We used meta-analysis to estimate the overall rate of contamination and meta-regression to identify heterogeneity. We studied the following sources of heterogeneity: collection method, sample volume, positivity criteria, and study date. Contamination rate estimates were obtained for apheresis (AP), platelet rich plasma (PRP), and buffy coat (BC) collection methods. RESULTS: The search identified 6102 studies, and 22 were included for meta-analysis. Among these 22 studies, there were 21 AP cohorts (4,072,022 components), 4 PRP cohorts (138,869 components), and 15 BC cohorts (1,474,679 components). The overall mean contamination rate per 1000 components was 0.51 (95% CI: 0.38-0.67) including AP (0.23, 95% CI: 0.18-0.28), PRP, (0.38, 95% CI: 0.15-0.70), and BC (1.12, 95% CI: 0.51-1.96). There was considerable variability within each collection method. Sample volume, positivity criteria, and publication year were significant sources of heterogeneity. CONCLUSION: The bacterial contamination rate of platelets by primary culture is 1 in 1961. AP and PRP components showed a lower contamination rate than BC components. There is clinically significant between-study variability for each method. Larger sample volumes increased sensitivity, and bacterial contamination rates have decreased over time.

The comparative safety of bacterial risk control strategies for platelet components: a simulation study.

BACKGROUND: Bacterial contamination of platelets is a problem that can lead to harmful septic transfusion reactions. The US Food and Drug Administration published a guidance in September 2019 detailing several permissible risk control strategies. Our objective was to compare the safety of each bacterial testing strategy for apheresis platelets. STUDY DESIGN AND METHODS: We used simulation to compare safety of the nine risk control strategies involving apheresis platelet testing. The primary outcome was the risk of exposure. An exposure event occurred if a patient received platelets exceeding a specific contamination threshold (>0, 103 , and 105 colony-forming units (CFU/mL). We generated a range of bacterial contamination scenarios (inoculum size, doubling time, lag time) and compared risk of exposure for each policy in each contamination scenario. We then computed the average risk difference over all scenarios. RESULTS: At the 0 CFU/mL exposure threshold, two-step policies that used secondary culture ranked best (all top three), while single-step 24-hour culture with 3-day expiration ranked last (ninth). This latter policy performed well (median rank of 1) at both the 103 and 105 CFU/mL thresholds, but 48-hour culture with 7-day expiration performed relatively poorly. At these higher thresholds, median ranks of two-step policies that used secondary culture were again top three. Two-step policies that used rapid testing improved at the higher (105 CFU/mL) harm threshold, with median rankings between 1 and 5. CONCLUSION: Two-step policies that used secondary culture were generally safer than single-step policies. Performance of two-step policies that used rapid testing depended on the CFU per milliter threshold of exposure used.

Current advances in transfusion medicine: a 2019 review of selected topics from the AABB Clinical Transfusion Medicine Committee.

BACKGROUND: The AABB Clinical Transfusion Medicine Committee (CTMC) compiles an annual synopsis of the published literature covering important developments in the field of transfusion medicine (TM) for the board of director's review. This synopsis is now made available as a manuscript published in TRANSFUSION. STUDY DESIGN AND METHODS: CTMC committee members review original manuscripts including TM-related topics published in different journals between late 2018 and 2019. The selection of topics and manuscripts are discussed at committee meetings and are chosen based on relevance and originality. After the topics and manuscripts are selected, committee members work in pairs to create a synopsis of the topics, which is then reviewed by two committee members. The first and senior authors of this manuscript assembled the final manuscript. Although this synopsis is comprehensive, it is not exhaustive, and some papers may have been excluded or missed. RESULTS: The following topics are included: infectious risks to the blood supply, iron donor studies, pre-transfusion testing interference and genotyping, cold agglutinin disease (CAD), HLA alloimmunization in platelet transfusions, patient blood management, updates to TACO and TRALI definitions, pediatric TM, and advances in apheresis medicine. CONCLUSION: This synopsis provides easy access to relevant topics and may be useful as an educational tool.

Cyclin D3 coordinates the cell cycle during differentiation to regulate erythrocyte size and number.

