The antioxidant capacity of erythrocyte concentrates is increased during the first week of storage and correlated with the uric acid level

Impacts of cigarette smoking on blood circulation: do we need a new approach to blood donor selection?

Smoking is a major public health problem and is considered the leading cause of preventable death worldwide. Gas-phase smoke carries bioactive substances and toxic compounds, affecting human health and reducing life spans. The negative effects of smoking on red blood cell (RBC) quality include destroying RBCs and increasing carboxy hemoglobin (COHb). Smoking increases the concentrations of heavy metals such as cadmium (Cd) and lead (Pb) in the blood. Moreover, tobacco smoking has been found to be associated with heightened platelet (PLT)-dependent thrombin level which will induce a prothrombotic state. Smoking may affect the blood circulation of donors, and subsequently the blood components, and ultimately the recipients of transfusion. Nevertheless, there are no restrictions on smoking for volunteer blood donor screenings currently. We reviewed the articles about the influence of smoking on smokers' blood circulation as well as the impact of donated blood products on transfusion when these smokers act as blood donors. We aim to attract blood collection centers' attention to strengthen the management of blood donors who smoke, avoiding their use in massive transfusion protocol and susceptible recipients, especially pediatric ones.

The Effect of the Donor's and Recipient's Sex on Red Blood Cells Evaluated Using Transfusion Simulations

The hypothesis of the potential impact of the sex of red blood cell (RBC) concentrate (RCC) donors, as well as the sex of the recipients, on the clinical outcome, is still under evaluation. Here, we have evaluated the sex impact on RBC properties using in vitro transfusion models. Using a "flask model", RBCs from RCCs (representing the donor)-at different storage lengths-were incubated in a sex-matched and sex-mismatched manner with fresh frozen plasma pools (representing the recipient) at 37 °C, with 5% of CO2 up to 48 h. Standard blood parameters, hemolysis, intracellular ATP, extracellular glucose and lactate were quantified during incubation. Additionally, a "plate model", coupling hemolysis analysis and morphological study, was carried out in similar conditions in 96-well plates. In both models, RBCs from both sexes hemolyzed significantly less in female-derived plasma. No metabolic or morphological differences were observed between sex-matched and -mismatched conditions, even though ATP was higher in female-derived RBCs during incubations. Female plasma reduced hemolysis of female- as well as male-derived RBCs, which may be related to a sex-dependent plasma composition and/or sex-related intrinsic RBC properties.

Supplementation with uric and ascorbic acid protects stored red blood cells through enhancement of non-enzymatic antioxidant activity and metabolic rewiring

Redox imbalance and oxidative stress have emerged as generative causes of the structural and functional degradation of red blood cells (RBC) that happens during their hypothermic storage at blood banks. The aim of the present study was to examine whether the antioxidant enhancement of stored RBC units following uric (UA) and/or ascorbic acid (AA) supplementation can improve their storability as well as post-transfusion phenotypes and recovery by using in vitro and animal models, respectively. For this purpose, 34 leukoreduced CPD/SAGM RBC units were aseptically split in 4 satellite units each. UA, AA or their mixture were added in the three of them, while the fourth was used as control. Hemolysis as well as redox and metabolic parameters were studied in RBC units throughout storage. The addition of antioxidants maintained the quality parameters of stored RBCs, (e.g., hemolysis, calcium homeostasis) and furthermore, shielded them against oxidative defects by boosting extracellular and intracellular (e.g., reduced glutathione; GSH) antioxidant powers. Higher levels of GSH seemed to be obtained through distinct metabolic rewiring in the modified units: methionine-cysteine metabolism in UA samples and glutamine production in the other two groups. Oxidatively-induced hemolysis, reactive oxygen species accumulation and membrane lipid peroxidation were lower in all modifications compared to controls. Moreover, denatured/oxidized Hb binding to the membrane was minor, especially in the AA and mix treatments during middle storage. The treated RBC were able to cope against pro-oxidant triggers when found in a recipient mimicking environment in vitro, and retain control levels of 24h recovery in mice circulation. The currently presented study provides (a) a detailed picture of the effect of UA/AA administration upon stored RBCs and (b) insight into the differential metabolic rewiring when distinct antioxidant "enhancers" are used.

