Clinical outcomes in hospitalized plasma and platelet transfusion recipients prior to and following widespread blood donor SARS-CoV-2 infection and vaccination.

BACKGROUND: The safety of transfusion of SARS-CoV-2 antibodies in high plasma volume blood components to recipients without COVID-19 is not established. We assessed whether transfusion of plasma or platelet products during periods of increasing prevalence of blood donor SARS-CoV-2 infection and vaccination was associated with changes in outcomes in hospitalized patients without COVID-19. METHODS: We conducted a retrospective cohort study of hospitalized adults who received plasma or platelet transfusions at 21 hospitals during pre-COVID-19 (3/1/2018-2/29/2020), COVID-19 pre-vaccine (3/1/2020-2/28/2021), and COVID-19 post-vaccine (3/1/2021-8/31/2022) study periods. We used multivariable logistic regression with generalized estimating equations to adjust for demographics and comorbidities to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Among 21,750 hospitalizations of 18,584 transfusion recipients without COVID-19, there were 697 post-transfusion thrombotic events, and oxygen requirements were increased in 1751 hospitalizations. Intensive care unit length of stay (n = 11,683) was 3 days (interquartile range 1-5), hospital mortality occurred in 3223 (14.8%), and 30-day rehospitalization in 4144 (23.7%). Comparing the pre-COVID, pre-vaccine and post-vaccine study periods, there were no trends in thromboses (OR 0.9 [95% CI 0.8, 1.1]; p = .22) or oxygen requirements (OR 1.0 [95% CI 0.9, 1.1]; p = .41). In parallel, there were no trends across study periods for ICU length of stay (p = .83), adjusted hospital mortality (OR 1.0 [95% CI 0.9-1.0]; p = .36), or 30-day rehospitalization (p = .29). DISCUSSION: Transfusion of plasma and platelet blood components collected during the pre-vaccine and post-vaccine periods of the COVID-19 pandemic was not associated with increased adverse outcomes in transfusion recipients without COVID-19.

Leveraging Donor Populations to Study the Epidemiology and Pathogenesis of Transfusion-Transmitted and Emerging Infectious Diseases.

The tragedy of transfusion-associated hepatitis and HIV spurred a decades-long overhaul of the regulatory oversight and practice of blood transfusion. Consequent to improved donor selection, testing, process control, clinical transfusion practice and post-transfusion surveillance, transfusion in the United States and other high-income countries is now a very safe medical procedure. Nonetheless, pathogens continue to emerge and threaten the blood supply, highlighting the need for a proactive approach to blood transfusion safety. Blood donor populations and the global transfusion infrastructure are under-utilized resources for the study of infectious diseases. Blood donors are large, demographically diverse subsets of general populations for whom cross-sectional and longitudinal samples are readily accessible for serological and molecular testing. Blood donor collection networks span diverse geographies, including in low- and middle-income countries, where agents, especially zoonotic pathogens, are able to emerge and spread, given limited tools for recognition, surveillance and control. Routine laboratory storage and transportation, coupled with data capture, afford access to rich epidemiological data to assess the epidemiology and pathogenesis of established and emerging infections. Subsequent to the State of the Science in Transfusion Medicine symposium in 2022, our working group (WG), "Emerging Infections: Impact on Blood Science, the Blood Supply, Blood Safety, and Public Health" elected to focus on "leveraging donor populations to study the epidemiology and pathogenesis of transfusion-transmitted and emerging infectious diseases." The 5 landmark studies span (1) the implication of hepatitis C virus in post-transfusion hepatitis, (2) longitudinal evaluation of plasma donors with incident infections, thus informing the development of a widely used staging system for acute HIV infection, (3) explication of the dynamics of early West Nile Virus infection, (4) the deployment of combined molecular and serological donor screening for Babesia microti, to characterize its epidemiology and infectivity and facilitate routine donor screening, and (5) national serosurveillance for SARS-CoV-2 during the COVID-19 pandemic. The studies highlight the interplay between infectious diseases and transfusion medicine, including the imperative to ensure blood transfusion safety and the broader application of blood donor populations to the study of infectious diseases.

Evaluation of Ortho VITROS and Roche Elecsys S and NC Immunoassays for SARS-CoV-2 Serosurveillance Applications.

