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Additive solutions are used to limit changes that red blood cells (RBCs) undergo during storage. Several studies have shown better preservation of glucose and redox metabolism using the alkaline additive solution PAGGGM (phosphate-adenine-glucose-guanosine-gluconate-mannitol). In this randomized open-label intervention trial in 20 healthy volunteers, the effect of storage, PAGGGM vs SAGM (saline-adenine-glucose-mannitol), on posttransfusion recovery (PTR) and metabolic restoration after transfusion was assessed. Subjects received an autologous biotinylated RBC concentrate stored for 35 days in SAGM or PAGGGM. As a reference for the PTR, a 2-day stored autologous biotinylated RBC concentrate stored in SAGM was simultaneously transfused. RBC phenotype and PTR were assessed after transfusion. Biotinylated RBCs were isolated from the circulation for metabolomics analysis up to 24 hours after transfusion. The PTR was significantly higher in the 2-day stored RBCs than in 35-day stored RBCs 2 and 7 days after transfusion: 96% (90 to 99) vs 72% (66 to 89) and 96% (90 to 99) vs 72% (66 to 89), respectively. PTR of SAGM- and PAGGGM-stored RBCs did not differ significantly. Glucose and redox metabolism were better preserved in PAGGGM-stored RBCs. The differences measured in the blood bag remained present only until 1 day after transfusion. No differences in RBC phenotype were found besides an increased complement C3 deposition on 35-day RBCs stored in PAGGGM. Our data indicate that despite better metabolic preservation, PAGGGM is not a suitable alternative for SAGM because storage in PAGGGM did not result in an increased PTR. Finally, RBCs recovered from circulation after transfusion showed reversal of the metabolic storage lesion in vivo within a day. This study is registered in the Dutch trial register (NTR6492).

Platelet components are commonly transfused to patients for a variety of indications, including patients with low platelet counts or patients with platelet dysfunction who are bleeding or at high risk of bleeding. Although the risk of pathogen contamination of platelet components has declined significantly over the last 40 years, it remains a concern for the patients, for blood banks and for physicians. Pathogen inactivation (PI) technologies have been developed to mitigate this risk. This review focuses on the residual risks of transfusion-transmitted bacterial infections by platelet transfusion after PI. We describe and assess the relationship between the bacterial load and the timing and capacity of reduction of the different PI technologies, as well as the risks that could represent spore-forming microorganisms and the possible introduction of microorganisms after PI.

Background and Objectives: In many countries, whole blood (WB) donations with collection times between 12 and 15 min are not allowed to be used for platelet concentrates (PC). Since the development of guidelines, many process-related changes have been introduced. We aimed to determine the effect of WB with long collection times on PC quality. Materials and Methods: Five participating centres tested buffy coat (BC)-derived PC in platelet additive solution type E prepared from only WB collections lasting 12 min (study group, n = 8). One centre produced platelet-rich plasma (PRP)-derived PC from single donations (12 min). All PC were stored at 22 ± 2°C and sampled on Days 1, 6 and 8 post-collection for in vitro quality determination. Results: Average collection time was significantly longer in the study group compared to controls (8.9 ± 2.6 vs. 7.3 ± 1.3 min, p < 0.001). There were no differences in volume, platelet concentration, basal CD62P expression, soluble-CD62P and CCL5 levels, or nucleotide content between the groups. Stimulation with TRAP-6 resulted in comparable levels of cell surface CD62P. On Day 8, all PC fulfilled requirements for pH. The findings from single PRP-derived PC centre were similar. Conclusion: PC with one BC and single PRP derived from collections lasting >12 min had equivalent in vitro quality to controls during storage. This study provides evidence that 12–15 min donations should not be excluded for PC preparation and justifies to readdress the guidelines to

Objectives Our objectives were to determine the separation characteristics and blood product quality of a gravity-driven microfiltration blood separation system (HemoClear, The Netherlands). Background A range of centrifugal blood separation devices, including intraoperative cell salvage devices (cell savers) and apheresis machines, are available to assist in preparing both allogenic and autologous blood products. These devices are expensive to operate and require extensive training. Methods and materials Nine whole blood units were collected under standard conditions and analysed for haematological parameters, thromboelastographic properties, platelet morphology and activation, and red blood cell (RBC) deformability and morphology. Three whole blood units were separated by means of the HemoClear device, into a liquid and cellular component. The cellular component was diluted with SAGM and cold stored for 14 days. To simulate cell salvage six whole blood units were diluted with isotonic saline, followed by multiple HemoClear separation rounds. Results The recovery of both RBCs (100 ± 1.6%) and white blood cells (99 ± 4.5%) after undiluted filtration were very high, while platelet recovery was high (83 ± 3.0%). During the filtration, and cold storage after filtration storage both the non-deformable RBC fraction and the RBC maximum elongation remained stable. Parameters of thromboelastography indicated that platelets remain functional after filtration and after 7 days of cold storage. In the cell salvage simulation the total protein load in the cellular fraction was reduced by 65 ± 4.1% after one washing round and 84 ± 1.9% after two consecutive washing rounds. Conclusion The novel blood filter studied effectively separates whole blood into diluted plasma and platelet-rich RBCs. Moreover, the device effectively washed diluted whole blood, driving over 80% of proteins to the liquid component.

Background: Transfusion-related acute lung injury (TRALI) is a severe complication of blood transfusion that is thought of as a two-hit event: first the underlying patient condition (e.g., sepsis), and then the transfusion. Transfusion factors include human leukocyte antigen antibodies or biologic response modifiers (BRMs) accumulating during storage. Preclinical studies show an increased TRALI risk with longer stored platelets, clinical studies are conflicting. We aim to discover whether longer platelet concentrate (PC) storage time increases TRALI risk in a controlled human experiment. Study Design and Methods: In a randomized controlled trial, 18 healthy male volunteers received a first hit of experimental endotoxemia (2 ng/kg lipopolysaccharide), and a second hit of fresh (2-day old) or aged (7-day old) autologous PC, or physiological saline. After 6 h, changes in TRALI pathways were determined using spirometry, chest X-ray, and bronchoalveolar lavage (BAL). Results: All subjects reacted adequately to lipopolysaccharide infusion and satisfied SIRS criteria (increased pulse [>90/min] and temperature [>38°C]). There were no differences between the saline, fresh, and aged PC groups in BAL-fluid protein (95 ± 33 μg/ml; 83 ± 21 μg/ml and 104 ± 29 μg/ml, respectively) and relative neutrophil count (1.5 ± 0.5%; 1.9 ± 0.8% and 1.3 ± 0.8%, respectively), nor in inflammatory BAL-fluid BRMs (Interleukin-6, CXCL8, TNFα (Formula presented.) and myeloperoxidase), clinical respiratory parameters, and spirometry results. All chest X-rays were normal. Conclusions: In a human endotoxemia model of autologous platelet transfusion, with an adequate first hit and platelet storage lesion, transfusion of 7-day-old PC does not increase pulmonary inflammation compared with 2-day-old PC.

Background: Platelets (PLTs) differ in glycolytic activity, resulting in rapid acidification of ‘poor’ storing PLT concentrates (PCs) in plasma, or depletion of glucose when stored in PLT additive solution (PAS). We aimed to understand why PLT glycolysis rates vary between donors and how this affects storage performance. Study Design and Methods: Buffy coats from donors 70 years were selected and single-donor PCs in plasma or PAS-E were prepared. PCs were stored for 8 days at 22 ± 2°C and sampled regularly for analysis. Mitochondrial activity was analyzed with an Oroboros oxygraph. Age groups, or subgroups divided into quartiles based on glucose consumption, were analyzed with ANOVA. Results: In each comparison, PCs of the different groups were not different in volume and cellular composition. PLTs with the highest glucose consumption had a higher initial mean platelet volume (MPV) and developed higher CD62P expression and Annexin A5 binding during storage. Higher glycolytic activity in these PLTs was not a compensation for lower mitochondrial ATP production, because mitochondrial ATP-linked respiration of fresh PLTs correlated positively with MPV (R2 = 0.71). Donors of high glucose-consuming PLTs had more health-related issues. Storage properties of PCs from donors over 70 were not significantly different compared to PCs from donors younger than 45 years. Conclusions: High glucose-consuming PCs developing higher activation levels, not only displayed enhanced mitochondrial activity but were also found to contain larger PLTs, as determined by MPV. Storage performance of PLTs was found to be associated with donor health, but not with donor age.

