Effect of storage time and donor sex of transfused red blood cells on 1-year survival in patients undergoing cardiac surgery: an observational study

Estimated median density identifies donor age and sex differences in red blood cell biological age

BACKGROUND

Donors possess heterogeneous red cell concentrates (RCCs) in terms of the biological age of their red blood cells (RBCs) as a direct result of various donor-dependent factors influencing rates of erythropoiesis. This study aimed to estimate the median biological age of RBCs in RCCs based on donor age and sex to investigate inherent differences in blood products' biological ages over hypothermic storage using estimated median densities (EMDs).

STUDY DESIGN

Sixty RCCs were collected from four donor groups; male and female teenagers (17-19 years old) and seniors (75+ years old). A Percoll density-based separation approach was used to quantify the EMDs indicative of biological age. EMD and mean corpuscular hemoglobin (MCHC) were compared by correlation analyses.

RESULTS

Differences in the median biological age of RCC units were observed with male donors having significantly higher EMDs compared to females (p < .001). Teen male donors possessed the highest EMDs with significantly elevated levels of biologically aged RBCs compared to both female donor groups, regardless of storage duration (p < .05). Throughout most of the 42-day storage period, senior donors, particularly senior females, demonstrated the strongest correlation between EMD and MCHC (R2 > 0.5).

CONCLUSIONS

This study provides further evidence that there are inherent differences between the biological age profiles of RBCs between blood donors of different sex and age. Our findings further highlight that biological age may contribute to RBC quality during storage and that donor characteristics need to be considered when evaluating transfusion safety and efficacy.

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.

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.

Red Blood Cell Donor Sex Associated Effects on Morbidity and Mortality in the Extremely Preterm Newborn

Transfusion exposure increases the risk of death in critically ill patients of all ages. This was thought to relate to co-morbidities in the transfusion recipient. However, donor characteristics are increasingly recognised as critical to transfusion recipient outcome with systematic reviews suggesting blood donor sex influences transfusion recipient health. Originally focusing on plasma and platelet transfusions, retrospective studies report greater risks of adverse outcomes such as transfusion related acute lung injury in those receiving products from female donors. There is increasing awareness that exposure to red blood cells (RBCs) poses a similar risk. Recent studies focusing on transfusion related outcomes in extremely preterm newborns report conflicting data on the association between blood donor sex and outcomes. Despite a renewed focus on lower versus higher transfusion thresholds in neonatal clinical practice, this group remain a heavily transfused population, receiving on average 3-5 RBC transfusions during their primary hospital admission. Therefore, evidence supporting a role for better donor selection could have a significant impact on clinical outcomes in this high-risk population. Here, we review the emerging evidence for an association between blood donor sex and clinical outcomes in extremely preterm newborns receiving one or more transfusions.

Association between in-ICU red blood cells transfusion and 1-year mortality in ICU survivors

BACKGROUND

Impact of in-ICU transfusion on long-term outcomes remains unknown. The purpose of this study was to assess in critical-care survivors the association between in-ICU red blood cells transfusion and 1-year mortality.

METHODS

FROG-ICU, a multicenter European study enrolling all-comers critical care patients was analyzed (n = 1551). Association between red blood cells transfusion administered in intensive care unit and 1-year mortality in critical care survivors was analyzed using an augmented inverse probability of treatment weighting-augmented inverse probability of censoring weighting method to control confounders.

RESULTS

Among the 1551 ICU-survivors, 42% received at least one unit of red blood cells while in intensive care unit. Patients in the transfusion group had greater severity scores than those in the no-transfusion group. According to unweighted analysis, 1-year post-critical care mortality was greater in the transfusion group compared to the no-transfusion group (hazard ratio (HR) 1.78, 95% CI 1.45-2.16). Weighted analyses including 40 confounders, showed that transfusion remained associated with a higher risk of long-term mortality (HR 1.21, 95% CI 1.06-1.46).

