The operational and financial impact of adding anaerobic screening of platelets.

BACKGROUND AND OBJECTIVES: We evaluated the operational and safety impact of implementing anaerobic culture screening of apheresis and pooled platelets at the American Red Cross on the already established use of the aerobic culture screening of each donation performed no sooner than 24 h following collection. MATERIALS AND METHODS: Platelets were screened for bacterial contamination with the BACT/ALERT 3D® (bioMérieux, Durham, NC) microbial detection testing system. The addition of anaerobic culture to the already existing aerobic culture resulted in sampling an additional 8-10 mL from each donation. RESULTS: Implementation of anaerobic testing resulted in an approximate 3.5-fold increased rate of False Positive BACT/ALERT alarms. There was a modest increase in the rate of True Positive alarms of 1.4-fold with increased detection of Klebsiella and Propionibacterium species, including Cutibacterium acnes. In addition, there was an approximate 3.5-fold increase rate of False Positives and a 13.5-fold increase rate of Indeterminates, the majority (~57%) were due to Cutibacterium acnes. The combined costs and lost revenue associated with adding anaerobic screening increased by ~$1,000,000/year due to testing cost and product discards. CONCLUSION: The addition of anaerobic culture to aerobic culture to the original donation (without the introduction of sampling delay) resulted in a significant increase in the rate of alerts. The 40% increased rate of True Positive alarms may have modestly improved platelet safety. However, there was a disproportionate increase in the rate of False Positive and Indeterminate bacterial culture alarms, which added substantial cost and overall loss of platelet products.

Young apheresis platelet donors show significant and sustained growth over the last decade in the US, 2010-2019: A favorable sign of the resiliency of the platelet supply.

BACKGROUND: Platelet demand continues to rise and US hospitals frequently face shortages. The peak median age of apheresis platelet donors (APD) is believed to have increased over the last decade, raising concerns that the APD base is not being adequately replenished with young donors. STUDY DESIGN/METHODS: American Red Cross (ARC) apheresis platelet collections were evaluated from calendar years 2010 through 2019. APD, products per procedure/split rate (PPP) and donation frequencies were stratified into age groups. RESULTS/FINDINGS: The number of unique APD from calendar year 2010 through 2019 in the ARC donor pool increased from 87,573 to 115,372 donors, representing a 31.7% overall growth. Donors in the 16-40 year-old (y) age group increased by 78.8% overall, with the largest absolute increases seen in the 26-30 y (4852 donors, 99.9% growth), followed by the 31-35 y (3991, 94.1%) group. Donors aged 56+ increased by 50.4% overall, with the largest increase seen in the 66-70 y (5988 donors, 108.1% growth) group. Middle-aged donors, aged 41-55 y, demonstrated a decrease of 16.5%. Over the last decade, the youngest age groups (16-40 y) comprised 61.3% of first-time donors (FTD). Annual donation frequency increased with increasing age and PPP. The highest donation frequencies were seen in the oldest age groups. CONCLUSION: Although the peak median age of APD increased over the study period, relative contribution of the 16-40 y APD base also increased. Older donors exhibited the highest donation frequencies and thus contributed the largest volume of apheresis platelet units. Platelet donor activity declined in the middle age (41-55 y) group.

COVID-19 convalescent plasma donors: Unique motivations in unique times?

BACKGROUND: Early in the SARS-CoV-2 pandemic, many blood collection organizations (BCOs) were asked to collect and distribute COVID-19 convalescent plasma (CCP) as a potential treatment for this new virus and resulting disease. However, recruiting CCP donors presented unique challenges for BCOs, as there were few recovered patients at this time, and like the general population, most potential CCP donors had no blood donation experience. Thus, many CCP donors were new donors, and their donation motivations were unknown. MATERIALS AND METHODS: Donors who gave CCP at least once between April 27th and September 15th, 2020, were emailed a link to an online survey regarding their experience with COVID-19 and their motivations for donating CCP and blood. RESULTS: Of the 14,225 invitations sent, 3471 donors responded (24.4%). Most donors had never donated blood before (n = 1406), followed by lapsed donors (n = 1050), and recent donors (n = 951). There was a significant relationship between self-reported donation experience and fear of CCP donation (X2  = 119.2, p < .001). Motivations ranked "very important" by responding donors were wanting to help someone in need, a feeling of responsibility, and feeling a duty to donate. Donors with more severe disease were more likely to respond with feelings of a sense of duty to donate CCP (Χ2  = 8.078, p = .044) or altruism (Χ2  = 8.580, p = .035). CONCLUSIONS: Overwhelmingly, altruism and a sense of duty and responsibility were the reasons that CCP donors decided to donate. These insights can be useful for motivating donors for specialized donation programs or if wide scale CCP recruitment is needed in the future.

