Timing of gamma irradiation and blood donor sex influences in vitro characteristics of red blood cells

Functional effects of an African glucose-6-phosphate dehydrogenase (G6PD) polymorphism (Val68Met) on red blood cell hemolytic propensity and post-transfusion recovery

BACKGROUND

Donor genetic variation is associated with red blood cell (RBC) storage integrity and post-transfusion recovery. Our previous large-scale genome-wide association study demonstrated that the African G6PD deficient A- variant (rs1050828, Val68Met) is associated with higher oxidative hemolysis after cold storage. Despite a high prevalence of X-linked G6PD mutation in African American population (>10%), blood donors are not routinely screened for G6PD status and its importance in transfusion medicine is relatively understudied.

STUDY DESIGN AND METHODS

To further evaluate the functional effects of the G6PD A- mutation, we created a novel mouse model carrying this genetic variant using CRISPR-Cas9. We hypothesize that this humanized G6PD A- variant is associated with reduced G6PD activity with a consequent effect on RBC hemolytic propensity and post-transfusion recovery.

RESULTS

G6PD A- RBCs had reduced G6PD protein with ~5% residual enzymatic activity. Significantly increased in vitro hemolysis induced by oxidative stressors was observed in fresh and stored G6PD A- RBCs, along with a lower GSH:GSSG ratio. However, no differences were observed in storage hemolysis, osmotic fragility, mechanical fragility, reticulocytes, and post-transfusion recovery. Interestingly, a 14% reduction of 24-h survival following irradiation was observed in G6PD A- RBCs compared to WT RBCs. Metabolomic assessment of stored G6PD A- RBCs revealed an impaired pentose phosphate pathway (PPP) with increased glycolytic flux, decreasing cellular antioxidant capacity.

DISCUSSION

This novel mouse model of the common G6PD A- variant has impaired antioxidant capacity like humans and low G6PD activity may reduce survival of transfused RBCs when irradiation is performed.

Blood donor, component, and recipient-specific factors associated with venous thromboembolism in transfused hospitalized adult patients: Data from the recipient epidemiology and donor evaluation Study-III (REDS-III)

OBJECTIVE

Growing evidence suggests multiple pathophysiological mechanisms linking red blood cells (RBC) transfusions to thrombosis. This study examined blood donor, component, and recipient factors which may be associated with thromboembolic outcomes following RBC transfusion.

METHODS

We utilized the Recipient Epidemiology Donor Evaluation Study-III (REDS-III) database on patients transfused in 12 hospitals between 2013-2016. Stratified Cox proportional hazards regression models with time-dependent exposures were used to examine associations of donor and component modification characteristics on venous thromboembolism (VTE) in patients transfused RBC units.

RESULTS

59,603 patients were transfused 229,500 RBC units during 79,298 hospitalizations with post-transfusion VTE occurring in 1869 (2.4%) of patients. In adjusted regression analyses, a per RBC-unit risk of VTE was present for gamma irradiation (HR = 1.03; 95% CI: 1.02-1.03), female donor sex (HR = 1.01; 95% CI: 1.00-1.01), storage duration greater than 5 weeks (HR = 1.01; 95% CI: 1.01-1.02), AS-1 storage solution (HR = 1.01; 95% CI: 1.00-1.01), and apheresis-derived collections (HR = 1.01; 95% CI: 1.01-1.02). Among recipient factors, male sex (HR = 1.03; 95% CI: 1.02-1.04), pre-transfusion hemoglobin level (HR = 0.94; 95% CI: 0.94-0.94), body mass index strata (HR = 1.11; 95% CI: 1.08-1.14), and principal diagnoses including malignancy (HR = 1.13; 95% CI: 1.10-1.16), cardiac arrest (HR = 1.38; 95% CI:1.07-1.77) and hip fracture (HR = 1.59; 95% CI:1.53-1.66) were associated with VTE in adjusted analyses.

DISCUSSION

We identified several donor, component, and recipient-specific factors associated with VTE in transfused hospitalized adult patients. In adjusted models, the dose-dependent associations of donor and component-specific factors with VTE were modest and unlikely to be clinically significant in the majority of transfused patients. Additional mechanistic and clinical studies linking blood donor and component factors with thrombotic outcomes are needed.