A study to assess the relationship between donor uric acid levels and supernatant hemolysis in stored packed red blood cell units

BACKGROUND

Most of the red blood cell (RBC) storage lesions can be attributed to oxidative stress encountered by the RBCs throughout the duration of their storage. Various donor variables at the time of donation may be responsible for the total antioxidant capacity of the supernatant and thus, the "storability" and the magnitude of development of these RBC storage lesions. It is known that uric acid (UA) is responsible for more than 60% of the TAC of the blood. This study aims to explore the relationship between donor UA levels and the difference in percentage hemolysis, an important RBC storage lesion, on day 1 and day 21, in stored packed RBCs (PRBCs) units.

MATERIALS AND METHODS

The serum UA of 100 healthy voluntary male blood donors was estimated at the time of blood donation. The percentage hemolysis in the supernatant of the leukoreduced citrate phosphate dextrose/saline-adenine-glucose-mannitol RBC units (n = 100) prepared from these donors was calculated on day 1 and day 21. The difference in percentage hemolysis between donors with high normal serum UA levels (>7 mg/dL) was compared to that of the donors with low normal serum UA levels (<5 mg/dL) to observe the effect of donor UA levels on the difference in percentage hemolysis.

RESULTS

The mean of the differences in percentage hemolysis in the supernatant in low UA group (<5 mg/dL) was higher than the mean of the differences in percentage hemolysis in the supernatant in high UA group (>7 mg/dL) and this was statistically significant (P < 0.001). The donor serum UA level and difference in percentage hemolysis on day 21 and day 1 were found to be negatively co-related.

CONCLUSION

Higher levels of serum UA of blood donors seem to have a protective effect on the stored PRBC units as shown in this study. Hence, the potential of UA as one of the constituents of RBC additive solutions might lead to the enhancement of the quality of stored PRBC units by decreasing the RBC storage lesions.

Evaluation of Antioxidants Using Electrochemical Sensors: A Bibliometric Analysis

The imbalance of oxidation and antioxidant systems in the biological system can lead to oxidative stress, which is closely related to the pathogenesis of many diseases. Substances with antioxidant capacity can effectively resist the harmful damage of oxidative stress. How to measure the antioxidant capacity of antioxidants has essential application value in medicine and food. Techniques such as DPPH radical scavenging have been developed to measure antioxidant capacity. However, these traditional analytical techniques take time and require large instruments. It is a more convenient method to evaluate the antioxidant capacity of antioxidants based on their electrochemical oxidation and reduction behaviors. This review summarizes the evaluation of antioxidants using electrochemical sensors by bibliometrics. The development of this topic was described, and the research priorities at different stages were discussed. The topic was investigated in 1999 and became popular after 2010 and has remained popular ever since. A total of 758 papers were published during this period. In the early stages, electrochemical techniques were used only as quantitative techniques and other analytical techniques. Subsequently, cyclic voltammetry was used to directly study the electrochemical behavior of different antioxidants and evaluate antioxidant capacity. With methodological innovations and assistance from materials science, advanced electrochemical sensors have been fabricated to serve this purpose. In this review, we also cluster the keywords to analyze different investigation directions under the topic. Through co-citation of papers, important papers were analyzed as were how they have influenced the topic. In addition, the author’s country distribution and category distribution were also interpreted in detail. In the end, we also proposed perspectives for the future development of this topic.

The relationship between glycosylated hemoglobin level and red blood cell storage lesion in blood donors

BACKGROUND

Glycosylated hemoglobin (HbA1c), not routinely screened in blood donors, is associated with morphological, biochemical, and functional abnormalities of red blood cells (RBCs) and with enhanced oxidative stress. We aimed to explore HbA1c levels in blood donors and their effect on RBC storage.

STUDY DESIGN AND METHODS

An analytical cross-sectional study was conducted on 875 eligible blood donors aged 18-60 years from May 1, 2021, to August 30, 2021. Two selected groups of donors (HbA1c <6.5%, n = 10; HbA1c ≥ 6.5%, n = 10) exhibiting as similar as possible baseline values (such as age, sex, and living habits, etc.) were recruited for blood donation in leukoreduced CPDA-1 units. RBC morphological, biochemical, structural, and oxidative stress states were measured during 5-35 days of storage.