DEHP, di(2-ethylhexyl) phthalate, is the most common member of the class of ortho-phthalates, which are used as plasticizers. The Medical Device Regulation has restricted the use of phthalates in medical devices. Also DEHP has been added to the Annex XIV of REACH, "Registration, Evaluation, Authorisation and Restriction of Chemicals" due to its endocrine disrupting properties to the environment. As such, the sunset date for commercialisation of DEHP-containing blood bags is May 27Based on data as well as the input of relevant stakeholders a rationale for the validation of each component was composed.The red cell components will require the most extensive validation as their quality is directly affected by the absence of DEHP, as opposed to platelet and plasma components.Studies in the scope of evaluating the quality of blood products obtained with non-DEHP devices, under the condition that they are carried out according to these recommendations, could be used by all members of the EBA to serve as scientific support in the authorization process specific to their jurisdiction or for their internal validation use.

Background and Objectives: Transfusion-associated circulatory overload (TACO) is the primary cause of transfusion-related mortality. Speed and volume of transfusion are major risk factors. The aim of this study was to investigate the interaction of red blood cell (RBC) transfusion speed and volume on the development of TACO. Materials and Methods: A validated model for TACO in anaemic Lewis rats with an acute myocardial infarction was used. The effect on pulmonary hydrostatic pressure of one, two or four units of packed RBCs transfused in either 30 or 60 min was evaluated (3.3–26.6 ml·kg −1·hr −1). Pulmonary capillary pressure was measured as left ventricular end-diastolic pressure (LVEDP). Cardiac stress biomarkers atrial natriuretic-peptide (ANP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured 1-h post-transfusion. Results: Thirty animals were included (n = 5 per group). Transfusion of RBCs increased LVEDP in a volume-dependent manner (ΔLVEDP [mmHg]: −0.95, +0.50, +6.26, p < 0.001). Fast transfusion increased overall ΔLVEDP by +3.5 mmHg and up to +11.8 mmHg in the four units' group (p = 0.016). Doubling transfusion speed increased ΔLVEDP more than doubling volume in the larger volume groups. No difference in ANP or NT-proBNP were seen in high transfusion volume or groups. Conclusion: Transfusion volume dose-dependently increased LVEDP, with speed of transfusion rapidly elevating LVEDP at higher transfusion volumes. ANP and NT-proBNP were not impacted by transfusion volume or speed in this model. TACO is seen as purely volume overload, however, this study emphasizes that limiting transfusion speed, as a modifiable risk factor, might aid in preventing TACO.

Item does not contain fulltext BACKGROUND AND OBJECTIVES: Di-ethyl-hexyl-phthalate (DEHP) is currently the main plasticizer used for whole blood collection systems. However, in Europe, after May 2025, DEHP may no longer be used above 0.1% (w/w) in medical devices. DEHP stabilizes red cell membranes, thereby suppressing haemolysis during storage. Here we compared in vitro quality parameters of red cell concentrates (RCCs) collected and stored in DEHP-, DINCH- or DINCH/BTHC-PVC hybrid blood bags with saline-adenine-glucose-mannitol (SAGM) or phosphate-adenine-glucose-guanosine-saline-mannitol (PAGGSM) storage solution. Last, we performed haemovigilance surveillance for RCC collected in DINCH-PVC and stored in PAGGSM/BTHC-PVC. MATERIALS AND METHODS: In vitro quality parameters of RCC were determined during 42 days of storage. Haemovigilance surveillance was conducted to compare the frequency and type of transfusion reaction. RESULTS: Haemolysis levels were increased in SAGM/BTHC-PVC as compared to SAGM/DEHP-PVC (0.66% ± 0.18% vs. 0.36% ± 0.17%). PAGGSM storage solution was able to adequately suppress haemolysis to levels observed during storage in SAGM/DEHP-PVC, both in BTHC-PVC (0.38% ± 0.12%), and to a slightly lesser extent in DINCH-PVC (0.48% ± 0.17%). A total of 1650 PAGGSM/BTHC-PVC and 5662 SAGM/DEHP-PVC RCC were transfused yielding a transfusion reaction frequency of 0.24% (95% CI 0.0000-0.0048) and 0.44% (95% CI 0.0027-0.0061) respectively. CONCLUSION: The in vitro quality of RCC stored in PAGGSM/BTHC-PVC and SAGM/DEHP-PVC is comparable. There is no indication that transfusion of erythrocytes stored in PAGGSM/BTHC-PVC results in increased transfusion reaction frequency. These initial results provide a basis for further clinical evaluation to narrow down the confidence interval of transfusion reaction frequency.

BACKGROUND AND OBJECTIVES: Di(2-ethylhexyl) phthalate (DEHP) must be removed from blood bag sets in Europe by 27 May 2025. DEHP is known to interact with the red blood cell (RBC) membrane, resulting in reduced haemolysis and thus prolonging shelf-life. Current non-DEHP alternatives result in increased haemolysis requiring reconsideration of the RBC shelf-life. Although the immediate impact of eliminating DEHP is to the European community, the non-DEHP movement could affect blood bag set availability globally. The purpose of this survey is to understand blood centre readiness regarding the transition to non-DEHP blood collection and storage systems. MATERIALS AND METHODS: A 24-question on-line survey was completed by members of the Biomedical Excellence for Safer Transfusion Collaborative research network. RESULTS: Responses were obtained from 16 blood collection or processing institutions. A majority of respondents (12/16) indicated that both shelf-life and haemolysis were equally important in selecting non-DEHP blood bag sets. Six respondents would accept a lower RBC product shelf-life compared to current practice. Respondents were not clear on the best non-DEHP vinyl material or RBC storage solution. Three European blood centres indicated they have developed non-DEHP transition plans. One challenge identified regarding the transition to non-DEHP is the extensive validation testing that will be required. CONCLUSION: Blood centres in Europe are concerned with meeting the sunset date for DEHP, considering that limited non-DEHP blood bag and RBC storage solutions are currently available. Banning DEHP in Europe, which may have global ramifications, represents a major challenge not yet fully understood by the transfusion medicine community.

Background and objectives Colloid osmotic pressure (COP) is a principal determinant of intravascular fluid homeostasis and a pillar of fluid therapy and transfusion. Transfusion-associated circulatory overload (TACO) is a leading complication of transfusion, and COP could be responsible for recruiting additional fluid. Study objective was to measure COP of blood products as well as investigate the effects of product concentration and storage lesion on COP. Materials and methods Three units of each product were sampled longitudinally. COP was measured directly as well as the determinants thereof albumin and total protein. Conventional blood products, that is red blood cell (RBC), fresh-frozen plasma (FFP) and platelet concentrates (PLTs), were compared with their concentrated counterparts: volume-reduced RBCs, hyperconcentrated PLTs, and fully and partially reconstituted lyophilized plasma (prLP). Fresh and maximally stored products were measured to determine changes in protein and COP. We calculated potential volume load (PVL) to estimate volume recruited using albumin's water binding per product. Results Colloid osmotic pressure varies widely between conventional products (RBCs, 1·9; PLTs, 7·5; and FFP, 20·1 mmHg); however, all are hypooncotic compared with human plasma COP (25·4 mmHg). Storage lesion did not increase COP. Concentrating RBCs and PLTs did not increase COP; only prLP showed a supraphysiological COP of 47·3 mm Hg. The PVL of concentrated products was lower than conventional products. Conclusion Colloid osmotic pressure of conventional products was low. Therefore, third-space fluid recruitment is an unlikely mechanism in TACO. Concentrated products had a lower calculated fluid load and may prevent TACO. Finally, storage did not significantly increase oncotic pressure of blood products.