CONCLUSIONS

Our results suggest a high incidence of in-ICU RBC transfusion and that in-ICU transfusion is associated with a higher 1-year mortality among in-ICU survivors. Trial registration ( NCT01367093 ; Registered 6 June 2011).

Mortality Among Patients Undergoing Blood Transfusion in Relation to Donor Sex and Parity: A Natural Experiment

IMPORTANCE

Prior evidence suggests that plasma and platelet transfusions from female and parous donors are associated with adverse clinical outcomes, which has led to the predominant use of male donors for plasma and platelets in many countries. However, studies on red blood cell transfusions have been conflicting.

OBJECTIVE

To determine whether blood donor sex and parity affect mortality of patients undergoing transfusion with red blood cells.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used nationwide blood bank and health register data in Sweden and involved a natural experiment created by donor sex and parity being concealed and randomly allocated. Patients were included if they were 18 to 90 years old, did not have a history of blood transfusion, and received a transfusion between January 1, 2010, and December 31, 2017. Patients were followed up from their first red blood cell transfusion until death, emigration, or end of study (June 30, 2018). Data analysis was performed between June 15 and December 15, 2021.

EXPOSURES

(1) Female vs male donors and (2) parous or nonparous female vs male donors.

MAIN OUTCOMES AND MEASURES

Overall survival up to 2 years estimated using inverse probability-weighted Kaplan-Meier estimates and relative risk for additional transfusions within 24 hours.

RESULTS

Among the 368 778 included patients (mean [SD] age, 66.3 [17.7] years; 57.3% female), 2-year survival differences comparing red blood cell transfusions from female and parous donors to male donors were -0.1% (95% CI, -1.3% to 1.1%) and 0.3% (95% CI, -0.6% to 1.2%), respectively. No statistically significant survival differences were observed regardless of patient sex or age. Median (IQR) hemoglobin counts for female donors (13.5 [13.0-14.0] g/dL) were lower than for male donors (14.9 [14.4-15.5] g/dL). Red blood cell transfusions from female donors were associated with a relative risk of 1.12 (95% CI, 1.08-1.17) for additional transfusions within 24 hours but not after adjusting for donor hemoglobin counts (relative risk, 1.03; 95% CI, 0.98-1.08). Pretransfusion patient characteristics were naturally distributed as-if randomized.

CONCLUSIONS AND RELEVANCE

In this nationwide cohort study involving a natural experiment, after accounting for the lower hemoglobin values in blood from female donors, patients undergoing transfusion with blood from female or parous donors did not have higher 2-year mortality compared with recipients of blood from male donors.

Donor-recipient sex is associated with transfusion-related outcomes in critically ill patients

Transfusion of female RBCs to male recipients increases the risk of ICU mortality compared with female blood to female recipients.

Receiving RBCs from female donors is associated with a trend toward ARDS.

Transfusion of red blood cells (RBCs) from female donors has been associated with increased risk of mortality. This study aims to investigate the associations between donor-recipient sex and posttransfusion mortality and morbidity in critically ill patients who received RBC transfusions from either male-only donors or from female-only donors (unisex-transfusion cases). Survival analysis was used to compare 4 groups: female-to-female, female-to-male, male-to-female, and male-to-male transfusion. Multivariate logistic model was used to evaluate the association between donor sex and intensive care unit (ICU) mortality. Associations between transfusion and acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), and nosocomial infections were assessed. Of the 6992 patients included in the original cohort study, 403 patients received unisex-transfusion. Survival analysis and the logistic model showed that transfusion of female RBCs to male patients was associated with an increased ICU mortality compared with transfusion of female RBCs to female patients (odds ratio, 2.43; 95% confidence interval, 1.02-5.77; P < .05). There was a trend toward increased ARDS in patients receiving RBC from female donors compared with those receiving blood from males (P = .06), whereas AKI was higher in donor-recipient sex-matched transfusion groups compared with sex-mismatched groups (P = .05). This was an exploratory study with potential uncontrolled confounders that limits broad generalization of the findings. Results warrant further studies investigating biological mechanisms underlying the association between donor sex with adverse outcomes as well as studies on the benefit of matching of blood between donor and recipient.