Sickle cell trait results in a high leukoreduction quality control failure rate for whole blood donations.

BACKGROUND: Prior studies have shown that sickle cell trait (SCT) is the most common reason attributed to leukoreduction (LR) filter failure due to physical blockage. However, current Food and Drug Administration (FDA) guidelines do not require blood collectors to take a specific action to mitigate inadequate LR that may occur among donors with SCT. We sought to determine the scope of inadequate LR among whole blood (WB) donations collected from individuals with SCT and processed under standard manufacturing conditions. STUDY DESIGN AND METHODS: Between 8/2021 and 2/2022, a total of 40 red blood cells units (RBCs) manufactured from WB donations collected from donors historically positive for SCT had residual leukocyte testing performed. All 40 of the units had appeared to successfully complete leukofiltration. RESULTS: Out of the 40 units tested, 22 failed routine residual leukocyte quality control testing (55% failure rate, 95% confidence interval 40%-70%). Nine out of the 22 failures resulted in more than 100 residual leukocytes per microliter of product. CONCLUSION: Even when leukofiltration appears to have been completed successfully, WB units collected from donors with SCT have a high (55% in aggregate) rate of inadequate leukoreduction. Correlating this result with previous studies showing that of up to 50% of WB units collected from donors with SCT fail to pass through the leukoreduction filter, we estimate that only 25% of WB donations collected from individuals with SCT will result in a leukoreduced RBC unit that meets all FDA requirements. Blood centers should encourage individuals with SCT to donate platelets or plasma, rather than WB.

Cryoprecipitated anti-hemophiliac factor manufactured from plasma frozen within 24 h after phlebotomy meets AABB quality standards.

BACKGROUND: Cryoprecipitated antihemophiliac factor (CryoAHF) manufacturing in the US has not kept pace with the increasing demand for hospital transfusion services. Association for Advancement of Blood and Biologics (AABB) and Food and Drug Administration (FDA) require that CryoAHF be manufactured from fresh frozen plasma within 8 h (FFP). We evaluated whether CryoAHF manufactured from plasma frozen within 24 h (PF24) met regulatory quality control (QC) requirements to increase available plasma for CryoAHF. STUDY DESIGN AND METHODS: In a "worst-case scenario" feasibility study, we produced 21 single units of CryoAHF from type-O whole blood-derived PF24 frozen between 20 and 24 h after collection. A follow-up QC validation was conducted wherein 69 PF24 units across three sites were manufactured into CryoAHF. Factor VIII (FVIII) and fibrinogen levels were measured. RESULTS: CryoAHF manufactured in our feasibility study from PF24 contained FVIII levels of 208 ± 61 IU (mean ± SD) and 509 ± 152 mg of fibrinogen levels per unit. CryoAHF manufactured in our QC validation from PF24 yielded FVIII levels of 214 ± 58 IU and 607 ± 176 mg of fibrinogen levels per unit. The coagulation factor levels from each of the individual CryoAHF units exceeded the minimum AABB and FDA requirement of ≥80 IU of FVIII per unit and ≥150 mg of fibrinogen per unit. There was no decrease in FVIII or fibrinogen levels in CryoAHF produced from PF24 as compared to historic QC results of CryoAHF produced from FFP. CONCLUSION: These studies demonstrated that CryoAHF produced from PF24 meets AABB and FDA QC requirements. FDA approved the American Red Cross request to manufacture CryoAHF singles and pools from PF24 as source material.

Acquired platelet storage container leaks and contamination with environmental bacteria: A preventable cause of bacterial sepsis.