Transfusion of whole blood rather than blood components is gaining popularity. It is easy to use, with one transfusion product to administer rather than 3, and is held at one storage temperature. It only contains anticoagulant-preservative solution, while components contain various storage solutions, which in theory may induce dilution coagulopathy. In this review, the quality of platelets in stored whole blood is summarized. In cold-stored whole blood, the platelet count declines by 1% to 2% per day. The responsiveness to various agonists declines during the storage time, but this appears to have a limited impact on clotting time or on clot strength as measured with thromboelastography. Animal studies have confirmed that platelets from stored whole blood participate equally well in clot formation. The recovery of platelets in stored whole blood is acceptable during at least 15 days of storage. The survival of platelets after transfusion is only 1 day, but this is likely to be sufficient for the intended patient group requiring massive transfusions, as the platelets are rapidly consumed in the wound area. In addition to the logistic benefits, there are drawbacks, most importantly having a sufficiently large inventory with an acceptable outdating rate, particularly since massive transfusions are rare, while requiring a lot of whole blood. The positive experience of the United States military with whole blood transfusion is often brought forward for introduction in the civilian blood bank, but patients with trauma are only a small fraction of the civilian population requiring massive transfusions. It needs to be determined whether in the resourceful environment of the hospital, these patients benefit from whole blood transfusions. Optimization of whole blood storage, with focus on platelet quality, needs to be performed to allow extension of the storage time beyond 15 days to a point where the number of units in inventory and outdating can be balanced.

Background This multi-national study evaluated changes in platelet (PLT) unit distributions at 12 national or regional blood collectors over a 10-year period. Methods Data on the total number of PLT distributions, the collection method, that is apheresis vs whole blood-derived (WBD), the PLT unit characteristics and post-collection modifications were obtained from 12 national or regional blood collectors from 2008 through 2017. Individual WBD PLT units were converted to apheresis equivalent units (i.e. a dose of PLTs) by dividing by 4, the typical pool size; WBD units that were pooled before distribution were counted as a single dose. Results Overall at these 12 blood collectors, the total number of PLTs distributed in 2008 was 1 373 200, which rose by 10·2% to 1 513 803 in 2017. The Japanese Red Cross, which distributes only apheresis PLTs, had a 13·4% increase in the number of distributions between the years 2008 and 2017, while the other 11 blood collectors combined demonstrated a 6·8% increase in distributions between these two years. Between the years 2008 and 2017, the changes in the proportion of apheresis, platelet-rich plasma and buffy coat PLT distributions were -29·9%, -70·7% and 80·0%, respectively. Conclusion The number of PLT distributions increased during the 10-year study period despite prophylactic PLT transfusion thresholds having remained fairly consistent over the last decade. Perhaps this increase is in part driven by increased administration of platelets to patients with massive haemorrhage or an increase in stem cell transplantation. The use of buffy coat PLTs is increasing at these collectors.

Labeling of platelets (PLTs) is essential for research purposes, in order to measure the recovery and survival of transfused PLTs in vivo. Biotinylation is a promising new alternative to the gold standard of radioactive labeling. This review highlights 4 key publications that provide significant insights into biotin-labeled PLTs (bioPLTs). Stohlawetz et al. established that transfusion of bioPLTs in human recipients is possible. De Bruin et al. developed a standardized, reproducible protocol for biotinylation of PLTs as a promising method to trace and isolate transfused PLTs in vivo, with reduced levels of PLT activation markers. Muret et al. developed a nonwashing biotin labeling method to implement in a blood bank environment. Finally, in a preclinical study, Ravanat et al. showed that different densities of biotin can be used to concurrently monitor multiple populations of human PLTs in the circulation of the same subject. These studies have made major contributions to the development of bioPLTs as a viable option for use in human research, and indicate that bioPLTs can be safely administered, preferably at a low density of biotin.

Introduction Red blood cell (RBC) transfusion is associated with an increased risk of pro-thrombotic events, but the underlying mechanism is poorly understood. We hypothesized that RBC transfusion modulates platelet activity in critically ill patients with and without sepsis. Methods In a prospective cohort study, 37 critically ill patients receiving a single RBC unit to correct for anemia were sampled prior to and 1 h after transfusion. Platelet exposure of P-selectin, CD63 and binding of PAC-1 as well as formation of platelet-leukocyte complexes were measured by flow cytometry. The ability of plasma from critically ill patients to induce ex vivo platelet aggregation was assessed by flow cytometry after incubation with platelets from a healthy donor. Results RBC transfusion neither triggered the expression of platelet activation markers nor the formation of platelet-leukocyte complexes. Plasma from critically ill patients induced more spontaneous platelet aggregation prior to RBC transfusion compared to healthy controls, which was further augmented following RBC transfusion. Also collagen-induced platelet aggregation was already increased prior to RBC transfusion compared to healthy controls, and this response was unaffected by RBC transfusion. In contrast, ristocetin-induced platelet agglutination was decreased when compared to controls, suggesting impaired vWF-dependent platelet agglutination, even in the presence of high vWF levels. Following RBC transfusion, ristocetin-induced platelet agglutination further decreased. There were no differences between septic and non-septic recipients in all assays. Conclusion Ex vivo platelet aggregation is disturbed in the critically ill. Transfusion of a RBC unit may further increase the spontaneous platelet aggregatory response.

Objective To investigate the relation between donor characteristics and TRALI incidence. Background Transfusion-related acute lung injury (TRALI) is a potentially fatal complication of transfusion. In pre-clinical studies and several clinical studies, TRALI has been related to loss of product quality during red blood cell (RBC) storage, called the “storage lesion”. Donor characteristics, as for example age, genetics and life style choices influence this “storage lesion”. We hypothesized that donor sex, age and blood type is related to TRALI incidence. Methods/materials We performed a secondary analysis of two cohort studies, designed to identify TRALI risk factors by matching TRALI patients to transfused controls. We obtained donor sex, age and blood type from the Dutch Blood Bank Sanquin and investigated TRALI incidence in patients who were exposed to a certain donor characteristic. We used Kruskal-Wallis testing to compare the number of transfused products and Chi2 testing to compare proportions of TRALI patients and transfused control. Results After implementation of the male-donor only plasma strategy, patients received more transfusion products from male donors. However, we did not detect a relation between TRALI incidence and donor sex. Both TRALI patients and transfused controls received mainly products from donors over 41 years old, but donor age did not influence TRALI risk. Donor blood type, the transfusion of blood type-compatible and blood type-matched products also had no influence on TRALI incidence. Conclusion We conclude that in two cohorts of TRALI patients, donor age, donor sex and donor blood type are unrelated to TRALI.

Background. - Anaemia and coagulopathy are common issues in critically ill patients. Transfusion can be lifesaving, however, is associated with potential life threatening adverse events. As an international transfusion guideline for this specific patient population is lacking, we hypothesize that a high heterogeneity in transfusion practices exists. In this pilot-study we assessed transfusion practice in a university hospital in the Netherlands and tested the feasibility of this protocol for an international multi-centre study.Methods. - A prospective single centre cohort study was conducted. For seven days all consecutive non-readmitted patients to the adult Intensive Care Unit (ICU) were included and followed for 28 days. Patients were prospectively followed until ICU discharge or up to day 28. Patient outcome data was collected at day 28. Workload for this study protocol was scored in hours and missing data.Results. - In total, 48 patients were included, needed in total three hours patient to include and collect all data, with 1.6% missing data showing the feasibility of the data acquisition. Six (12.5%) patients received red blood cells (RBCs), three patients (6.3%) received platelet concentrates, and two (4.2%) patients received plasma units. In total eight (16.7%) patients were transfused with one or more blood products. Median pre- and post-transfusion haemoglobin (Hb) levels were 7.6 (6.7-7.7) g/dL and 8.1 (7.6-8.7) g/dL, respectively.Conclusion. - In this pilot-study we proved the feasibility of our protocol and observed in this small population a restrictive transfusion practice for all blood products. (C) 2019 Societe francaise de transfusion sanguine (SFTS). Published by Elsevier Masson SAS. All rights reserved.