RESULTS

Elevated HbA1c prevalence was 37%, including 31.7% (277/875) in the prediabetes range (HbA1c 5.7%-6.4%) and 5.4% (47/875) in the diabetes range (HbA1c ≥ 6.5%). Age, body mass index (BMI), smoking, and alcohol consumption were the main factors influencing the HbA1c levels. During storage, high-HbA1c group had abnormal RBC morphology, impaired membrane function, and ion imbalance (higher mean corpuscular volume, distribution width, hemolysis rate, potassium ion efflux, and phosphatidylserine exposure) as compared with low HbA1c group. Additionally, RBC oxidative stress was significantly increased in donors with high HbA1c levels during 21-35 days.

DISCUSSION

Blood donors proportion with abnormal HbA1c levels was relatively high, and donor HbA1c levels may be associated with stored RBCs capacity. Our study provides new insights into the different effects of donor HbA1c levels on RBC storage lesions.

Storage of red blood cell concentrates: Clinical impact

The storage of red blood cells for transfusion purposes induces modifications of biochemical and biological properties. Moreover, these modifications are modulated by the donors' characteristics and the cell processing. These ex vivo alterations were suspected to decrease the transfusion efficiency and even to induce adverse events. This short article will review the red blood cells storage lesions and the clinical data related to them. In particular, the questions regarding the donors and recipients sex will be discussed.

Donor sex, age and ethnicity impact stored red blood cell antioxidant metabolism through mechanisms in part explained by glucose 6-phosphate dehydrogenase levels and activity

Red blood cell storage in the blood bank promotes the progressive accumulation of metabolic alterations that may ultimately impact the erythrocyte capacity to cope with oxidant stressors. However, the metabolic underpinnings of the capacity of RBCs to resist oxidant stress and the potential impact of donor biology on this phenotype are not known. Within the framework of the REDS-III RBC-Omics study, RBCs from 8,502 healthy blood donors were stored for 42 days and tested for their propensity to hemolyze following oxidant stress. A subset of extreme hemolyzers donated a second unit of blood, which was stored for 10, 23, and 42 days and profiled again for oxidative hemolysis and metabolomics (599 samples). Alterations of RBC energy and redox homeostasis were noted in donors with high oxidative hemolysis. RBCs from females, donors over 60 years old, donors of Asian/South Asian race-ethnicity, and RBCs stored in additive solution-3 were each independently characterized by improved antioxidant metabolism compared to, respectively, males, donors under 30 years old, Hispanic and African American race ethnicity donors, and RBCs stored in additive solution-1. Merging metabolomics data with results from an independent GWAS study on the same cohort, we identified metabolic markers of hemolysis and G6PD-deficiency, which were associated with extremes in oxidative hemolysis and dysregulation in NADPH and glutathione-dependent detoxification pathways of oxidized lipids. Donor sex, age, ethnicity, additive solution and G6PD status impact the metabolism of the stored erythrocyte and its susceptibility to hemolysis following oxidative insults.

Image- and Fluorescence-Based Test Shows Oxidant-Dependent Damages in Red Blood Cells and Enables Screening of Potential Protective Molecules

An increase of oxygen saturation within blood bags and metabolic dysregulation occur during storage of red blood cells (RBCs). It leads to the gradual exhaustion of RBC antioxidant protective system and, consequently, to a deleterious state of oxidative stress that plays a major role in the apparition of the so-called storage lesions. The present study describes the use of a test (called TSOX) based on fluorescence and label-free morphology readouts to simply and quickly evaluate the oxidant and antioxidant properties of various compounds in controlled conditions. Here, TSOX was applied to RBCs treated with four antioxidants (ascorbic acid, uric acid, trolox and resveratrol) and three oxidants (AAPH, diamide and H₂O₂) at different concentrations. Two complementary readouts were chosen: first, where ROS generation was quantified using DCFH-DA fluorescent probe, and second, based on digital holographic microscopy that measures morphology alterations. All oxidants produced an increase of fluorescence, whereas H₂O₂ did not visibly impact the RBC morphology. Significant protection was observed in three out of four of the added molecules. Of note, resveratrol induced diamond-shape “Tirocytes”. The assay design was selected to be flexible, as well as compatible with high-throughput screening. In future experiments, the TSOX will serve to screen chemical libraries and probe molecules that could be added to the additive solution for RBCs storage.

Sex-related aspects of the red blood cell storage lesion

BACKGROUND

Several factors contribute to the manifestation of red blood cell (RBC) storage lesions, with one of the most interesting being the "donor variation effect". Since many haematological characteristics of blood donors are sex-dependent, sex hormones and their age-dependent variation may affect the storage profile of RBCs.

