Donor-variation effect on red blood cell storage lesion: A close relationship emerges

Survival of transfused red blood cells from a donor with alpha-thalassemia trait in a recipient with sickle cell disease

BACKGROUND

Post-transfusion survival of donor red blood cells (RBCs) is important for effective chronic transfusion therapy in conditions including sickle cell disease (SCD). Biotin labeling RBCs allows direct in vivo measurement of multiple donor RBC units simultaneously post-transfusion.

STUDY DESIGN AND METHODS

In an observational trial of patients with SCD receiving monthly chronic transfusion therapy, aliquots of RBCs from one transfusion episode were biotin-labeled and infused along with the unlabeled RBC units. Serial blood samples were obtained to measure RBC survival. Donor units were tested for RBC indices, hemoglobin fractionation, and glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. For microcytic donor RBCs (MCV < 70 fL), HBA1 and HBA2 genetic testing was performed on whole blood.

RESULTS

We present one recipient, a pediatric patient with SCD and splenectomy who received two RBC units with aliquots from each unit labeled at distinct biotin densities (2 and 18 μg/mL biotin). One donor unit was identified to have microcytosis (MCV 68.5 fL after biotinylation); whole blood sample obtained at a subsequent donation showed 2-gene deletion alpha-thalassemia trait (ɑ-3.7kb/ɑ-3.7kb) and normal serum ferritin. G6PD activity was >60% of normal mean for both. The RBCs with alpha-thalassemia RBC had accelerated clearance and increased surface phosphatidylserine post-transfusion, as compared with the normocytic RBC (half life 65 vs. 86 days, respectively).

DISCUSSION

Post-transfusion RBC survival may be lower for units from donors with alpha-thalassemia trait, although the impact of thalassemia trait donors on transfusion efficacy requires further study.

Red blood cell transfusion-related dynamics of extracellular vesicles in intensive care patients: a prospective subanalysis

Extracellular vesicles (EVs) accumulate during packed red blood cell (PRBC) storage. To date, the involvement of EVs in transfusion-related immunomodulation (TRIM) has not been prospectively evaluated in intensive care unit (ICU) patients. This was a prospective subanalysis of a recent observational feasibility study in postoperative ICU patients after: (1) open aortic surgery (Aorta), (2) bilateral lung transplantation (LuTx), and (3) other types of surgery (Comparison). Patient plasma was collected three times each before and after leukoreduced PRBC transfusion at 30-min intervals. The total number of EVs and EVs derived from erythrocytes (EryEVs), total platelets (total PEVs), activated platelets, granulocytes (GEVs), monocytes, and myeloid cells in PRBC samples and patient plasma were analyzed by flow cytometry. Statistical analysis was performed by Spearman's correlation test, linear mixed models and pairwise comparisons by Wilcoxon matched-pairs test. Twenty-three patients (Aorta n = 5, LuTx n = 9, Comparison n = 9) were included in the final analysis. All EV subgroups analyzed were detectable in all PRBCs samples (n = 23), but concentrations did not correlate with storage time. Moreover, all EVs analyzed were detectable in all plasma samples (n = 138), and EV counts were consistent before transfusion. Concentrations of total EVs, EryEVs, total PEVs, and GEVs increased after transfusion compared with baseline in the entire cohort but not in specific study groups. Furthermore, the change in plasma EV counts (total EVs and EryEVs) after transfusion correlated with PRBC storage time in the entire cohort. Extracellular vesicles were detectable in all PRBC and plasma samples. Individual EV subtypes increased after transfusion in the entire cohort, and in part correlated with storage duration. Future clinical studies to investigate the role of EVs in TRIM are warranted and should anticipate a larger sample size.Trial registration: Clinicaltrials.gov: NCT03782623.

Towards the crux of sex-dependent variability in red cell concentrates

Donor sex can alter the RBC 'storage lesion' progression, contributing to dissimilarities in blood product quality, and thus adverse post-transfusion reactions. The mechanisms underlying the reduced sensitivity of female RBCs to storage-induced stress are partially ascribed to the differential effects of testosterone, progesterone, and estrogen on hemolytic propensity. Contributing to this is the increased proportion of more robust, biologically 'young' subpopulations of RBCs in females. Herein, we discuss the impact of sex hormones on RBCs and the relevance of these biological subpopulations to provide further insight into sex-dependent blood product variability.

Association of blood donor characteristics and in vitro haemolysis of packed red blood cell concentrates during storage

BACKGROUND AND OBJECTIVES

Blood donor variability can affect the storage properties of packed red blood cells (PRBCs). This study aimed to determine the association of donor characteristics with in vitro storage haemolysis of PRBCs.

MATERIALS AND METHODS

In the prospective observational study, a total of 109 whole blood donors were enrolled using the purposive sampling method. A pre-donation sample was collected for haemoglobin (Hb) and serum uric acid (UA) levels. PRBC aliquots were tested for potassium, lactate dehydrogenase (LDH), Hb, haematocrit, plasma Hb and haemolysis on days 1, 21 and 35 of storage. The association of these parameters with donor age, sex, donation status, dietary pattern and body mass index was determined.

RESULTS

Mean haemolysis was significantly higher in PRBCs from donors with UA levels ≤6 mg/dL than donors with UA levels >6 mg/dL on day 35 of storage (0.22 ± 0.11 vs. 0.18 ± 0.07, p = 0.03). Median plasma Hb (mg/L) was significantly higher in PRBCs from first-time donors on day 21 (586 vs. 509, p = 0.05) and day 35 (1507 vs. 1358, p = 0.02) of storage in comparison to frequent donors. Significantly higher mean potassium (p = 0.04 day 1; p = 0.02 day 21) and median LDH values (p = 0.02 day 1, p = 0.05 day 21) were observed in PRBCs from male donors. A statistically significant positive association was observed between donor UA and LDH levels of PRBCs on day 35 of storage (β coefficient: 715.52, p-value: 0.003) on multiple regression analysis.

CONCLUSION

In vitro haemolysis of PRBCs is affected by blood donor characteristics.

Peroxiredoxin 2: An Important Element of the Antioxidant Defense of the Erythrocyte

Peroxiredoxin 2 (Prdx2) is the third most abundant erythrocyte protein. It was known previously as calpromotin since its binding to the membrane stimulates the calcium-dependent potassium channel. Prdx2 is present mostly in cytosol in the form of non-covalent dimers but may associate into doughnut-like decamers and other oligomers. Prdx2 reacts rapidly with hydrogen peroxide (k > 10⁷ M^-1 s^-1). It is the main erythrocyte antioxidant that removes hydrogen peroxide formed endogenously by hemoglobin autoxidation. Prdx2 also reduces other peroxides including lipid, urate, amino acid, and protein hydroperoxides and peroxynitrite. Oxidized Prdx2 can be reduced at the expense of thioredoxin but also of other thiols, especially glutathione. Further reactions of Prdx2 with oxidants lead to hyperoxidation (formation of sulfinyl or sulfonyl derivatives of the peroxidative cysteine). The sulfinyl derivative can be reduced by sulfiredoxin. Circadian oscillations in the level of hyperoxidation of erythrocyte Prdx2 were reported. The protein can be subject to post-translational modifications; some of them, such as phosphorylation, nitration, and acetylation, increase its activity. Prdx2 can also act as a chaperone for hemoglobin and erythrocyte membrane proteins, especially during the maturation of erythrocyte precursors. The extent of Prdx2 oxidation is increased in various diseases and can be an index of oxidative stress.

