Effect of Blood Donor Characteristics on Transfusion Outcomes: A Systematic Review and Meta-Analysis

Potential Predictors for Deterioration of Renal Function After Transfusion

BACKGROUND

Transfusion of packed red blood cells (pRBCs) is still associated with risks. This study aims to determine whether renal function deterioration in the context of individual transfusions in individual patients can be predicted using machine learning. Recipient and donor characteristics linked to increased risk are identified.

METHODS

This study was registered at ClinicalTrials.gov (NCT05466370) and was conducted after local ethics committee approval. We evaluated 3366 transfusion episodes from a university hospital between October 31, 2016, and August 31, 2020. Random forest models were tuned and trained via Python auto-sklearn package to predict acute kidney injury (AKI). The models included recipients' and donors' demographic parameters and laboratory values, donor questionnaire results, and the age of the pRBCs. Bootstrapping on the test dataset was used to calculate the means and standard deviations of various performance metrics.

RESULTS

AKI as defined by a modified Kidney Disease Improving Global Outcomes (KDIGO) criterion developed after 17.4% transfusion episodes (base rate). AKI could be predicted with an area under the curve of the receiver operating characteristic (AUC-ROC) of 0.73 ± 0.02. The negative (NPV) and positive (PPV) predictive values were 0.90 ± 0.02 and 0.32 ± 0.03, respectively. Feature importance and relative risk analyses revealed that donor features were far less important than recipient features for predicting posttransfusion AKI.

CONCLUSIONS

Surprisingly, only the recipients' characteristics played a decisive role in AKI prediction. Based on this result, we speculate that the selection of a specific pRBC may have less influence than recipient characteristics.

Neonatal Blood Banking Practices

There is little formal guidance to direct neonatal blood banking practices and, as a result, practices vary widely across institutions. In this vulnerable patient population with a high transfusion burden, considerations for blood product selection include freshness, extended-storage media, pathogen inactivation, and other modifications. The authors discuss the potential unintended adverse impacts in the neonatal recipient. Concerns such as immunodeficiency, donor exposures, cytomegalovirus transmission, volume overload, transfusion-associated hyperkalemia, and passive hemolysis from ABO incompatibility have driven modifications of blood components to improve safety.

Association of blood donor characteristics with hemoglobin content in leukoreduced packed red blood cells

BACKGROUND AND OBJECTIVES

A complex relationship exists between donor characteristics and red blood cell quality which remains partly explored. The present study aimed to determine the correlation of donor characteristics with the hemoglobin (Hb) content of leukoreduced packed red blood cells (PRBC).

MATERIALS AND METHODS

This prospective cross-sectional study was conducted on 100 blood donors. A pre-donation sample was collected for hemoglobin and hematocrit estimation. Whole blood was collected in quintuple blood bags and packed red cells were prepared. Sample from each packed red cell unit was estimated for hemoglobin and hematocrit. The volume, total Hb, actual total Hb, volume and Hb lost during processing, mathematical total Hb and hematocrit of each PRBC unit was calculated using formulas. The donor characteristics were analysed for correlation with Hb content of PRBC.

RESULTS

The mean age of the 100 donors enrolled in the study was 36.3 ± 9.9 years. Majority of the donors were vegetarian, non-alcoholic, non-smokers, and had a pre-donation hemoglobin level of more than 14 g/dl. The mean pre-donation Hb of the donors was 14.8 ± 1.5 g/dl. There was a strong positive correlation of donor pre-donation hemoglobin with total Hb (r = 1.000, p = 0.000), actual Hb (r = 0.518, p = 0.000) and mathematical hemoglobin (r = 0.951, p = 0.000) using the Pearson correlation test. A strong positive correlation was observed between the total and actual hemoglobin (r = 0.518, p = 0.000) of the units. There was no association of other donor characteristics with Hb content of leukoreduced PRBC.

CONCLUSION

Donor pre-donation hemoglobin showed a strong positive correlation with the actual hemoglobin content of leukoreduced packed red blood cells.

Screening of subclinical functional hemoglobin and red blood cell abnormalities among blood donors of Fayoum University Hospital in Egypt: Are RET-He, and IRF useful screening tools?

BACKGROUND

The effectiveness of red cell transfusion in a given blood unit that relied on both quantity and quality of donated cells undoubtedly affects prognostic outcomes.

OBJECTIVE

We aimed to determine the frequency of subclinical functional hemoglobin and red cell abnormalities in donated blood of Fayoum University Hospital in Egypt. Additionally, to assess the usefulness of reticulocyte mean hemoglobin content (RET-He) and immature reticulocyte fraction (IRF) as screening measures for such abnormalities.

MATERIAL AND METHODS

This cross-sectional study enrolled 200 volunteer blood donors who met the national standard criterion of blood donation. Complete blood count with reticulocyte parameters, serum ferritin, sickling test, G6PD assay, Mentzer index, and naked-eye single tube red cell osmotic fragility test were carried out.

RESULTS

Functional red cell abnormalities represented 44 % of this cohort. Out of them, 4.5 % had iron deficiency, 11 % had a positive sickling test, 19 % had G6PD deficiency, and 9.5 % had suspicious thalassemia. The sensitivity and specificity test for RET-He in selective identification of functional hemoglobin abnormalities in donated blood were 83.3 % and 61.2 %, respectively at a cutoff value of 26.9. Though there was no statistically significant effect of RET-He on the selective detection of G6PD deficiency, IRF had a statistically significant high level with a p-value of 0.04.

CONCLUSION

Subclinical functional red cell abnormalities seem to be prevalent among blood donors. Reticulocyte/ erythrocyte indices could be useful screening tools for red cell abnormalities. Further studies are required for assessing the impact of transfusing such abnormalities to neonates and other critical recipients.