Platelet concentrates (PCs) represent a blood transfusion product with a major concern for safety as their storage temperature (20-24°C) allows bacterial growth, and their maximum storage time period (less than a week) precludes complete microbiological testing. Pathogen inactivation technologies (PITs) provide an additional layer of safety to the blood transfusion products from known and unknown pathogens such as bacteria, viruses, and parasites. In this context, PITs, such as Mirasol Pathogen Reduction Technology (PRT), have been developed and are implemented in many countries. However, several studies have shown in vitro that Mirasol PRT induces a certain level of platelet shape change, hyperactivation, basal degranulation, and increased oxidative damage during storage. It has been suggested that Mirasol PRT might accelerate what has been described as the platelet storage lesion (PSL), but supportive molecular signatures have not been obtained. We aimed at dissecting the influence of both variables, that is, Mirasol PRT and storage time, at the proteome level. We present comprehensive proteomics data analysis of Control PCs and PCs treated with Mirasol PRT at storage days 1, 2, 6, and 8. Our workflow was set to perform proteomics analysis using a gel-free and label-free quantification (LFQ) approach. Semi-quantification was based on LFQ signal intensities of identified proteins using MaxQuant/Perseus software platform. Data are available via ProteomeXchange with identifier PXD008119. We identified marginal differences between Mirasol PRT and Control PCs during storage. However, those significant changes at the proteome level were specifically related to the functional aspects previously described to affect platelets upon Mirasol PRT. In addition, the effect of Mirasol PRT on the platelet proteome appeared not to be exclusively due to an accelerated or enhanced PSL. In summary, semi-quantitative proteomics allows to discern between proteome changes due to Mirasol PRT or PSL, and proves to be a methodology suitable to phenotype platelets in an unbiased manner, in various physiological contexts.

Background: Transfusion transmitted bacterial infection (TTBI) due to contamination of platelets is an important risk of blood transfusion. Our strategies to decrease bacterial contamination include skin disinfection, diversion of the first blood flow, and bacterial screening. Despite these intervention strategies, a residual risk remains. Methods: To assess this remaining risk, we retrospectively examined TTBI cases registered in the national notification database Transfusion and Transplantation Reactions in Patients (TRIP) during 2008–2019. In addition, we retrospectively examined all cases in which platelets that tested positive in the bacterial screening had already been transfused from 2013 to 2019. The bacterial screening was performed by sampling platelet concentrates 17–25 hours after blood collection, followed by a 7-day incubation of aerobic and anaerobic blood culture bottles in the BacT/ALERT® system. The distribution of bacterial species in the bacterial screening of platelets was also characterized. Results: We found 16 cases of possible/probable/certain TTBI associated with platelet transfusion in 2008–2019, including two certain TTBI (with one fatal case); in all of these cases, bacterial screening was negative. From 2013 to 2019, 1,382 out of 432,305 distributed platelets were positive (0.32%) in the bacterial screening, and 469 had already been transfused. In 20 of these 469 cases, a transfusion reaction was reported, 5 potentially related to contaminated buffy coat-derived platelets. Bacterial screening showed mostly skin bacteria, including Cutibacterium spp. and coagulase-negative staphylococci. Most virulent bacteria were detected within 48 hours. Conclusions: In summary, our two approaches demonstrate a small residual risk of TTBI due to platelet contamination, with two certain TTBIs, including one fatal case, per 668,896 distributed platelets during 12 years.

The current reference method in the United States for measuring in vivo population red blood cell (RBC) kinetics utilizes chromium-51 (51 Cr) RBC labeling for determining RBC volume, 24-hour posttransfusion RBC recovery, and long-term RBC survival. Here we provide evidence supporting adoption of a method for kinetics that uses the biotin-labeled RBCs (BioRBCs) as a superior, versatile method for both regulatory and investigational purposes. RBC kinetic analysis using BioRBCs has important methodologic, analytical, and safety advantages over 51 Cr-labeled RBCs. We critically review recent advances in labeling human RBCs at multiple and progressively lower biotin label densities for concurrent, accurate, and sensitive determination of both autologous and allogeneic RBC population kinetics. BioRBC methods valid for RBC kinetic studies, including successful variations used by the authors, are presented along with pharmacokinetic modeling approaches for the accurate determination of RBC pharmacokinetic variables in health and disease. The advantages and limitations of the BioRBC method-including its capability of determining multiple BioRBC densities simultaneously in the same individual throughout the entire RBC life span-are presented and compared with the 51 Cr method. Finally, potential applications and limitations of kinetic BioRBC determinations are discussed.

Background Over a century of advancements in the field of additive solutions for red blood cell (RBC) storage has made transfusion therapy a safe and effective practice for millions of recipients worldwide. Still, storage in the blood bank results in the progressive accumulation of metabolic alterations, a phenomenon that is mitigated by storage in novel storage additives, such as alkaline additive solutions. While novel alkaline additive formulations have been proposed, no metabolomics characterization has been performed to date. Study design and methods We performed UHPLC-MS metabolomics analyses of red blood cells stored in SAGM (standard additive in Europe), (PAGGSM), or alkaline additives SOLX, E-SOL 5 and PAG3M for either 1, 21, 35 (end of shelf-life in the Netherlands), or 56 days. Results Alkaline additives (especially PAG3M) better preserved 2,3-diphosphoglycerate and adenosine triphosphate (ATP). Deaminated purines such as hypoxanthine were predictive of hemolysis and morphological alterations. Guanosine supplementation in PAGGSM and PAG3M fueled ATP generation by feeding into the nonoxidative pentose phosphate pathway via phosphoribolysis. Decreased urate to hypoxanthine ratios were observed in alkaline additives, suggestive of decreased generation of urate and hydrogen peroxide. Despite the many benefits observed in purine and redox metabolism, alkaline additives did not prevent accumulation of free fatty acids and oxidized byproducts, opening a window for future alkaline formulations including (lipophilic) antioxidants. Conclusion Alkalinization via different strategies (replacement of chloride anions with either high bicarbonate, high citrate/phosphate, or membrane impermeant gluconate) results in different metabolic outcomes, which are superior to current canonical additives in all cases.

BACKGROUND Several circumstances require the accurate measurement of red blood cell (RBC) survival and clearance, such as determination of posttransfusion recovery of stored RBCs to investigate the effect of new additive solutions. To this end, biotin as a marker of RBCs to track donor RBCs in the blood of the recipient has been used in many studies. However, so far only experimental, nonvalidated, biotin-labeled red cell concentrates (RCCs) are transfused. The goal of this study was to produce a standardized biotin-labeled RCC product in a fast, simple, and sterile manner that can be used for clinical research and for the evaluation of new blood products according to Good Practice Guidelines (GPG) for blood establishments. STUDY DESIGN AND METHODS RCC fractions were labeled with two different concentrations of biotinylation reagent in a closed system, to prevent bacterial contamination of the end product. Using flow cytometry, the reproducibility and robustness of the biotin labeling was assessed, as well as the stability of the biotin label on the (un-)irradiated RCC fraction. Additionally, parameters such as phosphatidylserine (PS) exposure, sodium (Na), potassium (K), free hemoglobin, adenosine triphosphate (ATP), pH, and morphology were determined prior to and after biotin labeling to rule out detrimental effects of the labeling procedure on the RCC. RESULTS Our data show that RCCs can be labeled under sterile conditions in a closed system with two different biotinylation reagent concentrations, without affecting the biological activity. CONCLUSION An easy, rapid (

Background There are few studies investigating the effect of irradiation on red blood cells (RBCs) during storage. This study analyzed changes in in vitro quality of RBCs irradiated at several points during storage with the aim of providing evidence to support current maximum pre- and postirradiation storage limits. Study design and methods Each of seven participating centers produced four pools of 7 standard RBC units (SAGM, AS-3, or PAGGSM), which were then split back into 7 units. All units in a pool were from sex-matched blood donors. Every week during 6 weeks of refrigerated storage, 1 unit was irradiated, while 1 unit was not irradiated (control). Units were tested weekly for biochemical variables, morphology, and mechanical fragility. Results The earlier during storage that units were irradiated, the higher the hemolysis and K+ at end of storage. Irrespective of the timing of irradiation, there was a rapid increase in extracellular K+ , followed by a more gradual increase in hemolysis. ATP levels decreased faster in irradiated units and were reduced below accepted values if irradiated early. Irradiated female RBCs had an absolute lower hemolysis and K+ level compared to male RBCs at all time points. Conclusions The method of blood component manufacturing determined the absolute levels of hemolysis and potassium in irradiated and nonirradiated units, but did not influence the effect that timing of irradiation had on the in vitro quality characteristics. This study provides support for the current Council of Europe guidelines on the time limitations for the irradiation of RBCs.