The impact of biological age of red blood cell on in vitro endothelial activation markers

Introduction: Blood donor characteristics influence red blood cell transfusion outcomes. As donor sex affects the distribution of young to old RBCs in the circulation, we hypothesized that the amount of circulating young RBCs in the blood product are associated with immune suppression.

Materials and Methods: Blood samples were collected from healthy volunteers and density fractionated into young and old subpopulations. In an activated endothelial cell model, RBC adhesion to endothelium and secretion of endothelial activation markers were assessed. The impact of RBC biological age was also assessed in a T cell proliferation assay and in a whole blood stimulation assay.

Results: After Percoll fractionation, young RBCs contained more reticulocytes compared to old RBCs. Young RBCs associated with lower levels of E-selectin, ICAM-1, and vWF from activated endothelial cells compared to old RBCs. RBC subpopulations did not affect T cell proliferation or cytokine responses following whole blood stimulation.

Conclusion: Young RBCs contain more reticulocytes which are associated with lower levels of endothelial activation markers compared to old RBCs.

MicroRNAs as Quality Assessment Tool in Stored Packed Red Blood Cell in Blood Banks

Micro-ribonucleic acids are control gene expression in cells. They represent the changed cellular states that occur can be employed as biomarkers. Red blood cells alter biochemically and morphologically while they are being stored, which could be detrimental to transfusion. The effect of storage on the erythrocyte transcriptome is not mostly investigated. Because adult erythrocytes lack a nucleus, it has long been assumed that they lack deoxyribonucleic acid and ribonucleic acid. On the other hand, erythrocytes contain a diverse range of ribonucleic acids, of which micro-ribonucleic acids are key component. Changes in this micro-ribonucleic acid protect cells from death and adenine triphosphate depletion, and they are linked to specific storage lesions. As a result, changes in micro-ribonucleic acid in stored erythrocytes may be used as a marker to assess the quality and safety of stored erythrocytes. Therefore, this review ams to review the role of microRNA in stored packed red blood cells as quality indicator. Google Scholar, PubMed, Scopus, and Z-libraries are used for searching articles and books. The article included in this paper was written in the English language and had the full article. During long storage of RBCs, miR-16-2-3p, miR-1260a, miR-1260b, miR-4443, miR-4695-3p, miR-5100, let-7b, miR-16, miRNA-1246, MiR-31-5p, miR-203a, miR-654-3p, miR-769-3p, miR-4454, miR-451a and miR-125b- 5p are up regulated. However, miR-96, miR-150, miR-196a, miR-197, miR-381 and miR-1245a are down regulated after long storage of RBCs. The changes of this microRNAs are linked to red blood cell lesions. Therefore, micro-ribonucleic acids are the potential quality indicator in stored packed red blood cells in the blood bank. Particularly, micro-ribonucleic acid-96 is the most suitable biomarker for monitoring red blood cell quality in stored packed red blood units.

Association of blood donor's biological characteristics on outcomes of cardiac surgery patients receiving red blood cells transfusion

OBJECTIVES

This study aimed to assess the association of blood donor variables on the outcome of patients undergoing cardiac surgery.

STUDY DESIGN AND METHODS

A retrospective observational study was conducted on patients who had cardiac surgery between January 2018 and December 2020. Blood donor characteristics such as age (≤ or >30 years), sex, and body mass index (BMI) (≤ or >25 kg/m²) were analyzed for association with patient outcomes (length of hospital stay (LOS), mortality, and readmission). Sex matching was done as fully match, fully mismatch, and partial mismatch. Cox regression and Linear regression models were used to study the association with mortality and readmission, and LOS.

RESULTS

During the study period, 5788 patients had cardiac surgery; receiving a total of 20,348 red cell units. Of which, 522 (9%) died, 531 (9.2%) re-admitted and median LOS was 11 days (IQR 7-18). BMI >25 kg/m² (β, 2.96; p = 0.000), female to male transfusion (partial mismatch: β, 4.42; p = 0.001; fully mismatch: β, 9.0; p = 0.02) negatively affected LOS. BMI >25 kg/m² (HR, 2.07; p = 0.00) and partial mismatch transfusion to male patients (HR, 1.60; p = 0.01) increased mortality. Fully mismatch transfusion to female patients (HR, 1.24; p = 0.01) and partial mismatch to male patients (HR, 1.86; p = 0.01) increased readmission. No association of donor age on patient outcome was observed.

DISCUSSION

Blood donor sex, and BMI can influence mortality and LOS in cardiac surgery patients. The use of computer tools to match the patient's and donor's characteristics can assist to eliminate these types of adverse consequences.

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.

Corpuscular Fragility and Metabolic Aspects of Freshly Drawn Beta-Thalassemia Minor RBCs Impact Their Physiology and Performance Post Transfusion: A Triangular Correlation Analysis In Vitro and In Vivo

The clarification of donor variation effects upon red blood cell (RBC) storage lesion and transfusion efficacy may open new ways for donor–recipient matching optimization. We hereby propose a “triangular” strategy for studying the links comprising the transfusion chain—donor, blood product, recipient—as exemplified in two cohorts of control and beta-thalassemia minor (βThal+) donors (n = 18 each). It was unraveled that RBC osmotic fragility and caspase-like proteasomal activity can link both donor cohorts to post-storage states. In the case of heterozygotes, the geometry, size and intrinsic low RBC fragility might be lying behind their higher post-storage resistance to lysis and recovery in mice. Moreover, energy-related molecules (e.g., phosphocreatine) and purine metabolism factors (IMP, hypoxanthine) were specifically linked to lower post-storage hemolysis and phosphatidylserine exposure. The latter was also ameliorated by antioxidants, such as urate. Finally, higher proteasomal conservation across the transfusion chain was observed in heterozygotes compared to control donors. The proposed “triangularity model” can be (a) expanded to additional donor/recipient backgrounds, (b) enriched by big data, especially in the post-transfusion state and (c) fuel targeted experiments in order to discover new quality biomarkers and design more personalized transfusion medicine schemes.

Deformability of Stored Red Blood Cells

Red blood cells (RBCs) deformability refers to the cells’ ability to adapt their shape to the dynamically changing flow conditions so as to minimize their resistance to flow. The high red cell deformability enables it to pass through small blood vessels and significantly determines erythrocyte survival. Under normal physiological states, the RBCs are attuned to allow for adequate blood flow. However, rigid erythrocytes can disrupt the perfusion of peripheral tissues and directly block microvessels. Therefore, RBC deformability has been recognized as a sensitive indicator of RBC functionality. The loss of deformability, which a change in the cell shape can cause, modification of cell membrane or a shift in cytosol composition, can occur due to various pathological conditions or as a part of normal RBC aging (in vitro or in vivo). However, despite extensive research, we still do not fully understand the processes leading to increased cell rigidity under cold storage conditions in a blood bank (in vitro aging), In the present review, we discuss publications that examined the effect of RBCs’ cold storage on their deformability and the biological mechanisms governing this change. We first discuss the change in the deformability of cells during their cold storage. After that, we consider storage-related alterations in RBCs features, which can lead to impaired cell deformation. Finally, we attempt to trace a causal relationship between the observed phenomena and offer recommendations for improving the functionality of stored cells.