Does donor sex influence the potential for transfusion with washed packed red blood cells to limit transfusion-related immune responses in preterm newborns?

OBJECTIVE

To evaluate the association of donor sex with transfusion-associated recipient immune responses in preterm newborns receiving unwashed and washed blood.

DESIGN

A cohort study using data collected during the Effect of Washed versus Unwashed Packed Red Blood Cell Transfusion on Immune Responses in the Extremely Preterm Newborn randomised trial.

SETTING

Participants were recruited from two South Australian hospitals between September 2015 and December 2020.

PATIENTS

Preterm newborns (<29 weeks).

INTERVENTIONS

Transfusion with unwashed and washed packed red blood cells (PRBCs) from either exclusively male or any female donor for the first three transfusions.

MAIN OUTCOMES MEASURES

The primary outcome was the change from baseline in post-transfusion plasma cytokine concentrations, specifically interferon gamma, interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12, IL-17A and tumour necrosis factor (TNF).

RESULTS

In total, 153 newborns were evaluated. By the third transfusion, the magnitude of pretransfusion to post-transfusion change in cytokines between the groups differed for IL-6 (p=0.003), IL-12 (p=0.008), IL-17A (p=0.003) and TNF (p=0.007). On post hoc comparison, compared with the unwashed-any female donor group, IL-6 (p<0.05), IL-12 (p<0.05) and IL-17A (p<0.01) were lower in the washed-exclusively male donor group, and IL-6 (p<0.01), IL-12 (p<0.05) and TNF (p<0.01) were lower in the washed-any female donor group.

CONCLUSION

These findings suggest that transfusion with unwashed PRBCs from female donors is associated with an increased recipient immune response, an effect that can be ameliorated with pretransfusion washing. Larger randomised controlled studies confirming this mechanistic link between donor sex and transfusion-associated morbidity are warranted.

TRIAL REGISTRATION NUMBER

ACTRN12613000237785.

Effect of Donor Sex on Recipient Mortality in Transfusion

BACKGROUND

Conflicting observational evidence exists regarding the association between the sex of red-cell donors and mortality among transfusion recipients. Evidence to inform transfusion practice and policy is limited.

METHODS

In this multicenter, double-blind trial, we randomly assigned patients undergoing red-cell transfusion to receive units of red cells from either male donors or female donors. Patients maintained their trial-group assignment throughout the trial period, including during subsequent inpatient and outpatient encounters. Randomization was conducted in a 60:40 ratio (male donor group to female donor group) to match the historical allocation of red-cell units from the blood supplier. The primary outcome was survival, with the male donor group as the reference group.

RESULTS

A total of 8719 patients underwent randomization before undergoing transfusion; 5190 patients were assigned to the male donor group, and 3529 to the female donor group. At baseline, the mean (±SD) age of the enrolled patients was 66.8±16.4 years. The setting of the first transfusion was as an inpatient in 6969 patients (79.9%), of whom 2942 (42.2%) had been admitted under a surgical service. The baseline hemoglobin level before transfusion was 79.5±19.7 g per liter, and patients received a mean of 5.4±10.5 units of red cells in the female donor group and 5.1±8.9 units in the male donor group (difference, 0.3 units; 95% confidence interval [CI], -0.1 to 0.7). Over the duration of the trial, 1141 patients in the female donor group and 1712 patients in the male donor group died. In the primary analysis of overall survival, the adjusted hazard ratio for death was 0.98 (95% CI, 0.91 to 1.06).

CONCLUSIONS

This trial showed no significant difference in survival between a transfusion strategy involving red-cell units from female donors and a strategy involving red-cell units from male donors. (Funded by the Canadian Institutes of Health Research; iTADS ClinicalTrials.gov number, NCT03344887.).

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.

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.

Association Between Blood Donor Demographics and Post-injury Multiple Organ Failure after Polytrauma

OBJECTIVE

To test the hypothesis that blood donor demographics are associated with transfused polytrauma patients' post-injury multiple organ failure (MOF) status.

SUMMARY OF BACKGROUND DATA

Traumatic shock and MOF are preventable causes of death and post-traumatic hemorrhage is a frequent indication for transfusion. The role of blood donor demographics on transfusion recipients is not well known.

METHODS

A log-linear analysis accounting for the correlated structure of the data based on our prospective MOF database was utilized. Tests for trend and interaction were computed using a likelihood ratio procedure.

RESULTS

A total of 229 critically injured transfused trauma patients were included, with 68% of them being males and a mean age of 45 years. On average 10 units of blood components were transfused per patient. A total of 4379 units of blood components were donated by donors aged 46 years on average, 74% of whom were males. Blood components used were red blood cells (47%), cryoprecipitate (29%), fresh frozen plasma (24%), and platelets (less than 1%). Donor-recipient sex mismatched red blood cells transfusions were more likely to be associated with MOF ( P = 0.0012); fresh frozen plasma and cryoprecipitate recipients were more likely to experience MOF when transfused with a male (vs female) component ( P = 0.0014 and <0.0001, respectively). Donor age was not significantly associated with MOF for all blood components.

CONCLUSIONS

Blood components donor sex, but not age, may be an important factor associated with post-injury MOF. Further validation of our findings will help guide future risk mitigation strategies specific to blood donor demographics.

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.

