Red blood cells as oxygen carrier during normothermic machine perfusion of kidney grafts: Friend or foe?

Renal ex vivo normothermic machine perfusion (NMP) is under development as an assessment tool for high-risk kidney grafts and as a means of achieving more physiologically accurate organ preservation. On-going hemolysis has been reported during NMP, as this technique relies on red blood cells for oxygen delivery. In this study, we confirm the occurrence of progressive hemolysis during 6-hour kidney NMP. NMP-associated erythrostasis in the glomeruli and in peri-glomerular vascular networks points to an interaction between the red blood cells and the graft. Continuous hemolysis resulted in prooxidative changes in the perfusate, which could be quenched by addition of fresh frozen plasma. In a cell-based system, this hemolysis induced redox stress and exhibited toxic effects at high concentrations. These findings highlight the need for a more refined oxygen carrier in the context of renal NMP.

Towards standardized human platelet lysate production in Europe: An initiative of the European Blood Alliance.

Human platelet lysate (hPL) is a supplement for cell culture media that can be derived from platelet concentrates. As not-for-profit blood establishments, we endorse the evolution of maximally exploiting the potential of donated blood and its derived components, including platelets. The decision to use platelet concentrates to supply hPL as a cell culture supplement should align with the principles and values that blood establishments hold towards the use of donated blood components in transfusion. As a consequence, questions on ethics, practical standardization of hPL production and logistics as well as on assuring hPL quality and safety need careful consideration. We therefore propose an opinion on some of these matters based on available literature and on discussions within the proceedings of the Working Group on Innovation and New Products of the European Blood Alliance. In addition, we propose collaboration among European blood establishments to streamline efforts of hPL supply to maximize the potential of hPL and its application in the wider field of medicine.

The effect of near-infrared low-level light on the in vitro quality of platelets during storage.

BACKGROUND AND OBJECTIVES: Near-infrared (NIR) light has been successfully applied to improve the quality of mouse platelets during storage. Because it is suspected that the mitochondria contain the primary photon acceptor, we hypothesized that human platelets for transfusion may be affected similarly and could benefit from NIR light treatment. MATERIALS AND METHODS: The optimal light dose was determined using portions of platelet concentrates (PCs) in PAS-E. A pool-and-split design was used to prepare PCs in PAS-E or plasma (n = 6). On day 1, one unit of both pairs was illuminated with 830 nm light (light-emitting diodes, 15 J/cm2). PCs were stored at 22°C and sampled regularly for analysis. Data were compared with their corresponding controls with a paired two-sided t-test. RESULTS: Illuminated platelets in PAS-E were less activated with significantly lower CD62P expression (day 8: 10.8 ± 1.8 vs. 12.2 ± 2.6, p < 0.05) and lower Annexin A5 binding (day 8: 11.8 ± 1.9 vs. 13.1 ± 2.4, ns). They produced significantly less lactate resulting in a higher pH (days 6-10). ATP content and mitochondrial membrane potential were not affected. Although these trends were also observed for PCs in plasma, the differences did not reach statistical significance as compared with the control group. CONCLUSION: Our study demonstrates that the glycolysis rate of human platelets can be modulated through the use of NIR, possibly through mitochondrial aerobic metabolism, but this requires confirmation. If NIR illumination can be further optimized, it may potentially become a useful tool in situations in which glycolysis and platelet activation are exacerbated.

Current transfusion practice and need for new blood products to ensure blood supply for patients with major hemorrhage in Europe.