Osmotic hemolysis is a donor-specific feature of red blood cells under various storage conditions and genetic backgrounds

BACKGROUND

Transfusion research has recently focused on the discovery of red blood cell (RBC) storage capacity biomarkers and the elucidation of donor variation effects. This shift of focus can further strengthen personalization of transfusion therapy, by revealing probable links between donor biology, RBC storage lesion profile, and posttransfusion performance.

STUDY DESIGN AND METHODS

We performed a paired correlation analysis of osmotic fragility in freshly drawn RBCs and during cold storage in different preservative solutions at weekly intervals until unit's expiration date (n = 231), or following 24 h reconstitution in allogeneic plasma (n = 32) from healthy controls or transfusion-dependent beta-thalassemia patients.

RESULTS

We observed exceptional correlation profiles (r > 0.700, p < 10^-5 in most cases) of RBC osmotic fragility in the ensemble of samples, as well as in subgroups characterized by distinct genetic backgrounds (sex, beta-thalassemia traits, glucose-6-phosphate dehydrogenase deficiency) and storage strategies (additive solutions, whole blood, RBC concentrates). The mean corpuscular fragility (MCF) of fresh and stored RBCs at each storage time significantly correlated with the MCF of stored RBCs measured at all subsequent time points of the storage period (e.g., MCF values of storage day 21 correlated with those of storage days 28, 35 and 42). A similar correlation profile was also observed between the osmotic hemolysis of fresh/stored RBCs before and following in vitro reconstitution in plasma from healthy controls or beta-thalassemia patients.

CONCLUSION

Our findings highlighted the potential of osmotic fragility to serve as a donor-signature on RBCs at every step of any individual transfusion chain (donor, blood product, and probably, recipient).

Non-invasive monitoring of red blood cells during cold storage using handheld Raman spectroscopy

BACKGROUND

The current best practices allow for the red blood cells (RBCs) to be stored for prolonged periods in blood banks worldwide. However, due to the individual-related variability in donated blood and RBCs continual degradation within transfusion bags, the quality of stored blood varies considerably. There is currently no method for assessing the blood product quality without compromising the sterility of the unit. This study demonstrates the feasibility of monitoring storage lesion of RBCs in situ while maintaining sterility using an optical approach.

STUDY DESIGN AND METHODS

A handheld spatially offset Raman spectroscopy (RS) device was employed to non-invasively monitor hemolysis and metabolic changes in 12 red cell concentrate (RCC) units within standard sealed transfusion bags over 7 weeks of cold storage. The donated blood was analyzed in parallel by biochemical (chemical analysis, spectrophotometry, hematology analysis) and RS measurements, which were then correlated through multisource correlation analysis.

RESULTS

Raman bands of lactate (857 cm^-1 ), glucose (787 cm^-1 ), and hemolysis (1003 cm^-1 ) were found to correlate strongly with bioanalytical data over the length of storage, with correlation values 0.98 (95% confidence interval [CI]: 0.86-1.00; p = .0001), 0.95 (95% CI: 0.71-0.99; p = .0008) and 0.97 (95% CI: 0.79-1.00; p = .0004) respectively.

DISCUSSION

This study demonstrates the potential of collecting information on the clinical quality of blood units without breaching the sterility using Raman technology. This could significantly benefit quality control of RCC units, patient safety and inventory management in blood banks and hospitals.

Familial pseudohyperkalemia induces significantly higher levels of extracellular potassium in early storage of red cell concentrates without affecting other standard measures of quality: A case control and allele frequency study

BACKGROUND

Familial pseudohyperkalemia (FP) is characterized by an increased rate of potassium leakage in refrigerated red cells and is associated with the minor allele of the single nucleotide polymorphism rs148211042 (R723Q) in the ABCB6 gene. The study aims were to obtain the minor allele frequencies of ABCB6 variants and to measure supernatant potassium accumulation, and other red cell storage parameters, in red cell concentrates (RCC) from carriers of variant rs148211042 under standard blood bank conditions.

STUDY DESIGN

Whole blood units were collected from 6 FP individuals and 11 controls and processed into RCC in additive solution. RCC were sampled and tested over cold storage for full blood count, extracellular potassium, glucose, lactate, microvesicle release, deformability, hemolysis, pH, adenosine triphosphate, and 2,3-diphosphoglycerate.

RESULTS

Screening of genotyped cohorts identified that variant rs148211042 is present in 1 in 394 British citizens of European ancestry. FP RCC had significantly higher supernatant potassium at all time points from day 3 onwards (p < .001) and higher mean cell volume (p = .032) than controls. The initial rate of potassium release was higher in FP RCC; supernatant potassium reached 46.0 (23.8-57.6) mmol/L (mean [range]) by day 5, increasing to 68.9 (58.8-73.7) mmol/L by day 35. Other quality parameters were not significantly different between FP RCC and controls.

CONCLUSION

These data suggest that if a blood donor has FP, reducing the RCC shelf-life to 5 days may be insufficient to reduce the risk of hyperkalemia in clinical scenarios such as neonatal large volume transfusion.

Effect of Leukoreduction on Hematobiochemical Parameters and Storage Hemolysis in Canine Whole Blood Units

Simple Summary

During the storage of blood units, cells undergo many changes, defined as storage lesions; these are biochemical, morphological and immunological modifications and seem to be responsible for adverse post-transfusion effects in recipients. The pre-storage leukoreduction seems to reduce them. The aims of this study are both to evaluate the human filter effectiveness and the effect of pre-storage leukoreduction in stored canine whole blood units. We tested whole blood units, leukoreduced and not, obtained from seven enrolled subjects, until the 42nd day. The white blood cell (WBC) and platelet (PLT) counts are reported to express the leukoreduction effectiveness. As indicators of storage-induced hemolysis, the lactate dehydrogenase activity (LDH) and sodium, potassium, and chlorine electrolytes were measured in plasma, and the red blood cell (RBC) count, hemoglobin concentration (Hgb), and hematocrit (Hct) were obtained with the complete blood count (CBC). The mean corpuscular volume (MCV) values and morphological index obtained from blood smear evaluation were used as indices of morphological changes. We observed that the leukoreduction filter for human use is equally effective on canine whole blood and that leukoreduction has a partially protective role to prevent some storage lesions.