Assessment of thermally stabilized electrospun poly(vinyl alcohol) materials as cell permeable membranes for a novel blood salvage device

The use of Intraoperative Cell Salvage (ICS) is currently limited in oncological surgeries, due to safety concerns associated with the ability of existing devices to successfully remove circulating tumour cells. In this work, we present the first stages towards the creation of an alternative platform to current cell savers, based on the extremely selective immunoaffinity membrane chromatography principle. Non-woven membranes were produced via electrospinning using poly(vinyl alcohol) (PVA), and further heat treated at 180 °C to prevent their dissolution in aqueous environments and preserve their fibrous morphology. The effects of the PVA degree of hydrolysis (DH) (98 % vs 99 %), method of electrospinning (needleless DC vs AC), and heat treatment duration (1-8 h) were investigated. All heat treated supports maintained their cytocompatibility, whilst tensile tests indicated that the 99 % hydrolysed DC electrospun mats were stronger compared to their 98 % DH counterparts. Although, and at the described conditions, AC electrospinning produced fibres with more than double the diameter compared to those from DC electrospinning, it was not chosen for subsequent experiments because it is still under development. Evidence of unimpeded passage of SY5Y neuroblastoma cells and undiluted defibrinated sheep's blood in flow-through filtration experiments confirmed the successful creation of 3D networks with minimum resistance to mass transfer and lack of non-specific cell binding to the base material, paving the way for the development of novel, highly selective ICS devices for tumour surgeries.

An overview of red blood cell and platelet alloimmunisation in transfusion

Post-transfusion alloimmunisation is the main complication of all those observed after one or more transfusion episodes. Alloimmunisation is observed after the transfusion of red blood cell concentrates but also of platelet concentrates. Besides alloimmunisation due to antigens carried almost exclusively by red blood cells such as those of the Rhesus-Kell system, alloimmunisation often raises against HLA antigens; the main responsibility for that, apart from platelet transfusions, lies with residual leukocytes in the products transfused, hence the central importance of effective leukoreduction right from the blood product preparation stage. Alloimmunization is not restricted to transfusion, but it is also observed during pregnancies, carrying out microtransfusions of blood from the fetus immunizing the mother through the placenta (in a retrograde way). Preexisting maternal-fetal immunization can complicate a transfusion program and intensify the creation of alloantibodies in several blood and tissue group systems. The occurrence of autoantibodies, created by several pathogenic reasons, can also interfere with the propensity of certain recipients of blood components to produce alloantibodies. The genetic condition of individuals is in fact strongly linked to the ability or not to recognize antigenic variants foreign to their own biological program and mount an alloimmune response. Some hemoglobin diseases, in carriers of which transfusions can be iterative and lifelong, are complicated by frequent alloimmunizations and amplification of the complications of these alloimmunizations, imposing even stricter transfusion rules. This review details the mechanisms favoring the occurrence of alloimmunization and the immunological principles for the production of molecular and cellular tools for alloimmunization. It concludes with the main preventive measures available to limit the occurrence of these frequent complications of varying severity but sometimes severe.

The Effect of Sex-Mismatched Red Blood Cell Transfusion on Endothelial Cell Activation in Critically Ill Patients

BACKGROUND

Observational studies suggest that sex-mismatched transfusion is associated with increased mortality. Mechanisms driving mortality are not known but may include endothelial activation. The aim of this study is to investigate the effects of sex-mismatched red blood cell (RBC) transfusions on endothelial cell activation markers in critically ill patients.

STUDY DESIGN AND METHODS

In patients admitted to the intensive care unit who received a single RBC unit, blood samples were drawn before (T0), 1 h after (T1), and 24 h after transfusion (T24) for analysis of soluble syndecan-1, soluble intercellular adhesion molecule-1, soluble thrombomodulin (sTM), von Willebrand factor antigen, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNFα). Changes in the levels of these factors were compared between sex-matched and sex-mismatched groups.

RESULTS

Of 69 included patients, 32 patients were in the sex-matched and 37 patients were in the sex-mismatched group. Compared to baseline, sex-matched transfusion was associated with significant reduction in sTM level (p value = 0.03). Between-group comparison showed that levels of syndecan-1 and sTM were significantly higher in the sex-mismatched group compared to the sex-matched group at T24 (p value = 0.04 and 0.01, respectively). Also, TNFα and IL-6 levels showed a statistically marginal significant increase compared to baseline in the sex-mismatched group at T24 (p value = 0.06 and 0.05, respectively), but not in the sex-matched group.

DISCUSSION

Transfusion of a single sex-mismatched RBC unit was associated with higher syndecan-1 and sTM levels compared to transfusion of sex-matched RBC unit. These findings may suggest that sex-mismatched RBC transfusion is associated with endothelial activation.

Technologies for measuring red blood cell deformability

Human red blood cells (RBCs) are approximately 8 μm in diameter, but must repeatedly deform through capillaries as small as 2 μm in order to deliver oxygen to all parts of the body. The loss of this capability is associated with the pathology of many diseases, and is therefore a potential biomarker for disease status and treatment efficacy. Measuring RBC deformability is a difficult problem because of the minute forces (∼pN) that must be exerted on these cells, as well as the requirements for throughput and multiplexing. The development of technologies for measuring RBC deformability date back to the 1960s with the development of micropipette aspiration, ektacytometry, and the cell transit analyzer. In the past 10 years, significant progress has been made using microfluidics by leveraging the ability to precisely control fluid flow through microstructures at the size scale of individual RBCs. These technologies have now surpassed traditional methods in terms of sensitivity, throughput, consistency, and ease of use. As a result, these efforts are beginning to move beyond feasibility studies and into applications to enable biomedical discoveries. In this review, we provide an overview of both traditional and microfluidic techniques for measuring RBC deformability. We discuss the capabilities of each technique and compare their sensitivity, throughput, and robustness in measuring bulk and single-cell RBC deformability. Finally, we discuss how these tools could be used to measure changes in RBC deformability in the context of various applications including pathologies caused by malaria and hemoglobinopathies, as well as degradation during storage in blood bags prior to blood transfusions.