SARS-CoV-2 seroprevalence studies are instrumental in monitoring epidemic activity and require well-characterized, high-throughput assays, and appropriate testing algorithms. The U.S. Nationwide Blood Donor Seroprevalence Study performed monthly cross-sectional serological testing from July 2020 to December 2021, implementing evolving testing algorithms in response to changes in pandemic activity. With high vaccine uptake, anti-Spike (S) reactivity rates reached >80% by May 2021, and the study pivoted from reflex Roche anti-nucleocapsid (NC) testing of Ortho S-reactive specimens to parallel Ortho S/NC testing. We evaluated the performance of the Ortho NC assay as a replacement for the Roche NC assay and compared performance of parallel S/NC testing on both platforms. Qualitative and quantitative agreement of Ortho NC with Roche NC assays was evaluated on preselected S/NC concordant and discordant specimens. All 190 Ortho S+/Roche NC+ specimens were reactive on the Ortho NC assay; 34% of 367 Ortho S+/Roche NC- specimens collected prior to vaccine availability and 43% of 37 Ortho S-/Roche NC+ specimens were reactive on the Ortho NC assay. Performance of parallel S/NC testing using Ortho and Roche platforms was evaluated on 200 specimens collected in 2019 and 3,903 study specimens collected in 2021. All 200 pre-COVID-19 specimens tested negative on the four assays. Cross-platform agreement between Roche and Ortho platforms was 96.4% (3,769/3,903); most discordant results had reactivity close to the cutoffs on the alternate assays. These findings, and higher efficiency and throughput, support the use of parallel S/NC testing on either Roche or Ortho platforms for large serosurveillance studies. IMPORTANCE Seroprevalence studies like the U.S. Nationwide Blood Donor Seroprevalence Study (NBDS) have been critical in monitoring SARS-CoV-2 epidemic activity. These studies rely on serological assays to detect antibodies indicating prior infection. It is critical that the assays and testing algorithms used in seroprevalence studies have adequate performance (high sensitivity, high specificity, ability to discriminate vaccine-induced and infection-induced antibodies, etc.), as well as appropriate characteristics to support large-scale studies, such as high throughput and low cost. In this study we evaluated the performance of Ortho's anti-nucleocapsid assay as a replacement for the Roche anti-nucleocapsid assay and compared performance of parallel anti-spike and anti-nucleocapsid testing on both platforms. These data demonstrate similar performance of the Ortho and Roche anti-nucleocapsid assays and that parallel anti-spike and anti-nucleocapsid testing on either platform could be used for serosurveillance applications.

Population-Weighted Seroprevalence From Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection, Vaccination, and Hybrid Immunity Among US Blood Donations From January to December 2021.

BACKGROUND: Previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) vaccination, independently and combined ("hybrid immunity"), result in partial protection from subsequent infection and strong protection from severe disease. Proportions of the US population who have been infected, vaccinated, or have hybrid immunity remain unclear, posing a challenge for assessing effective pandemic mitigation strategies. METHODS: In this serial cross-sectional study, nationwide blood donor specimens collected during January-December 2021 were tested for anti-spike and anti-nucleocapsid antibodies, and donor COVID-19 vaccination history of ≥1 dose was collected. Monthly seroprevalence induced from SARS-CoV-2 infection, COVID-19 vaccination, or both, were estimated. Estimates were weighted to account for demographic differences from the general population and were compared temporally and by demographic factors. RESULTS: Overall, 1 123 855 blood samples were assayed. From January to December 2021, the weighted percentage of donations with seropositivity changed as follows: seropositivity due to vaccination without previous infection, increase from 3.5% (95% confidence interval, 3.4%-3.7%) to 64.0%, (63.5%-64.5%); seropositivity due to previous infection without vaccination, decrease from 15.6% (15.2%-16.0%) to 11.7% (11.4%-12.0%); and seropositivity due to hybrid immunity, increase from 0.7% (0.6%-0.7%) to 18.9% (18.5%-19.3%). Combined seroprevalence from infection, vaccination, or both increased from 19.8% (19.3%-20.2%) to 94.5% (93.5%-94.0%). Infection- and vaccination-induced antibody responses varied significantly by age, race-ethnicity, and region, but not by sex. CONCLUSIONS: Our results indicate substantial increases in population humoral immunity from SARS-CoV-2 infection, COVID-19 vaccination, and hybrid immunity during 2021. These findings are important to consider in future COVID-19 studies and long-term pandemic mitigation efforts.

The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P): A research program striving to improve blood donor safety and optimize transfusion outcomes across the lifespan.