Abstract

Storage lesions (SLs) occur when the red blood cell quality is altered during the preservation of blood units. Pre-storage leukoreduction would limit the number of SLs. The aims of this study were to evaluate the effectiveness of a leukoreduction filter for human use and the effect of pre-storage leukoreduction on some ematobiochemical parameters in stored canine whole blood. Seven canine blood units were tested. Each one was divided into two units—one leukoreduced (LRWB) and one non-leukoreduced (nLRWB). On each unit, we determined the complete blood count (CBC), lactate-dehydrogenase (LDH), electrolytes (Na⁺, K⁺, Cl⁻), morphological index (MI) and hemolysis, on storage days 0, 7, 14, 21, 28, 35, and 42. Leukoreduction allowed a 98.30% recovery of the RBC count, retaining 99.69% and 94.91% of WBCs and PLTs, respectively. We detected a significant increase of LDH and MI with strongly higher values in nLRWB compared to LRWB. A progressive increase in electrolytes and LDH concentrations was observed as indices of stored hemolysis. LDH showed significantly lower values in LRWB units compared to nLRWB, suggesting its release from leukocytes. In the majority of units, hemolysis reached 1% on the 42nd day of storage. We assert the human leukoreduction filter effectiveness on canine whole blood, and we recommend using nLRWB before day 14, especially for critically ill patients. The difference of the basal hemolysis (day 0) percentages observed between subjects suggests that more studies should be performed to confirm a possible inter-individual donor biological variability of RBC membrane resistance, as happens in humans.

β-thalassemia minor is a beneficial determinant of red blood cell storage lesion

Blood donor genetics and lifestyle affect the quality of red blood cell (RBC) storage. Heterozygotes for beta thalassemia (bThal⁺) constitute a non-negligible proportion of blood donors in the Mediterranean and other geographical areas. The unique hematological profile of bThal⁺ could affect the capacity of enduring storage stress, however, the storability of bThal⁺ RBC is largely unknown. In this study, RBC from 18 bThal⁺ donors were stored in the cold and profiled for primary (hemolysis) and secondary (phosphatidylserine exposure, potassium leakage, oxidative stress) quality measures, and metabolomics, versus sex- and age-matched controls. The bThal⁺ units exhibited better levels of storage hemolysis and susceptibility to lysis following osmotic, oxidative and mechanical insults. Moreover, bThal⁺ RBC had a lower percentage of surface removal signaling, reactive oxygen species and oxidative defects to membrane components at late stages of storage. Lower potassium accumulation and higher uratedependent antioxidant capacity were noted in the bThal⁺ supernatant. Full metabolomics analyses revealed alterations in purine and arginine pathways at baseline, along with activation of the pentose phosphate pathway and glycolysis upstream to pyruvate kinase in bThal⁺ RBC. Upon storage, substantial changes were observed in arginine, purine and vitamin B6 metabolism, as well as in the hexosamine pathway. A high degree of glutamate generation in bThal⁺ RBC was accompanied by low levels of purine oxidation products (IMP, hypoxanthine, allantoin). The bThal mutations impact the metabolism and the susceptibility to hemolysis of stored RBC, suggesting good post-transfusion recovery. However, hemoglobin increment and other clinical outcomes of bThal⁺ RBC transfusion deserve elucidation by future studies.

miRNA96 expression level within red blood cells is probably associated with RSL indicators during the storage of red blood cell units

BACKGROUND AND OBJECTIVES

Many biochemical and hematological changes occur during the storage of RBC units. Collectively, these changes are known as RSLs. Previous studies found miRNA96 as non-coding RNA that its expression level changed during RBC storage. However, its correlation with mechanical and biochemical RSL indicators is not yet determined. Therefore, this study aimed to assess possible correlations between miRNA96a and some RSLs indicators to clarify its biomarker capability for evaluating the storage quality of RBC units.

MATERIALS AND METHODS

Samples were collected from ten leuko-reduced RBC units on days 0, 14, 28, and 42 of storage. miRNA96 gene expression level and RSLs indicators including hemolysis, mechanical fragility index (MFI), total antioxidant capacity (TAC), lipid peroxidation (TBARs), thiol groups, and RBC indices were measured on the days mentioned above.

RESULTS

Significant correlations were found between the changes in miRNA96 expression level and the levels of hemolysis, TAC, TBARs, and MFI indices (p values < 0.05). The donors were classified into the high risk group and low risk group, according to four important characteristics and lifestyle habits (smoking, physical activity, age, and BMI). The high risk group had a significantly lower rate of hemolysis, free hemoglobin, MFI, TAC, and a higher rate of lipid peroxidation compared to low risk group (p values < 0.05).

CONCLUSION

The finding suggested that upregulation of miRNA96 could prevent hemolysis of RBCs, despite the accumulation of oxidative injuries in them. The miRNA96 expression level was probably a potential predictor for mechanical and biochemical RSL indicators.

Effects of storage and leukocyte reduction on the concentration and procoagulant activity of extracellular vesicles in canine packed red cells

OBJECTIVES

To characterize the size and procoagulant activity of extracellular vesicles (EV) that accumulate in canine packed red blood cells (pRBCs) over time and the effect of leukocyte reduction on these characteristics.

DESIGN

Prospective cohort study.

SETTING

Private small animal specialty referral hospital and university research laboratories.

ANIMALS

Ten healthy blood donor dogs.

INTERVENTIONS

Five pRBCs units were obtained according to standard protocols, and 5 were leukocyte-reduced prior to processing. Platelet-free supernatant from the pRBC units was collected on days 0, 10, 20, 32, and 42.

MEASUREMENTS AND MAIN RESULTS

Nanoparticle tracking analysis was performed to determine the size and concentration of EVs. Thrombin generation associated with phosphatidylserine-positive EVs was determined using a capture assay. Factor Xa generation associated with phosphatidylserine-positive EVs and tissue factor-positive EVs was measured in a subset of EVs isolated by centrifugation of the supernatant at 20,000 × g. R package nparLD and the Mann-Whitney U-test were used to determine the effect of duration of storage and the effect of leukocyte reduction, respectively. Small (mean < 125 nm) procoagulant EVs accumulated over time, with significant increases occurring on or after day 20 in both non-leukocyte reduced and leukocyte-reduced units. The procoagulant activity of the EVs was due to phosphatidylserine, not tissue factor. Increases in EV concentration and procoagulant activity occurred earlier in non-leukocyte reduced units. Extracellular vesicle accumulation and procoagulant activity were not decreased at any individual time point by leukocyte reduction.

CONCLUSIONS

Further studies characterizing and determining the clinical relevance of small procoagulant EVs in pRBCs are warranted.

Oxygen in Red Blood Cell Concentrates: Influence of Donors' Characteristics and Blood Processing

Objective: Unexpectedly wide distribution (<10 to >90%) of hemoglobin oxygen saturation (sO₂) within red cell concentrates (RCCs) has recently been observed. Causes of such variability are not yet completely explained whereas the roles of oxygen and oxidative lesions during the storage of RCCs are known. The objectives of the present study are to characterize sO₂ distribution in RCCs produced in a Swiss blood center and to investigate the influence of processing and donors’ characteristics.