BACKGROUND: New blood products are considered for treatment of patients with major hemorrhage. The aim of this report is to describe the current transfusion practices in Europe for patients with major hemorrhage and explore the need for new or modified blood products to ensure prehospital and in-hospital blood supply. STUDY DESIGN AND METHOD: The European Blood Alliance (EBA) Working Group on Innovation and New Blood Products' subgroup on major hemorrhage performed a survey among the EBA member states. RESULTS: The response rate was 58% (17 responses from 15 of the 26 EBA member states). Of these, sixteen (94%) provide massive transfusion packages (MTPs) with balanced ratio of red blood cells and plasma. Seven of the respondents included platelets from the start of treatment. Eleven (65%) provide prehospital blood products, mainly red cell concentrates or dried and/or thawed plasma with 5 days of extended storage. Two countries provide prehospital whole blood. Twelve respondents (71%) saw a need for implementation of new or modified blood components in their institution. The top three priorities were whole blood (12 of 12, 100%), dried plasma (8 of 12, 67%), and cold-stored platelets (7 of 12, 58%). DISCUSSION: Current national guidelines for use of blood products in patients with major hemorrhage in Europe agree on the use of balanced transfusion, however the timing and source of platelets differ. Blood products for prehospital transfusion are available in several European countries. An interest in new or modified blood products for patients with major hemorrhage was observed, especially for whole blood.

Efficacy and safety of platelet additive solution-E stored platelet concentrates.

INTRODUCTION: In 2018, platelet (PLT) additive solution-E (PAS-E) was introduced. The implementation of PAS-E was expected to diminish the number of allergic reactions in recipients following a PLT transfusion. Here, we evaluated the efficacy and safety of transfusions with PLTs stored in PAS-E. STUDY DESIGN AND METHODS: After implementation of PAS-E, data were collected from 2 cohorts of patients with hematological disorders as well as oncology patients, receiving PLTs in PAS-E. A similar patient group in a recent RCT, receiving PLTs in plasma, was used as a historical control group for both cohorts. Endpoints were corrected count increments (CCIs), bleeding scores (only reported in cohort 1), and the incidence of adverse reactions. RESULTS: In cohort 1, the mean 1-h CCI was 14.3 ± 6.9, and the 24-h CCI was 8.7 ± 5.6. In cohort 2, the 1-h CCI was 11.6 ± 7.8 and the 24-h CCI was 7.0 ± 6.1. In the control group, the 1-h CCI was 15.4 ± 5.5 and 24-h CCI 8.7 ± 4.8. Bleeding complications of WHO grade ≥2 occurred in 40% of patients in cohort 1 compared to 44% in plasma PCs. The incidence of adverse reactions was 1.2% in the two PAS-E cohorts, compared to 3.0% in plasma PCs. National hemovigilance data showed a significant reduction in allergic reactions with PAS-E PC transfusions as compared to plasma PCs with an odds ratio of 0.46 (CI 95% 0.37-0.58). CONCLUSION: The CCIs of PLTs in PAS-E were decreased compared to plasma PCs, but clinically acceptable. Allergic transfusion reactions were decreased in PAS-E PCs compared to plasma PCs.

Recommendations for in vitro evaluation of blood components collected, prepared and stored in non-DEHP medical devices.

BACKGROUND AND OBJECTIVES: 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 27th 2025. There are major concerns in meeting this deadline as these systems have not yet been fully validated and/or CE-marked. Also, since DEHP is known to affect red cell quality during storage, it is imperative to transit to non-DEHP without affecting blood product quality. Here, EBA members aim to establish common grounds on the evaluation and assessment of blood components collected, prepared and stored in non-DEHP devices. MATERIALS AND METHODS: Based on data as well as the input of relevant stakeholders a rationale for the validation of each component was composed. RESULTS: 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. CONCLUSION: 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.

Donor variation in stored platelets: Higher metabolic rates of platelets are associated with mean platelet volume, activation and donor health.

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 <45, 45-70 and >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.

The history of buffy coat platelet concentrates: The Dutch story.

The buffy coat method as a source for platelet concentrates was developed in the 1970s and is still used in many blood centres around the world. Development of the method sparked various technological advances in blood collection, processing and storage. At the time, the need for platelet concentrates sharply increased because of better treatment regimens for (onco)haematological diseases, which forced blood centres to standardize and automate their production processes as much as the technology would allow. In this review, a historical overview of the Dutch experiences is provided in the context of the international developments.

Clinical and in vitro evaluation of red blood cells collected and stored in a non-DEHP plasticized bag system.

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.