Platelet additive solutions (PASs) have undergone many reformulations in order to further improve platelet storage. Studies of platelets stored in PAS-F (containing acetate, magnesium and potassium as key constituents) showed that platelets may be stored for 13 days with recovery and survival outcomes that are equal or even superior to 7-day stored platelets in plasma. Clinically, patients transfused with platelets in PAS have fewer allergic reactions, while for febrile reactions data are conflicting. Transfusion-related acute lung injury (TRALI) occurs less frequently if PAS is used for buffy coat-derived platelets, but for apheresis platelets there is no difference. For PAS-B and PAS-C, corrected count increments (CCIs) are lower than for platelets stored in plasma, but for PAS-E (like PAS-F also with acetate, magnesium and potassium but with additional phosphate), though limited data is available in the literature, the CCIs seem to be comparable to those observed for platelets in plasma. With platelets in PAS, there is an accumulated dilution effect of anticoagulant and PAS as well as a loss of number and function (due to storage and/or pathogen inactivation treatment) of platelets, of which it is not clear how this impacts clinical outcomes of patients undergoing massive transfusion. Worst-case in vitro studies, where the entire plasma fraction is replaced by supernatant of platelets in PAS, do show an effect on the ability of reconstituted whole blood to clot, but in a more realistic scenario, functional clotting parameters are not different. In this review, recent laboratory and clinical data are discussed, focusing on studies published after 2010.

BACKGROUND Hyperfibrinolysis has been observed in patients heavily transfused with solvent/detergent-treated pooled plasma (S/D plasma). We compared coagulation and fibrinolytic variables in blood containing S/D plasma with blood containing fresh-frozen plasma (FFP), with and without α2-antiplasmin or tranexamic acid (TXA) supplementation. STUDY DESIGN AND METHODS Whole blood samples were reconstituted from red blood cells, platelet (PLT) concentrates, and varying mixtures of FFP and S/D plasma. Hematocrit and PLT count of reconstituted whole blood samples were varied. For a subset of runs, α2-antiplasmin or TXA was added to S/D plasma whole blood samples. Thromboelastography (TEG) analysis was performed to assess 50% clot lysis time (CLT50%), maximum amplitude (MA), and initial clotting time (R-time). RESULTS The change in CLT50% of whole blood as the plasma compartment transitions from FFP to S/D plasma was −52% (95% confidence interval [CI], −60% to −45%; p

Background We investigated whether improving the metabolic status of red blood cell concentrates before freezing could extend the postthaw shelf life beyond 14 days while still meeting the requirements for hemolysis (0.8%) and total adenylate (>82% of original values). Study design and methods At Day 8 after collection, four leukoreduced red blood cell concentrates in saline-adenine-glucose-mannitol (SAGM) were pooled, mixed, and split (n = 4). Of these concentrates, two were rejuvenated in Rejuvesol. In addition, two leukoreduced red blood cell concentrates in phosphate-adenine-glucose-guanosine-gluconate-mannitol (PAGGGM) were pooled, mixed, and split at Day 8 after collection (n = 4). All concentrates were glycerolized, frozen, and stored for at least 2 weeks at -80°C. After thawing and deglycerolization, from each pair, one red blood cell concentrate was resuspended in SAGM, and one was suspended in AS-3. During postthaw storage at 2 to 6°C for 35 days, all concentrates were sampled weekly and analyzed for hematologic, metabolic, and morphologic parameters. Results Both Rejuvesol and PAGGGM treatment produced increased adenosine triphosphate and total adenylate and 2,3-diphosphoglycerate levels compared with untreated red blood cell concentrates. Regardless of prefreeze Rejuvesol or PAGGGM treatment, postthaw hemolysis remained below 0.8% during 7 days in SAGM and during 35 days in AS-3. At Day 35 of postthaw storage in AS-3, total adenylate in nonrejuvenated red blood cell concentrates had decreased to 72% of the original values; whereas, in prefreeze Rejuvesol-treated and PAGGGM-treated concentrates, adenylate values were still were at 101% and 98%, respectively. Conclusion Based on maximum allowable hemolysis of 0.8% and total adenylate content greater than 82% of the original value, thawed, prefreeze Rejuvesol-treated or PAGGGM-treated red blood cell concentrates can be stored for 35 days at 2 to 6oC in AS-3.

BACKGROUND: Platelet-rich plasma (PRP) is frequently used in the treatment of acute and chronic wounds. One of the major problems concerning the use of PRP is the absence of a well-characterized and standardized product, which leads to a high variety in study outcomes. Therefore, more studies on the composition and standardization of PRP in wound healing are needed. STUDY DESIGN AND METHODS: Platelet concentrates derived from healthy blood donors were made in plasma (PC-plasma) or platelet additive solution (PC-PAS). The effects of PC-plasma, PC-PAS, and plasma were then tested on proliferation, differentiation, and migration of fibroblasts, as well as sprouting of endothelial cells in fibrin gels and chemotaxis of white blood cells (WBCs). RESULTS: PC-plasma stimulates the migration and proliferation of human dermal fibroblasts more than plasma or platelets alone. Furthermore, platelet factors decrease the expression of α-smooth muscle actin in dermal fibroblast cultures. PC-plasma also stimulates sprouting of endothelial cells. Finally, PC-plasma also acts as a strong chemoattractant for WBCs. CONCLUSIONS: Allogeneic PC-plasma has beneficial effects on various aspects of wound healing in vitro and is superior to plasma or platelets alone. PC-plasma is an attractive candidate for further in vivo evaluation.

BACKGROUND Transfusion‐associated circulatory overload (TACO) is the predominant complication of transfusion resulting in death. The pathophysiology is poorly understood, but inability to manage volume is associated with TACO, and observational data suggest it is different from simple cardiac overload due to fluids. We developed a two‐hit TACO animal model to assess the role of volume incompliance (“first‐hit”) and studied whether volume overload (“second‐hit”) by red blood cell (RBC) transfusion is different compared to fluids (Ringer's lactate [RL]). MATERIALS AND METHODS Male adult Lewis rats were stratified into a control group (no intervention) or a first hit: either myocardial infarction (MI) or acute kidney injury (AKI). Animals were randomized to a second hit of either RBC transfusion or an equal volume of RL. A clinically relevant difference was defined as an increase in left ventricular end‐diastolic pressure (ΔLVEDP) of +4.0 mm Hg between the RBC and RL groups. RESULTS In control animals (without first hit) LVEDP was not different between infusion groups (Δ + 1.6 mm Hg). LVEDP increased significantly more after RBCs compared to RL in animals with MI (Δ7.4 mm Hg) and AKI (Δ + 5.4 mm Hg), respectively. Volume‐incompliant rats matched clinical TACO criteria in 92% of transfused versus 25% of RL‐infused animals, with a greater increase in heart rate and significantly higher blood pressure. CONCLUSION To our knowledge, this is the first animal model for TACO, showing that a combination of volume incompliance and transfusion is essential for development of circulatory overload. This model allows for further testing of mechanistic factors as well as therapeutic approaches.