Methods: The level of sO₂ was measured in 1701 leukocyte-depleted RCCs derived from whole blood donations in both top–bottom (TB; component filtered, SAGM) and top–top (TT; whole blood filtration, PAGGSM) RCCs. The sO₂ value was measured non-invasively through the PVC bag prior to storage by resonance Raman spectroscopy. Gender, age, blood type, hemoglobin level, and living altitude of donors, as well as process method and time-to-process were recorded.

Results: Overall, the sO₂ exhibited a wide non-Gaussian distribution with a mean of 51.2 ± 18.5%. Use of top-top kits resulted in a 16% higher sO₂ (P < 0.0001) than with top-bottom ones. Waiting time before processing only had a modest impact, but the blood processing itself reduced the sO₂ by almost 12% (P < 0.0001). sO₂ was also significantly affected by some donors’ characteristics. RCCs from men exhibited 25% higher sO₂ (P < 0.0001) than those donated by women. Multivariate analysis revealed that the apparent correlation observed with hemoglobin level and age was actually due to multicollinearity with the sex variable. Finally, we noticed no significant differences across blood type but found that altitude of residence was associated with the sO₂ (i.e., higher in higher living place).

Conclusion: These data confirm wide sO₂ distribution in RCCs reported recently. The sO₂ was impacted by the processing and also by donors’ characteristics such as the gender and the living altitude, but not by the hemoglobin level, blood group and donor age. This study provides new hints on the factors influencing red blood cells storage lesions, since they are known to be related to O₂ content within the bags, giving clues to better process and to better store RCCs and therefore potentially improve the efficacy of transfusion.

Metabolic rejuvenation upgrades circulatory functions of red blood cells stored under blood bank conditions

BACKGROUND

Red blood cells (RBC) change upon hypothermic conservation, and storage for 6 weeks is associated with the short-term clearance of 15% to 20% of transfused RBCs. Metabolic rejuvenation applied to RBCs before transfusion replenishes energetic sources and reverses most storage-related alterations, but how it impacts RBC circulatory functions has not been fully elucidated.

STUDY DESIGN AND METHODS

Six RBC units stored under blood bank conditions were analyzed weekly for 6 weeks and rejuvenated on Day 42 with an adenine-inosine-rich solution. Impact of storage and rejuvenation on adenosine triphosphate (ATP) levels, morphology, accumulation of storage-induced microerythrocytes (SMEs), elongation under an osmotic gradient (by LORRCA), hemolysis, and phosphatidylserine (PS) exposure was evaluated. The impact of rejuvenation on filterability and adhesive properties of stored RBCs was also assessed.

RESULTS

Rejuvenation of RBCs restored intracellular ATP to almost normal levels and decreased the PS exposure from 2.78% to 0.41%. Upon rejuvenation, the proportion of SME dropped from 28.2% to 9.5%, while the proportion of normal-shaped RBCs (discocytes and echinocytes 1) increased from 47.7% to 67.1%. In LORCCA experiments, rejuvenation did not modify the capacity of RBCs to elongate and induced a reduction in cell volume. In functional tests, rejuvenation increased RBC filterability in a biomimetic splenic filter (+16%) and prevented their adhesion to endothelial cells (-87%).

CONCLUSION

Rejuvenation reduces the proportion of morphologically altered and adhesive RBCs that accumulate during storage. Along with the improvement in their filterability, these data show that rejuvenation improves RBC properties related to their capacity to persist in circulation after transfusion.

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.

Donor-dependent aging of young and old red blood cell subpopulations: Metabolic and functional heterogeneity

BACKGROUND

Characteristics of red blood cells (RBCs) are influenced by donor variability. This study assessed quality and metabolomic variables of RBC subpopulations of varied biologic age in red blood cell concentrates (RCCs) from male and female donors to evaluate their contribution to the storage lesion.

STUDY DESIGN AND METHODS

Red blood cell concentrates from healthy male (n = 6) and female (n = 4) donors were Percoll separated into less dense ("young", Y-RCCs) and dense ("old", O-RCCs) subpopulations, which were assessed weekly for 28 days for changes in hemolysis, mean cell volume (MCV), hemoglobin concentration (MCHC), hemoglobin autofluorescence (HGB), morphology index (MI), oxygen affinity (p50), rigidity, intracellular reactive oxygen species (ROS), calcium ([Ca²⁺ ]), and mass spectrometry-based metabolomics.

RESULTS

Young RCCs having disc-to-discoid morphology showed higher MCV and MI, but lower MCHC, HGB, and rigidity than O-RCCs, having discoid-to-spheroid shape. By Day 14, Y-RCCs retained lower hemolysis and rigidity and higher p50 compared to O-RCCs. Donor sex analyses indicated that females had higher MCV, HGB, ROS, and [Ca²⁺ ] and lower hemolysis than male RBCs, in addition to having a decreased rate of change in hemolysis by Day 28. Metabolic profiling indicated a significant sex-related signature across all groups with increased markers of high membrane lipid remodeling and antioxidant capacity in Y-RCCs, whereas O-RCCs had increased markers of oxidative stress and decreased coping capability.

CONCLUSION

The structural, functional, and metabolic dissimilarities of Y-RCCs and O-RCCs from female and male donors demonstrate RCC heterogeneity, where RBCs from females contribute less to the storage lesion and age slower than males.

Unit-to-unit variability in the deformability of red blood cells

BACKGROUND

In blood banking practice, the storage duration is used as the primary criterion for inventory management, and usually, the packed red blood cells (PRBC) units are supplied primarily according to first-in-first-out (FIFO) principle. However, the actual functionality of individual PRBC units is mostly ignored. One of the main features of the RBCs not accounted for under this approach is the deformability of the red cells, i.e., their ability to affect the recipients' blood flow. The objective of the study was to analyze unit-to-unit variability in the deformability of PRBCs during their cold storage.

METHODS

RBC samples were obtained from twenty leukoreduced PRBC units, stored in SAGM. The deformability of cells was monitored from the day of donation throughout 42 days. RBC deformability was determined using the computerized cell flow-properties analyzer (CFA) based on cell elongation under a shear stress of 3.0 Pa, expressed by the elongation-ratio (ER). The image analysis determines the ER for each cell and provides the ER distribution in the population of 3000-6000 cells.

RESULTS

The deformability of freshly-collected RBCs exhibited marked variability already on the day of donation. We also found that the aging curve of PRBC deformability varies significantly among donors.

SIGNIFICANCE

The present study has demonstrated that storage duration is only one of the factors, and seemingly not even the major one, affecting the PRBCs functionality. Therefore, the FIFO approach is not sufficient for assessing the potential transfusion outcome, and the PRBC functionality should be determined explicitly for each unit.

Blood Donors' Age, Haemoglobin Type, G6PD Status, and Blood Group Impact Storability of CPDA-1 Banked Whole Blood: A Repeated-Measure Cohort Study in Cape Coast, Ghana

Background

The high prevalence of haemoglobin variants and glucose 6-phosphate dehydrogenase disorder (G6PDd) in sub-Saharan Africa means that substantial proportions of donor blood units carry these red cell abnormalities.

Aim

This study investigated the impact that inherited haemoglobin variants and/or G6PD status have on whole blood banked at 4–6°C for 35 days.