Processing methods and storage duration impact extracellular vesicle counts in red blood cell units

Extracellular vesicles (EVs) are active components of red blood cell (RBC) concentrates and may be associated with beneficial and adverse effects of transfusion. Elucidating controllable factors associated with EV release in RBC products is thus important to better manage the quality and properties of RBC units. Erythrocyte-derived EVs (EEVs) and platelet-derived EVs (PEVs) were counted in 1226 RBC units (administered to 280 patients) using a standardized cytometry-based method. EV size and CD47 and annexin V expression were also measured. The effects of donor characteristics, processing methods, and storage duration on EV counts were analyzed by using standard comparison tests, and analysis of covariance was used to determine factors independently associated with EV counts. PEV as well as EEV counts were higher in whole-blood-filtered RBC units compared with RBC-filtered units; PEV counts were associated with filter type (higher with filters associated with higher residual platelets), and CD47 expression was higher on EEVs in RBC units stored longer. Multivariate analysis showed that EEV counts were strongly associated with filter type (P < .0001), preparation, and storage time (+25.4 EEV/µL per day [P = .01] and +42.4 EEV/µL per day [P < .0001], respectively). The only independent factor associated with PEV counts was the residual platelet count in the unit (+67.1 PEV/µL; P < .0001). Overall, processing methods have an impact on EV counts and characteristics, leading to large variations in EV quantities transfused into patients. RBC unit processing methods might be standardized to control the EV content of RBC units if any impacts on patient outcomes can be confirmed. The IMIB (Impact of Microparticles in Blood) study is ancillary to the French ABLE (Age of Transfused Blood in Critically Ill Adults) trial (ISRCTN44878718).

Save it-don't waste it! Maximizing utilization of erythrocytes from previously stored whole blood

BACKGROUND

Recent military and civilian experience suggests that fresh whole blood may be the preferred for treatment of hemorrhagic shock, but its use is limited by its 21-day shelf life. The red blood cell storage lesion and coagulation status of packed red blood cells (pRBCs) salvaged from expired whole blood are unknown. We hypothesized that pRBCs can be salvaged from previously stored whole blood.

METHODS

Cold stored, low-titer, O-positive, nonleukoreduced, whole blood units were obtained at 21 days of storage. Erythrocytes were separated by centrifugation, resuspended in AS-3, and stored for 21 additional days as salvaged pRBCs. The red blood cell storage lesion parameters of microvesicles, Band-3, free hemoglobin, annexin V, and erythrocyte osmotic fragility were measured and compared with pRBCs prepared at the time of donation and stored in AS-3 for 42 days (standard pRBCs). In additional experiments, murine pRBCs were prepared from expired whole blood units and compared with those stored under standard conditions. Mice underwent hemorrhage and resuscitation with standard and salvaged pRBC units, and serum cytokines and free hemoglobin were determined.

RESULTS

There were no significant differences in microvesicle formation or cell-free hemoglobin concentration between salvaged and standard pRBCs. There was decreased Band-3 and increased phosphatidylserine in the salvaged units as well as greater osmotic fragility. Salvaged pRBCs maintained consistent clot firmness. After hemorrhage and resuscitation in a murine model, salvaged pRBCs did not demonstrate increased serum cytokine levels.

CONCLUSION

Salvaged pRBCs from previously stored whole blood accumulate the red blood cell storage lesion in a similar fashion to standard pRBCs and maintain consistent coagulability when reconstituted with plasma. Salvaged pRBCs are not associated with an increased inflammatory response when used for resuscitation in a murine model. Salvaged pRBCs may be a viable product for utilization in the treatment of traumatic hemorrhagic shock.

