In vivo genotoxicity assessment of N-(-9 acridinyl)-b-alanine hydrochloride (S-300) using a validated Pig-a mutagenesis assay.

BACKGROUND: N-(-9 acridinyl)-b-alanine hydrochloride (S-300) is the main byproduct of red blood cell (RBC) amustaline/glutathione(GSH) pathogen reduction, currently undergoing phase III US clinical trials following successful European studies(1-3). Phosphatidylinositol glycan, class A (Pig-a) X-linked gene mutagenesis is a validated mammalian in vivo mutation assay for genotoxicity, assessed as clonal loss of glycosylphosphatidylinositol-linked CD59 cell-surface molecules on reticulocytes (RETs) and RBCs. METHODS: Male Sprague-Dawley rats received continuous infusion of S-300 up to the maximum feasible dose (240 mg/kg/day-limited by solubility and volume) for 28 days. Positive controls received a known mutagen by oral gavage on Days 1-3. Plasma levels of S-300 were assessed by HPLC before, during and after infusion. CD59-negative RBCs and RETs were enumerated in pre-dose and Day 28 samples, using a flow cytometric method. Outcome was evaluated by predetermined criteria using concurrent and historical controls. Toxicity was assessed by laboratory measures and necropsy. RESULTS: S-300 reached maximum, dose-dependent levels (3-15 µmol/L) within 2-8 h that were sustained for 672 h and undetectable 2 h after infusion. Circulating RET levels indicated a lack of hematopoietic toxicity. Necropsy revealed minimal-mild observations related to poor S-300 solubility at high concentrations. Pig-a assessment met the preset acceptability criteria and revealed no increase in mutant RBCs or RETs. CONCLUSIONS: Maximum feasible S-300 exposure of rats by continuous infusion for 28 days was not genotoxic as assessed by an Organization for Economic Cooperation and Development-compliant, mammalian, in vivo Pig-a gene mutation assay that meets the requirements of International Conference on Harmonization (ICH) S2(R1) and FDA guidances on genotoxicity testing.

Longitudinal analysis of annual national hemovigilance data to assess pathogen reduced platelet transfusion trends during conversion to routine universal clinical use and 7-day storage.

BACKGROUND: France converted to universal pathogen reduced (PR; amotosalen/UVA) platelets in 2017 and extended platelet component (PC) shelf-life from 5- to 7-days in 2018 and 2019. Annual national hemovigilance (HV) reports characterized longitudinal PC utilization and safety over 11 years, including several years prior to PR adoption as the national standard of care. METHODS: Data were extracted from published annual HV reports. Apheresis and pooled buffy coat [BC] PC use was compared. Transfusion reactions (TRs) were stratified by type, severity, and causality. Trends were assessed for three periods: Baseline (2010-14; ~7% PR), Period 1 ([P1] 2015-17; 8%-21% PR), and Period 2 ([P2] 2018-20; 100% PR). RESULTS: PC use increased by 19.1% between 2010 and 2020. Pooled BC PC production increased from 38.8% to 68.2% of total PCs. Annual changes in PCs issued averaged 2.4% per year at baseline, -0.02% (P1) and 2.8% (P2). The increase in P2 coincided with a reduction in the target platelet dose and extension to 7-day storage. Allergic reactions, alloimmunization, febrile non-hemolytic TRs, immunologic incompatibility, and ineffective transfusions accounted for >90% of TRs. Overall, TR incidence per 100,000 PCs issued declined from 527.9 (2010) to 345.7 (2020). Severe TR rates declined 34.8% between P1-P2. Forty-six transfusion-transmitted bacterial infections (TTBI) were associated with conventional PCs during baseline and P1. No TTBI were associated with amotosalen/UVA PCs. Infections with Hepatitis E (HEV) a non-enveloped virus resistant to PR, were reported in all periods. DISCUSSION: Longitudinal HV analysis demonstrated stable PC utilization trends with reduced patient risk during conversion to universal 7-day amotosalen/UVA PCs.

Beyond COVID-19 and lessons learned in the United States.