MATERIALS AND METHODS

Fresh blood from 200 healthy male and female donors underwent haematological, biochemical and physiological analysis. Three selected groups of donors (men, n=8; pre-menopausal women, n=8; and post-menopausal women, n=4) exhibiting as similar as possible baseline values were recruited for blood donation in leukoreduced CPD/SAGM units. RBC indices, haemolysis and propensity for haemolysis, reactive oxygen species (ROS) and plasma antioxidant capacity were measured bi-weekly.

RESULTS

Female blood was characterised by lower plasma antioxidant capacity and free haemoglobin (Hb) levels in vivo, in spite of the higher RBC osmotic fragility, compared to male blood. Comparatively low Hb concentration was also measured in stored RBCs from female donors, as in vivo. Mean corpuscular Hb (MCH), mean corpuscular Hb concentration (MCHC), and plasma antioxidant capacity were also lower in female donors throughout storage, even though baseline levels were equal to those of the male group. There was no difference in propensity of stored RBCs for haemolysis between male and female units but intracellular ROS levels were significantly lower in female RBCs. Increased end-of-storage extracellular potassium and recruitment of protein stress markers (clusterin, Hb) to the RBC membrane were observed in the units of post- vs pre-menopausal female donors at mid-storage onwards.

DISCUSSION

Donor's sex has an impact on Hb concentration and redox parameters of stored RBCs. In addition, menopause seems to promote RBC membrane remodelling, at least during prolonged storage. Our pilot study provides new insights on the different effects on RBC storage lesion according to sex.

Antioxidant power measurement in platelet concentrates treated by two pathogen inactivation systems in different blood centres

BACKGROUND AND OBJECTIVES

The antioxidant power measurement can be useful to validate the execution of the pathogen inactivation treatment of platelet concentrates. The aim of this study is to evaluate the technology on different blood preparations including INTERCEPT and Mirasol treatments that are in routine use in Belgium and Luxemburg.

MATERIALS AND METHODS

The antioxidant power measurement was tested on 78 apheresis platelet concentrates and 54 pools of buffy-coats-derived platelet concentrates before and after INTERCEPT treatment. In addition, 100 Reveos platelet pools were tested before and after Mirasol treatment. The antioxidant power was quantified electrochemically using disposable devices and was expressed as equivalent ascorbic acid concentration.

RESULTS

Mean results for apheresis platelet concentrates were of 90 ± 14 and 35 ± 10 µmol/l eq. ascorbic acid before and after INTERCEPT treatment, respectively. The mean results for pools of buffy-coats-derived platelet concentrates were of 81 ± 10 and 29 ± 4 eq. µmol/l ascorbic acid before and after INTERCEPT treatment, respectively. For buffy-coats-derived platelet concentrates treated by Mirasol technology, the mean results were of 98 ± 11 and 32 ± 10 µmol/l eq. ascorbic acid before and after illumination, respectively.

CONCLUSION

The antioxidant power significantly decreases with pathogen inactivation treatments for platelet concentrates treated by INTERCEPT or Mirasol technologies.

Restoration of Physiological Levels of Uric Acid and Ascorbic Acid Reroutes the Metabolism of Stored Red Blood Cells

After blood donation, the red blood cells (RBCs) for transfusion are generally isolated by centrifugation and then filtrated and supplemented with additive solution. The consecutive changes of the extracellular environment participate to the occurrence of storage lesions. In this study, the hypothesis is that restoring physiological levels of uric and ascorbic acids (major plasmatic antioxidants) might correct metabolism defects and protect RBCs from the very beginning of the storage period, to maintain their quality. Leukoreduced CPD-SAGM RBC concentrates were supplemented with 416 µM uric acid and 114 µM ascorbic acid and stored during six weeks at 4 °C. Different markers, i.e., haematological parameters, metabolism, sensitivity to oxidative stress, morphology and haemolysis were analyzed. Quantitative metabolomic analysis of targeted intracellular metabolites demonstrated a direct modification of several metabolite levels following antioxidant supplementation. No significant differences were observed for the other markers. In conclusion, the results obtained show that uric and ascorbic acids supplementation partially prevented the metabolic shift triggered by plasma depletion that occurs during the RBC concentrate preparation. The treatment directly and indirectly sustains the antioxidant protective system of the stored RBCs.

Cigarette smoking and antioxidant defences in packed red blood cells prior to storage

BACKGROUND

Red blood cells from smoking donors can have more lesions from oxidative stress, decreasing the benefits of blood transfusion. We aimed to explore the effect of cigarette smoking on the oxidative status of packed red blood cells (PRBCs) prior to storage.