BACKGROUND: The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P) is a new iteration of prior National Heart, Lung, and Blood Institute (NHLBI) REDS programs that focus on improving transfusion recipient outcomes across the lifespan as well as the safety and availability of the blood supply. STUDY DESIGN AND METHODS: The US program includes blood centers and hospitals (22 including 6 free-standing Children's hospitals) in four geographic regions. The Brazilian program has 5 participating hemocenters. A Center for Transfusion Laboratory Studies (CTLS) and a Data Coordinating Center (DCC) support synergistic studies and activities over the 7-year REDS-IV-P program. RESULTS: The US is building a centralized, vein-to-vein (V2V) database, linking information collected from blood donors, their donations, the resulting manufactured components, and data extracts from hospital electronic medical records of transfused and non-transfused patients. Simultaneously, the Brazilian program is building a donor, donation, and component database. The databases will serve as the backbone for retrospective and prospective observational studies in transfusion epidemiology, transfusion recipient outcomes, blood component quality, and emerging blood safety issues. Special focus will be on preterm infants, patients with sickle cell disease, thalassemia or cancer, and the effect of donor biologic variability and component manufacturing on recipient outcomes. A rapid response capability to emerging safety threats has resulted in timely studies related to Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2). CONCLUSIONS: The REDS-IV-P program endeavors to improve donor-recipient-linked research with a focus on children and special populations while also maintaining the flexibility to address emerging blood safety issues.

Evaluation of Commercially Available High-Throughput SARS-CoV-2 Serologic Assays for Serosurveillance and Related Applications.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurveys can estimate cumulative incidence for monitoring epidemics, requiring assessment of serologic assays to inform testing algorithm development and interpretation of results. We conducted a multilaboratory evaluation of 21 commercial high-throughput SARS-CoV-2 serologic assays using blinded panels of 1,000 highly characterized specimens. Assays demonstrated a range of sensitivities (96%-63%), specificities (99%-96%), and precision (intraclass correlation coefficient 0.55-0.99). Durability of antibody detection was dependent on antigen and immunoglobulin targets; antispike and total Ig assays demonstrated more stable longitudinal reactivity than antinucleocapsid and IgG assays. Assays with high sensitivity, specificity, and durable antibody detection are ideal for serosurveillance, but assays demonstrating waning reactivity are appropriate for other applications, including correlation with neutralizing activity and detection of anamnestic boosting by reinfections. Assay performance must be evaluated in context of intended use, particularly in the context of widespread vaccination and circulation of SARS-CoV-2 variants.

Donor genetic and nongenetic factors affecting red blood cell transfusion effectiveness.

BACKGROUNDRBC transfusion effectiveness varies due to donor, component, and recipient factors. Prior studies identified characteristics associated with variation in hemoglobin increments following transfusion. We extended these observations, examining donor genetic and nongenetic factors affecting transfusion effectiveness.METHODSThis is a multicenter retrospective study of 46,705 patients and 102,043 evaluable RBC transfusions from 2013 to 2016 across 12 hospitals. Transfusion effectiveness was defined as hemoglobin, bilirubin, or creatinine increments following single RBC unit transfusion. Models incorporated a subset of donors with data on single nucleotide polymorphisms associated with osmotic and oxidative hemolysis in vitro. Mixed modeling accounting for repeated transfusion episodes identified predictors of transfusion effectiveness.RESULTSBlood donor (sex, Rh status, fingerstick hemoglobin, smoking), component (storage duration, γ irradiation, leukoreduction, apheresis collection, storage solution), and recipient (sex, BMI, race and ethnicity, age) characteristics were associated with hemoglobin and bilirubin, but not creatinine, increments following RBC transfusions. Increased storage duration was associated with increased bilirubin and decreased hemoglobin increments, suggestive of in vivo hemolysis following transfusion. Donor G6PD deficiency and polymorphisms in SEC14L4, HBA2, and MYO9B genes were associated with decreased hemoglobin increments. Donor G6PD deficiency and polymorphisms in SEC14L4 were associated with increased transfusion requirements in the subsequent 48 hours.CONCLUSIONDonor genetic and other factors, such as RBC storage duration, affect transfusion effectiveness as defined by decreased hemoglobin or increased bilirubin increments. Addressing these factors will provide a precision medicine approach to improve patient outcomes, particularly for chronically transfused RBC recipients, who would most benefit from more effective transfusion products.FUNDINGFunding was provided by HHSN 75N92019D00032, HHSN 75N92019D00034, 75N92019D00035, HHSN 75N92019D00036, and HHSN 75N92019D00037; R01HL126130; and the National Institute of Child Health and Human Development (NICHD).