BACKGROUND: Apheresis platelets (AP) may be contaminated by environmental bacteria via container defects acquired during processing, transport, storage, or transfusion, as highlighted by a recent series of septic reactions related to Acinetobacter spp. and other bacterial strains. STUDY DESIGN AND METHODS: The frequency and nature of acquired container defect reports to one manufacturer were evaluated from January 2019 to July 2020. The published incidence of contamination and sepsis due to environmental bacteria with culture screened AP in the United States was reviewed for the period of 2010-2019. RESULTS: Review of a manufacturers' records showed 23 US reports of leaks involving 24 containers attributed to postmanufacturing damage, at a rate of 44 per million distributed storage containers. Analysis of returned containers showed evidence of scratches, impressions, and/or piercings. Literature review of US hemovigilance data revealed that environmental bacteria comprised 7% of confirmed positive primary bacterial culture screens, were responsible for 14%-16% of reported septic, and 8 of 28 (29%) fatal reactions with bacterial-culture screened AP. Sepsis cases have been reported with culture screened, point-of-issue (POI) tested, or pathogen-reduced AP. DISCUSSION: Environmental contamination of AP is rare but can cause sepsis. Container damage provides a pathway for contamination after culture screening, POI bacteria testing, or pathogen reduction. Blood collectors and transfusion services should have procedures to ensure proper inspection, handling, storage, and transport of AP to avoid damage and should enhance efforts to detect defects prior to release and to eliminate bacteria from all contacting surfaces to minimize the risk of contamination.

Access to and safety of COVID-19 convalescent plasma in the United States Expanded Access Program: A national registry study.

BACKGROUND: The United States (US) Expanded Access Program (EAP) to coronavirus disease 2019 (COVID-19) convalescent plasma was initiated in response to the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19. While randomized clinical trials were in various stages of development and enrollment, there was an urgent need for widespread access to potential therapeutic agents. The objective of this study is to report on the demographic, geographical, and chronological characteristics of patients in the EAP, and key safety metrics following transfusion of COVID-19 convalescent plasma. METHODS AND FINDINGS: Mayo Clinic served as the central institutional review board for all participating facilities, and any US physician could participate as a local physician-principal investigator. Eligible patients were hospitalized, were aged 18 years or older, and had-or were at risk of progression to-severe or life-threatening COVID-19; eligible patients were enrolled through the EAP central website. Blood collection facilities rapidly implemented programs to collect convalescent plasma for hospitalized patients with COVID-19. Demographic and clinical characteristics of all enrolled patients in the EAP were summarized. Temporal patterns in access to COVID-19 convalescent plasma were investigated by comparing daily and weekly changes in EAP enrollment in response to changes in infection rate at the state level. Geographical analyses on access to convalescent plasma included assessing EAP enrollment in all national hospital referral regions, as well as assessing enrollment in metropolitan areas and less populated areas that did not have access to COVID-19 clinical trials. From April 3 to August 23, 2020, 105,717 hospitalized patients with severe or life-threatening COVID-19 were enrolled in the EAP. The majority of patients were 60 years of age or older (57.8%), were male (58.4%), and had overweight or obesity (83.8%). There was substantial inclusion of minorities and underserved populations: 46.4% of patients were of a race other than white, and 37.2% of patients were of Hispanic ethnicity. Chronologically and geographically, increases in the number of both enrollments and transfusions in the EAP closely followed confirmed infections across all 50 states. Nearly all national hospital referral regions enrolled and transfused patients in the EAP, including both in metropolitan and in less populated areas. The incidence of serious adverse events was objectively low (<1%), and the overall crude 30-day mortality rate was 25.2% (95% CI, 25.0% to 25.5%). This registry study was limited by the observational and pragmatic study design that did not include a control or comparator group; thus, the data should not be used to infer definitive treatment effects. CONCLUSIONS: These results suggest that the EAP provided widespread access to COVID-19 convalescent plasma in all 50 states, including for underserved racial and ethnic minority populations. The study design of the EAP may serve as a model for future efforts when broad access to a treatment is needed in response to an emerging infectious disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT#: NCT04338360.

Small proline-rich repeat 3 is a novel coordinator of PDGFRß and integrin ß1 crosstalk to augment proliferation and matrix synthesis by cardiac fibroblasts.