Method

This repeated-measure cohort study was undertaken on 103 donor blood units collected into blood bag containing CPDA-1 anticoagulant. On days 0, 7, 14, 21, and 35, full blood count, osmotic-induced haemolysis, and plasma K+ levels were estimated. Also, on day 0, G6PD status, haemoglobin variants, % foetal haemoglobin, and blood group of donor units were determined using methaemoglobin reductase, cellulose acetate electrophoresis, modified Bekte alkali denaturation assay, and slide haemagglutination test, respectively.

Result

Overall, although plasma K+ levels increased during storage, donor units from individuals ≥20 years, G6PD normal, Hb AC, or blood group B had comparatively higher percentage change in plasma K+ during storage. Osmotically induced haemolysis of donor units was significantly decreased in Hb AC (compared with Hb A or AS) donor units on days 7, 14, 21, and 35 (p < 0.0001 in each case). G6PDd donor units had comparatively reduced osmotic-induced lysis compared with G6PD normal units, reaching a statistical significance on day 35 (p = 0.043). Also, Hb AC units had comparatively nonstatistically higher plasma K+ at all time points (compared with Hb A or AS). Furthermore, whereas donor units from individuals ≥20 years showed significantly higher median free haemoglobin on day 21 (compared to donor <20 years), when donor units were stratified per Hb variants, only Hb AS units had median free haemoglobin below the 0.8% threshold after 35 days' storage.

Conclusion

Age of donor, blood group, Hb AC variant, and G6PD status may be important considerations in the storability of whole blood.

Neutrophil Adaptations upon Recruitment to the Lung: New Concepts and Implications for Homeostasis and Disease

Neutrophils have a prominent role in all human immune responses against any type of pathogen or stimulus. The lungs are a major neutrophil reservoir and neutrophilic inflammation is a primary response to both infectious and non-infectious challenges. While neutrophils are well known for their essential role in clearance of bacteria, they are also equipped with specific mechanisms to counter viruses and fungi. When these defense mechanisms become aberrantly activated in the absence of infection, this commonly results in debilitating chronic lung inflammation. Clearance of bacteria by phagocytosis is the hallmark role of neutrophils and has been studied extensively. New studies on neutrophil biology have revealed that this leukocyte subset is highly adaptable and fulfills diverse roles. Of special interest is how these adaptations can impact the outcome of an immune response in the lungs due to their potent capacity for clearing infection and causing damage to host tissue. The adaptability of neutrophils and their propensity to influence the outcome of immune responses implicates them as a much-needed target of future immunomodulatory therapies. This review highlights the recent advances elucidating the mechanisms of neutrophilic inflammation, with a focus on the lung environment due to the immense and growing public health burden of chronic lung diseases such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD), and acute lung inflammatory diseases such as transfusion-related acute lung injury (TRALI).

Improved quantitative detection of biotin-labeled red blood cells by flow cytometry

BACKGROUND

Biotin-labeled red blood cells (BioRBC) can be tracked after transfusion, providing a convenient and safe way to measure RBC survival in vivo. RBC survival is of interest for determining optimal blood storage conditions and for assessing the impact of genetic and biologic variants in blood donors on the survival of transfused RBCs. Here we present an improved, platform-independent assay for quantifying biotin on BioRBC. This approach is also useful for detecting BioRBC in peripheral blood samples as rare events.

STUDY DESIGN AND METHODS

We optimized the signal-to-noise ratio of the detecting reagent (phycoerythrin-conjugated streptavidin [SA-PE]) by determining the SA-PE concentration yielding the greatest separation index between BioRBC and unlabeled RBCs. We calibrated the fluorescence intensity measurements to molecules of equivalent soluble fluorochrome (MESF), a quantitative metric of fluorochrome binding and therefore of biotin bound per RBC. We then characterized the limit of blank and limit of quantification (LoQ) for BioRBC labeled at different densities.

RESULTS

Biotin-labeled RBCs at sulfo-NHS-biotin concentrations of 3 to 30 μg/mL (27-271 nmol/mL RBCs) ranged from approximately 32,000 to 200,000 MESF/RBC. The LoQ ranged from one in 274,000 to one in 649,000, depending on biotin-labeling density.

CONCLUSION

Increased sensitivity to detect BioRBC may facilitate tracking over longer periods and/or reduction of the BioRBC dose. Total RBC-bound biotin dose has been shown to correlate with the likelihood of developing antibodies to BioRBC. Lowering the dose of labeled cells may help avoid this eventuality.

Thalassemia trait and G6PD deficiency in Thai blood donors

BACKGROUND

Thalassemia trait and G6PD deficiency are asymptomatic and volunteers with these variants are eligible for blood donation.

AIMS

This study aimed to investigate prevalence and hematologic profiles of blood donors with thalassemia trait and G6PD deficiency and the influence of these abnormalities have on donor retention and blood component preparation.

METHODS

Prospectively recruited blood donors were investigated for thalassemia and G6PD deficiency. Characteristic data, hematologic profiles, proportions of prepared blood components, donor return rate within 12 months and adverse reactions in patients receiving red cell transfusions were compared among thalassemia trait, G6PD deficiency, and normal donors.

RESULTS

In Thai blood donors, thalassemia trait prevalence was 21.1% and G6PD deficiency prevalence based on G6PD activity was 7.7%. Blood donors with thalassemia trait had significantly lower hemoglobin, MCV, and MCH than blood donors without thalassemia trait (Hb 13.55 ± 1.00 vs. 13.96 ± 1.25 g/dL, MCV 76.70 ± 6.69 vs. 87.01 ± 5.10 fL, and MCH 25.06 ± 2.17 vs. 28.67 ± 1.91 pg, all respectively and all p < 0.01). However, the hematologic profiles of blood donors with G6PD deficiency were not significantly different from the hematologic profiles of blood donors with normal G6PD activity. No significant difference was observed among thalassemia trait, G6PD deficiency, and normal donors relative to donor retention and blood component preparation.

CONCLUSION

The high prevalence of thalassemia trait and G6PD deficiency in Thai blood donors observed in this study does not adversely affect donor retention and blood component preparation.

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.

Donor characteristics do not influence transfusion-related acute lung injury incidence in a secondary analysis of two case-control studies

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.

Intradonor reproducibility and changes in hemolytic variables during red blood cell storage: results of recall phase of the REDS-III RBC-Omics study

BACKGROUND

Genetic determinants may underlie the susceptibility of red blood cells (RBCs) to hemolyze in vivo and during routine storage. This study characterized the reproducibility and dynamics of in vitro hemolysis variables from a subset of the 13,403 blood donors enrolled in the RBC-Omics study.

STUDY DESIGN AND METHODS

RBC-Omics donors with either low or high hemolysis results on 4°C-stored leukoreduced (LR)-RBC samples from enrollment donations stored for 39 to 42 days were recalled 2 to 12 months later to donate LR-RBCs. Samples of stored LR-RBCs from the unit and from transfer bags were evaluated for spontaneous and stress-induced hemolysis at selected storage time points. Intradonor reproducibility of hemolysis variables was evaluated in transfer bags over two donations. Hemolysis data at serial storage time points were generated on LR-RBCs from parent bags and analyzed by site, sex, race/ethnicity, and donation frequency.