Residual risk of transfusion-transmitted hepatitis B virus (TT-HBV) infection by NAT-screened blood components: A review of observed versus modeled infectivity from donors with window period and occult HBV infections.

BACKGROUND: The residual transfusion-transmitted hepatitis B virus (TT-HBV) risk with different testing strategies depends on the sensitivity of screening assays, the prevalence of hepatitis B surface antigen (HBsAg) compared to HBV-DNA in window period (WP) and occult HBV infections (OBIs), and infectivity of blood in these infection stages. We compared modeled WP and OBI transmission risk in a multiregional individual donation nucleic acid amplification technology (ID-NAT) screening study with observed TT-HBV infection rates in several lookback studies. STUDY DESIGN AND METHODS: The WP and OBI risk was estimated from ID-NAT screening data in six geographic regions. The 50% infectious dose (ID50 ), a key factor in the applied risk models, was assumed to be 100-fold higher in OBI than in WP blood. The relative proportion of WP and OBI TT-risk was estimated for different screening scenarios and expressed as a percentage of the ID-NAT yield rate to allow for comparison with observed TT-rates in lookback studies. RESULTS: Despite sevenfold to eightfold higher HBV ID-NAT yield rates in OBI than WP in South-East Asia and Europe, our models predicted that 40 (26-55)% of total residual TT-HBV risk was due to OBI, comparable to 37% observed in a Japanese hemovigilance study. Modeled TT-OBI risk was approximately 10-fold higher than observed rates of 2%-8% in five lookback studies but comparable to one other study (36%). CONCLUSION: Although the observed TT-OBI rate was generally lower than the modeled risk, the relative risk of WP versus OBI transmission was not incompatible with the observational infectivity data. This supports the validity of our assumptions in the infectivity-based models for estimating worst-case residual risk with different testing scenarios.

Minipool testing for SARS-CoV-2 RNA in United States blood donors.

BACKGROUND: SARS-CoV-2 RNA prevalence in blood donors from large geographic areas of high community transmission is limited. We tested residual donor plasma minipools (MPs) to determine SARS-CoV-2 RNAemia prevalence in six United States areas. STUDY DESIGN/METHODS: Blood donations collected from 7 March 2020 to 25 September 2020 were tested for SARS-CoV-2 RNA (vRNA) in MP of 6 or 16 donations using the Grifols Procleix SARS-CoV-2 research-use only (RUO) transcription-mediated amplification (TMA) assay. Reactive results were confirmed using an alternate target region TMA assay. Reactive MPs were tested by TMA after serial dilution to estimate viral load. Testing for anti-SARS-CoV-2 antibodies and infectivity was performed. RESULTS: A total of 17,995 MPs corresponding to approximately 258,000 donations were tested for vRNA. Three confirmed reactive MP16 were identified. The estimated prevalence of vRNA reactive donations was 1.16/100,000 (95% CI 0.40, 3.42). The vRNA-reactive samples were non-reactive for antibody, and the estimated viral loads of the (presumed single) positive donations within each MP ranged from <1000 to <4000 copies/ml. When tested, no infectivity was observed in inoculated permissive cell cultures. DISCUSSION: Blood donation MP-nucleic acid testing (NAT) indicated that SARS-CoV-2 RNAemia is infrequent and, when detected, the vRNA was at low concentrations. Only one RNA-reactive MP could be tested for infectivity for operational reasons and was not infectious in cell culture. These findings support current recommendations from international and national regulatory agencies to not screen donors by NAT.

Multiple-ancestry genome-wide association study identifies 27 loci associated with measures of hemolysis following blood storage.