Oxidative stress activates red cell adhesion to laminin in sickle cell disease.

Vaso-occlusive crises are the hallmark of sickle cell disease (SCD). They are believed to occur in two steps, starting with adhesion of deformable low-dense red blood cells (RBCs), or other blood cells such as neutrophils, to the wall of post-capillary venules, followed by trapping of the denser RBCs or leukocytes in the areas of adhesion because of reduced effective lumen-diameter. In SCD, RBCs are heterogeneous in terms of density, shape, deformability and surface proteins, which accounts for the differences observed in their adhesion and resistance to shear stress. Sickle RBCs exhibit abnormal adhesion to laminin mediated by Lu/BCAM protein at their surface. This adhesion is triggered by Lu/BCAM phosphorylation in reticulocytes but such phosphorylation does not occur in mature dense RBCs despite firm adhesion to laminin. In this study, we investigated the adhesive properties of sickle RBC subpopulations and addressed the molecular mechanism responsible for the increased adhesion of dense RBCs to laminin in the absence of Lu/BCAM phosphorylation. We provide evidence for the implication of oxidative stress in post-translational modifications of Lu/BCAM that impact its distribution and cis-interaction with glycophorin C at the cell surface activating its adhesive function in sickle dense RBCs.

A Homozygous Mutation on the HBA1 Gene Coding for Hb Charlieu (HBA1: c.320T>C) Together with ß-Thalassemia Trait Results in Severe Hemolytic Anemia.

A 4-year-old boy, a ß-thalassemia (ß-thal) carrier, with an unexplained severe chronic microcytic anemia was referred to us. Sequencing of the α-globin genes revealed a Hb Charlieu [α106(G13)Leu→Pro, HBA1: c.320T>C, p.Leu107Pro] mutation present on both HBA1 genes. Quantitative polymerase chain reaction (qPCR) confirmed αCharlieu mRNA in the proband and his parents, showing that the mutation does not affect mRNA stability. However, we were unable to detect the Hb Charlieu protein by capillary electrophoresis (CE), reverse phase electrophoresis, cation exchange electrophoresis or isoelectric focusing. Mass spectrometry (MS) allowed us to confirm the presence of the Hb Charlieu peptide in erythrocyte progenitors. These findings suggest that the mutation affects the stability of αCharlieu. As hemoglobin (Hb) heat stability tests showed no abnormalities in erythrocytes, we speculated that αCharlieu is already degraded during red blood cell (RBC) development. The clinical severity in the proband and the presence of new methylene blue-stained aggregates in his reticulocytes indicates that incorporation of αCharlieu destabilizes Hb. This, combined with an excess of unstable free α-globins as the result of ß-thal minor, results in severely impaired erythropoiesis and, as a consequence, severe and chronic microcytic anemia in the proband.

Residual pyruvate kinase activity in PKLR-deficient erythroid precursors of a patient suffering from severe haemolytic anaemia.

OBJECTIVE: Here, we present a 7-year-old patient suffering from severe haemolytic anaemia. The most common cause of chronic hereditary non-spherocytic haemolytic anaemia is red blood cell pyruvate kinase (PK-R) deficiency. Because red blood cells rely solely on glycolysis to generate ATP, PK-R deficiency can severely impact energy supply and cause reduction in red blood cell lifespan. We determined the underlying cause of the anaemia and investigated how erythroid precursors in the patient survive. METHODS: PK activity assays, Western blot and Sanger sequencing were employed to determine the underlying cause of the anaemia. Patient erythroblasts were cultured and reticulocytes were isolated to determine PK-R and PKM2 contribution to glycolytic activity during erythrocyte development. RESULTS: We found a novel homozygous mutation (c.583G>A) in the PK-R coding gene (PKLR). Although this mutation did not influence PKLR mRNA production, no PK-R protein could be detected in the red blood cells nor in its precursors. In spite of the absence of PK-R, the reticulocytes of the patient exhibited 20% PK activity compared with control. Western blotting revealed that patient erythroid precursors, like controls, express residual PKM2. CONCLUSIONS: We conclude that PKM2 rescues glycolysis in PK-R-deficient erythroid precursors.