The COVID-19 pandemic severely tested the resilience of the US blood supply with wild fluctuations in blood donation and utilisation rates as community donation opportunities ebbed and hospitals post-poned elective surgery. Key stakeholders in transfusion services, blood centres, supply chains and manufacturers reviewed their experiences during the SARS-CoV-2 pandemic as well as available literature to describe successes, opportunities for improvement and lessons learned. The blood community found itself in uncharted territory responding to restriction of its access to donors (approximately 20% decrease) and some supplies; environmental adjustments to address staff and donor concerns about coronavirus transmission; and the development of a new product (COVID-19 convalescent plasma [CCP]). In assuring that the needs of the patients were paramount, the donation process was safe, that clinicians had access to CCP, and vendor relationships aligned, the blood banking community relearned its primary focus: improving patient outcomes.

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.

Evaluation of amotosalen and UVA pathogen-reduced apheresis platelets after 7-day storage.

BACKGROUND: Amotosalen/UVA pathogen-reduced platelet components (PRPCs) with storage up to 7 days are standard of care in France, Switzerland, and Austria. PRPCs provide effective hemostasis with reduced risk of transfusion-transmitted infections and transfusion-associated graft versus host disease, reduced wastage and improved availability compared with 5-day-stored PCs. This study evaluated the potency of 7-day PRPCs by in vitro characterization and in vivo pharmacokinetic analysis of autologous PCs. STUDY DESIGN AND METHODS: The in vitro characteristics of 7-day-stored apheresis PRPCs suspended in 100% plasma or 65% platelet additive solution (PAS-3)/35% plasma, thrombin generation, and in vivo radiolabeled post-transfusion recovery and survival of 7-day-stored PRPCs suspended in 100% plasma were compared with either 7-day-stored or fresh autologous conventional platelets. RESULTS: PRPCs after 7 days of storage maintained pH, platelet dose, in vitro physiologic characteristics, and thrombin generation when compared to conventional 7-day PCs. In vivo, the mean post-transfusion survival was 151.4 ± 20.1 h for 7-day PRPCs in 100% plasma (Test) versus 209.6 ± 13.9 h for the fresh autologous platelets (Control), (T-ΔC: 72.3 ± 8.8%: 95% confidence interval [CI]: 68.5, 76.1) and mean 24-h post-transfusion recovery 37.6 ± 8.4% for Test versus 56.8 ± 9.2% for Control (T-ΔC: 66.2 ± 11.2%; 95% CI: 61.3, 71.1). DISCUSSION: PRPCs collected in both 100% plasma as well as 65% PAS-3/35% plasma and stored for 7 days retained in vitro physiologic characteristics. PRPCs stored in 100% plasma for 7 days retained in vivo survival. Lower in vivo post-radiolabeled autologous platelet recovery is consistent with reported reduced count increments for allogenic transfusion.

Comparative risk of pulmonary adverse events with transfusion of pathogen reduced and conventional platelet components.

BACKGROUND: Platelet transfusion carries risk of transfusion-transmitted infection (TTI). Pathogen reduction of platelet components (PRPC) is designed to reduce TTI. Pulmonary adverse events (AEs), including transfusion-related acute lung injury and acute respiratory distress syndrome (ARDS) occur with platelet transfusion. STUDY DESIGN: An open label, sequential cohort study of transfusion-dependent hematology-oncology patients was conducted to compare pulmonary safety of PRPC with conventional PC (CPC). The primary outcome was the incidence of treatment-emergent assisted mechanical ventilation (TEAMV) by non-inferiority. Secondary outcomes included: time to TEAMV, ARDS, pulmonary AEs, peri-transfusion AE, hemorrhagic AE, transfusion reactions (TRs), PC and red blood cell (RBC) use, and mortality. RESULTS: By modified intent-to-treat (mITT), 1068 patients received 5277 PRPC and 1223 patients received 5487 CPC. The cohorts had similar demographics, primary disease, and primary therapy. PRPC were non-inferior to CPC for TEAMV (treatment difference -1.7%, 95% CI: (-3.3% to -0.1%); odds ratio = 0.53, 95% CI: (0.30, 0.94). The cumulative incidence of TEAMV for PRPC (2.9%) was significantly less than CPC (4.6%, p = .039). The incidence of ARDS was less, but not significantly different, for PRPC (1.0% vs. 1.8%, p = .151; odds ratio = 0.57, 95% CI: (0.27, 1.18). AE, pulmonary AE, and mortality were not different between cohorts. TRs were similar for PRPC and CPC (8.3% vs. 9.7%, p = .256); and allergic TR were significantly less with PRPC (p = .006). PC and RBC use were not increased with PRPC. DISCUSSION: PRPC demonstrated reduced TEAMV with no excess treatment-related pulmonary morbidity.