Introduction In vitro qualitative differences exist in red cell concentrates (RCCs) units processed from whole blood (WB) depending on the method of processing. Minimal literature exists on differences in processing and variability in quality data. Therefore, we collected information from blood manufacturers worldwide regarding (1) details of WB collection and processing used to produce RCCs and (2) quality parameters and testing as part of routine quality programmes. Methods A secure web-based survey was developed, refined after pilot data collection and distributed to blood centres. Descriptive analyses were performed. Results Data from ten blood centres in nine countries were collected. Six blood centres (60%) processed RCCs using the top-and-top (TAT) method which produces RCCs and plasma, and eight centres (80%) used the bottom-and-top (BAT) which additionally produces buffy coat platelets. Five of the centres used both processing methods; however, four favoured BAT processing. One centre utilized the Reveos automated system exclusively. All centres performed pre-storage leucoreduction. Other parameters demonstrated variability, including active cooling at collection, length of hold before processing, donor haemoglobin limits, acceptable collection weights, collection sets, time to leucoreduction, centrifugation speeds, extraction devices and maximum RCC shelf life. Quality marker testing also differed amongst blood centres. Trends towards higher RCC unit volume, haemolysis and residual leucoctyes were seen in the TAT compared with BAT processing across centres. Conclusion Methods and parameters of WB processing and quality testing of RCCs differ amongst surveyed blood manufacturers. Further studies are needed to assess variations and to potentially improve methods and product quality.

Burn injury has severe impact on the physiologic homeostasis. Platelet counts show a distinct course post-burn injury, with a nadir at day 3 followed by a thrombocytotic period with at peak at day 15, with a gradual return to normal. So far, it is unknown how the functionality and activational status of platelets develop post burn. In this study, we investigated if the function, activation and growth factor content of platelets of burn patients are affected and how this evolves in time. Six burn patients with over 15% total burned surface area were followed during 1 month. Standard hematological and coagulation analyses, thromboelastography (TEG), platelet-function analyzer-100 (PFA), several platelet activation parameters (CD62P-CD63, AnnexinV) and growth factors (TGFb1, VEGF, PDGF-AB/BB, EGF, TGFb2, FGF-2, PDGF-AA) analyses were performed. TEG analyses showed procoagulant changes. PFA-100 analyses were nearly all within normal range. CD62P and CD63 and Annexin-V indicated no clear activation of platelets. Growth factor content followed the same course as the platelet count, reflecting a constant growth factor per platelet ratio. Concluding, platelets post burn-injury appears to be functional and not overly activated. However, burn patients seem to remain in a procoagulant state for an extensive period, which may impact their pathology.

BACKGROUND: Labeling of platelets (PLTs) is required to measure the recovery and survival of transfused PLTs in vivo. Currently a radioactive method is used to label PLTs. However, application of those radiolabeling methods is limited by both safety issues and the inability to isolate transfused PLTs from the circulation. Biotin-labeled PLTs are an attractive nonradioactive option. However, no validated protocol to biotinylate PLTs is currently available for human studies. STUDY DESIGN AND METHODS: Six PLT concentrates (PCs) were subaliquoted and biotinylated on Days 1 and 7 of storage. To distinguish the effect of the processing steps from the effects of biotin incubation, two control groups were used: 1) “sham” samples were processed without the biotinylation reagent and 2) control samples were assessed without any processing other than the PC isolation. For the biotinylation procedure, 50 mL of PCs was washed twice and incubated with 5 mg/L biotin for 30 minutes in a closed system. As measures of PLT activation, phosphatidylserine exposure and CD62p expression were assessed. RESULTS: After biotinylation, 98.4% ± 0.9% of PLTs were labeled. PLT counts, pH, and “swirling” were within the range accepted by the Dutch blood bank for standard PLT products. Biotinylated PLTs were more activated compared than controles but not more than sham samples, but were more activated than the controls. CONCLUSION: We developed a standardized and reproducible protocol according to Good Practice Guidelines standards, for biotin labeling of PLTs for clinical purposes. This method can be applied as nonradioactive alternative assess survival and recovery of transfused PLTs in vivo.

Background For a clinical platelet (PLT) transfusion trial conducted in three countries, the production of PLT concentrates (PCs) that were pathogen inactivated with the Mirasol technology was set up and validated. While the Mirasol procedure is applied to an established PLT product, the PLT processing procedure still had to be modified to ensure a treated PC was of sufficient quality. Further, the effect of simulated transport conditions and the effect of ambient light on Mirasol-treated PCs was determined. Study Design and Methods Platelet concentrates in plasma were made from pooled buffy coats followed by Mirasol treatment. To mimic transport conditions, units were left unagitated for 6 h at room temperature. To mimic ambient light exposure, units were held unagitated for 4 h in direct fluorescent tube light. Results Measures had to be taken to allow 7-day storage of treated concentrates. In one site, PCs made from five buffy coats with >450 × 109 PLTs were removed from inventory. Another site went from five to four buffy coats per pool. Interruption of agitation for 6 h on day 3 did not induce meaningful changes in in vitro measures, even when stored up to 7 days. Exposure to ambient light for 4 h, either on day 3 or 6, had no effect on in vitro measures. Conclusion The Mirasol pathogen inactivation process can be implemented in routine, but changes to current PLT processing methods might be needed. Transport conditions and 4-h-long ambient light exposure have no negative effect on the in vitro quality of Mirasol-treated PCs.

BACKGROUND Transfusion of a single unit of stored red blood cells (RBCs) has been hypothesized to induce supra-physiological levels of non-transferrin bound iron (NTBI), which may enhance inflammation and act as a nutrient for bacteria. We investigated the relation between RBC storage time and iron levels in a clinically relevant “two-hit” human transfusion model. STUDY DESIGN AND METHODS Eighteen healthy male volunteers (ages 18-35 years) were infused with 2 ng lipopolysaccharide (LPS)/kg to induce systemic inflammatory response syndrome. Two hours later, each participant received either 1 unit of 2-day stored (2D) autologous RBCs, 35-day stored (35D) autologous RBCs, or an equal volume of saline. Every 2 hours up to 8 hours after LPS infusion, hemoglobin, hemolysis parameters, and iron parameters, including NTBI, were measured. RESULTS Transfusion of both 2D and 35D RBCs caused increases in hemoglobin, plasma iron, and transferrin saturation; whereas levels remained stable in the saline group. Transfusion of 35D RBCs did not result in hemolysis nor did it lead to increased levels of NTBI compared with 2D RBCs or saline. LPS induced increases in ferritin, haptoglobin, bilirubin, and lactate dehydrogenase that were similar in all three groups. CONCLUSION We conclude that 35D autologous RBCs do not cause hemolysis or increased levels of NTBI during human endotoxemia.

Background and Objectives In mice, loss of sialic acid resulting in shedding of glycoprotein (GP) Ibα and GPV has been linked to platelet survival. The aim of this study was to determine whether loss of sialic acid and the GPIb-IX-V complex contributes to development of the platelet storage lesion (PSL) in human platelet concentrates (PCs). Materials and methods PCs (stored in plasma (with or without Mirasol treatment); PAS-C or PAS-E) were stored at room temperature. Flow cytometry was used to monitor membrane expression of the GPIb-IX-V complex, CD62P, surface glycans and PS exposure. The functionality of stored platelets was determined employing aggregometry and ristocetin-induced VWF binding. Results Storage time of PCs in blood banks is limited to 7 days. During this time period, a minor but gradually increasing subpopulation of GPIbα-negative platelets was observed. Also, ristocetin-induced VWF binding was impaired in a small population of platelets. Mean surface expression of GPIbα and GPV remained stable until day 9, whereas CD62P expression increased; also a rapid decrease in ADP-induced aggregation was observed for PAS-C, PAS-E and Mirasol-treated PCs. Upon prolonged storage (>9 days), a slow decline in surface expression of GPIbα and GPV was observed; no major changes were observed in surface sialylation with the exception of Mirasol-treated platelets. Conclusion In a small population of stored platelets, changes in GPIbα occur from day 2 onwards. Loss of sialic acid and subsequent shedding of GPIbα and GPV is not an early event during the development of the PSL.