Role of redox iron towards an increase in mortality among patients: a systemic review and meta-analysis

An increase in biochemical concentrations of non-transferrin bound iron (NTBI) within the patients with an increase in serum iron concentration was evaluated with the following objectives: (a) Iron overloading diseases/conditions with free radicle form of ‘iron containing’ reactive oxygen species (ROS) and its imbalance mediated mortality, and (b) Intervention with iron containing drugs in context to increased redox iron concentration and treatment induced mortality. Literature search was done within Pubmed and cochrane review articles. The Redox iron levels are increased during dys-erythropoiesis and among transfusion recipient population and are responsive to iron-chelation therapy. Near expiry ‘stored blood units’ show a significant rise in the ROS level. Iron mediated ROS damage may be estimated by the serum antioxidant level, and show reduction in toxicity with high antioxidant, low pro-oxidant levels. Iron drug therapy causes a significant increase in NTBI and labile iron levels. Hospitalized patients on iron therapy however show a lower mortality rate. Serum ferritin is a mortality indicator among the high-dose iron therapy and transfusion dependent population. The cumulative difference of pre-chelation to post chelation ROS iron level was 0.97 (0.62; 1.32; N=261) among the transfusion dependent subjects and 2.89 (1.81–3.98; N=130) in the post iron therapy ‘iron ROS’ group. In conclusion, iron mediated mortality may not be mediated by redox iron among multi-transfused and iron overloaded patients.

Sex-mismatched red blood cell transfusions and mortality: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Selection of a compatible red blood cell (RBC) unit does not include matching for donor sex. This systematic review and meta-analysis aims to summarize the evidence examining the impact of sex-mismatched RBC transfusion on recipient mortality.

MATERIALS AND METHODS

Ovid MEDLINE, Ovid EMBASE, CINAHL, PubMed, Web of Science and the Cochrane Database of Systematic Reviews were searched from inception up to 23 November 2018. Randomized controlled trials and observational studies were included in the search. Eligible studies reported on the impact of sex-matched compared to sex-mismatched RBC transfusion on recipient mortality. Two investigators independently extracted data and assessed study quality. A three-level meta-analytic model was applied to emphasize the unknown dependence among the effect sizes.

RESULTS

Five retrospective observational studies (n = 86 737) were included; no RCTs were found. Sex-mismatched RBC transfusions were associated with a higher risk of death compared with sex-matched transfusions (pooled hazard ratio [HR]: 1·13; 95% confidence interval [CI]: 1·02-1·24). In the subgroup of cardiovascular surgery (n = 57 712), there was no significant increase in mortality with sex-mismatched transfusions (pooled HR: 1·08; 95% CI: 0·95-1·22). The data were prone to confounding, selection bias and reporting bias. Certainty of the evidence was very low.

CONCLUSION

Sex-mismatched RBC transfusions were associated with an increased risk of death in this pooled analysis. However, the certainty of the evidence was very low from observational studies. The need to match donor and recipient sex for transfusions requires further investigation because of the potential widespread impact.

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.

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.

Critical developments of 2017: a review of the literature from selected topics in transfusion. A committee report from the AABB Clinical Transfusion Medicine Committee

BACKGROUND

The AABB compiles an annual synopsis of the published literature covering important developments in the field of Transfusion Medicine. For the first time, an abridged version of this work is being made available in TRANSFUSION, with the full-length report available as an Appendix S1 (available as supporting information in the online version of this paper).

STUDY DESIGN AND METHODS

Papers published in 2016 and early 2017 are included, as well as earlier papers cited for background. Although this synopsis is comprehensive, it is not exhaustive, and some papers may have been excluded or missed.

RESULTS

The following topics are covered: duration of red blood cell storage and clinical outcomes, blood donor characteristics and patient outcomes, reversal of bleeding in hemophilia and for patients on direct oral anticoagulants, transfusion approach to hemorrhagic shock, pathogen inactivation, pediatric transfusion medicine, therapeutic apheresis, and extracorporeal support.

CONCLUSION

This synopsis may be a useful educational tool.