RESULTS

A total of 664 donors were successfully recalled. Analysis of intradonor reproducibility revealed that osmotic and oxidative hemolysis demonstrated good and moderate reproducibility (Pearson's r = 0.85 and r = 0.53, respectively), while spontaneous hemolysis reproducibility was poor (r = 0.40). Longitudinal hemolysis in parent bags showed large increases over time in spontaneous (508.6%) and oxidative hemolysis (399.8%) and smaller increases in osmotic (9.4%) and mechanical fragility (3.4%; all p < 0.0001).

CONCLUSION

Spontaneous hemolysis is poorly reproducible in donors over time and may depend on site processing methods, while oxidative and osmotic hemolysis were reproducible in donors and hence could reflect consistent heritable phenotypes attributable to genetic traits. Spontaneous and oxidative hemolysis increased over time of storage, whereas osmotic and mechanical hemolysis remained relatively stable.

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.

Real Age: Red Blood Cell Aging During Storage

BACKGROUND

During cold storage, some red blood cell (RBC) units age more rapidly than others. Yet, the Food and Drug Administration has set a uniform storage limit of 42 days. Objectives of this review are to present evidence for an RBC storage lesion and suggest that functional measures of stored RBC quality-which we call real age-may be more appropriate than calendar age.

METHODS

During RBC storage, biochemical substances and byproducts accumulate and RBC shape alters. Factors that influence the rate of degradation include donor characteristics, bio-preservation conditions, and vesiculation. Better understanding of markers of RBC quality may lead to standardized, quantifiable, and operationally practical measures to improve donor selection, assess quality of an RBC unit, improve storage conditions, and test efficacy of the transfused product.

RESULTS

The conundrum is that clinical trials of younger versus older RBC units have not aligned with in vitro aging data; that is, the units transfused were not old enough. In vitro changes are considerable beyond 28 to 35 days, and average storage age for older transfused units was 14 to 21 days.

CONCLUSIONS

RBC product real age varies by donor characteristics, storage conditions, and biological changes during storage. Metrics to measure temporal changes in quality of the stored RBC product may be more appropriate than the 42-day expiration date. Randomized trials and observational studies are focused on average effect, but, in the evolving age of precision medicine, we must acknowledge that vulnerable populations and individuals may be harmed by aging blood.

Effects of donor age, donor sex, blood-component processing, and storage on cell-derived microparticle concentrations in routine blood-component preparation

BACKGROUND

A number of factors cause increases in the number of cell-derived microparticles (MPs) in blood components. However, the overall effects of these factors on the concentration of MPs during routine blood-component preparation have not fully been elucidated.

AIM

To evaluate the effects of donor age, donor sex, blood-component preparation, and storage on MP concentrations.

METHODS

Flow cytometry was used to quantitate the number of whole blood-derived MPs.

RESULTS

The total MP concentration was similar in male and female donors (26,044 ± 1254 particles/μL vs. 27,696 ± 1584 particles/μL). The total MP concentration did not differ significantly among the different age groups: 18-30 years (28,730 ± 1600 particles/μL), 31-40 years (24,972 ± 5947 particles/μL), and 41-58 years (25,195 ± 1727 particles/μL). However, the total number of MPs in fresh plasma (152,110 ± 46,716 particles/μL) was significantly higher (p <  0.05) than that in unprocessed whole blood (26,752 ± 985 particles/μL), fresh packed red blood cells (PRBCs) (28,574 ± 1028 particles/μL), and platelet concentrate (PC) (33,072 ± 1858 particles/μL). Furthermore, the total numbers of MPs in stored PRBCs and fresh-frozen plasma (FFP) were significantly higher (p <  0.05) than those in fresh PRBCs and fresh plasma, respectively.

CONCLUSIONS

The study suggests that donor factors, blood-component processing and storage contribute to the MP concentration in routine blood-product preparation. The findings can improve quality control and management of blood-product manufacturing in routine transfusion laboratories.

Red cell transfusion in paediatric patients with thalassaemia and sickle cell disease: Current status, challenges and perspectives

Notwithstanding the high safety level of the currently available blood for transfusion and the decreasing frequency of transfusion-related complications, administration of labile blood products to paediatric patients still poses unique challenges and considerations. The incidence of thalassaemia and sickle cell disease in the paediatric population may be high enough under specific racial and geographical contexts. Red cell transfusion is the cornerstone of β-thalassaemia treatment and one of the most effective ways to prevent or correct specific acute and chronic complications of sickle cell disease. However, this life-saving strategy comes with its own complications, such as additional iron overload, alloimmunization and haemolytic reactions, among others. In paediatrics, the dependency of the transfusion outcome upon disease and other recipient characteristics is more prominent compared with the adults, owing to differences in developmental maturity and physiology that render them more susceptible to common risks, exacerbate the host response to transfused cells, and modify the type or the clinical severity of the transfusion-related morbidity. The adverse branch of red cell transfusion is likely the overall effect of several factors acting synergistically to shape the clinical phenotype of this therapy, including inherent donor/blood unit variables, like antigenicity, red cell deformability and extracellular vesicles, as well as recipient variables, such as history of alloimmunization and inflammation level at time of transfusion. This review focuses on paediatric patients with β-thalassaemia and sickle cell disease as a recipient group with distinct transfusion-related characteristics, and introduces new concepts for consideration, not adequately studied and elucidated so far.

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.

Blood and Blood Components: From Similarities to Differences

Blood transfusion is made possible because, in most countries and organizations, altruistic individuals voluntarily, anonymously, and generously donate (without compensation) either whole blood or separated components that are then processed and distributed by professionals, prior to being allocated to recipients in need. Being part of modern medicine, blood transfusion uses so-called standard blood components when relative to cellular fractions and fresh plasma. However, as will be discussed in this paper, strictly speaking, such so-called labile blood components are not completely standard. Furthermore, the prevalent system based on voluntary, non-remunerated blood donation is not yet universal and, despite claims by the World Health Organization that 100% of blood collection will be derived from altruistic donations by 2020 (postponed to 2025), many obstacles may hinder this ambition, especially when relative to the collection of the enormous amount of plasma destined for fractionation into plasma derivative or drugs. Finally, country organizations also vary due to the economy, sociology, politics, and epidemiology. This paper then, discusses the particulars (of which ethical considerations) of blood transfusion diversity and the consequences for donors, patients, and society.

Transfusion of autologous extracellular vesicles from stored red blood cells does not affect coagulation in a model of human endotoxemia

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 < 0.01) in the stored product (p < 0.001). Vesicles appeared to be mostly RBC derived.

CONCLUSION

After transfusion, extracellular vesicles from stored RBC products, but not from fresh products, could be detected in the circulation of healthy volunteers. However, infusion of stored RBC extracellular vesicles did not augment thrombin generation compared to endotoxemic controls. Also, levels of d-dimer and thrombin-antithrombin complex were unaffected. In conclusion, transfusion of autologous RBCs containing high levels of extracellular vesicles does not enhance coagulation in human volunteers with endotoxemia.