Is pathogen reduction an acceptable alternative to irradiation for risk mitigation of transfusion-associated graft versus host disease?

Transfusion-associated graft versus host disease (TA-GVHD) is a highly morbid and often fatal adverse event associated with transfusion of cellular blood products [platelets, red blood cells (RBCs) and whole blood] and more rarely with never-frozen plasma products. It is caused by residual viable donor T-lymphocytes that proliferate and actively target recipient tissues. Selective or universal irradiation of blood components using gamma-irradiation and more recently, X-ray irradiation, are the most commonly applied interventions and have been validated by the demonstration of in vitro T-lymphocyte inactivation, in murine models of TA-GVHD and by years of clinical experience. Irradiation, however, has multiple limitations including a sharp dose-response curve that renders quality control of dosage critically important, the use of radioactive radiation sources that are a terrorism risk, and selective implementation in many countries that leads to inadvertent omission and patient risk exposure. Certain pathogen reduction technologies (PRT) for platelets have been approved by regulatory authorities and endorsed by professional societies as an alternative to irradiation for reducing the risk of TA-GVHD, and PRT for RBCs and whole blood are in development. While the mechanism of action of T-lymphocyte inactivation differs from gamma/X-ray irradiation, the impact on T-lymphocyte inactivation for PRT is equivalent or superior to that of irradiation as demonstrated by sensitive in vitro lymphocyte proliferation assays and in vivo mouse models that approximate human TA-GVHD. Clinical trials and cumulative routine-use experience attest to the efficacy of PRT when used as an alternative to irradiation. While T-lymphocyte inactivation efficacy varies between PRT platforms, the implementation of PRT for platelets increases blood safety for patients beyond the mitigation of TA-GVHD, by decreasing the risk of transfusion transmitted infections with known viruses, bacteria and parasites as well as emerging pathogens.

A survey of US hospitals on platelet inventory management, transfusion practice, and platelet availability.

BACKGROUND: A survey of US hospitals was conducted to increase our understanding of the current state of platelet (PLT) practice and supply. The survey captures information on transfusion practice and inventory management, including stock levels, outdate rates, ability to return or transfer PLTs, and low dose PLTs. Notably, the survey also elucidates PLT availability challenges and impact to patient care. STUDY DESIGN AND METHODS: A 27 question online survey was distributed directly to over 995 US hospitals and indirectly through blood centers to many more between September 27 and October 25, 2019. Descriptive statistics were used for respondent characteristics. Bivariate analysis was performed and correlation coefficients, chi square tests, and p values determined statistical significance of relationships between variables. RESULTS: Four hundred and eighty-one hospitals completed the survey of which 21.6%, 53.2%, and 25.2% were characterized as small, medium, and large hospitals, respectively. Some key observations from this survey include: (1) there is an opportunity for greater adherence to evidence-based guidelines; (2) higher outdate rates occur in hospitals stocking less than five PLTs and the ability to return or transfer PLTs lowers outdates; (3) use of low dose apheresis PLTs varies; and (4) decreased PLT availability is commonly reported, especially in hospitals with high usage, and can lead to delays in transfusions or surgeries. CONCLUSION: This survey represents a comprehensive national assessment of inventory management practices and PLT availability challenges in US hospitals. Findings from this survey can be used to guide further research, help shape future guidance for industry, and assist with policy decisions.

Fatal sepsis associated with a storage container leak permitting platelet contamination with environmental bacteria after pathogen reduction.