Nearly 6 million Americans suffer from heart failure. Increased fibrosis contributes to functional decline of the heart that leads to heart failure. Previously, we identified a mechanosensitive protein, small proline-rich repeat 3 (SPRR3), in vascular smooth muscle cells of atheromas. In this study, we demonstrate SPRR3 expression in cardiac fibroblasts which is induced in activated fibroblasts following pressure-induced heart failure. Sprr3 deletion in mice showed preserved cardiac function and reduced interstitial fibrosis in vivo and reduced fibroblast proliferation and collagen expression in vitro. SPRR3 loss resulted in reduced activation of Akt, FAK, ERK, and p38 signaling pathways, which are coordinately regulated by integrins and growth factors. SPRR3 deletion did not impede integrin-associated functions including cell adhesion, migration, or contraction. SPRR3 loss resulted in reduced activation of PDGFRß in fibroblasts. This was not due to the reduced PDGFRß expression levels or decreased binding of the PDGF ligand to PDGFRß. SPRR3 facilitated the association of integrin ß1 with PDGFRß and subsequently fibroblast proliferation, suggesting a role in PDGFRß-Integrin synergy. We postulate that SPRR3 may function as a conduit for the coordinated activation of PDGFRß by integrin ß1, leading to augmentation of fibroblast proliferation and matrix synthesis downstream of biomechanical and growth factor signals.

Conservation of Rh negative Low Titer O Whole Blood (LTOWB) and the need for a national conversation to define its use in trauma transfusion protocols.

Low-titer group O whole blood (LTOWB) use is growing steadily in the United States. Although the percentage of O negative LTOWB use by Red Cross hospitals has remained steady at ~23% over the last 2 years, this elevated use rate is twice that of O negative RBC components. Given the more restricted group O donor pool, this level of use will make it difficult to expand the use of this product. Evaluation of hospital practices regarding females of childbearing potential show significant variability with some hospitals transfusing O positive, with others choosing to restrict this population to O negative LTOWB or only O negative RBC component therapy. To ensure access of LTOWB to all patients who may benefit and to maintain sufficient supplies, we recommend developing standardized practice recommendations for its use.

COVID-19 convalescent plasma donor characteristics, product disposition, and comparison with standard apheresis donors.

BACKGROUND: With coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) offering an early treatment option for COVID-19, blood collectors needed to quickly overcome obstacles to recruiting and qualifying eligible donors. We provide attributes of CCP donors and products and compare to standard donors and products. STUDY DESIGN AND METHODS: Information on CCP donors was gathered from the American Red Cross qualification website through product collection. Data from 2019 for standard plasma/platelet apheresis (SA) and whole blood (WB) donor demographics and SA donations including product disposition and reactions were used for comparison. RESULTS: Of almost 59 000 donors registering on the website, 75% reported an existing COVID-19 diagnostic polymerase chain reaction or an antibody test. The majority (56.2%) of 10 231 CCP donors were first-time donors in contrast to SA or WB donor populations, which were only 3.0% and 30.6%, respectively, first-time donors. The number of female donors was 12% higher than SA donors. Older (≥ 65 years) and younger (16-19 years) were comparatively underrepresented in CCP donors. Deferral (10.2%) and Quantity Not Sufficient rates (6.4%) for presenting CCP donations were higher than SA (8.2% and 1.1%, respectively). Human leukocyte antigen antibody reactivity was the highest cause of product loss for CCP donations vs SA donations (9.6% vs 1.3%). Acute adverse events also occurred at a higher rate among both first-time and repeat CCP donations compared to SA. CONCLUSIONS: CCP donors were more likely to be first-time and female donors than WB or SA donors. CCP donations had a higher rate of donor adverse reactions, deferrals, and product loss than SA donations.

Adoption trends of point of issue Verax PGD rapid test for bacterial screening of platelets between 2013 and 2018 among hospitals supplied by the American Red Cross and impact on platelet availability.