BackgroundThe evolutionary pressure of endemic malaria and other erythrocytic pathogens has shaped variation in genes encoding erythrocyte structural and functional proteins, influencing responses to hemolytic stress during transfusion and disease.MethodsWe sought to identify such genetic variants in blood donors by conducting a genome-wide association study (GWAS) of 12,353 volunteer donors, including 1,406 African Americans, 1,306 Asians, and 945 Hispanics, whose stored erythrocytes were characterized by quantitative assays of in vitro osmotic, oxidative, and cold-storage hemolysis.ResultsGWAS revealed 27 significant loci (P < 5 × 10-8), many in candidate genes known to modulate erythrocyte structure, metabolism, and ion channels, including SPTA1, ALDH2, ANK1, HK1, MAPKAPK5, AQP1, PIEZO1, and SLC4A1/band 3. GWAS of oxidative hemolysis identified variants in genes encoding antioxidant enzymes, including GLRX, GPX4, G6PD, and SEC14L4 (Golgi-transport protein). Genome-wide significant loci were also tested for association with the severity of steady-state (baseline) in vivo hemolytic anemia in patients with sickle cell disease, with confirmation of identified SNPs in HBA2, G6PD, PIEZO1, AQP1, and SEC14L4.ConclusionsMany of the identified variants, such as those in G6PD, have previously been shown to impair erythrocyte recovery after transfusion, associate with anemia, or cause rare Mendelian human hemolytic diseases. Candidate SNPs in these genes, especially in polygenic combinations, may affect RBC recovery after transfusion and modulate disease severity in hemolytic diseases, such as sickle cell disease and malaria.

Blood donor exposome and impact of common drugs on red blood cell metabolism.

Computational models based on recent maps of the RBC proteome suggest that mature erythrocytes may harbor targets for common drugs. This prediction is relevant to RBC storage in the blood bank, in which the impact of small molecule drugs or other xenometabolites deriving from dietary, iatrogenic, or environmental exposures ("exposome") may alter erythrocyte energy and redox metabolism and, in so doing, affect red cell storage quality and posttransfusion efficacy. To test this prediction, here we provide a comprehensive characterization of the blood donor exposome, including the detection of common prescription and over-the-counter drugs in blood units donated by 250 healthy volunteers in the Recipient Epidemiology and Donor Evaluation Study III Red Blood Cell-Omics (REDS-III RBC-Omics) Study. Based on high-throughput drug screenings of 1366 FDA-approved drugs, we report that approximately 65% of the tested drugs had an impact on erythrocyte metabolism. Machine learning models built using metabolites as predictors were able to accurately predict drugs for several drug classes/targets (bisphosphonates, anticholinergics, calcium channel blockers, adrenergics, proton pump inhibitors, antimetabolites, selective serotonin reuptake inhibitors, and mTOR), suggesting that these drugs have a direct, conserved, and substantial impact on erythrocyte metabolism. As a proof of principle, here we show that the antacid ranitidine - though rarely detected in the blood donor population - has a strong effect on RBC markers of storage quality in vitro. We thus show that supplementation of blood units stored in bags with ranitidine could - through mechanisms involving sphingosine 1-phosphate-dependent modulation of erythrocyte glycolysis and/or direct binding to hemoglobin - improve erythrocyte metabolism and storage quality.

Zika virus RNA and IgM persistence in blood compartments and body fluids: a prospective observational study.

BACKGROUND: Characterisation of the dynamics of Zika virus persistence following acute infection is needed to inform blood donor and diagnostic testing policies and understand the natural history of Zika virus infection. We aimed to characterise the natural history, persistence, and clinical outcomes of Zika virus infection through a prospective study in initially asymptomatic Zika virus RNA-positive blood donors. METHODS: Zika virus-infected blood donors identified through Zika virus nucleic acid amplification test (NAAT) screening at three blood collection organisations in the USA were enrolled into a 1-year follow-up study, with blood and body fluid samples and detailed symptom data collected at up to seven visits. All samples were tested for Zika virus RNA by real-time PCR (rtPCR); follow-up plasma, whole blood, and urine were also tested by replicate NAAT. Plasma was tested for flavivirus-specific IgM and IgG by ELISA. Zika virus RNA persistence for each assay or sample type and plasma antibody persistence from estimated date of plasma NAAT-detectable infection were calculated from follow-up data using survival statistical methods. FINDINGS: Between July 6, 2016 and March 7, 2017, we enrolled 53 participants. From the estimated date of plasma NAAT-detectable infection, Zika virus RNA was detectable in plasma for 9·9 days (95% CI 8·1-12·0), in red blood cells for 95·4 days (62·8-129·1), and in whole blood for 73·5 days (39·8-107·5). Replicate NAATs (one or more of eight replicates positive) extended detection of Zika virus RNA in plasma to 34·8 days (19·9-56·2) and in whole blood (at least one of two tests positive) to 104·8 days (76·7-129·9). Urine was rtPCR reactive up to 14·5 days (10·5-20·3) and saliva up to 26·4 days (19·7-38·7). Zika virus IgM persisted for 237·7 days (128·7-459·5) from estimated time since plasma NAAT-detectable infection. Zika virus RNA fell below detectable limits more rapidly in the saliva of participants with pre-existing dengue virus IgG than in those without. Of 25 donors identified pre-seroconversion with symptom data at the first or second study visit, 16 (64%) developed multiple Zika virus-related symptoms after asymptomatic index donations, compared with nine (36%) of 25 donors detected after seroconversion. INTERPRETATION: Determination of viral marker persistence is enhanced by follow-up of blood donors who are pre-symptomatic or asymptomatic, Zika virus RNA-positive, and antibody negative. Zika virus RNA persists in red blood cells for several months following clearance from plasma and body fluids, and replicate, highly sensitive NAATs extend RNA detection in all compartments. Whole blood testing can extend detection of acute infection for diagnostics and monitoring of pregnant women, sexual partners, and travellers. FUNDING: National Heart, Lung, and Blood Institute, Biomedical Advanced Research and Development Authority.