BACKGROUND: Pathogen reduction technology and enhanced bacterial culture screening promise to significantly reduce the risk of transfusion-associated septic reactions due to contaminated platelets. Recent reports suggest that these interventions lack efficacy for post-collection and processing contamination with environmental organisms if the storage bag integrity is compromised. CASE REPORT: We report a fatal septic transfusion reaction in a 63-year-old patient with chronic kidney and liver disease who received a pathogen reduced platelet transfusion in anticipation of surgery. METHODS: The residual platelet concentrate was cultured, with the detected microorganisms undergoing 16S genotype sequencing. Separate pathogen reduction studies were performed on the recovered bacteria, including assessment for amotosalen photoproducts. The storage container was subjected to pressure testing and microscopic examination. Environmental culture screening was performed at the hospital. RESULTS: Gram negative rods were detected in the platelet unit and cultures of both platelet component and the patient's blood grew Acinetobacter baumannii complex, Leclercia adecarboxylata and Staphylococcus saprophyticus. These strains were effectively inactivated with >7.2, 7.7, and >7.1 log10 kill, respectively. The platelet storage container revealed a leak visible only on pressure testing. Hospital environmental cultures were negative and the contamination source is unknown. A. baumannii complex and S. saprophyticus 16S genotyping sequences were identical to those implicated in a previously reported septic reaction. CONCLUSION: Findings are compatible with post-processing environmental contamination of a pathogen reduced platelet concentrate via a non-visible, acquired storage container leak. Efforts are warranted to actively prevent damage to, and detect defects in, platelet storage containers, and to store and transport components in clean environments.

Prevalence of natural and acquired antibodies to amustaline/glutathione pathogen reduced red blood cells.

BACKGROUND: The INTERCEPT™ Blood System for Red Blood Cells (RBCs) utilizes amustaline (S-303) and glutathione (GSH) to inactivate pathogens and leukocytes in transfused RBCs. Treatment-emergent low titer non-hemolytic antibodies to amustaline/GSH RBC were detected in clinical trials using a prior version of the process. The amustaline/GSH process was re-formulated to decrease S-303 RBC adduct formation. STUDY DESIGN AND METHODS: A standard three-cell antibody screening panel was modified to include reagent red cells (RRC) with high (S-303H) or low (S-303L) S-303 adduct density as assessed by flow cytometry, representative of the original and current amustaline/GSH treatment processes, respectively. General hospital and RBC transfusion-dependent patients never exposed, and clinical trial subjects exposed to amustaline/GSH RBC were screened for antibodies to amustaline/GSH RBC using a standardized agglutination assay. RESULTS: Twelve (0.1%) of 10,721 general hospital and 5 (0.5%) of 998 repeatedly-transfused patients not previously exposed to amustaline/GSH RBCs expressed natural, low titer (2-32) IgM and/or IgG (non-IgG1 or IgG3 isotype) antibodies with acridine (a structural element of amustaline) (n = 14) or non-acridine (n = 3) specificity. 11 of 17 sera reacted with S-303L panel RRCs. In clinical studies 81 thalassemia and 25 cardiac surgery patients were transfused with a total of 1085 amustaline/GSH RBCs and no natural or treatment-emergent S-303 antibodies were detected. CONCLUSION: Standardized RRC screening panels are sensitive for the detection of natural and acquired S-303-specific antibodies. Natural low titer antibodies to amustaline/GSH RBC are present in 0.15% of naïve patients. The clinical relevance of these antibodies appears minimal but is under further investigation.

Characterization of Ebola convalescent plasma donor immune response and psoralen treated plasma in the United States.