MATERIALS AND METHODS

We compared serum vitamin C, plasmatic malondialdehyde (MDA), and non-protein thiol groups (GSH) levels in PRBCs, as well glutathione peroxidase (GPx) and glutathione s-transferase (GST) activity in PRBCs from smoking (n=36) and non-smoking (n=36) donors. We also correlated urinary cotinine levels with these parameters.

RESULTS

Cigarette smoking was associated with decreased serum levels of vitamin C and GPx, and increased GST activity in PRBCs. We found negative correlations between cotinine, GPx activity and vitamin C levels, and a positive correlation between cotinine and GST activity.

DISCUSSION

Cigarette smoking changed antioxidant defences of PRBCs prior to storage and these parameters are correlated with cotinine levels. Increased RBC antioxidants such as GST may reflect an exposure to oxidants during erythropoiesis. Because of the inability of mature RBCs to resynthesise antioxidants, PRBCs from smokers may have higher risk of storage lesions than those from non-smoker donors.

Recipient's effects on stored red blood cell performance: the case of uremic plasma

BACKGROUND

Despite universal administration of erythropoiesis-stimulating agents, patients with end-stage renal disease (ESRD) are at high risk for presenting persistent anemia. Due to ambiguities in optimal hemoglobin targets and evidence of recombinant human erythropoietin (EPO)-related toxicity, an increase in blood transfusions has been observed in chronic renal disease over the past years. The probable effects of uremic plasma on the performance of stored red blood cells (RBCs) after transfusion have not been investigated.

STUDY DESIGN AND METHODS

Leukoreduced RBCs after short or long storage in CPD-SAGM (n = 5) were assessed for hemolysis, surface removal signaling, reactive oxygen species (ROS) accumulation, and shape distortions before and after reconstitution with healthy (n = 10) or uremic plasma from ESRD patients (n = 20) for 24 hours at physiologic temperature, by using a previously reported in vitro model of transfusion.

RESULTS

Temperature and cell environment shifts from blood bag to plasma independently and in synergy affected the RBC physiology. Outcome measures at transfusion-simulating conditions might not be analogous to timing of storage lesion. The uremic plasma ameliorated the susceptibility of stored RBCs to hemolysis, phosphatidylserine externalization, and ROS generation after stimulation by oxidants, but negatively affected shape homeostasis versus healthy plasma. Creatinine, uric acid, and EPO levels had correlations with the performance of stored RBCs in ESRD plasma.

CONCLUSION

Renal insufficiency and EPO supplementation likely affect the recovery of donor RBCs and the reactivity of RBCs after transfusion by exerting both toxic and cytoprotective influences on them. ESRD patients constitute a specific recipient group that deserves further examination.

General overview of blood products in vitro quality: Processing and storage lesions

Blood products are issued from blood collection. Collected blood is immediately mixed with anticoagulant solutions that immediately induce chemical and/or biochemical modifications. Collected blood is then transformed into different blood products according to various steps of fabrication. All these steps induce either reversible or irreversible "preparation-related" lesions that combine with "storage-related" lesions. This short paper aims to provide an overview of the alterations that are induced by the "non-physiological" processes used to prepare blood products that are used in clinical practice.

Proteomics of Stored Red Blood Cell Membrane and Storage-Induced Microvesicles Reveals the Association of Flotillin-2 With Band 3 Complexes

The storage of erythrocyte concentrates (ECs) induces lesions that notably affect metabolism, protein activity, deformability of red blood cells (RBCs), as well as the release of oxygen. Band 3 is one of the proteins affected during the ex vivo aging of RBCs. This membrane protein is an anion transporter, an anchor site for the cytoskeleton and other membrane proteins as well as a binding site for glycolytic enzymes and bears blood group antigens. In the present study, band 3 complexes were isolated from RBCs stored for 7 and 42 days in average (n = 3), as well as from microvesicles (n = 3). After extraction of membrane proteins with a deoxycholate containing buffer, band 3 complexes were co-immunoprecipitated on magnetic beads coated with two anti-band 3 antibodies. Both total membrane protein extracts and eluates (containing band 3 complexes) were separated on SDS-PAGE and analyzed by bottom-up proteomics. It revealed that three proteins were present or absent in band 3 complexes stemming from long-stored or short-stored ECs, respectively, whereas the membrane protein contents remained equivalent. These potential markers for storage-induced RBC aging are adenylosuccinate lyase (ADSL), α-adducin and flotillin-2, and were further analyzed using western blots. ADSL abundance tended to increase during storage in both total membrane protein and band 3 complexes, whereas α-adducin mainly tended to stay onto the membrane extract. Interestingly, flotillin-2 was equivalently present in total membrane proteins whereas it clearly co-immunoprecipitated with band 3 complexes during storage (1.6-fold-change, p = 0.0024). Moreover, flotillin-2 was enriched (almost threefold) in RBCs compared to microvesicles (MVs) (p < 0.001) and the amount found in MVs was associated to band 3 complexes. Different types of band 3 complexes are known to exist in RBCs and further studies will be required to better understand involvement of this protein in microvesiculation during the storage of RBCs.