BACKGROUND It is thought that the clearance of transfused red blood cells (RBCs) is related both to the storage time of the transfusion product and to the inflammatory status of the recipient. We investigated these effects in a randomized, “two-hit,” healthy volunteer transfusion model, comparing autologous RBCs that were stored for 35 days with those that were stored for 2 days. STUDY DESIGN AND METHODS Healthy male volunteers donated 1 unit of autologous RBCs either 2 days (2D) or 35 days (35D) before the study date. The experiment was started by infusion of 2 ng/kg lipopolysaccharide (“first hit”). Two hours later, the stored RBCs (“second hit”) were reinfused, followed by the labeling of RBCs with biotin. Clearance of biotin-labeled RBCs (BioRBCs) was measured during the 5-hour posttransfusion endotoxemia period along with measurements of phosphatidylserine (PS) exposure, lactadherin binding, and expression of CD47 (cluster of differentiation 47; a transmembrane protein encoded by the CD47 gene). RESULTS In the 2D stored RBCs group, 1.5% ± 3.4% of infused BioRBCs were cleared from the circulation 5 hours posttransfusion versus 4.8% ± 4.0% in the 35D stored RBCs group (p = 0.1). There were no differences in PS exposure, lactadherin binding, or CD47 expression between fresh and stored RBCs or between pretransfusion and posttransfusion measurements. CONCLUSION Our study shows a low clearance of RBCs even during endotoxemia. Furthermore, short-term clearance of BioRBCs during endotoxemia was not related to storage duration. Consistent with these observations, PS exposure, lactadherin binding, and CD47 expression did not differ between 2D and 35D stored cells before or after transfusion. We conclude that, in the presence of endotoxemia, clearance of 35D stored autologous RBCs is not increased compared with 2D stored fresh RBCs.

Background and Objectives: Previously it has been shown that platelet (PLT) storage performance is consistent by donor. Differences involved metabolic activity, which might be caused by mitochondrial (dys)function, associated with age and age-related diseases like Type 2 diabetes (T2D). We aimed to test PLTs from young donors in comparison with PLTs from older donors with or without diagnosis for T2D. Materials and methods: Fifteen whole blood donors 45 years with and without T2D. The sPC were stored for 8 days and analysed at regular intervals for in vitro quality. Results: Donors were 24 ± 3, 60 ± 7 (without T2D) and 59 ± 8 (with T2D) years old. All sPC groups had comparable volume and PLT content. On Day 8, sPC from young donors showed higher pH37°C than sPC from older donors (6.84 ± 0.15 vs. 6.40 ± 0.48, P

BACKGROUND Red blood cell (RBC) transfusion has been related to thromboembolic events. Microvesicles in the RBC product may support coagulation because they have procoagulant effects in vitro. We investigated whether transfusion of RBCs containing extracellular vesicles promotes coagulation in human recipients. As transfusion is mostly administered to ill patients, we used a model of endotoxemia. STUDY DESIGN AND METHODS Eighteen healthy volunteers were randomized to receive either saline or fresh (2 days stored) or stored autologous (35 days stored) RBC transfusion (Dutch Trial Register: NTR4455). Two hours after infusion of lipopolysaccharide (LPS, from Escherichia coli, 2 ng/kg body weight), subjects received either saline or fresh or stored RBCs. Blood was sampled every 2 hours up to 8 hours after LPS infusion. Vesicles were measured with a flow cytometer (A50-Micro, Apogee Flow Systems). RESULTS LPS resulted in increased thrombin generation compared to baseline. During storage, the total number of extracellular vesicles increased from 1.4 × 108 /mL (interquartile range [IQR], 8.3 × 107 -1.9 × 108 /mL) in the fresh product to 1.7 × 1010 /mL (IQR, 7.9 × 109 -2.3 × 1010 /mL; p

BACKGROUND During storage, the activity of the red blood cell (RBC) antioxidant system decreases. Glucose-6-phosphate dehydrogenase (G6PD) is essential for protection against oxidative stress by producing NADPH. G6PD function of RBC transfusion products is reported to remain stable during storage, but activity was measured in hemolysates and not in individual RBCs. We hypothesized that analysis of G6PD activity in individual RBC identifies storage-dependent changes in G6PD function. STUDY DESIGN AND METHODS Seven units of stored leukoreduced RBCs, stored in saline-adenine-glucose-mannitol, were sampled every week up to 6 weeks of storage. G6PD activity was determined with the cytofluorometric method and expressed as mean fluorescent intensity (MFI) per RBC. RESULTS During storage, G6PD activity decreased significantly. Mean MFI after 3 days of storage was 27.8 ± 8.8 and gradually decreased significantly to 18.0 ± 8.3 after 42 days. CONCLUSION G6PD activity decreases during storage of leukoreduced RBCs. Our results may form a new target to improve storage conditions of RBCs and subsequently improve the quality of transfusion products.

BACKGROUND Pathogen reduction technologies (PRTs) increase the safety of the blood supply, but are also associated with cell damage. Our aim was to investigate the effect of Mirasol PRT on platelet (PLT) concentrates stored in plasma and whether the use of a PLT additive solution (PAS) is able to improve in vitro quality. STUDY DESIGN AND METHODS Twenty-two buffy coats (BCs) were pooled and split into two equal parts. To one half, 2 units of plasma were added, and to the other, 2 units of SSP+ PAS were added. Each part was equally split in half again (to resemble pooling five BCs) and PLT concentrates were prepared. One plasma PLT concentrate was Mirasol treated, and the other served as control; similarly, one SSP+ PLT concentrate was Mirasol treated, and the other not. PLT concentrates were stored for 8 days (n = 12). RESULTS Mirasol PRT led to elevated lactate production in PLT concentrates in plasma, giving lower pH values throughout storage. The use of SSP+ mostly abrogated this effect, and Mirasol-treated PLT concentrates in SSP+ had only slightly higher lactate production rates and annexin A5 binding as control PLT concentrates in plasma. However, irrespective whether plasma or SSP+ was used, Mirasol PRT led to higher CD62P expression and lower hypotonic shock response (HSR) scores. CONCLUSION Mirasol treatment leads to higher PLT activation and lower HSR scores both when stored in plasma or SSP+. However, if Mirasol-treated PLTs are stored in SSP+, lactate metabolism and annexin A5 binding are lower, showing that PAS can partly mitigate the effect of PRT. The clinical relevance of this finding needs to be demonstrated.

Transfusion-transmitted infections (TTI) have been greatly reduced in numbers due to the strict donor selection and screening procedures, i.e. the availability of technologies to test donors for endemic infections, and routine vigilance of regulatory authorities in every step of the blood supply chain (collection, processing and storage). However, safety improvement is still a matter of concern because infection zero-risk in transfusion medicine is non-existent. Alternatives are required to assure the safety of the transfusion product and to provide a substitution to systematic blood screening tests, especially in less-developed countries or at the war-field. Furthermore, the increasing mobility of the population due to traveling poses a new challenge in the endemic screening tests routinely used, because non-endemic pathogens might emerge in a specific population. Pathogen reduction treatments sum a plethora of active approaches to eliminate or reduce potential threatening pathogen load from blood transfusion products. Despite the success of pathogen reduction treatments applied to plasma products, there is still a long way to develop and deploy pathogen reduction treatments to cellular transfusion products (such as platelets, RBCs or even to whole blood) and there is divergence on its acceptance worldwide. While the use of pathogen reduction treatments in platelets is performed routinely in a fair number of European blood banks, most of these treatments are not (or just) licensed in the USA or elsewhere in the world. The development of pathogen reduction treatments for RBC and whole blood is still in its infancy and under clinical trials. In this review, we discuss the available and emerging pathogen reduction treatments and their advantages and disadvantages. Furthermore, we highlight the importance of characterizing standard transfusion products with current and emerging approaches (OMICS) and clinical outcome, and integrating this information on a database, thinking on the benefits it might bring in the future toward personalized transfusion therapies.