Degradation of red blood cell deformability during cold storage in blood bags

Red blood cells (RBCs) stored in blood bags develop a storage lesion that include structural, metabolic, and morphologic transformations resulting in a progressive loss of RBC deformability. The speed of RBC deformability loss is donor‐dependent, which if properly characterized, could be used as a biomarker to select high‐quality RBC units for sensitive recipients or to provide customized storage timelines depending on the donor. We used the microfluidic ratchet device to measure the deformability of red blood cells stored in blood bags every 14 days over a span of 56 days. We observed that storage in blood bags generally prevented RBC deformability loss over the current standard 42‐day storage window. However, between 42 and 56 days, the deformability loss profile varied dramatically between donors. In particular, we observed accelerated RBC deformability loss for a majority of male donors, but for none of the female donors. Together, our results suggest that RBC deformability loss could be used to screen for donors who can provide stable RBCs for sensitive transfusion recipients or to identify donors capable of providing RBCs that could be stored for longer than the current 42‐day expiration window.

The contribution and potential of older blood donors in Asia Pacific regions

OBJECTIVES

To investigate the blood supply contribution of older donors in five Asia Pacific regions.

BACKGROUND

Older people are often the largest blood user group. Thus, as the population ages blood supply needs increase. Minimum and maximum donation age criteria potentially constrain the size of the donor pool.

MATERIALS AND METHODS

Haemoglobin values and demographic frequency analytics (sex, age and blood type) were analysed on blood donors aged 60 years or more, from Hong Kong, Indonesia, Japan, Singapore and South Korea over 12 months.

RESULTS

Data on  434357 donations was analysed. ABO Rh(D) frequencies of older donors matched that of national frequencies. Older donors were a disproportionately smaller proportion of the total donor pool for each country. Indonesia was the only region with no maximum age limit. Median haemoglobin for older males ranged from 14.2 to 14.8 g/dl and for females 13.1 to 13.9 g/dl. The frequency of female donors was between 15% and 33% of older donors. Older donors had higher donation frequency and lower deferral rates.

CONCLUSION

Older donors are loyal and regular donors but under-represented in all regions studied. They could help meet future blood supply needs, especially post-menopausal female donors. Studies including ferritin levels are needed to determine if upper age limits can be safely modified.

The Impact of COVID-19 on Blood Transfusion Services: A Systematic Review and Meta-Analysis

Introduction

While SARS-CoV-2's main transmission route is through respiratory droplets, research has found that viral RNA could be detected in blood samples, causing concerns over the safety of blood donations and blood products. This paper therefore aims to systematically search for studies that have addressed their country's lack of donations and analyse the risk of blood transfusion-transmission. As such, it will answer the question "should blood services focus more on donation vigilance or worry more about the risks of transmission through blood products?"

Methods

38 articles were identified through a systematic review adopting the PRISMA and STROBE guidelines. Meta-analysis was conducted using OpenMeta software.

Results

The average decrease in blood donations was found to be 38%, with some regions showing up to 67% decrease. To assess the risk of actual blood transfusion-transmission, three datasets were analysed. Firstly, the viral load in COVID-19 patients was studied and found to have less than 1% detection rate (ARD = -0.831, 95% -0.963, -0.699). Secondly, the prevalence of finding viral RNA in a pool of donations was nearly -1.503 (ARD = -1.538, -1.468). Lastly, recipients who were given blood products of positive donors were found to be -0.911 (ARD 95% = -1.247, -0.575).

Discussion/Conclusion

Blood centres should focus more on launching initiatives and policies that would increase their countries' blood supply as the virus has no direct threat to blood safety.

Association of Blood Donor Sex and Age With Outcomes in Very Low-Birth-Weight Infants Receiving Blood Transfusion

IMPORTANCE

There are conflicting data on the association between blood donor characteristics and outcomes among patients receiving transfusions.

OBJECTIVE

To evaluate the association of blood donor sex and age with mortality or serious morbidity in very low-birth-weight (VLBW) infants receiving blood transfusions.

DESIGN, SETTING, AND PARTICIPANTS

This is a cohort study using data collected from 3 hospitals in Atlanta, Georgia. VLBW infants (≤1500 g) who received red blood cell (RBC) transfusion from exclusively male or female donors were enrolled from January 2010 to February 2014. Infants received follow-up until 90 days, hospital discharge, transfer to a non-study-affiliated hospital, or death. Data analysis was performed from July 2019 to December 2020.

EXPOSURES

Donor sex and mean donor age.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite outcome of death, necrotizing enterocolitis (Bell stage II or higher), retinopathy of prematurity (stage III or higher), or moderate-to-severe bronchopulmonary dysplasia. Modified Poisson regression, with consideration of covariate interactions, was used to estimate the association between donor sex and age with the primary outcome, with adjustment for the total number of transfusions and birth weight.

RESULTS

In total, 181 infants were evaluated, with a mean (SD) birth weight of 919 (253) g and mean (SD) gestational age of 27.0 (2.2) weeks; 56 infants (31%) received RBC transfusion from exclusively female donors. The mean (SD) donor age was 46.6 (13.7) years. The primary outcome incidence was 21% (12 of 56 infants) among infants receiving RBCs from exclusively female donors, compared with 45% (56 of 125 infants) among those receiving RBCs from exclusively male donors. Significant interactions were detected between female donor and donor age (P for interaction = .005) and between female donor and number of transfusions (P for interaction < .001). For the typical infant, who received a median (interquartile range) of 2 (1-3) transfusions, RBC transfusion from exclusively female donors, compared with male donors, was associated with a lower risk of the primary outcome (relative risk, 0.29; 95% CI, 0.16-0.54). The protective association between RBC transfusions from female donors, compared with male donors, and the primary outcome increased as the donor age increased, but decreased as the number of transfusions increased.