Time-Course Investigation of Small Molecule Metabolites in MAP-Stored Red Blood Cells Using UPLC-QTOF-MS

Red blood cells (RBCs) are routinely stored for 35 to 42 days in most countries. During storage, RBCs undergo biochemical and biophysical changes known as RBC storage lesion, which is influenced by alternative storage additive solutions (ASs). Metabolomic studies have been completed on RBCs stored in a number of ASs, including SAGM, AS-1, AS-3, AS-5, AS-7, PAGGGM, and MAP. However, the reported metabolome analysis of laboratory-made MAP-stored RBCs was mainly focused on the time-dependent alterations in glycolytic intermediates during storage. In this study, we investigated the time-course of alterations in various small molecule metabolites in RBCs stored in commercially used MAP for 49 days using ultra-high performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-QTOF-MS). These alterations indicated that RBC storage lesion is related to multiple pathways including glycolysis, pentose phosphate pathway, glutathione homeostasis, and purine metabolism. Thus, our findings might be useful for understanding the complexity of metabolic mechanisms of RBCs in vitro aging and encourage the deployment of systems biology methods to blood products in transfusion medicine.

Redox Status, Procoagulant Activity, and Metabolome of Fresh Frozen Plasma in Glucose 6-Phosphate Dehydrogenase Deficiency

OBJECTIVE

Transfusion of fresh frozen plasma (FFP) helps in maintaining the coagulation parameters in patients with acquired multiple coagulation factor deficiencies and severe bleeding. However, along with coagulation factors and procoagulant extracellular vesicles (EVs), numerous bioactive and probably donor-related factors (metabolites, oxidized components, etc.) are also carried to the recipient. The X-linked glucose 6-phosphate dehydrogenase deficiency (G6PD-), the most common human enzyme genetic defect, mainly affects males. By undermining the redox metabolism, the G6PD- cells are susceptible to the deleterious effects of oxidants. Considering the preferential transfusion of FFP from male donors, this study aimed at the assessment of FFP units derived from G6PD- males compared with control, to show whether they are comparable at physiological, metabolic and redox homeostasis levels.

METHODS

The quality of n = 12 G6PD- and control FFP units was tested after 12 months of storage, by using hemolysis, redox, and procoagulant activity-targeted biochemical assays, flow cytometry for EV enumeration and phenotyping, untargeted metabolomics, in addition to statistical and bioinformatics tools.

RESULTS

Higher procoagulant activity, phosphatidylserine positive EVs, RBC-vesiculation, and antioxidant capacity but lower oxidative modifications in lipids and proteins were detected in G6PD- FFP compared with controls. The FFP EVs varied in number, cell origin, and lipid/protein composition. Pathway analysis highlighted the riboflavin, purine, and glycerolipid/glycerophospholipid metabolisms as the most altered pathways with high impact in G6PD-. Multivariate and univariate analysis of FFP metabolomes showed excess of diacylglycerols, glycerophosphoinositol, aconitate, and ornithine but a deficiency in riboflavin, flavin mononucleotide, adenine, and arginine, among others, levels in G6PD- FFPs compared with control.

CONCLUSION

Our results point toward a different redox, lipid metabolism, and EV profile in the G6PD- FFP units. Certain FFP-needed patients may be at greatest benefit of receiving FFP intrinsically endowed by both procoagulant and antioxidant activities. However, the clinical outcome of G6PD- FFP transfusion would likely be affected by various other factors, including the signaling potential of the differentially expressed metabolites and EVs, the degree of G6PD-, the redox status in the recipient, the amount of FFP units transfused, and probably, the storage interval of the FFP, which deserve further investigation by future studies.