Whole blood is not usually collected close to the processing site, which results in a holding time between collection and processing. In some countries, the holding time is limited to 8 hours, after which the units are cooled, rendering them useless for platelet preparation. Other countries allow a 24-hour ("overnight") ambient hold to allow platelet preparation. The impact of this holding time on subsequent blood components will be reviewed in this article. In addition, there are various "in-process" holding times that further prolong the time before the final blood component is ready. Particularly, these in-process holding times are not well defined and poorly controlled, but can nevertheless affect the biochemical and functional characteristics of blood components. Furthermore, current, non–evidence-based, guidelines have restricted the length of some of these holding times. This article summarizes the evidence and fills gaps where evidence is lacking.

Background and Objectives There are concerns about the haemostatic function of platelets stored in platelet additive solution (PAS). Aim of this study was to compare the haemostatic function of PAS-C–platelets to plasma–platelets in reconstituted whole blood. Materials and Methods In our experiment, whole blood was reconstituted with red blood cells, solvent–detergent (SD) plasma and either PAS-C–platelets or plasma–platelets (n = 7) in a physiological ratio. On storage days 2, 5, 8 and 13, the agonist-induced aggregation (multiple electrode aggregometry), clot formation (thromboelastography) and agonist-induced CD62P responsiveness (flow cytometry) were measured. Results Samples with PAS-C–platelets showed significantly lower aggregation than plasma–platelets when induced with adenosine diphosphate, −6 U (95% confidence interval: −8; −4) or thrombin receptor-activating protein, −15 U (−19; −10). Also when activated with collagen and ristocetin, the PAS-C–platelets showed less aggregation, although not statistically significant. All samples with PAS-C–platelets showed significantly lower agonist-induced CD62P responsiveness than samples with plasma–platelets. However, there was no difference regarding all TEG parameters. Conclusion Our findings demonstrate that the function – aggregation and CD62P responsiveness – of PAS-C–platelets in reconstituted whole blood is inferior to that of plasma–platelets, which may have implications in the setting of massive transfusions.

Background and Objectives Interventions to prevent and detect bacterial contamination of platelet concentrates (PCs) have reduced, but not eliminated the sepsis risk. Standardized bacterial strains are needed to validate detection and pathogen reduction technologies in PCs. Following the establishment of the First International Reference Repository of Platelet Transfusion-Relevant Bacterial Reference Strains (the ‘repository’), the World Health Organization (WHO) Expert Committee on Biological Standardisation (ECBS) endorsed further repository expansion. Materials and Methods Sixteen bacterial strains, including the four repository strains, were distributed from the Paul-Ehrlich-Institut (PEI) to 14 laboratories in 10 countries for enumeration, identification and growth measurement on days 2, 4 and 7 after low spiking levels [10–25 colony-forming units (CFU)/PC bag]. Spore-forming (Bacillus cereusPEI-B-P-07-S, Bacillus thuringiensisPEI-B-P-57-S), Gram-negative (Enterobacter cloacaePEI-B-P-43, Morganella morganiiPEI-B-P-74, PEI-B-P-91, Proteus mirabilisPEI-B-P-55, Pseudomonas fluorescensPEI-B-P-77, Salmonella choleraesuisPEI-B-P-78, Serratia marcescensPEI-B-P-56) and Gram-positive (Staphylococcus aureusPEI-B-P-63, Streptococcus dysgalactiaePEI-B-P-71, Streptococcus bovisPEI-B-P-61) strains were evaluated. Results Bacterial viability was conserved after transport to the participating laboratories with one exception (M. morganiiPEI-B-P-74). All other strains showed moderate-to-excellent growth. Bacillus cereus, B. thuringiensis, E. coli, K. pneumoniae, P. fluorescens, S. marcescens, S. aureus and S. dysgalactiae grew to >106 CFU/ml by day 2. Enterobacter cloacae, P. mirabilis, S. epidermidis, S. bovis and S. pyogenes achieved >106 CFU/ml at day 4. Growth of S. choleraesuis was lower and highly variable. Conclusion The WHO ECBS approved all bacterial strains (except M. morganiiPEI-B-P-74 and S. choleraesuisPEI-B-P-78) for repository enlargement. The strains were stable, suitable for spiking with low CFU numbers, and proliferation was independent of the PC donor.

Background and Objectives The accumulation of non-polar lipids arachidonic acid, 5-hydroxyeicosatetraenoic acid (HETE), 12-HETE and 15-HETE during storage of transfusion products may play a role in the onset of transfusion-related acute lung injury (TRALI), a syndrome of respiratory distress after transfusion. Materials and Methods We investigated non-polar lipid accumulation in red blood cells (RBCs) stored for 42 days, plasma stored for 7 days at either 4 or 20°C and platelet (PLT) transfusion products stored for 7 days. Furthermore, we investigated whether transfusion of RBCs with increased levels of non-polar lipids induces TRALI in a ‘two-hit’ human volunteer model. All products were produced following Dutch Blood Bank protocols and are according to European standards. Non-polar lipids were measured with high-performance liquid chromotography followed by mass spectrometry. Results All non-polar lipids increased in RBCs after 21 days of storage compared to baseline. The non-polar lipid concentration in plasma increased significantly, and the increase was even more pronounced in products stored at 20°C. In platelets, baseline levels of 5-HETE and 15-HETE were higher than in RBCs or plasma. However, the non-polar lipids did not change significantly during storage of PLT products. Infusion of RBCs with increased levels of non-polar lipids did not induce TRALI in LPS-primed human volunteers. Conclusion We conclude that non-polar lipids accumulate in RBC and plasma transfusion products and that accumulation is temperature dependent. Accumulation of non-polar lipids does not appear to explain the onset of TRALI (Dutch Trial Register – NTR4455).

Background The plasticizer di(2-ethylhexyl)phthalate (DEHP) is a common component in blood bags. DEHP is noncovalently bound to polyvinylchloride (PVC) polymer and can leach into the blood product. There are public concerns that exposure to DEHP might induce developmental and reproductive toxicity in humans. The aim of this study was to evaluate an alternative plasticizer, di(isononyl) cyclohexane-1,2-dicarboxylate (Hexamoll DINCH, BASF SE), for its use in blood bags. Study Design and Methods Whole blood (WB) was collected into DEHP-containing and DEHP-free collection systems. After overnight hold, WB was centrifuged and separated in plasma, buffy coat, and red blood cells (RBCs). Buffy coats and plasma were used to make platelet (PLT) concentrates in DEHP-free systems. After addition of additive solution (AS), SAG-M, PAGGS-M, AS-3, or PAGGG-M, RBCs were leukoreduced and analyzed for in vitro characteristics and plasticizer levels during storage. Results The use of DINCH-based systems had no effect on WB composition, blood processing, and plasma quality. PLT in vitro quality variables were maintained during storage in DEHP-free systems. During storage in SAG-M, hemolysis was significantly higher in DINCH-PVC while potassium leakage and adenosine triphosphate content were comparable. During storage in alternative ASs, hemolysis was reduced compared to storage in SAG-M. Conclusions The complete absence of DEHP in the collection system had no effect on WB composition, processing, or plasma and PLT quality. During storage in SAG-M, the absence of DEHP resulted in increased hemolysis. With alternative ASs like PAGGS-M, AS-3, or PAGGG-M, the absence of DEHP had no effect on hemolysis. Leakage of DINCH into the blood product was less pronounced than that of DEHP.