Stored RBC metabolism as a function of caffeine levels.

BACKGROUND: Coffee consumption is extremely common in the United States. Coffee is rich with caffeine, a psychoactive, purinergic antagonist of adenosine receptors, which regulate red blood cell energy and redox metabolism. Since red blood cell (purine) metabolism is a critical component to the red cell storage lesion, here we set out to investigate whether caffeine levels correlated with alterations of energy and redox metabolism in stored red blood cells. STUDY DESIGN AND METHODS: We measured the levels of caffeine and its main metabolites in 599 samples from the REDS-III RBC-Omics (Recipient Epidemiology Donor Evaluation Study III Red Blood Cell-Omics) study via ultra-high-pressure-liquid chromatography coupled to high-resolution mass spectrometry and correlated them to global metabolomic and lipidomic analyses of RBCs stored for 10, 23, and 42 days. RESULTS: Caffeine levels positively correlated with increased levels of the main red cell antioxidant, glutathione, and its metabolic intermediates in glutathione-dependent detoxification pathways of oxidized lipids and sugar aldehydes. Caffeine levels were positively correlated with transamination products and substrates, tryptophan, and indole metabolites. Expectedly, since caffeine and its metabolites belong to the family of xanthine purines, all xanthine metabolites were significantly increased in the subjects with the highest levels of caffeine. However, high-energy phosphate compounds ATP and DPG were not affected by caffeine levels, despite decreases in glucose oxidation products-both via glycolysis and the pentose phosphate pathway. CONCLUSION: Though preliminary, this study is suggestive of a beneficial correlation between the caffeine levels and improved antioxidant capacity of stored red cells.

Nicotine exposure increases markers of oxidant stress in stored red blood cells from healthy donor volunteers.

BACKGROUND: Cigarette smoking is a frequent habit across blood donors (approx. 13% of the donor population), that could compound biologic factors and exacerbate oxidant stress to stored red blood cells (RBCs). STUDY DESIGN AND METHODS: As part of the REDS-III RBC-Omics (Recipient Epidemiology Donor Evaluation Study III Red Blood Cell-Omics) study, a total of 599 samples were sterilely drawn from RBC units stored under blood bank conditions at Storage Days 10, 23, and 42 days, before testing for hemolysis parameters and metabolomics. Quantitative measurements of nicotine and its metabolites cotinine and cotinine oxide were performed against deuterium-labeled internal standards. RESULTS: Donors whose blood cotinine levels exceeded 10 ng/mL (14% of the tested donors) were characterized by higher levels of early glycolytic intermediates, pentose phosphate pathway metabolites, and pyruvate-to-lactate ratios, all markers of increased basal oxidant stress. Consistently, increased glutathionylation of oxidized triose sugars and lipid aldehydes was observed in RBCs donated by nicotine-exposed donors, which were also characterized by increased fatty acid desaturation, purine salvage, and methionine oxidation and consumption via pathways involved in oxidative stress-triggered protein damage-repair mechanisms. CONCLUSION: RBCs from donors with high levels of nicotine exposure are characterized by increases in basal oxidant stress and decreases in osmotic hemolysis. These findings indicate the need for future clinical studies aimed at addressing the impact of smoking and other sources of nicotine (e.g., nicotine patches, snuff, vaping, secondhand tobacco smoke) on RBC storage quality and transfusion efficacy.