CONCLUSIONS AND RELEVANCE

These findings suggest that RBC transfusion from female donors, particularly older female donors, is associated with a lower risk of death or serious morbidity in VLBW infants receiving transfusion. Larger studies confirming these findings and examining potential mechanisms are warranted.

Multiple-ancestry genome-wide association study identifies 27 loci associated with measures of hemolysis following blood storage

BackgroundThe evolutionary pressure of endemic malaria and other erythrocytic pathogens has shaped variation in genes encoding erythrocyte structural and functional proteins, influencing responses to hemolytic stress during transfusion and disease.MethodsWe sought to identify such genetic variants in blood donors by conducting a genome-wide association study (GWAS) of 12,353 volunteer donors, including 1,406 African Americans, 1,306 Asians, and 945 Hispanics, whose stored erythrocytes were characterized by quantitative assays of in vitro osmotic, oxidative, and cold-storage hemolysis.ResultsGWAS revealed 27 significant loci (P < 5 × 10-8), many in candidate genes known to modulate erythrocyte structure, metabolism, and ion channels, including SPTA1, ALDH2, ANK1, HK1, MAPKAPK5, AQP1, PIEZO1, and SLC4A1/band 3. GWAS of oxidative hemolysis identified variants in genes encoding antioxidant enzymes, including GLRX, GPX4, G6PD, and SEC14L4 (Golgi-transport protein). Genome-wide significant loci were also tested for association with the severity of steady-state (baseline) in vivo hemolytic anemia in patients with sickle cell disease, with confirmation of identified SNPs in HBA2, G6PD, PIEZO1, AQP1, and SEC14L4.ConclusionsMany of the identified variants, such as those in G6PD, have previously been shown to impair erythrocyte recovery after transfusion, associate with anemia, or cause rare Mendelian human hemolytic diseases. Candidate SNPs in these genes, especially in polygenic combinations, may affect RBC recovery after transfusion and modulate disease severity in hemolytic diseases, such as sickle cell disease and malaria.

Current Understanding of the Relationship between Blood Donor Variability and Blood Component Quality

While differences among donors has long challenged meeting quality standards for the production of blood components for transfusion, only recently has the molecular basis for many of these differences become understood. This review article will examine our current understanding of the molecular differences that impact the quality of red blood cells (RBC), platelets, and plasma components. Factors affecting RBC quality include cytoskeletal elements and membrane proteins associated with the oxidative response as well as known enzyme polymorphisms and hemoglobin variants. Donor age and health status may also be important. Platelet quality is impacted by variables that are less well understood, but that include platelet storage sensitive metabolic parameters, responsiveness to agonists accumulating in storage containers and factors affecting the maintenance of pH. An increased understanding of these variables can be used to improve the quality of blood components for transfusion by using donor management algorithms based on a donors individual molecular and genetic profile.

Pragmatic, double-blind, randomised trial evaluating the impact of red blood cell donor sex on recipient mortality in an academic hospital population: the innovative Trial Assessing Donor Sex (iTADS) protocol

INTRODUCTION

With over 1 million units of blood transfused each year in Canada, their use has a significant clinical and economic impact on our health system. Adequate screening of blood donors is important to ensure the safety and clinical benefit of blood products. Some adverse transfusion reactions have been shown to be related to donor factors (eg, lung injury), whereas other adverse outcomes have been theoretically related to donor factors (mortality and infection). Our clinical trial will test whether male donor blood leads to a greater benefit for transfusion recipients compared with female donor blood.

METHODS AND ANALYSIS

We have designed a pragmatic, double-blind, randomised trial that will allocate transfusion recipients to receive either male-only or female-only donor transfusions. We will enrol 8850 adult patients requiring at least one transfusion at four sites over an approximate 2-year period. Randomisation and allocation will occur in the blood bank prior to release of the units of blood for transfusion. Our primary outcome is mortality. An intent-to-treat analysis will be applied using all randomised and transfused patients. The principal analysis will be a survival analysis comparing the time from randomisation to death between patients allocated to male donor red blood cells (RBCs) and female donor RBCs.

ETHICS AND DISSEMINATION

Approval has been obtained from research ethics boards of all involved institutions, as well as from privacy offices of Canadian Blood Services, Institute for Clinical Evaluative Science and The Ottawa Hospital Data Warehouse. Our findings will be published in peer-reviewed journals and presented at relevant stakeholder conferences and meetings.

TRIAL REGISTRATION NUMBER

NCT03344887; Pre-results.

Periodontitis increases risk of viable bacteria in freshly drawn blood donations

BACKGROUND

The aim of the study was to determine if periodontitis, which often causes transient bacteraemia, associates with viable bacteria in standard blood donations.

MATERIALS AND METHODS

This was a cross-sectional study of 60 self-reported medically healthy blood donors aged over 50 years. According to standard procedures, whole blood was separated by fractionation into plasma, buffy-coat, and red blood cell (RBC)-fractions. The buffy-coat was screened for bacterial contamination using BacT/ALERT. Samples from plasma and RBC-fractions were incubated anaerobically and aerobically at 37°C for 7 days on trypticase soy blood agar (TSA). For identification, colony polymerase chain reaction was performed using primers targeting 16S rDNA.

RESULTS

From 62% of the donors with periodontitis, bacterial growth was observed on at least 1 out of 4 plates inoculated with plasma or RBCs, whereas only 13% of plates inoculated with plasma or RBCs from periodontally healthy controls yielded bacterial growth (relative risk 6.4, 95% CI: 2.1; 19.5; p=0.0011). None of the donors tested positive for bacterial contamination using BacT/ALERT. Cutibacterium acnes was found in 31% of the donations from donors with periodontitis and in 10% of the donations from periodontally healthy donors. In addition, Staphylococcus species, Bacillus mycoides, Aggregatibacter aphrophilus, and Corynebacterium kroppenstedtii were detected.