Red blood cells ageing markers: a multi-parametric analysis

BACKGROUND

Red blood cells collected in citrate-phosphate-dextrose can be stored for up to 42 days at 4 °C in saline-adenine-glucose-mannitol additive solution. During this controlled, but nevertheless artificial, ex vivo ageing, red blood cells accumulate lesions that can be reversible or irreversible upon transfusion. The aim of the present study is to follow several parameters reflecting cell metabolism, antioxidant defences, morphology and membrane dynamics during storage.

MATERIALS AND METHODS

Five erythrocyte concentrates were followed weekly during 71 days. Extracellular glucose and lactate concentrations, total antioxidant power, as well as reduced and oxidised intracellular glutathione levels were quantified. Microvesiculation, percentage of haemolysis and haematologic parameters were also evaluated. Finally, morphological changes and membrane fluctuations were recorded using label-free digital holographic microscopy.

RESULTS

The antioxidant power as well as the intracellular glutathione concentration first increased, reaching maximal values after one and two weeks, respectively. Irreversible morphological lesions appeared during week 5, where discocytes began to transform into transient echinocytes and finally spherocytes. At the same time, the microvesiculation and haemolysis started to rise exponentially. After six weeks (expiration date), intracellular glutathione was reduced by 25%, reflecting increasing oxidative stress. The membrane fluctuations showed decreased amplitudes during shape transition from discocytes to spherocytes.

DISCUSSION

Various types of lesions accumulated at different chemical and cellular levels during storage, which could impact their in vivo recovery after transfusion. A marked effect was observed after four weeks of storage, which corroborates recent clinical data. The prolonged follow-up period allowed the capture of deep storage lesions. Interestingly, and as previously described, the severity of the changes differed among donors.

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.

Metabolism of Citrate and Other Carboxylic Acids in Erythrocytes As a Function of Oxygen Saturation and Refrigerated Storage

State-of-the-art proteomics technologies have recently helped to elucidate the unanticipated complexity of red blood cell metabolism. One recent example is citrate metabolism, which is catalyzed by cytosolic isoforms of Krebs cycle enzymes that are present and active in mature erythrocytes and was determined using quantitative metabolic flux analysis. In previous studies, we reported significant increases in glycolytic fluxes in red blood cells exposed to hypoxia in vitro or in vivo, an observation relevant to transfusion medicine owing to the potential benefits associated with hypoxic storage of packed red blood cells. Here, using a combination of steady state and quantitative tracing metabolomics experiments with ¹³C_1,2,3-glucose, ¹³C₆-citrate, ¹³C₅¹⁵N₂-glutamine, and ¹³C₁-aspartate via ultra-high performance liquid chromatography coupled on line with mass spectrometry, we observed that hypoxia in vivo and in vitro promotes consumption of citrate and other carboxylates. These metabolic reactions are theoretically explained by the activity of cytosolic malate dehydrogenase 1 and isocitrate dehydrogenase 1 (abundantly represented in the red blood cell proteome), though moonlighting functions of additional enzymes cannot be ruled out. These observations enhance understanding of red blood cell metabolic responses to hypoxia, which could be relevant to understand systemic physiological and pathological responses to high altitude, ischemia, hemorrhage, sepsis, pulmonary hypertension, or hemoglobinopathies. Results from this study will also inform the design and testing of novel additive solutions that optimize red blood cell storage under oxygen-controlled conditions.

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.

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

BACKGROUND AND OBJECTIVES

Red blood cells (RBCs) suffer from lesions during cold storage, depending in part on their ability to counterbalance oxidative stress by activating their antioxidant defence. The aim of this study was to monitor the antioxidant power (AOP) in erythrocyte concentrates (ECs) during cold storage.

MATERIALS AND METHODS

Six ECs were prepared in saline-adenine-glucose-mannitol (SAGM) additive solution and followed during 43 days. The AOP was quantified electrochemically using disposable electrode strips and compared with results obtained from a colorimetric assay. Haematological data, data on haemolysis and the extracellular concentration of uric acid were also recorded. Additionally, a kinetic model was developed to extract quantitative kinetic data on the AOP behaviour.

RESULTS

The AOP of total ECs and their extracellular samples attained a maximum after 1 week of storage prior to decaying and reaching a plateau, as shown by the electrochemical measurements. The observed trend was confirmed with a colorimetric assay. Uric acid had a major contribution to the extracellular AOP. Interestingly, the AOP and uric acid levels were linked to the sex of the donors.

CONCLUSION

The marked increase in AOP during the first week of storage suggests that RBCs are impacted early by the modification of their environment. The AOP behaviour reflects the changes in metabolism activity following the adjustment of the extracellular uric acid level. Knowing the origin, interdonor variability and the effects of the AOP on the RBCs could be beneficial for the storage quality, which will have to be further studied.

Morphology, membrane nanostructure and stiffness for quality assessment of packed red blood cells

Transfusion of packed red blood cells (PRBC) to patients in critical states is often accompanied by post-transfusion complications. This may be related with disturbance of properties of PRBC and their membranes during long-term storage in the hemopreservative solution. The purpose of our work is the study of transformation of morphology, membranes stiffness and nanostructure for assessment of PRBC quality, in vitro. By atomic force microscopy we studied the transformation of cell morphology, the appearance of topological nanodefects of membranes and by atomic force spectroscopy studied the change of membrane stiffness during 40 days of storage of PRBC. It was shown that there is a transition period (20–26 days), in which we observed an increase in the Young’s modulus of the membranes 1.6–2 times and transition of cells into irreversible forms. This process was preceded by the appearance of topological nanodefects of membranes. These parameters can be used for quality assessment of PRBC and for improvement of transfusion rules.

Red blood cell transfusion in surgical cancer patients: Targets, risks, mechanistic understanding and further therapeutic opportunities

Anemia is present in more than half of cancer patients and appears to be an independent prognostic factor of short- and long-term adverse outcomes. It increases in the advanced period of cancer and perioperatively, in patients with solid tumors who undergo surgery. As a result, allogeneic red blood cell (RBC) transfusion is an indispensable treatment in cancer. However, its safety remains controversial, based on several laboratory and clinical data reporting a linkage with increased risk for cancer recurrence, infection and cancer-related mortality. Immunological, inflammatory and thrombotic reactions mediated by the residual leukocytes and platelets, the stored RBCs per se, the biological response modifiers and the plasticizer of the unit may underlie infection and tumor-promoting effects. Although the causality between transfusion and infection has been established, the effects of transfusion on cancer recurrence remain confusing; this is mainly due to the extreme biological heterogeneity that characterizes RBC donations and cancer context. In fact, the functional interplay between donation-associated factors and recipient characteristics, including tumor biology per se, inflammation, infection, coagulation and immune activation state and competence may synergistically and individually define the clinical impact of each transfusion in any given cancer patient. Our understanding of how the potential risk is mediated is important to make RBC transfusion safer and to pave the way for novel, promising and highly personalized strategies for the treatment of anemia in surgical cancer patients.