Ethyl glucuronide, a marker of alcohol consumption, correlates with metabolic markers of oxidant stress but not with hemolysis in stored red blood cells from healthy blood donors.

BACKGROUND: Red blood cell (RBC) storage in the blood bank is associated with the progressive accumulation of oxidant stress. While the mature erythrocyte is well equipped to cope with such stress, recreative habits like alcohol consumption may further exacerbate the basal level of oxidant stress and contribute to the progress of the storage lesion. STUDY DESIGN AND METHODS: RBC levels of ethyl glucuronide, a marker of alcohol consumption, were measured via ultra-high-pressure liquid chromatography coupled with high-resolution mass spectrometry. Analyses were performed on 599 samples from the recalled donor population at Storage Days 10, 23, and 42 (n = 250), as part of the REDS-III RBC-Omics (Recipient Epidemiology Donor Evaluation Study III Red Blood Cell-Omics) study. This cohort consisted of the 5th and 95th percentile of donors with extreme hemolytic propensity out of the original cohort of 13,403 subjects enrolled in the REDS-III RBC Omics study. Ehtyl glucuronide levels were thus correlated to global metabolomics and lipidomics analyses and RBC hemolytic propensity. RESULTS: Ethyl glucuronide levels were positively associated with oxidant stress markers, including glutathione consumption and turnover, methionine oxidation, S-adenosylhomocysteine accumulation, purine oxidation, and transamination markers. Decreases in glycolysis and energy metabolism, the pentose phosphate pathway and ascorbate system were observed in those subjects with the highest levels of ethyl glucuronide, though hemolysis values were comparable between groups. CONCLUSION: Though preliminary, this study is suggestive that markers of alcohol consumption are associated with increases in oxidant stress and decreases in energy metabolism with no significant impact on hemolytic parameters in stored RBCs from healthy donor volunteers.

Impact of taurine on red blood cell metabolism and implications for blood storage.

BACKGROUND: Taurine is an antioxidant that is abundant in some common energy drinks. Here we hypothesized that the antioxidant activity of taurine in red blood cells (RBCs) could be leveraged to counteract storage-induced oxidant stress. STUDY DESIGN AND METHODS: Metabolomics analyses were performed on plasma and RBCs from healthy volunteers (n = 4) at baseline and after consumption of a whole can of a common, taurine-rich (1000 mg/serving) energy drink. Reductionistic studies were also performed by incubating human RBCs with taurine ex vivo (unlabeled or 13 C15 N-labeled) at increasing doses (0, 100, 500, and 1000 µmol/L) at 37°C for up to 16 hours, with and without oxidant stress challenge with hydrogen peroxide (0.1% or 0.5%). Finally, we stored human and murine RBCs under blood bank conditions in additives supplemented with 500 µmol/L taurine, before metabolomics and posttransfusion recovery studies. RESULTS: Consumption of energy drinks increased plasma and RBC levels of taurine, which was paralleled by increases in glycolysis and glutathione (GSH) metabolism in the RBC. These observations were recapitulated ex vivo after incubation with taurine and hydrogen peroxide. Taurine levels in the RBCs from the REDS-III RBC-Omics donor biobank were directly proportional to the total levels of GSH and glutathionylated metabolites and inversely correlated to oxidative hemolysis measurements. Storage of human RBCs in the presence of taurine improved energy and redox markers of storage quality and increased posttransfusion recoveries in FVB mice. CONCLUSION: Taurine modulates RBC antioxidant metabolism in vivo and ex vivo, an observation of potential relevance to transfusion medicine.

The evanescence and persistence of RBC alloantibodies in blood donors.

BACKGROUND: Blood donors represent a healthy population, whose red blood cell (RBC) alloantibody persistence or evanescence kinetics may differ from those of immunocompromised patients. A better understanding of the biologic factors impacting antibody persistence is warranted, as the presence of alloantibodies may impact donor health and the fate of the donated blood product. METHODS: Donor/donation data collected from four US blood centers from 2012 to 2016 as part of the Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) were analyzed. Clinically significant antibodies from blood donors with more than one donation who underwent at least one follow-up antibody screen after the initial antibody identification were included. Of 632,378 blood donors, 481 (128 males and 353 females) fit inclusion criteria. RESULTS: Antibody screens detected 562 alloantibodies, with 368 of 562 (65%) of antibodies being persistently detected and with 194 of 562 (35%) becoming evanescent. Factors associated with antibody persistence included antibody specificity, detection at the first donation, reported history of transfusion, and detection of multiple antibodies concurrently. Anti-D, C, and Fya were most likely to persist, while anti-M, Jka , and S were most frequently evanescent. CONCLUSIONS: These data provide insight into variables impacting the duration of antibody detection, and they may also influence blood donor center policies regarding donor recruitment/acceptance.