A randomized trial of blood donor iron repletion on red cell quality for transfusion and donor cognition and well-being

Although altruistic regular blood donors are vital for the blood supply, many become iron deficient from donation-induced iron loss. The effects of blood donation-induced iron deficiency on red cell transfusion quality or donor cognition are unknown. In this double-blind, randomized trial, adult iron-deficient blood donors (n = 79; ferritin < 15 μg/L and zinc protoporphyrin >60 μMol/mol heme) who met donation qualifications were enrolled. A first standard blood donation was followed by the gold-standard measure for red cell storage quality: a 51-chromium posttransfusion red cell recovery study. Donors were then randomized to intravenous iron repletion (1 g low-molecular-weight iron dextran) or placebo. A second donation ∼5 months later was followed by another recovery study. Primary outcome was the within-subject change in posttransfusion recovery. The primary outcome measure of an ancillary study reported here was the National Institutes of Health Toolbox-derived uncorrected standard Cognition Fluid Composite Score. Overall, 983 donors were screened; 110 were iron-deficient, and of these, 39 were randomized to iron repletion and 40 to placebo. Red cell storage quality was unchanged by iron repletion: mean change in posttransfusion recovery was 1.6% (95% confidence interval -0.5 to 3.8) and -0.4% (-2.0 to 1.2) with and without iron, respectively. Iron repletion did not affect any cognition or well-being measures. These data provide evidence that current criteria for blood donation preserve red cell transfusion quality for the recipient and protect adult donors from measurable effects of blood donation-induced iron deficiency on cognition. This trial was registered at www.clinicaltrials.gov as NCT02889133 and NCT02990559.

Donor genetic and non-genetic factors affecting red blood cell transfusion effectiveness

BACKGROUND

Red blood cell (RBC) transfusion effectiveness varies due to donor, component, and recipient factors. Prior studies identified characteristics associated with variation in hemoglobin increments following transfusion. We extended these observations, examining donor genetic and non-genetic factors affecting transfusion effectiveness.

METHODS

This is a multicenter retrospective study of 46,705 patients, and 102,043 evaluable RBC transfusions from 2013-2016 across 12 hospitals. Transfusion effectiveness was defined as hemoglobin, bilirubin, or creatinine increments following single RBC unit transfusion. Models incorporated a subset of donors with data on single nucleotide polymorphisms associated with osmotic and oxidative hemolysis in vitro. Mixed modelling accounting for repeated transfusion episodes identified predictors of transfusion effectiveness.

RESULTS

Blood donor (sex, Rh status, fingerstick hemoglobin, smoking), component (storage duration, gamma irradiation, leukoreduction, apheresis collection, storage solution), and recipient (sex, body mass index, race, age) characteristics were associated with hemoglobin and bilirubin but not creatinine increments following RBC transfusions. Increased storage duration was associated with increased bilirubin and decreased hemoglobin increments, suggestive of in vivo hemolysis following transfusion. Donor G6PD-deficiency and polymorphisms in SEC14L4, HBA2, and MYO9B genes were associated with decreased hemoglobin increments. Donor G6PD-deficiency and polymorphisms in SEC14L4 were associated with increased transfusion requirements in the subsequent 48 hours.

CONCLUSIONS

Donor genetic and other factors, such as RBC storage duration, affect transfusion effectiveness as defined by decreased hemoglobin or increased bilirubin increments. Addressing these factors will provide a precision medicine approach to improve patient outcomes, particularly for chronically-transfused RBC recipients, who would most benefit from more effective transfusion products.

The recipe for TACO: A narrative review on the pathophysiology and potential mitigation strategies of transfusion-associated circulatory overload

Transfusion associated circulatory overload (TACO) is one of the leading causes of transfusion related morbidity and mortality. TACO is the result of hydrostatic pulmonary edema following transfusion. However, up to 50% of all TACO cases appear after transfusion of a single unit, suggesting other factors, aside from volume, play a role in its pathophysiology. TACO follows a two-hit model, in which the first hit is an existing disease or comorbidity that renders patients volume incompliant, and the second hit is the transfusion. First hit factors include, amongst others, cardiac and renal failure. Blood product factors, setting TACO apart from crystalloid overload, include colloid osmotic pressure effects, viscosity, pro-inflammatory mediators and storage lesion byproducts. Differing hemodynamic changes, glycocalyx injury, endothelial damage and inflammatory reactions can all contribute to developing TACO. This narrative review explores pathophysiological mechanisms for TACO, discusses related therapeutic and preventative measures, and identifies areas of interest for future research.