Association of Blood Transfusion From Female Donors With and Without a History of Pregnancy With Mortality Among Male and Female Transfusion Recipients

IMPORTANCE

Transfusion of red blood cells from female donors has been associated with increased mortality in male recipients.

OBJECTIVE

To quantify the association between red blood cell transfusion from female donors with and without a history of pregnancy and mortality of red blood cell recipients.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of first-time transfusion recipients at 6 major Dutch hospitals enrolled from May 30, 2005, to September 1, 2015; the final follow-up date was September 1, 2015. The primary analysis was the no-donor-mixture cohort (ie, either all red blood cell transfusions exclusively from male donors, or all exclusively from female donors without a history of pregnancy, or all exclusively from female donors with a history of pregnancy). The association between mortality and exposure to transfusions from ever-pregnant or never-pregnant female donors was analyzed using life tables and time-varying Cox proportional hazards models.

EXPOSURES

Red blood cell transfusions from ever-pregnant or never-pregnant female donors, compared with red blood cell transfusions from male donors.

MAIN OUTCOMES AND MEASURES

All-cause mortality during follow-up.

RESULTS

The cohort for the primary analyses consisted of 31 118 patients (median age, 65 [interquartile range, 42-77] years; 52% female) who received 59 320 red blood cell transfusions exclusively from 1 of 3 types of donors (88% male; 6% ever-pregnant female; and 6% never-pregnant female). The number of deaths in this cohort was 3969 (13% mortality). For male recipients of red blood cell transfusions, all-cause mortality rates after a red blood cell transfusion from an ever-pregnant female donor vs male donor were 101 vs 80 deaths per 1000 person-years (time-dependent "per transfusion" hazard ratio [HR] for death, 1.13 [95% CI, 1.01-1.26]). For receipt of transfusion from a never-pregnant female donor vs male donor, mortality rates were 78 vs 80 deaths per 1000 person-years (HR, 0.93 [95% CI, 0.81-1.06]). Among female recipients of red blood cell transfusions, mortality rates for an ever-pregnant female donor vs male donor were 74 vs 62 per 1000 person-years (HR, 0.99 [95% CI, 0.87 to 1.13]); for a never-pregnant female donor vs male donor, mortality rates were 74 vs 62 per 1000 person-years (HR, 1.01 [95% CI, 0.88-1.15]).

CONCLUSIONS AND RELEVANCE

Among patients who received red blood cell transfusions, receipt of a transfusion from an ever-pregnant female donor, compared with a male donor, was associated with increased all-cause mortality among male recipients but not among female recipients. Transfusions from never-pregnant female donors were not associated with increased mortality among male or female recipients. Further research is needed to replicate these findings, determine their clinical significance, and identify the underlying mechanism.

Characteristics of resveratrol and serotonin on antioxidant capacity and susceptibility to oxidation of red blood cells in stored human blood in a time-dependent manner

Objective

In stored red blood cells (RBCs), which are used in diseases (e.g., acute blood loss and leukaemia), storage lesions arise by oxidative stress and other factors over time. This study investigated the protective effects of resveratrol and serotonin on stored RBCs.

Methods

Blood from each donor (n = 10) was placed in different bags containing 70 mL of citrate phosphate dextrose (total volume: 500 mL) and divided into three groups (n = 30): control, 60 µg/mL resveratrol, and 60 µg/mL serotonin. Malondialdehyde (MDA) and glutathione (GSH) levels, activity of glutathione peroxidase (GSH-Px), catalase, and carbonic anhydrase (CA), and susceptibility to oxidation in RBCs, and pH in whole blood were measured at baseline and on days 7, 14, 21, and 28.

Results

MDA levels and susceptibility to oxidation were increased in all three groups time-dependently, but this increase was greater in the serotonin group than in the other groups. Activity of GSH-Px, CAT, and CA, as well as GSH levels, were decreased in the control and serotonin groups time-dependently, but were significantly preserved in the resveratrol group. The pH was decreased in all groups time-dependently.