Direct comparison of three residual risk models for hepatitis B virus window period infections using updated input parameters.

BACKGROUND AND OBJECTIVES: Comparison of two models for estimating residual transfusion transmission risk by NAT screened window period (WP) donations in South African repeat donors gave identical results for HIV but not for HBV. In order to understand discrepant HBV modelling outcomes, the values of input parameters in three HBV WP risk models were reviewed and subsequently applied to the same South African screening data generated by HBsAg PRISM and two NAT assays (Ultrio and Ultrio Plus). Two of the models were also compared using individual donation (ID)-NAT screening data from different geographical regions. METHODS: Values of input parameters were derived from two published data sources and used in three risk models [(1) the incidence rate-WP risk day equivalent model, (2) the NAT yield WP ratio model and (3) the anti-HBc-negative HBsAg yield period ratio model] and subsequently applied to the same ID-NAT screening data. RESULTS: The HBV WP transmission risk in South African repeat donations during a one-year Ultrio Plus NAT screening period was estimated as 22, 43 and 17 per million, respectively, for the three models, as compared to 56, 117 and 48 per million for HBsAg PRISM screening. The approximate two-fold higher estimate calculated with the NAT yield WP ratio model was corroborated in repeat donations from three of four regions in a multi-regional study. When another set of model input values (with shorter viraemia periods and a higher proportion of acute occult infections) was applied to the South African screening data, the relative difference in risk estimates between the three models became smaller. CONCLUSIONS: Window period risk modelling for HBV is more complex than for HIV. Multiple factors affect the modelling outcomes. These include the values used for the length of transient HBsAg and HBV-DNA-positive phases, the proportion of acute occult and vaccine breakthrough infections and the assumption of random appearance of donors throughout the entire acute resolving infection phase. A substantial proportion of HBV WP NAT yields have very low viral load and lack donor follow-up data calling into question their definitive classification into the early acute (infectious) replication stage. Since these possible WP NAT yields most highly impact the NAT yield WP ratio model, we recommend relying on the more conservative estimates of the incidence rate-WP risk day equivalent model.

Equivalent inpatient mortality among direct-acting oral anticoagulant and warfarin users presenting with major hemorrhage.

BACKGROUND: Extrapolation of clinical trial results comparing warfarin and direct-acting oral anticoagulant (DOAC) users experiencing major hemorrhage to clinical care is challenging due to differences seen among non-randomized oral anticoagulant users, bleed location, and etiology. We hypothesized that inpatient all-cause-mortality among patients presenting with major hemorrhage differed based on the home-administered anticoagulant medication class, DOAC versus warfarin. METHODS: More than 1.5 million hospitalizations were screened and 3731 patients with major hemorrhage were identified in the REDS-III Recipient Database. Propensity score matching and stratification were used to account for potentially confounding factors. RESULTS: Inpatient all-cause-mortality was lower for DOAC (HR = 0.60, 95%CI 0.45-0.80, p = 0.0005) before accounting for confounding and competing events. Inpatient all-cause-mortality for 1266 propensity-score-matched patients compared using proportional hazards regression did not differ (HR = 0.84, 95%CI 0.58-1.22, p = 0.36). Inpatient all-cause-mortality in stratified analyses (warfarin as reference) produced: HR = 0.69 (95%CI 0.31-1.55) for traumatic head injuries; HR = 1.10 (95%CI 0.62-1.95) for non-traumatic head injuries; HR = 0.62 (95%CI 0.20-1.94) for traumatic, non-head injuries; and HR = 0.69 (95%CI 0.29-1.63) for non-traumatic, non-head injuries. Mean time to discharge was shorter for DOAC (HR = 1.17, 95%CI 1.05-1.30, p = 0.0034) in the propensity score matched analysis. Plasma transfusion occurred in 42% of warfarin hospitalizations and 11% of DOAC hospitalizations. Vitamin K was administered in 63% of warfarin hospitalizations. CONCLUSIONS: After accounting for differences in patient characteristics, location of bleed, and traumatic injury, inpatient survival was no different in patients presenting with major hemorrhage while on DOAC or warfarin.