Genome-wide association studies (GWASs) have identified a genetic variant of moderate effect size at 6p21.1 associated with erythrocyte traits in humans. We show that this variant affects an erythroid-specific enhancer of CCND3. A Ccnd3 knockout mouse phenocopies these erythroid phenotypes, with a dramatic increase in erythrocyte size and a concomitant decrease in erythrocyte number. By examining human and mouse primary erythroid cells, we demonstrate that the CCND3 gene product cyclin D3 regulates the number of cell divisions that erythroid precursors undergo during terminal differentiation, thereby controlling erythrocyte size and number. We illustrate how cell type-specific specialization can occur for general cell cycle components-a finding resulting from the biological follow-up of unbiased human genetic studies.

Response to random apheresis platelets versus HLA-selected platelets versus pooled platelets in HLA-sensitized patients.

BACKGROUND: It is unknown how pooled platelets (PPs) compare to random apheresis platelets (RAPs) when HLA-selected platelets (PLTs) are unavailable for HLA-sensitized patients. The aim of this study was to compare patient responses to RAPs, HLA-selected PLTs, and PPs in HLA-sensitized patients. STUDY DESIGN AND METHODS: This is a single-institution retrospective study of patients from January 2014 to April 2017 with a class I calculated panel-reactive antibody of 60% or more. Response to transfusion was determined by a corrected count increment (CCI) up to 1 hour after completion of transfusion. A CCI of 5 or more was considered successful. RESULTS: Seventy-seven units of RAPs, 412 units of HLA-selected PLT, and 388 units PPs were transfused. Mean CCIs when transfusing RAPs, HLA-selected PLTs, and PPs were 2.82, 11.44, and 4.77, respectively (p < 0.0001). Posttest comparison between RAPs and PPs revealed no significant difference in mean CCI while there was a significant difference between HLA-selected PLTs versus RAPs and HLA-selected PLTs versus PPs. The success rates of RAPs, HLA-selected PLTs, and PPs were 31%, 80%, and 35% respectively. There was no significant association of type of PLT and success rate when comparing RAPs versus PPs (p = 0.51) while there was a significant association between success rate and type of PLT transfusion when comparing HLA-selected PLTs with RAPs and PPs. CONCLUSION: HLA-selected PLTs resulted in higher mean CCIs and more successful transfusions. There was no significant difference in mean CCI or success rate when transfusing RAPs versus PPs to HLA-sensitized patients. Future studies should assess clinical outcomes in HLA-sensitized patients receiving each type of PLT product.

Evaluating safety and cost-effectiveness of platelets stored in additive solution (PAS-F) as a hemolysis risk mitigation strategy.

BACKGROUND: Platelet inventory constraints can result in minor ABO incompatibility and possible hemolysis. The aims of this study were to determine the reduction of isoagglutinin in titers of platelets stored in additive solution (PAS) and compare its safety, efficiency, and cost-effectiveness with full-volume and plasma-reduced platelets. STUDY DESIGN AND METHODS: Isoagglutinin titers were performed in paired whole blood donor samples and apheresis platelets collected in PAS (PAS-PLT) aliquot samples by the tube method. RESULTS: A total of 149 pairs of donor/platelet samples were tested: 75 group O, 59 group A, and 15 group B. For group O donor samples, the median anti-A IgG and IgM were 64 and 16, respectively, and the median anti-B IgG and IgM were 64 and 16, respectively. For group O PAS-PLT samples the mean anti-A IgG and IgM, and anti-B IgG and IgM were 32 and 8, and 16 and 8, respectively. For group A donor samples, the mean anti-B IgG and IgM was 8 in both cases; and both titers decreased to 2 in PAS-PLT. For group B donor samples, mean anti-A IgG and IgM was 16 in both cases; and both titers decreased to 4 in PAS-PLT. PAS-PLT demonstrated a net reduction in cost and improved efficiency when compared to plasma reduction. The use of PAS-PLT resulted in a 40% reduction of allergic transfusion reactions. CONCLUSION: The use of PAS decreases plasma isoagglutinin titers, transfusion reactions, and is cost-effective when compared to routine plasma reduction as a strategy to mitigate hemolysis risk from minor incompatible platelet transfusion.