Conclusion

Our study shows that resveratrol attenuates susceptibility to oxidation of RBCs and protects their antioxidant capacity, and partially preserves CA activity time-dependently.

Exploring donor and product factors and their impact on red cell post-transfusion outcomes

The impact of donor characteristics, red cell age, and red cell processing methods on recipient outcomes is an emerging area of research. Knowledge generated from exploring this transfusion continuum has the potential to change the way donors are selected and how donations are processed and stored with important clinical and operational impact. Recently, donor characteristics including age, gender, donation frequency, genetics, and ethnicity have been shown to affect product quality and possibly recipient outcomes. The structural, biochemical and immunological changes that occur with red cell storage appear to not cause harm to blood recipients after 14 randomized clinical trials. However, both in vitro and clinical data are now beginning to question the safety of blood stored for a shorter duration. Whole blood filtration, a method of blood processing, has been linked to inferior recipient outcomes when compared to red cell filtration. Collectively, this emerging body of literature suggests that pre-transfusion parameters impact product quality and recipient outcomes and that no 2 units of red cells are quite the same. This review will summarize both the pre-clinical and clinical studies evaluating these associations.

Ethnicity, sex, and age are determinants of red blood cell storage and stress hemolysis: results of the REDS-III RBC-Omics study

Genetic polymorphisms in blood donors may contribute to donor-specific differences in the survival of red blood cells (RBCs) during cold storage and after transfusion. Genetic variability is anticipated to be high in donors with racial admixture from malaria endemic regions such as Africa and Asia. The purpose of this study was to test the hypothesis that donor genetic background, reflected by sex and self-reported ethnicity, significantly modulates RBC phenotypes in storage. High throughput hemolysis assays were developed and used to evaluate stored RBC samples from 11 115 African American, Asian, white, and Hispanic blood donors from 4 geographically diverse regions in the United States. Leukocyte-reduced RBC concentrate-derived samples were stored for 39 to 42 days (1-6°C) and then evaluated for storage, osmotic, and oxidative hemolysis. Male sex was strongly associated with increased susceptibility to all 3 hemolysis measures (P < .0001). African American background was associated with resistance to osmotic hemolysis compared with other racial groups (adjusted P < .0001). Donor race/ethnicity was also associated with extreme (>1%) levels of storage hemolysis exceeding US Food and Drug Administration regulations for transfusion (hemolysis >1% was observed in 3.51% of Asian and 2.47% of African American donors vs 1.67% of white donors). These findings highlight the impact of donor genetic traits on measures of RBC hemolysis during routine cold storage, and they support current plans for genome-wide association studies, which may help identify hereditable variants with substantive effects on RBC storage stability and possibly posttransfusion outcomes.

Red blood cell storage time and transfusion: current practice, concerns and future perspectives

Red blood cells (RBCs) units are the most requested transfusion product worldwide. Indications for transfusion include symptomatic anaemia, acute sickle cell crisis, and acute blood loss of more than 30% of the blood volume, with the aim of restoring tissue oxygen delivery. However, stored RBCs from donors are not a qualitative equal product, and, in many ways, this is a matter of concern in the transfusion practice. Besides donor-to-donor variation, the storage time influences the RBC unit at the qualitative level, as RBCs age in the storage bag and are exposed to the so-called storage lesion. Several studies have shown that the storage lesion leads to post-transfusion enhanced clearance, plasma transferrin saturation, nitric oxide scavenging and/or immunomodulation with potential unwanted transfusion-related clinical outcomes, such as acute lung injury or higher mortality rate. While, to date, several studies have claimed the risk or deleterious effects of "old" vs "young" RBC transfusion regimes, it is still a matter of debate, and consideration should be taken of the clinical context. Transfusion-dependent patients may benefit from transfusion with "young" RBC units, as it assures longer inter-transfusion periods, while transfusion with "old" RBC units is not itself harmful. Unbiased Omics approaches are being applied to the characterisation of RBC through storage, to better understand the (patho)physiological role of microparticles (MPs) that are found naturally, and also on stored RBC units. Perhaps RBC storage time is not an accurate surrogate for RBC quality and there is a need to establish which parameters do indeed reflect optimal efficacy and safety. A better Omics characterisation of components of "young" and "old" RBC units, including MPs, donor and recipient, might lead to the development of new therapies, including the use of engineered RBCs or MPs as cell-based drug delivering tools, or cost-effective personalised transfusion strategies.