BACKGROUND: Point-of-issue tests, such as the Verax Pan Genera Detection (PGD) test, can be used to mitigate the occurrence of septic reactions. Little is known about how widespread the adoption of the PGD test is across US hospitals. STUDY DESIGN/METHODS: The Red Cross hemovigilance database was used to determine the numbers of PGD-positive test results between 2013 and 2018. An examination of the impact of a reactive PGD test on product availability was performed for 2018. RESULTS: The number of reported cases doubled, rising from approximately 50 to 100 per year between 2013 and 2018. A total of 475 initially reactive PGD tests during the entire study period were reported, and 7 (1.5%) of these were determined to be true positives. Hospitals surveyed reported testing platelet units once, with no repeat testing if the unit was PGD reactive. Evaluation of the reported PGD reactive cases for apheresis platelets for 2018 (n = 93) resulted in an estimated cost to the blood center of $87,000, which included the labor and material costs of working up the cases and the estimated value of the lost 64 units and co-components. In addition, there was a loss of the opportunity to collect over 85 apheresis platelets during the time the implicated donor was temporarily deferred. CONCLUSIONS: The number of hospital reports of reactive PGD tests has shown modest growth in the past 5 years. The number of initially reactive PGD tests that were confirmed was minimal. Blood centers can incur cost and platelet inventory loss from initially false-positive test results.

A multicenter evaluation of heterogeneity in cellular therapy processing laboratory procedure times to assess workload capacity.

BACKGROUND: Growth in size and complexity of clinical hematopoietic progenitor cell (HPC) transplant programs necessitates parallel increases in cellular therapy laboratory (CTL) workload. Typically individually developed, HPC product processing is labor and time intensive. Variation in procedure type and numbers across CTLs complicates direct comparisons, and benchmark data are not readily available. STUDY DESIGN AND METHODS: Studies were undertaken at seven CTLs. Transplant volume and staff numbers were determined. Staff recorded time performing tasks broken down into steps: paperwork, product acceptance, transport/infusion, processing, and cryopreservation. Times were added to obtain total times for 15 common CTL procedures. RESULTS: Annual transplant volume ranged from 53.4 to 463.2, with products processed by a range of 2 to 10 dedicated CTL staff. Paperwork time constituted 23.7% to 62.3% total time; product processing time accounted for 1.8 (for National Marrow Donor Program product receipt) to 62.6% (for red blood cell reduction of allogeneic HPC products from bone marrow) of total processing time. Mean time for 15 procedures ranged from 1.27 to 8.28 hours (standard deviation range, 0.35-2.71 hr). Mean time for products from bone marrow versus peripheral blood was 6.6 ± 2.0 versus 5.5 ± 1.1 hours (p = 0.02). Cryopreservation (6.5 ± 1.6 vs. 4.4 ± 0.85 hr; p < 0.01) and manipulation (6.4 ± 1.5 vs. 4.4 ± 0.85 hr; p < 0.01) added time. CONCLUSION: CTL procedures are time intensive, with wide intra- and inter-CTL variation. Paperwork accounted for substantial portion of total time across procedures. Bone marrow source, cryopreservation, and manipulation contributed to longer times. These findings provide concrete data on which to build regarding CTL workload capacity.

An exploration of the advantages of automated titration testing: low inter-instrument variability and equivalent accuracy for ABO and non-ABO antibody titres relative to tube testing.

BACKGROUND AND OBJECTIVES: Obtaining IgM and IgG titres is important in numerous clinical situations, including solid-organ transplant, obstetrics, and for testing of out-of-group plasma-containing components. Tube method is the most prevalent testing modality, though it is both labour-intensive and known for intra- and inter-laboratory variability. The utility of automated gel testing as a method to improve both inter- and intra-laboratory reproducibility is unknown. MATERIALS AND METHODS: Two academic centres participated in a study evaluating automated gel titreing. Group O plasma samples were used to measure titres of antibodies against ABO (IgM) with buffered gel cards and 4 minor and minor red-blood-cell antigens (IgG) anti-IgG gel cards. Multiple ORTHO VISION automated analyzers were used to assess inter-instrument variation. A subset of ABO (IgM) samples were compared between laboratories to evaluate inter-laboratory variability. Multiple samples were titred by tube and by automated gel technology to determine similarity of results. RESULTS: Testing demonstrated no significant difference between analysers or between sites when performing automated titrations (P ≥ 0·99). Non-ABO IgG titres were evaluated and demonstrated little inter-instrument variability. The IgM anti-A and -B titres obtained by automated gel testing were neither consistently higher nor lower than tube titres. Greater than 90% of titre values were within one dilution. CONCLUSION: Based on this study, our data suggest that titreing by automated gel testing is both highly reproducible (IgM and IgG) and does not differ significantly from manual tube testing results of direct agglutination (IgM).