X- and gamma-irradiation have similar effects on the in vitro quality of stored red cell components

BACKGROUND

Blood components are irradiated to inactivate lymphocytes to prevent transfusion-associated graft versus host disease. As there are little data regarding the effects of X-irradiation on red blood cell components (RBCs), the in vitro quality of stored red cells (standard, pediatric, washed, and intra-uterine transfusion [IUT]) following X- or gamma-irradiation was compared.

STUDY DESIGN AND METHODS

RBCs were pooled, split, and processed to produce standard (<14 days and < 5 days post-collection), pediatric (<5 days post-collection), washed (<14 days post-collection), or IUT RBCs (<5 days post-collection). Standard RBCs were either X- or gamma-irradiated (n = 10 pairs). A further 10 replicates were prepared by pooling and splitting three matched RBCs (X-, gamma-, and non-irradiated). All other RBCs were either X- or gamma-irradiated (n = 20 pairs). Red cell indices, hemolysis, potassium release, metabolism, microparticles, ATP, and 2,3-DPG were measured pre-irradiation and 6 h, 1, 2, 3, 7, 10, and 14 days post-irradiation, depending on the component type. Data were analyzed using two-way repeated measures ANOVA.

RESULTS

There were no significant differences in any in vitro quality measurements, with the exception of marginally higher potassium release in washed, IUT, and RBCs <5 days old (p < .0001) following X-irradiation. Both irradiation types increased generation of microvesicles, particularly in components that were older at the time of irradiation or stored for longer post-irradiation.

CONCLUSION

X- and gamma-irradiation have similar effects on the in vitro quality of RBCs, indicating that either technology is suitable for blood component irradiation.

DEHT is a suitable plasticizer option for phthalate-free storage of irradiated red blood cells

BACKGROUND AND OBJECTIVES

Due to increasing concerns about possible endocrine-disrupting properties, the use of the plasticizer di(2-ethylhexyl) phthalate (DEHP) will be banned in future blood storage. Di(2-ethylhexyl) terephthalate (DEHT) provides sufficient red blood cell (RBC) quality during conventional blood bank storage. It is important that a new plasticizer also maintains acceptable quality during exposure to high cell stress, such as irradiation, which is commonly used to prevent graft-versus-host disease.

MATERIALS AND METHODS

A total of 59 RBC units were collected and processed in polyvinyl chloride (PVC)-DEHT or PVC-DEHP blood bags combined with either saline-adenine-glucose-mannitol (SAGM) or phosphate-adenine-glucose-guanosine-saline-mannitol (PAGGSM) additive solution. All units were X-ray irradiated on day 2 post-collection. Sampling for assessment of parameters of storage lesion was performed on day 2 pre-irradiation and day 14 and 28 post-irradiation.

RESULTS

Though irradiation increased cell stress, DEHT/PAGGSM and current common European preference DEHP/SAGM were equally affected up to 14 days post-irradiation for all measured parameters. At day 28, haemolysis and microvesicle count were slightly increased in DEHT, whereas extracellular potassium ions, glucose, lactate, pH, mean corpuscular volume and microvesicle phosphatidylserine remained unaffected by plasticizer choice throughout storage. No individual unit exceeded 0.8% haemolysis, not even in DEHT/SAGM, the combination overall most affected by irradiation. Of the four combinations, membrane stability was least impacted in DEHP/PAGGSM.

CONCLUSION

We demonstrate that DEHT is a suitable plasticizer for storage of RBCs after X-ray irradiation cell stress. This strengthens the option of DEHT as a viable non-phthalate substitute for DEHP.

Metabolic profile of irradiated whole blood by chemical isotope-labeling liquid chromatography-mass spectrometry