Red blood cell components: time to revisit the sources of variability

Quality and safety of red blood cell (RBC) components is managed by screening of donors and strict regulatory controls of blood collection, processing and storage procedures. Despite these efforts, variations in RBC component quality exist as exemplified by the wide range in storage-induced haemolysis. This article provides a brief overview of the variables that contribute or potentially contribute to the quality of stored RBC components, including blood collection, processing, and donor-related variables. Particular focus is made on donor health and lifestyle factors that are not specifically screened and may impact on the physicobiochemical properties of RBCs and their storability. Inflammatory and oxidative stress states may be especially relevant as RBCs are susceptible to oxidative injury. Few studies have investigated the effect of specific donor-related variables on the quality of stored RBC components. Donor-related variables may be unaccounted confounders in the "age of blood" clinical studies that compared outcomes following transfusion of fresher or longer-stored RBC components. The conclusion is drawn that the blood donor is the greatest source of RBC component variability and the least "regulated" aspect of blood component production. It is proposed that more research is needed to better understand the connection between donor-related variables and quality consistency of stored RBC components. This could be very important given the impact of modern lifestyles that sees escalating rates of non-communicable health conditions that are associated with increased oxidative stress, such as hypertension, obesity and diabetes in children and adults, as well as an ageing population in many countries. The effect of these changes to global health and population demographics will impact on blood donor panels, and without significant new research, the consequences on the quality of stored blood components and transfusion outcomes are unknown.

Quality Assessment of Established and Emerging Blood Components for Transfusion

Blood is donated either as whole blood, with subsequent component processing, or through the use of apheresis devices that extract one or more components and return the rest of the donation to the donor. Blood component therapy supplanted whole blood transfusion in industrialized countries in the middle of the twentieth century and remains the standard of care for the majority of patients receiving a transfusion. Traditionally, blood has been processed into three main blood products: red blood cell concentrates; platelet concentrates; and transfusable plasma. Ensuring that these products are of high quality and that they deliver their intended benefits to patients throughout their shelf-life is a complex task. Further complexity has been added with the development of products stored under nonstandard conditions or subjected to additional manufacturing steps (e.g., cryopreserved platelets, irradiated red cells, and lyophilized plasma). Here we review established and emerging methodologies for assessing blood product quality and address controversies and uncertainties in this thriving and active field of investigation.

Red Blood Cell Transfusions in Greece: Results of a Survey of Red Blood Cell Use in 2013

Objective:

Greece is ranked as the second highest consumer of blood components in Europe. For an effective transfusion system and in order to reduce variability of transfusion practice by implementing evidence-based transfusion guidelines it is necessary to study and monitor blood management strategies. Our study was conducted in order to evaluate the use of red blood cell units (RBC-U) in nationwide scale mapping parameters that contribute to their proper management in Greece.

Materials and Methods:

The survey was conducted by the Working Committee of Transfusion Medicine&Apheresis of the Hellenic Society of Hematology from January to December 2013. The collected data included the number, ABO/D blood group, patients’ department, and storage age of RBC-U transfused.

Results:

The number of RBC-U evaluated was 103,702 (17.77%) out of 583,457 RBC-U transfused in Greece in 2013. RBC-U transfused by hospital department (mean percentage) was as follows: Surgery 29.34%, Internal Medicine 29.48%, Oncology/Hematology 14.65%, Thalassemia 8.87%, Intensive Care Unit 6.55%, Nephrology 1.78%, Obstetrics/Gynecology 1.46%, Neonatal&Pediatric 0.31%, Private Hospitals 8.57%. RBC-U distribution according to ABO/D blood group was: A: 39.02%, B: 12.41%, AB: 5.16%, O: 43.41%, D+: 87.99%, D-: 12.01%. The majority of RBC-U (62.46%) was transfused in the first 15 days of storage, 25.24% at 16 to 28 days, and 12.28% at 29-42 days.