Sepsis Attributed to Bacterial Contamination of Platelets Associated with a Potential Common Source - Multiple States, 2018.

During May-October 2018, four patients from three states experienced sepsis after transfusion of apheresis platelets contaminated with Acinetobacter calcoaceticus-baumannii complex (ACBC) and Staphylococcus saprophyticus; one patient died. ACBC isolates from patients' blood, transfused platelet residuals, and two environmental samples were closely related by whole genome sequencing. S. saprophyticus isolates from two patients' blood, three transfused platelet residuals, and one hospital environmental sample formed two whole genome sequencing clusters. This whole genome sequencing analysis indicated a potential common source of bacterial contamination; investigation into the contamination source continues. All platelet donations were collected using apheresis cell separator machines and collection sets from the same manufacturer; two of three collection sets were from the same lot. One implicated platelet unit had been treated with pathogen-inactivation technology, and two had tested negative with a rapid bacterial detection device after negative primary culture. Because platelets are usually stored at room temperature, bacteria in contaminated platelet units can proliferate to clinically relevant levels by the time of transfusion. Clinicians should monitor for sepsis after platelet transfusions even after implementation of bacterial contamination mitigation strategies. Recognizing adverse transfusion reactions and reporting to the platelet supplier and hemovigilance systems is crucial for public health practitioners to detect and prevent sepsis associated with contaminated platelets.

Effects of red-cell storage duration on patients undergoing cardiac surgery.

BACKGROUND: Some observational studies have reported that transfusion of red-cell units that have been stored for more than 2 to 3 weeks is associated with serious, even fatal, adverse events. Patients undergoing cardiac surgery may be especially vulnerable to the adverse effects of transfusion. METHODS: We conducted a randomized trial at multiple sites from 2010 to 2014. Participants 12 years of age or older who were undergoing complex cardiac surgery and were likely to undergo transfusion of red cells were randomly assigned to receive leukocyte-reduced red cells stored for 10 days or less (shorter-term storage group) or for 21 days or more (longer-term storage group) for all intraoperative and postoperative transfusions. The primary outcome was the change in Multiple Organ Dysfunction Score (MODS; range, 0 to 24, with higher scores indicating more severe organ dysfunction) from the preoperative score to the highest composite score through day 7 or the time of death or discharge. RESULTS: The median storage time of red-cell units provided to the 1098 participants who received red-cell transfusion was 7 days in the shorter-term storage group and 28 days in the longer-term storage group. The mean change in MODS was an increase of 8.5 and 8.7 points, respectively (95% confidence interval for the difference, -0.6 to 0.3; P=0.44). The 7-day mortality was 2.8% in the shorter-term storage group and 2.0% in the longer-term storage group (P=0.43); 28-day mortality was 4.4% and 5.3%, respectively (P=0.57). Adverse events did not differ significantly between groups except that hyperbilirubinemia was more common in the longer-term storage group. CONCLUSIONS: The duration of red-cell storage was not associated with significant differences in the change in MODS. We did not find that the transfusion of red cells stored for 10 days or less was superior to the transfusion of red cells stored for 21 days or more among patients 12 years of age or older who were undergoing complex cardiac surgery. (Funded by the National Heart, Lung, and Blood Institute; RECESS ClinicalTrials.gov number, NCT00991341.).

Acute autoimmune hemolytic anemia due to anti-Ena autoantibody successfully treated with rituximab.