Irradiated blood is a new type of blood product used to prevent transfusion-associated graft-versus-host disease. However, the effects of irradiation on the metabolism of plasma, red blood cells (RBCs), and peripheral blood mononuclear cells (PBMCs) are largely unknown. We developed a workflow for testing metabolic changes in whole blood to determine the impact of irradiation by chemical isotope labeling liquid chromatography-mass spectrometry (CIL LC-MS). Blood parameters, PBMC proliferation and apoptosis were examined before and after irradiation. Next, the amine/phenol metabolites in the blood components were assayed by ¹²C- and¹³C-dansylation labeling LC-MS. We identified 1654, 1730, and 1666 peak pairs in plasma, RBCs, and PBMCs, respectively. We screened out 367, 177, and 219 significant metabolites in plasma, RBCs, and PBMCs, respectively, by principle component analyses, volcano plots, and Venn plots. Metabolic pathway analyses showed that irradiation modulated taurine and hypotaurine metabolism in plasma and purine metabolism in RBCs and PBMCs. Changes in potential biomarkers, including an increase in hypoxanthine level and a decrease in adenine level, may be related to the dysfunction of DNA synthesis in PBMCs. The decreased AMP level in RBCs may interfere with RBC storage lesions. Our research provides a more comprehensive perspective on blood metabolism associated with irradiation.

Nanoscale Changes on RBC Membrane Induced by Storage and Ionizing Radiation: A Mini-Review

The storage lesions and the irradiation of blood cellular components for medical procedures in blood banks are events that may induce nanochanges in the membrane of red blood cells (RBCs). Alterations, such as the formation of pores and vesicles, reduce flexibility and compromise the overall erythrocyte integrity. This review discusses the alterations on erythrocytic lipid membrane bilayer through their characterization by confocal scanning microscopy, Raman, scanning electron microscopy, and atomic force microscopy techniques. The interrelated experimental results may address and shed light on the correlation of biomechanical and biochemical transformations induced in the membrane and cytoskeleton of stored and gamma-irradiated RBC. To highlight the main advantages of combining these experimental techniques simultaneously or sequentially, we discuss how those outcomes observed at micro- and nanoscale cell levels are useful as biomarkers of cell aging and storage damage.

Methodological considerations for linked blood donor-component-recipient analyses in transfusion medicine research

In recent years, there has been a concerted effort to improve our understanding of the quality and effectiveness of transfused blood components. The expanding use of large datasets built from electronic health records allows the investigation of potential benefits or adverse outcomes associated with transfusion therapy. Together with data collected on blood donors and components, these datasets permit an evaluation of associations between donor or blood component factors and transfusion recipient outcomes. Large linked donor-component recipient datasets provide the power to study exposures relevant to transfusion efficacy and safety, many of which would not otherwise be amenable to study for practical or sample size reasons. Analyses of these large blood banking-transfusion medicine datasets allow for characterization of the populations under study and provide an evidence base for future clinical studies. Knowledge generated from linked analyses have the potential to change the way donors are selected and how components are processed, stored and allocated. However, unrecognized confounding and biased statistical methods continue to be limitations in the study of transfusion exposures and patient outcomes. Results of observational studies of blood donor demographics, storage age, and transfusion practice have been conflicting. This review will summarize statistical and methodological challenges in the analysis of linked blood donor, component, and transfusion recipient outcomes.

Effect of donor, component, and recipient characteristics on hemoglobin increments following red blood cell transfusion

Significant research has focused individually on blood donors, product preparation and storage, and optimal transfusion practice. To better understand the interplay between these factors on measures of red blood cell (RBC) transfusion efficacy, we conducted a linked analysis of blood donor and component data with patients who received single-unit RBC transfusions between 2008 and 2016. Hemoglobin levels before and after RBC transfusions and at 24- and 48-hour intervals after transfusion were analyzed. Generalized estimating equation linear regression models were fit to examine hemoglobin increments after RBC transfusion adjusting for donor and recipient demographic characteristics, collection method, additive solution, gamma irradiation, and storage duration. We linked data on 23 194 transfusion recipients who received one or more single-unit RBC transfusions (n = 38 019 units) to donor demographic and component characteristics. Donor and recipient sex, Rh-D status, collection method, gamma irradiation, recipient age and body mass index, and pretransfusion hemoglobin levels were significant predictors of hemoglobin increments in univariate and multivariable analyses (P < .01). For hemoglobin increments 24 hours after transfusion, the coefficient of determination for the generalized estimating equation models was 0.25, with an estimated correlation between actual and predicted values of 0.5. Collectively, blood donor demographic characteristics, collection and processing methods, and recipient characteristics accounted for significant variation in hemoglobin increments related to RBC transfusion. Multivariable modeling allows the prediction of changes in hemoglobin using donor-, component-, and patient-level characteristics. Accounting for these factors will be critical for future analyses of donor and component factors, including genetic polymorphisms, on posttransfusion increments and other patient outcomes.