BACKGROUND: In 2014, passive immunization by transfusion of Ebola convalescent plasma (ECP) was considered for treating patients with acute Ebola virus disease (EVD). Early Ebola virus (EBOV) seroconversion confers a survival advantage in natural infection, hence transfusion of ECP plasma with high levels of neutralizing EBOV antibodies is a potential passive immune therapy. Techniques to reduce the risk of other transfusion-transmitted infections (TTIs) are warranted as recent ECP survivors are ineligible as routine blood donors. As part of an ongoing clinical trial to evaluate the safety and effectiveness of ECP, the impact of amotosalen/UVA pathogen reduction technology (PRT) on EBOV antibody characteristics was examined. STUDY DESIGN AND METHODS: Serum and plasma samples were collected from EVD-recovered subjects at multiple timepoints and evaluated by ELISA for antibodies to recombinant EBOV glycoprotein (GP) and irradiated whole EBOV antigen, as well as for EBOV microneutralization, classic plaque reduction neutralization test (PRNT) and EBOV pseudovirion neutralization assay (PsVNA) activity. RESULTS: Six subjects donated 40 individual ECP units. Substantial antibody titers and neutralizing activity results were demonstrated but were generally lower for the ACD plasma samples compared to the serum samples. Anti-EBOV titers by all assays remained essentially unchanged after PRT. CONCLUSION: Treatment of ECP with PRT to reduce the risk of TTI did not significantly reduce EBOV IgG antibody titers or neutralizing activity. Although ECP was used in the treatment of repatriated patients, no PRT units from this study were transfused to EVD patients. This inventory of PRT-treated ECP is currently available for future clinical evaluation.

Sepsis from an apheresis platelet contaminated with Acinetobacter calcoaceticus/baumannii complex bacteria and Staphylococcus saprophyticus after pathogen reduction.

BACKGROUND: Strategies to reduce platelet (PLT) bacterial contamination include donor screening, skin disinfection, sample diversion, bacterial culture, pathogen reduction (PR), and day-of-transfusion tests. We report bacterial sepsis following a pathogen-reduced PLT transfusion. CASE REPORT: An adult male with relapsed acute lymphoblastic leukemia was successfully treated for central catheter-associated Staphylococcus aureus bacteremia. A peripherally inserted central catheter (PICC) was placed. Chills, rigors, and flushing developed immediately after PICC-infused pathogen-reduced PLTs, progressing to septic shock requiring intensive care management. METHODS: PICC and peripheral blood (PB), transfused bag saline flushes (TBFs), environmental samples, and the pathogen-reduced untransfused co-component (CC) were cultured. Plasma metagenomic and bacterial isolate whole-genome sequencing; PLT mitochondrial DNA (mtDNA) testing of untransfused CC and TBF; CC testing for amotosalen (S-59)/S-59 photoproducts; isolate PR studies (INTERCEPT); and TBF polymerase chain reaction for recipient Y-chromosome DNA were performed. RESULTS: PB and PICC cultures grew Acinetobacter calcoaceticus/baumannii complex (ACBC). TBF was gram-positive; mass spectrometry identified ACBC and Staphylococcus saprophyticus (SS). CC Gram stain and cultures were negative. Environmental cultures, some done after decontamination, were ACBC/SS negative. Posttransfusion patient plasma and TBF ACBC sequences were genetically identical. No Y-chromosome signal was detected in TBF. S-59 photoproducts and evidence of mtDNA amplification inhibition were found in the CC. Spiking PR studies showed >5.9-log inactivation for both isolates. Donor skin cultures for Acinetobacter were negative. CONCLUSION: CC sterility, PR studies, residual S-59 photoproducts, and mtDNA amplification inhibition suggest successful PR. Unidentified environmental sources and inherent or acquired bag defects may have contributed to postmanufacturing pathogen-reduced PLT contamination.

Amustaline-glutathione pathogen-reduced red blood cell concentrates for transfusion-dependent thalassaemia.

Transfusion-dependent thalassaemia (TDT) requires red blood cell concentrates (RBCC) to prevent complications of anaemia, but carries risk of infection. Pathogen reduction of RBCC offers potential to reduce infectious risk. We evaluated the efficacy and safety of pathogen-reduced (PR) Amustaline-Glutathione (A-GSH) RBCC for TDT. Patients were randomized to a blinded 2-period crossover treatment sequence for six transfusions over 8-10 months with Control and A-GSH-RBCC. The efficacy outcome utilized non-inferiority analysis with 90% power to detect a 15% difference in transfused haemoglobin (Hb), and the safety outcome was the incidence of antibodies to A-GSH-PR-RBCC. By intent to treat (80 patients), 12·5 ± 1·9 RBCC were transfused in each period. Storage durations of A-GSH and C-RBCC were similar (8·9 days). Mean A-GSH-RBCC transfused Hb (g/kg/day) was not inferior to Control (0·113 ± 0·04 vs. 0·111 ± 0·04, P = 0·373, paired t-test). The upper bound of the one-sided 95% confidence interval for the treatment difference from the mixed effects model was 0·005 g/kg/day, within a non-inferiority margin of 0·017 g/kg/day. A-GSH-RBCC mean pre-transfusion Hb levels declined by 6·0 g/l. No antibodies to A-GSH-RBCC were detected, and there were no differences in adverse events. A-GSH-RBCCs offer potential to reduce infectious risk in TDT with a tolerable safety profile.