DISCUSSION

Periodontitis increased the risk of bacterial contamination of blood products. Contaminating bacteria are often associated with the RBC-fraction. As the BacT/ALERT test is generally performed on platelet products, routine screening fails to detect many occurrences of viable bacteria in the RBC-fraction.

Can red blood cell function assays assess response to red cell-modifying therapies?

BACKGROUND

Red blood cell (RBC)-modifying therapies have provided new opportunities for patients with sickle cell disease, although the absence of validated biomarkers of RBC function is a barrier to FDA approval and clinical adoption. Flow Adhesion (FA) and Mechanical Fragility (MF) biomarkers objectively stratify individuals with SCD into pro-adhesive vs pro-hemolytic phenotypes respectively, which may potentially help predict therapeutic responses.

OBJECTIVE

A Phase 3 clinical trial to determine the effectiveness of vepoloxamer, an RBC-modifying therapy in sickle cell disease (SCD), failed to meet its primary clinical outcome. The aim of this study was to determine whether standardized flow adhesion and mechanical fragility bioassays could differentiate cellular level "responders" from "non-responders" to vepoloxamer treatment.

METHODS

Standardized biomarkers of RBC function (adhesion and mechanical fragility) were utilized in this study to assess the effect of veploxamer on blood samples collected from SCD subjects and to determine whether our assays could differentiate cellular-level "responders" from "non-responders" to vepoloxamer treatment. A Wilcoxon signed-rank test was used to test for differences in adhesion in response to varying vepoloxamer treatments and a Wilcoxon Mann-Whitney test was used to assess differences in mechanical fragility, pre- and post-vepoloxamer treatment. A p-value<0.05 was considered significant.

RESULTS

In this study, we report that in vitro treatment with vepoloxamer reduced adhesion by >75%in 54%of patient samples and induced changes in the membranes of sickle erythrocytes (SSRBCs) making sickle cells behave more like normal erythrocytes (AARBCs) in terms of their resistance to hemolysis.

CONCLUSION

This study demonstrates that the standardized flow adhesion and mechanical fragility biomarkers described here may be useful tools to predict clinical responders to RBC-modifying therapies.

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.

Neonatal red blood cell transfusion

Transfusions are more common in premature infants with approximately 40% of low birth weight infants and up to 90% of extremely low birth weight infants requiring red blood cell transfusion. Although red blood cell transfusion can be life-saving in these preterm infants, it has been associated with higher rates of complications including necrotizing enterocolitis, bronchopulmonary dysplasia, retinopathy of prematurity and possibly abnormal neurodevelopment. The main objective of this review is to assess current red blood cell transfusion practices in the neonatal intensive care unit, to summarize available neonatal transfusion guidelines published in different countries and to emphasize the wide variation in transfusion thresholds that exists for red blood cell transfusion. This review also addresses certain issues specific to red blood cell processing for the neonatal population including storage time, irradiation, cytomegalovirus (CMV) prevention strategies and patient blood management. Future research avenues are proposed to better define optimal transfusion practice in neonatal intensive care units.

Transfusion in critical care: Past, present and future

Anaemia and coagulopathy are common in critically ill patients and are associated with poor outcomes, including increased risk of mortality, myocardial infarction, failure to be liberated from mechanical ventilation and poor physical recovery. Transfusion of blood and blood products remains the corner stone of anaemia and coagulopathy treatment in critical care. However, determining when the benefits of transfusion outweigh the risks of anaemia may be challenging in some critically ill patients. Therefore, the European Society of Intensive Care Medicine prioritised the development of a clinical practice guideline to address anaemia and coagulopathy in non-bleeding critically ill patients. The aims of this article are to: (1) review the evolution of transfusion practice in critical care and the direction for future developments in this important area of transfusion medicine and (2) to provide a brief synopsis of the guideline development process and recommendations in a format designed for busy clinicians and blood bank staff. These clinical practice guidelines provide recommendations to clinicians on how best to manage non-bleeding critically ill patients at the bedside. More research is needed on alternative transfusion targets, use of transfusions in special populations (e.g., acute neurological injury, acute coronary syndromes), use of anaemia prevention strategies and point-of-care interventions to guide transfusion strategies.

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.

Early Allograft Dysfunction Following Liver Transplant: Impact of Obesity, Diabetes, and Red Blood Cell Transfusion

PURPOSE

We examined the role of obesity and intraoperative red blood cell (RBC) and platelet transfusion in early allograft dysfunction (EAD) following liver transplantation (LT).

METHODS

This is a retrospective analysis of 239 adult deceased-donor LT recipients over a 10-year period. EAD was defined by Olthoff's criteria. Data collection included donor (D) and recipient (R) age, body mass index (BMI) ≥ 35 kg/m², diabetes mellitus, allograft macrosteatosis, and intraoperative (RBC) and platelet administration. We employed logistic regression to evaluate associations of these factors with EAD. Results are presented as odds ratios (OR) and 95% confidence intervals (CI) with corresponding P values. A P ≤ .05 was considered statistically significant.

RESULTS

EAD occurred in 85 recipients (36%). Macrosteatosis data were available for 199 donors. In the multivariate analyses, BMI-D ≥ 35 kg/m² increased the odds of developing EAD by 156% in the entire cohort (OR 2.56, 95% CI 1.09-6.01) and by 187% in recipients with macrosteatosis data (n = 199, OR 2.87, 95% CI 1.15-7.15). Each unit of RBCs increased the odds for EAD by 8% (OR 1.08, 95% CI 1.02-1.14) and, for the subgroup of 238 recipients with macrosteatosis data, by 9% (OR 1.09, 95% CI 1.02-1.16).

CONCLUSION

We found a significant independent association of donor obesity and intraoperative RBC transfusion with EAD but no such association for platelet administration, MELD score, age, recipient obesity, and diabetes.