Why might cord blood be a better source of platelets for transfusion to neonates?

Thrombocytopenia (defined as a platelet count <150×109/L) is a common condition in preterm neonates and may occur in 18-35% of all infants admitted to the Neonatal Intensive Care Unit (NICU). Neonatal platelet functionality in terms of reactivity is often described as reduced compared to adults, even in healthy, term neonates. However, this platelet "hyporeactivity" does not correspond to a global functional impairment of the normal delicately balanced neonatal hemostatic system. The extent to which neonatal thrombocytopenia and platelet hyporeactivity contribute to the bleeding risk in preterm neonates remains unknown. Prophylactic platelet transfusions are often administered to them to reduce the risk of bleeding. However, recent literature indicates that adopting a higher platelet transfusion threshold than a lower one results in significantly higher death rates or major bleeding and can be harmful. Although the mechanism by which this occurs is not entirely clear, a mismatch between adult transfused platelets and the neonatal hemostatic system, as well as volume overload, are speculated to be potentially involved. Therefore, future research should consider novel transfusion products that may be more suitable for premature neonates. Blood products derived from umbilical cord blood (UCB) are promising, as they might perfectly match neonatal blood features. Here, we discuss the current knowledge about UCB-derived products, focusing on UCB-derived platelet concentrates and their potential for future clinical application. We will discuss how they may overcome the potential risks of transfusing adult-derived platelets to premature infants while maintaining efficacy.

Brugia pahangi: immunization with early L3 ES alters parasite migration, and reduces microfilaremia and lymphatic lesion formation in gerbils (Meriones unguiculatus).

Previous studies have shown that intradermally (ID) injected Brugia pahangi L3 s migrate through various tissues and into the lymphatics of gerbils in a distinct pattern. Excretory/secretory products (ES) produced at the time of invasion of B. pahangi are likely to be important in this early migration phase of the parasite life cycle in their rodent host. Hence, early L3 ES was collected from 24h in vitro cultures of B. pahangi L3 larvae and used in immunization experiments to investigate the effect of immunity to early L3 ES on worm migration, survival and development of B. pahangi. Immunization of gerbils with ES in RIBI adjuvant produced antibodies to numerous ES proteins eliciting a strong humoral response to ES and indirect fluorescent antibody (IFA) assay using anti-ES serum recognized the ES proteins on the surface of B. pahangi L3 larvae. Following ES immunization, gerbils were challenged either ID or intraperitoneally (IP) with 100 L3 s of B. pahangi and euthanized at 3 or 106 days post inoculation (DPI). Immunization with early ES slowed the migration of ID inoculated L3 at 3 DPI and significantly altered the locations of adult worms at 106 DPI. Immunization did not induce protection in any treatment group. However, immunized animals had significantly fewer microfilariae per female worm suggesting the antigens in ES are important in microfilariae development or survival in the host. The number of lymphatic granulomas was also significantly reduced in ES immunized animals. It is important to note that microfilariae serve as a nidus in these granulomas. Our results shows immunization with early Brugia malayi L3 ES alters the worm migration, affects circulating microfilarial numbers and reduces lymphatic granulomas associated with B. pahangi infection in gerbils.

[Is whole blood transfusion also an option?] / Is transfusie met vol bloed ook een optie?

Whole blood is gaining popularity in the treatment of traumatic massive haemorrhage. The prospective study of Hazelton et al. in 2022 shows that mortality is reduced in patients treated with whole blood and components versus the use of components only. In this commentary, it is argued that in this study multiple factors complicate the interpretation of the study results. Besides the absence of randomisation , treatment protocols were not specified. Furthermore, the inclusion criterion of 1 or more RCC after arrival until discharge from trauma bay/emergency department allowed for inclusion of non-massive transfused patients (1-9RCC/24hrs, ±58% of patient population). Lastly, more plasma was used in the whole blood group. Whether this was caused by protocol, by choice or product availability is unknown. Overall, more information is required to confirm the positive outcome of the use of whole blood in diminishing mortality rates in traumatic massive haemorrhage.