Acute Zika virus infection in an asymptomatic blood donor at the onset of the Puerto Rico epidemic.

BACKGROUND: Zika virus (ZIKV) spread to Puerto Rico likely originated from southeastern Brazil approximately 8.5 months earlier than blood donation screening for ZIKV was initiated, but the time of ZIKV introduction in the blood donor population remains unknown. METHODS: To better understand when arboviral infections first appeared in the blood donor pool in Puerto Rico, we retrospectively screened for ZIKV RNA (as well as chikungunya [CHIKV] and dengue [DENV] viral RNA) a repository of 1186 linked blood donor and recipient samples collected from February 2015 to May 2016 as an endpoint efficacy measure following the introduction of platelet pathogen reduction (PR). Phylogenetic analysis identified relatedness of donor strain to other circulating strains, and molecular clock analysis identified the estimated time of introduction. RESULTS: An asymptomatic donor collected in December 2015 was ZIKV RNA confirmed positive, 4 months BEFORE investigational nucleic acid testing (NAT) implementation in April 2016, coincident and related to the first reported autochthonous cases. No CHIKV RNA or DENV RNA reactives were identified in donors or recipients, and no adverse events were reported from PR use in recipients. Phylogenetic analysis confirmed the molecular relatedness of the donor ZIKV strain to the Puerto Rico lineage likely introduced approximately 4.5 months earlier. CONCLUSION: This study identified an asymptomatic ZIKV infection in a blood donor occurring before those previously recognized by blood donation screening. NAT and PR continue to be used as acceptable strategies to prevent transfusion-transmitted arboviral infections worldwide; however, repeated arboviral outbreaks warrant consideration of PR as a more proactive approach.

Clinical impact of amotosalen-ultraviolet A pathogen-inactivated platelets stored for up to 7 days.

BACKGROUND: Universal pathogen inactivation of platelet concentrates (PCs) using amotosalen/ultraviolet A with 7-day storage was implemented in Switzerland in 2011. Routine-use data were analyzed at the University Hospital Basel, Switzerland. STUDY DESIGN: A retrospective two-cohort study of patient and PC characteristics, component usage, patient outcomes, count increments (CIs), and adverse events were analyzed for two consecutive 5-year periods with either 0- to 5-day-old conventional PC (C-PC) (n = 14,181) or 0- to 7-day-old pathogen-inactivated PC (PI-PC) (n = 22,579). RESULTS: In both periods, PCs were issued for transfusion on a "first in, first out" basis. With 7-day PI-PC, wastage was reduced from 8.7% to 1.5%; 16.6% of transfused PI-PCs were more than 5 days old. Transfusion of PI-PC more than 5 days old compared with 5 days old or less did not increase platelet and RBC use on the same or next day as an indirect measure of hemostasis and did not increase transfusion reactions. Mean corrected count increments (CCIs) for PI-PC stored for 5 days or less were 22.6% lower than for C-PC (p < 0.001), and declined with increasing storage duration for both, although the correlation was weak (r2 = 0.005-0.014). Mean number of PCs used per patient and duration of PC support were not different for hematology/oncology, allogeneic and autologous hematopoietic stem cell transplant (HSCT), and general medical/surgical patients, who used the majority (~92.0%) of PI-PCs. Five-year treatment-related mortality in allogeneic HSCT was unchanged in the PI-PC period. CONCLUSIONS: PI-PCs with 7-day storage reduced wastage and did not increase PC or red blood cell utilization or adverse reactions compared with fresh PI-PC or a historical control group, demonstrating preserved efficacy and safety.

Transfusion of pathogen-reduced platelet components without leukoreduction.