Association between recipient survival and blood donor age after blood transfusion in a surgery intensive care unit: a multicenter randomized controlled trial study protocol

BACKGROUND

Blood from younger individuals has been shown to improve physiological function in recipients in laboratory research, and many proteins from human peripheral blood show antisenescence capabilities. Thus, researchers have questioned whether blood from young donors is superior to blood from older donors. Blood transfusion is a key supportive therapy for trauma patients, and recent studies have reported the influence of blood donor age on recipient patient prognosis. Although some retrospective results found that blood from young donors improves survival, no influence of blood donor age was observed on outcomes in other study groups. The reasons for this discrepancy are complicated, but the fact that data were not obtained from randomized controlled trial (RCT) data should be considered. The current protocol and analysis method provide a feasible RCT design to evaluate the prognosis of severely ill surgery patients who were transfused with blood products from blood donors of different ages.

METHODS

The current study is a pragmatic multicenter RCT (open, parallel-group, non-masked, superiority trial). Recruited surgery intensive care unit patients will be randomized into three groups and transfused with blood products from male donors of different ages (< 25, 25-45, and > 45 years). Survival time will be measured within 28 days. The survival characteristics, possible interaction between variables, and potential factors associated with death will be analyzed by Kaplan-Meier analysis, two-way ANOVA, and Cox proportional hazards model, respectively.

TRIAL REGISTRATION

ChiCTR: ChiCTR190002. Registered on 22 March 2019. http://www.chictr.org.cn/showproj.aspx?proj=36867 .

Are single-donor red blood cell transfusions still relevant for preterm infants?

OBJECTIVE

To explore the worth of a single-donor program for preterm infants through the recipient profile and the impact on donor exposure, red blood cell (RBC) pack waste, storage duration, and transfusion performance.

STUDY DESIGN

Patients and transfusion characteristics were collected for 3 years (2015-2017) in preterm infants according to single-donor program prescription in a unit not practicing placental transfusion or erythropoietin supplementation.

RESULTS

Among 1048 eligible preterm infants, 161 met the inclusion criteria, and 51 received single-donor packs. Our single-donor program induced a donor number reduction (34% less than the transfusion number) and an extension of storage duration (median: 9 versus 7 days, p < 0.0001) without altering the transfusion performance. However, 41% of small packs were not used.

CONCLUSION

A single-donor program partially reduced donor exposure but led to drastic RBC pack waste. Optimization of transfusion alternatives may increase this phenomenon, calling into question the rationale of this practice.

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).

Intra-vital Observation of Lung Water Retention Following Intravenous Injection of Anti-MHC-class I (H-2K) Monoclonal Antibody in Mice

BACKGROUND/AIM

Leukocyte activation is thought to be a major step in sepsis-induced pulmonary edema. We attempted to confirm whether pulmonary edema can be reproduced under intravital microscopy in a model of transfusion-related acute lung injury (TRALI) using MHC class I-specific antibody.

MATERIALS AND METHODS

The surface pulmonary microcirculation was observed using an epi-fluorescence microscope through a thoracic window in 50 male mice. Monoclonal MHC class I-specific antibody (Ab) was administered to the animals, while the control group received saline. The leukocytes and macro-molecular leakage in the pulmonary circulation were analyzed.

RESULTS

Leukocytes accumulated in the capillaries (52.5±12.7 leukocytes per designated area in Ab group vs. 20.8±3.1 in control). The air-containing alveolus area significantly shrank from 2,224.9±934.9 μm² to 509.7±380.8 μm² in the Ab group.

CONCLUSION

Pulmonary edema develops rapidly following leukocyte accumulation in the lung. We confirmed that leukocyte accumulation without an underlining condition is sufficient to induce pulmonary edema.

Not all red cell concentrate units are equivalent: international survey of processing and in vitro quality data

INTRODUCTION

In vitro qualitative differences exist in red cell concentrates (RCCs) units processed from whole blood (WB) depending on the method of processing. Minimal literature exists on differences in processing and variability in quality data. Therefore, we collected information from blood manufacturers worldwide regarding (1) details of WB collection and processing used to produce RCCs and (2) quality parameters and testing as part of routine quality programmes.

METHODS

A secure web-based survey was developed, refined after pilot data collection and distributed to blood centres. Descriptive analyses were performed.

RESULTS

Data from ten blood centres in nine countries were collected. Six blood centres (60%) processed RCCs using the top-and-top (TAT) method which produces RCCs and plasma, and eight centres (80%) used the bottom-and-top (BAT) which additionally produces buffy coat platelets. Five of the centres used both processing methods; however, four favoured BAT processing. One centre utilized the Reveos automated system exclusively. All centres performed pre-storage leucoreduction. Other parameters demonstrated variability, including active cooling at collection, length of hold before processing, donor haemoglobin limits, acceptable collection weights, collection sets, time to leucoreduction, centrifugation speeds, extraction devices and maximum RCC shelf life. Quality marker testing also differed amongst blood centres. Trends towards higher RCC unit volume, haemolysis and residual leucoctyes were seen in the TAT compared with BAT processing across centres.

CONCLUSION

Methods and parameters of WB processing and quality testing of RCCs differ amongst surveyed blood manufacturers. Further studies are needed to assess variations and to potentially improve methods and product quality.

High prevalence of periodontitis in blood donors and the possibility of questionnaire-based screening - results of a cross-sectional study

BACKGROUND

Periodontitis is an inflammatory disease of high prevalence and, thus, of potential relevance to the management of blood donation.

OBJECTIVES

The aim of this cross-sectional study was to assess periodontal health and its associations to common blood parameters, as well as questionnaire-based periodontitis screening in blood donors.