Metabolic Linkage and Correlations to Storage Capacity in Erythrocytes from Glucose 6-Phosphate Dehydrogenase-Deficient Donors

Objective

In glucose 6-phosphate dehydrogenase (G6PD) deficiency, decreased NADPH regeneration in the pentose phosphate pathway and subnormal levels of reduced glutathione result in insufficient antioxidant defense, increased susceptibility of red blood cells (RBCs) to oxidative stress, and acute hemolysis following exposure to pro-oxidant drugs and infections. Despite the fact that redox disequilibrium is a prominent feature of RBC storage lesion, it has been reported that the G6PD-deficient RBCs store well, at least in respect to energy metabolism, but their overall metabolic phenotypes and molecular linkages to the storability profile are scarcely investigated.

Methods

We performed UHPLC-MS metabolomics analyses of weekly sampled RBC concentrates from G6PD sufficient and deficient donors, stored in citrate phosphate dextrose/saline adenine glucose mannitol from day 0 to storage day 42, followed by statistical and bioinformatics integration of the data.

Results

Other than previously reported alterations in glycolysis, metabolomics analyses revealed bioactive lipids, free fatty acids, bile acids, amino acids, and purines as top variables discriminating RBC concentrates for G6PD-deficient donors. Two-way ANOVA showed significant changes in the storage-dependent variation in fumarate, one-carbon, and sulfur metabolism, glutathione homeostasis, and antioxidant defense (including urate) components in G6PD-deficient vs. sufficient donors. The levels of free fatty acids and their oxidized derivatives, as well as those of membrane-associated plasticizers were significantly lower in G6PD-deficient units in comparison to controls. By using the strongest correlations between in vivo and ex vivo metabolic and physiological parameters, consecutively present throughout the storage period, several interactomes were produced that revealed an interesting interplay between redox, energy, and hemolysis variables, which may be further associated with donor-specific differences in the post-transfusion performance of G6PD-deficient RBCs.

Conclusion

The metabolic phenotypes of G6PD-deficient donors recapitulate the basic storage lesion profile that leads to loss of metabolic linkage and rewiring. Donor-related issues affect the storability of RBCs even in the narrow context of this donor subgroup in a way likely relevant to transfusion medicine.

Donor-specific individuality of red blood cell performance during storage is partly a function of serum uric acid levels

BACKGROUND

Previous investigations in leukoreduced units of red blood cells (RBCs) in mannitol additive solution revealed the close association of uric acid (UA) levels in vivo with the susceptibility of RBCs to storage lesion markers. In this study, we examined whether UA has a similar correlation with the capability of RBCs to cope with the oxidative provocations of storage under different conditions, namely, in CPDA-1 and in the absence of leukoreduction.

STUDY DESIGN AND METHODS

The UA-dependent antioxidant capacity of the supernatant was measured in nonleukoreduced units of RBCs in CPDA (n = 47). The possible effect of UA variability on the storage lesion profile was assessed by monitoring several physiologic properties of RBCs and supernatant, including cell shape, reactive oxygen species, and size distribution of extracellular vesicles, in units exhibiting the lowest or highest levels of UA activity (n = 16) among donors, throughout the storage period.

RESULTS

In stored RBC units, the UA-dependent antioxidant activity of the supernatant declined as a function of storage duration but always in strong relation to the UA levels in fresh blood. Contrary to units of poor-UA activity, RBCs with the highest levels of UA activity exhibited better profile of calcium- and oxidative stress-driven modifications, including a significant decrease in the percentages of spherocytes and of 100- to 300-nm-sized vesicles, typically associated with the exovesiculation of stored RBCs.

CONCLUSION

The antioxidant activity of UA is associated with donor-specific differences in the performance of RBCs under storage in nonleukoreduced CPDA units.

Oxidative stress and antioxidant defenses during blood processing and storage of erythrocyte concentrates

Oxidative lesions start accumulating in cells when the oxidant attacks overwhelm the antioxidant defenses. This review will briefly describe red blood cell storage lesions with emphasis on the consequences of oxidation and the cellular defense mechanisms, as well as the methods that can be used to monitor them. The sources of variability in red blood cell storage capacity depend on the donor characteristics, the product processing and the storage conditions. Suggestions to improve the product quality in order to ensure the best efficacy and safety for the transfused patient are also discussed.