Conclusion:

Despite a high intercenter variability in RBC transfusions, surgical and internal medicine patients were the most common groups of patients transfused with an increasing rate for internal medicine patients. The majority of RBC-U were transfused within the first 15 days of storage, which is possibly the consequence of blood supply insufficiency leading to the direct use of fresh blood. Benchmarking transfusion activity may help to decrease the inappropriate use of blood products, reduce the cost of care, and optimize the use of the voluntary donor’s gift.

Insights into red blood cell storage lesion: Toward a new appreciation

Red blood cell storage lesion (RSL) is a multifaceted biological phenomenon. It refers to deterioration in RBC quality that is characterized by lethal and sub-lethal, reversible and irreversible defects. RSL is influenced by prestorage variables and it might be associated with variable clinical outcomes. Optimal biopreservation conditions are expected to offer maximum levels of RBC survival and acceptable functionality and bioreactivity in-bag and in vivo; consequently, full appraisal of RSL requires understanding of how RSL changes interact with each other and with the recipient. Recent technological innovation in MS-based omics, imaging, cytometry, small particle and systems biology has offered better understanding of RSL contributing factors and effects. A number of elegant in vivo and in vitro studies have paved the way for the identification of quality control biomarkers useful to predict RSL profile and posttransfusion performance. Moreover, screening tools for the early detection of good or poor "storers" and donors have been developed. In the light of new perspectives, storage time is not the touchstone to rule on the quality of a packed RBC unit. At least by a biochemical standpoint, the metabolic aging pattern during storage may not correspond to the currently fresh/old distinction of stored RBCs. Finally, although each unit of RBCs is probably unique, a metabolic signature of RSL across storage variables might exist. Moving forward from traditional hematologic measures to integrated information on structure, composition, biochemistry and interactions collected in bag and in vivo will allow identification of points for intervention in a transfusion meaningful context.

Testosterone-dependent sex differences in red blood cell hemolysis in storage, stress, and disease

BACKGROUND

Red blood cell (RBC) hemolysis represents an intrinsic mechanism for human vascular disease. Intravascular hemolysis releases hemoglobin and other metabolites that inhibit nitric oxide signaling and drive oxidative and inflammatory stress. Although these pathways are important in disease pathogenesis, genetic and population modifiers of hemolysis, including sex, have not been established.

STUDY DESIGN AND METHODS

We studied sex differences in storage or stress-induced hemolysis in RBC units from the United States and Canada in 22 inbred mouse strains and in patients with sickle cell disease (SCD) using measures of hemolysis in 315 patients who had homozygous SS hemoglobin from the Walk-PHASST cohort. A mouse model also was used to evaluate posttransfusion recovery of stored RBCs, and gonadectomy was used to determine the mechanisms related to sex hormones.

RESULTS

An analysis of predisposition to hemolysis based on sex revealed that male RBCs consistently exhibit increased susceptibility to hemolysis compared with females in response to routine cold storage, under osmotic or oxidative stress, after transfusion in mice, and in patients with SCD. The sex difference is intrinsic to the RBC and is not mediated by plasmatic factors or female sex hormones. Importantly, orchiectomy in mice improves RBC storage stability and posttransfusion recovery, whereas testosterone repletion therapy exacerbates hemolytic response to osmotic or oxidative stress.

CONCLUSION

Our findings suggest that testosterone increases susceptibility to hemolysis across human diseases, suggesting that male sex may modulate clinical outcomes in blood storage and SCD and establishing a role for donor genetic variables in the viability of stored RBCs and in human hemolytic diseases.