METHODS

Generally healthy blood donors were recruited and underwent oral examination. Thereby, the decayed-, missing- and filled-teeth index (DMF-T) and periodontal status, including periodontal probing depth and clinical attachment loss, were assessed. Based on periodontal status, periodontitis severity was classified into no/mild, moderate or severe. Six yes/no questions regarding periodontal complaints and history were asked. Furthermore, common blood parameters were analysed.

RESULTS

A total of 148 participants (mean age 53·33 years) were included. The DMF-T was 15·28 ± 6·44. Nearly three quarters of participants suffered from a periodontitis (moderate 59·5% and severe 14·8%, total periodontitis 74·3%). Periodontitis severity was associated with the history of dental visits caused by periodontal complaints (P < 0·01) and previous periodontal therapy (P < 0·01). Only procalcitonin was initially found to be associated with blood periodontitis severity (P = 0·02). This observation was not confirmed by post-hoc testing between subgroups (P_i  > 0·2). No further association between periodontitis severity and blood parameters was found (P_i  > 0·05).

CONCLUSION

The prevalence of periodontitis in German blood donors is high. However, further studies with sensitive testing of bacteria in peripheral blood are required in order to determine the relevance of this result for the safety of blood components.

Ten years of TRALI mitigation: measuring our progress

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-associated mortality for which multiple mitigation strategies have been implemented over the past decade. However, product-specific TRALI rates have not been reported longitudinally and may help refine additional mitigation strategies.

STUDY DESIGN AND METHODS

This retrospective multicenter study included analysis of TRALI rates from 2007 through 2017. Numerators included definite or probable TRALI reports from five blood centers serving nine states in the United States. Denominators were components distributed from participating centers. Rates were calculated as per 100,000 components distributed (p < 0.05 significant).

RESULTS

One hundred four TRALI cases were reported from 10,012,707 components distributed (TRALI rate of 1.04 per 100,000 components). The TRALI rate was 2.25 for female versus 1.08 for male donated components (p < .001). The TRALI rate declined from 2.88 in 2007 to 0.60 in 2017. From 2007 to 2013, there was a significantly higher TRALI rate associated with female versus male plasma (33.85 vs. 1.59; p < 0.001) and RBCs (1.97 vs. 1.15; p = 0.03). From 2014 through 2017, after implementation of mitigation strategies, a significantly higher TRALI rate only from female-donated plateletpheresis continued to be observed (2.98 vs. 0.75; p = 0.04).

CONCLUSION

Although the TRALI rates have substantially decreased secondary to multiple strategies over the past decade, a residual risk remains, particularly with female-donated plateletpheresis products. Additional tools that may further mitigate TRALI incidence include the use of buffy coat pooled platelets suspended in male donor plasma or platelet additive solution due to the lower amounts of residual plasma.

Role of transfusions in the development of hospital-acquired urinary tract-related bloodstream infection among United States Veterans

BACKGROUND

Urinary tract-related bloodstream infection (BSI) is associated with substantial morbidity, mortality, and financial costs. We examined the role of red blood cell (RBC) transfusions on developing this condition among US Veterans.

METHODS

We conducted a matched case-control study among adult inpatients admitted to 4 Veterans Affairs hospitals. Cases were patients with a positive urine culture result obtained 48hours or longer after admission and a blood culture obtained within 14days of the urine culture, which grew the same organism. Controls included patients with a positive urine culture result who were at risk for but did not develop BSI (control group 1) and patients without a positive urine culture result who were present in the facility at the time of case diagnosis (control group 2).

RESULTS

Compared with the findings in control group 1, receipt of RBCs was not significantly associated with urinary tract-related BSI (odds ratio, 1.03; 95% confidence interval, 1.00-1.07; P = .07). However, we found increased odds of urinary tract-related BSI compared with the results in patients without infection (control group 2) (odds ratio, 1.11; 95% confidence interval, 1.06-1.17; P < .001).

CONCLUSIONS

Given the heightened risk of urinary tract-related BSI associated with receiving a greater number of RBC transfusions, adhering to recommendations to transfuse the minimum amount of blood products necessary may minimize the risk of this infection among Veterans.

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.

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.

Frequent blood donations alter susceptibility of red blood cells to storage- and stress-induced hemolysis

BACKGROUND

Frequent whole blood donations increase the prevalence of iron depletion in blood donors, which may subsequently interfere with normal erythropoiesis. The purpose of this study was to evaluate the associations between donation frequency and red blood cell (RBC) storage stability in a racially/ethnically diverse population of blood donors.

STUDY DESIGN

Leukoreduced RBC concentrate-derived samples from 13,403 donors were stored for 39 to 42 days (1-6°C) and then evaluated for storage, osmotic, and oxidative hemolysis. Iron status was evaluated by plasma ferritin measurement and self-reported intake of iron supplements. Donation history in the prior 2 years was obtained for each subject.

RESULTS

Frequent blood donors enrolled in this study were likely to be white, male, and of older age (56.1 ± 5.0 years). Prior donation intensity was negatively associated with oxidative hemolysis (p < 0.0001) in multivariate analyses correcting for age, sex, and race/ethnicity. Increased plasma ferritin concentration was associated with increased RBC susceptibility to each of the three measures of hemolysis (p < 0.0001 for all), whereas self-reported iron intake was associated with reduced susceptibility to osmotic and oxidative hemolysis (p < 0.0001 for both).

CONCLUSIONS

Frequent blood donations may alter the quality of blood components by modulating RBC predisposition to hemolysis. RBCs collected from frequent donors with low ferritin have altered susceptibility to hemolysis. Thus, frequent donation and associated iron loss may alter the quality of stored RBC components collected from iron-deficient donors. Further investigation is necessary to assess posttransfusion safety and efficacy in patients receiving these RBC products.

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.

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.

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.