BACKGROUND: Autoimmune hemolytic anemia (AIHA) due to anti-Ena has been previously reported in association with massive intravascular hemolysis, disseminated intravascular coagulation, and fatal outcomes. Here we report a case of successfully treated AIHA due to anti-Ena . CASE REPORT: A 69-year-old male with a past medical history of cirrhosis due to nonalcoholic steatohepatitis status post-orthotopic liver transplant presented with 1-month history of progressive anemia. At presentation, his hemoglobin (Hb) was 5.6 g/dL, hematocrit (Hct) 16%, reticulocytes 0.3%, direct bilirubin (bili) 4 g/dL, lactate dehydrogenase 533 units/L (reference, 125-220 units/L), and haptoglobin 254 mg/dL (reference, 40-273 mg/dL). Blood bank testing revealed an autoantibody present in his plasma and a direct antiglobulin test positive for immunoglobulin G (IgC) but negative for complement. He received 1 unit of an incompatible blood group O phenotypically matched red blood cell unit. RESULTS: Over the course of the next 5 days, the Hb and Hct decreased to 4.1 g/dL and 12%, respectively, direct bili increased to 12.3 mg/day, reticulocytes slightly increased to 0.9%, and haptoglobin decreased to less than 8 mg/dL. Marrow study showed a hypercellular marrow with erythroid hyperplasia. Additional workup performed at a reference laboratory identified an anti-Ena autoantibody. He received prednisone and weekly rituximab infusions and was monitored weekly. At the 2-month visit, Hb and Hct were 10 g/dL and 32%, respectively. CONCLUSION: Unlike two of the previously reported fatal cases of AIHA with anti-Ena specificity, this 69-year-old male treated with weekly rituximab infusion underwent clinical recovery and significant anemia improvement.

Redefining Blood Donation-Path to Inclusivity and Safety.

This Viewpoint reviews the vicissitudes of establishing fair and equitable blood donation policies based on research and improved serological testing and promotes expanding the pool of potential donors.

Wnt/ß-catenin pathway in tissue injury: roles in pathology and therapeutic opportunities for regeneration.

The Wnt/ß-catenin pathway is an evolutionarily conserved set of signals with critical roles in embryonic and neonatal development across species. In mammals the pathway is quiescent in many organs. It is reactivated in response to injury and is reported to play complex and contrasting roles in promoting regeneration and fibrosis. We review the current understanding of the role of the Wnt/ß-catenin pathway in injury of various mammalian organs and discuss the current advances and potential of Wnt inhibitory therapeutics toward promoting tissue regeneration and reducing fibrosis.-Bastakoty, D., Young, P. P. Wnt/ß-catenin pathway in tissue injury: roles in pathology and therapeutic opportunities for regeneration.

Prolonged hypoxia induces monocarboxylate transporter-4 expression in mesenchymal stem cells resulting in a secretome that is deleterious to cardiovascular repair.

MSCs encounter extended hypoxia in the wound microenvironment yet little is known about their adaptability to this prolonged hypoxic milieu. In this study, we evaluated the cellular and molecular response of MSCs in extended hypoxia (1% O2 ) versus normoxia (20% O2 ) culture. Prolonged hypoxia induced a switch toward anaerobic glycolysis transcriptome and a dramatic increase in the transcript and protein levels of monocarboxylate transporter-4 (MCT4) in MSCs. To clarify the impact of MCT4 upregulation on MSC biology, we generated MSCs which stably overexpressed MCT4 (MCT4-MSCs) at levels similar to wild-type MSCs following prolonged hypoxic culture. Consistent with its role to efflux lactate to maintain intracellular pH, MCT4-MSCs demonstrated reduced intracellular lactate. To explore the in vivo significance of MCT4 upregulation in MSC therapy, mice were injected intramuscularly following MI with control (GFP)-MSCs, MCT4-MSCs, or MSCs in which MCT4 expression was stably silenced (KDMCT4-MSCs). Overexpression of MCT4 worsened cardiac remodeling and cardiac function whereas silencing of MCT4 significantly improved cardiac function. MCT4-overexpressing MSC secretome induced reactive oxygen species-mediated cardiomyocyte but not fibroblast apoptosis in vitro and in vivo; lactate alone recapitulated the effects of the MCT4-MSC secretome. Our findings suggest that lactate extruded by MCT4-overexpressing MSCs preferentially induced cell death in cardiomyocytes but not in fibroblasts, leading ultimately to a decline in cardiac function and increased scar size. A better understanding of stem cells response to prolonged hypoxic stress and the resultant stem cell-myocyte/fibroblast cross-talk is necessary to optimize MSC-based therapy for cardiac regeneration.