BACKGROUND: Leukoreduction (LR) of platelet concentrate (PC) has evolved as the standard to mitigate risks of alloimmunization, clinical refractoriness, acute transfusion reactions (ATRs), and cytomegalovirus infection, but does not prevent transfusion-associated graft-versus-host disease (TA-GVHD). Amotosalen-ultraviolet A pathogen reduction (A-PR) of PC reduces risk of transfusion-transmitted infection and TA-GVHD. In vitro data indicate that A-PR effectively inactivates WBCs and infectious pathogens. STUDY DESIGN AND METHODS: A sequential cohort study evaluated A-PR without LR, gamma irradiation, and bacterial screening in hematopoietic stem cell transplant (HSCT) recipients. The first cohort received conventional PC (control) processed without LR, but with gamma irradiation and bacterial screening. The second cohort received A-PR PC (test) processed without: LR, bacterial screening, or gamma irradiation. The primary efficacy outcome was the 1-hour corrected count increment. The primary safety outcome was treatment-emergent ATR. Secondary outcomes included clinical refractoriness, and 100-day status for engraftment, TA-GVHD, HSCT-GVHD, infections, and mortality. RESULTS: Mean corrected count increment (× 103 ) of 33 test PC recipients was similar (18.9 ± 8.8 vs. 16.6 ± 8.4; p = 0.296) to that of 31 control PC recipients. Test recipients had a reduced, but nonsignificant, incidence of ATR (test = 9.1%, Control = 19.4%; p = 0.296). The frequencies of clinical refractoriness (0 of 33 vs. 4 of 31 patients) and refractory transfusions (6.6% vs. 19.3%) were lower in the test cohort (p = 0.05 and 0.02), respectively. No patient in either cohort had TA-GVHD. Day 100 engraftment, HSCT-GVHD, mortality, and infectious disease complications were similar between cohorts. CONCLUSIONS: This study indicated that A-PR PC without LR, gamma irradiation, or bacterial screening is feasible for support of HSCT.

Transfusion-related sepsis: a silent epidemic.

In this issue of Blood, Hong et al advocate for use of additional US Food and Drug Administration (FDA)­approved safety measures for transfusion. Most patients transfused with contaminated platelets do not show immediate clinical signs. Active surveillance suggests patient risk 10- to 40-fold higher than passive hemovigilance.

Red blood cells treated with the amustaline (S-303) pathogen reduction system: a transfusion study in cardiac surgery.

BACKGROUND: Nucleic acid-targeted pathogen inactivation technology using amustaline (S-303) and glutathione (GSH) was developed to reduce the risk of transfusion-transmitted infectious disease and transfusion-associated graft-versus-host disease with red blood cell (RBC) transfusion. STUDY DESIGN AND METHODS: A randomized, double-blind, controlled study was performed to assess the in vitro characteristics of amustaline-treated RBCs (test) compared with conventional (control) RBCs and to evaluate safety and efficacy of transfusion during and after cardiac surgery. The primary device efficacy endpoint was the postproduction hemoglobin (Hb) content of RBCs. Exploratory clinical outcomes included renal and hepatic failure, the 6-minute walk test (a surrogate for cardiopulmonary function), adverse events (AEs), and the immune response to amustaline-treated RBCs. RESULTS: A total of 774 RBC unis were produced. Mean treatment difference in Hb content was -2.27 g/unit (95% confidence interval, -2.61 to -1.92 g/unit), within the prespecified equivalence margins (±5 g/unit) to declare noninferiority. Amustaline-treated RBCs met European guidelines for Hb content, hematocrit, and hemolysis. Fifty-one (25 test and 26 control) patients received study RBCs. There were no significant differences in RBC usage or other clinical outcomes. Observed AEs were within the spectrum expected for patients of similar age undergoing cardiovascular surgery requiring RBCs transfusion. No patients exhibited an immune response specific to amustaline-treated RBCs. CONCLUSION: Amustaline-treated RBCs demonstrated equivalence to control RBCs for Hb content, have appropriate characteristics for transfusion, and were well tolerated when transfused in support of acute anemia. Renal impairment was characterized as a potential efficacy endpoint for pivotal studies of RBC transfusion in cardiac surgery.