Is transfusie met vol bloed ook een optie?

Is whole blood transfusion also an option? Whole blood is gaining popularity in the treatment of traumatic massive haemorrhage. The prospective study of Hazelton et al. in 2022 shows that mortality is reduced in patients treated with whole blood and components versus the use of components only. In this commentary, it is argued that in this study multiple factors complicate the interpretation of the study results. Besides the absence of randomisation , treatment protocols were not specified. Furthermore, the inclusion criterion of 1 or more RCC after arrival until discharge from trauma bay/emergency department allowed for inclusion of non-massive transfused patients (1-9RCC/24hrs, ±58% of patient population). Lastly, more plasma was used in the whole blood group. Whether this was caused by protocol, by choice or product availability is unknown. Overall, more information is required to confirm the positive outcome of the use of whole blood in diminishing mortality rates in traumatic massive haemorrhage.

Allogeneic Serum Eye Drops: A Randomized Clinical Trial to Evaluate the Clinical Effectiveness of Two Drop Sizes.

INTRODUCTION: Allogeneic serum from blood donors is starting to be used to treat patients with dry eye disease (DED). However, the optimal dose is not known. We therefore aimed to evaluate the clinical efficaciousness and user-friendliness of micro-sized versus conventional-sized allogeneic serum eye drops (SEDs). METHODS: In a randomized trial, patients with DED first receive micro-sized SEDs (7 µl/unit) for 1 month, followed by a 1-month washout, before receiving conventional-sized SEDs (50 µl/unit) for 1 month; or vice versa. The primary endpoint was the Ocular Surface Disease Index (OSDI) score. Secondary endpoints were tear break-up time (TBT), tear production (TP), and presence of corneal punctate lesions (CP). The user-friendliness of both application systems was also compared. A linear mixed model for cross-over design was applied to compare both treatments. RESULTS: Forty-nine patients completed the trial. The mean OSDI score significantly improved from 52 ± 3 to 41 ± 3 for micro-sized SEDs, and from 54 ± 3 to 45 ± 3 for conventional-sized SEDs. Non-inferiority (margin = 6) of micro-sized SEDs was established. We demonstrate a significant improvement for TBT in case of conventional-sized SEDs and for CP in both treatment groups. TP trended towards an improvement in both treatment groups. The user-friendliness of the conventional drop system was significantly higher. CONCLUSIONS: For the first time, non-inferiority of micro-sized allogeneic SEDs was established. The beneficial effect of both SED volumes was similar as measured by the OSDI score. Although user-friendliness of the micro drop system was significantly lower, it is an attractive alternative as it saves valuable donor serum. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03539159).

Malaria-associated adhesion molecule activation facilitates the destruction of uninfected red blood cells.

Severe malarial anemia (SMA) is the main cause of malaria-associated infant mortality in malaria endemic countries. One major factor that contributes to SMA is the accumulation of uninfected red blood cells (uRBCs) in the spleen. We report the activation of adhesion molecules Lutheran/basal cell adhesion molecule (Lu/BCAM) and CD44 on uRBCs from Plasmodium falciparum in vitro cultures and patients with malaria that mediates adherence to the splenic extracellular matrix (ECM) components laminin-α5 and hyaluronic acid (HA), respectively. This tight ECM-adhesion molecule interaction was associated with elevated intracellular Ca2+ levels, increased shedding of microvesicles, and Lu/BCAM clustering on altered uRBCs. Moreover, we observed that a soluble parasite-derived factor promoted the adhesive phenotype of uRBCs, as the incubation of RBCs with filtered malaria-conditioned medium reproduced the same adhesive effect in malaria culture-derived uRBCs. Eventually, Lu/BCAM and CD44 activation facilitate the adherence to ECM components of the red pulp, resulting in the enhanced splenic retention of uRBCs. Our results suggest a novel adhesion molecule-dependent mechanism that augments malaria-induced anemia.

Quality of Platelets in Stored Whole Blood.

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.