Comparing transfusion reactions between pre-storage and post-storage leukoreduced apheresis platelets: an analysis using propensity score matching.

Transfusion reactions induced by platelet transfusions may be reduced and alleviated by leukocyte reduction of platelets. Although leukoreduction of apheresis platelets can be performed either pre-storage or post-storage, seldom studies directly compare the incidence of transfusion reaction in these two different blood products. We conducted a retrospective study to compare the transfusion reactions between pre-storage and post-storage leukoreduced apheresis platelets. We reviewed the general characteristics and the transfusion reactions, symptoms, and categories for inpatients who received pre-storage or post-storage leukoreduced apheresis platelets. Propensity-score matching was performed to adjust for baseline differences between groups. A total of 40,837 leukoreduction apheresis platelet orders were reviewed. 116 (0.53%) transfusion reactions were reported in 21,884 transfusions with pre-storage leukoreduction, and 174 (0.91%) reactions were reported in 18,953 transfusions with post-storage leukoreduction. Before propensity-score matching, the odds ratio for transfusion reactions in the pre-storage group relative to the post-storage group was 0.57 (95% confidence interval [CI] 0.45-0.72, P < 0.01); the odds ratio after matching was 0.63 (95% CI 0.49-0.80, P < 0.01). A two-proportion z-test revealed pre-storage leukoreduction significantly decreases the symptoms of chills, fever, itching, urticaria, dyspnea, and hypertension as compared with those in post-storage leukoreduction. Pre-storage leukoreduced apheresis platelet significantly decreased febrile non-hemolytic transfusion reaction as compared with post-storage groups. This study suggests pre-storage leukoreduction apheresis platelet significantly decreases the transfusion reaction as compared with those in post-storage leukoreduction.

A randomized control trial for evaluation of transfusion related immuno-modulation in patients with meningioma.

BACKGROUND: Blood transfusion necessity in neurosurgery varies based on surgical type, blood loss, and patient anemia. Leukocytes in red blood cells (RBCs) component release pro-inflammatory cytokines during storage, contributing to transfusion-related immunomodulation (TRIM). Our aim was to examine the impact of the leukocyte content in transfused PRBCs on patients undergoing neurosurgery for meningioma tumours. STUDY DESIGN AND METHODS: This prospective randomized controlled trial conducted from 2018 to 2020 by dividing patients randomly into non-leukoreduced (NLR) (n = 65) and leuko-reduced (LR) (n = 65) groups based on PRBCs received during surgery and hospital stay. Hospital and ICU stays, mechanical ventilation duration, and postoperative bacterial infections were observed. Hematological parameters and cytokine levels (IL-10, INF-gamma, and FAS-L) were assessed at pre-transfusion, 24 h, and 7 days post-transfusion. Data analysis included Mann-Whitney U test, Friedman test, Fisher's chi-square test, with statistical significance at p < 0.05. RESULTS: In our study, ICU and hospital stay duration showed no significant difference (p = 0.06) between groups. However, NLR group had longer mean mechanical ventilation (18 ± 40.1 h) than the LR group (12.8 ± 8.6 h). Both groups showed statistically significant increase in Fas-L level on days 1 and 7 (p < 0.05). The IL-10 levels rose 43% in the NLR group, while and decreased by 7% the LR group on day 1. On day 7, IL-10 increased by 75% in NLR and decreased by 40% in LR, with no significance (p > 0.05). CONCLUSION: In conclusion, leukoreduction appeared to offer some immune response protection in term of reducing mechanical ventilation timings and cytokine level changes.

Efficient Chimeric Antigen Receptor T-Cell Generation Starting with Leukoreduction System Chambers of Thrombocyte Apheresis Sets.

Introduction: Primary human blood cells represent an essential model system to study physiology and disease. However, human blood is a limited resource. During healthy donor plateletpheresis, the leukoreduction system chamber (LRSC) reduces the leukocyte amount within the subsequent platelet concentrate through saturated, fluidized, particle bed filtration technology. Normally, the LRSC is discarded after apheresis is completed. Compared to peripheral blood, LRSC yields 10-fold mononuclear cell concentration. Methods: To explore if those retained leukocytes are attractive for research purposes, we isolated CD3+ T cells from the usually discarded LRSCs via density gradient centrifugation in order to manufacture CD19-targeted chimeric antigen receptor (CAR) T cells. Results: Immunophenotypic characterization revealed viable and normal CD4+ and CD8+ T-cell populations within LRSC, with low CD19+ B cell counts. Magnetic-activated cell sorting (MACS) purified CD3+ T cells were transduced with CD19 CAR-encoding lentiviral self-inactivating vectors using concentrated viral supernatants. Robust CD19 CAR cell surface expression on transduced T cells was confirmed by flow cytometry. CD19 CAR T cells were further enriched through anti-CAR MACS, yielding 80% CAR+ T-cell populations. In vitro CAR T cell expansion to clinically relevant numbers was achieved. To prove functionality, CAR T cells were co-incubated with the human CD19+ B cell precursor leukemia cell line Nalm6. Compared to unmodified T cells, CD19 CAR T cells effectively eradicated Nalm6 cells. Conclusion: Taken together, we can show that lymphocytes isolated from LRSCs of plateletpheresis sets can be efficiently used for the generation of functional CAR T cells for experimental purposes.

Leukoreduction of red blood cell units decreases dysregulatory micro RNAs during routine storage: An observational study with In-silico analysis.

BACKGROUND: Red Blood cells (RBCs) bring about harmful consequences during storage. MicroRNA (miRNA) dysregulation in stored RBCs could represent potential biomarkers of storage lesions. Although leukoreduction prevents damage to RBCs, it is uncertain whether leukoreduction of RBCs would impact the dysregulation of miRNAs during storage. This study evaluated the potential role of miRNAs for any alteration of leukoreduced (LR) and non-leukoreduced (NLR) RBCs till 21 days of storage. STUDY DESIGN AND METHODS: In this prospective study, thirty male volunteers' blood was equally divided into leukoreduced RBCs (LR) and NLR RBC (NLR) bags and stored till Day 21 at 4-60c. Selected miRNAs were quantified on Days 0 and 21. Further, bioinformatic tools were used to analyze the selected miRNAs and their predicted target genes (mRNAs) and identify the miRNA-mRNA regulatory relationships. RESULTS: A significantly higher fold change values of three miRNAs (miR-96-5p, miR-197-3p, miR-769-3p) were observed in NLR RBCs (p < .05). A significantly higher (p < .05) expression levels of miR-150-5p and miR-197-3p were observed in NLR RBCs till 21 days of storage. Further, the correlation with mRNA quantification confirmed the regulatory role of these miRNAs upon functional pathway enrichment analysis. DISCUSSION: A higher level of dysregulation of miRNAs was observed in NLR RBCs. Validation from In-Silico analysis suggested the regulatory role of miRNAs in cell apoptosis, senescence, and RBC-related signaling pathways. This indicated that stored LR RBCs would likely have better in vivo survival and function following transfusion. However, an in vivo study of miRNA in RBCs is warranted for conclusive evidence.

In-line leukoreduction filters: A new source of microparticle for human and animal study.

INTRODUCTION: The isolation of microparticles (MPs) from leukoreduction filters (LRFs) during cell extraction process introduced LRFs as a precious source of MPs for animal and human study. METHOD: LRFs were collected from Tehran Blood Transfusion Center. The back-flushing method was used for leukocyte extraction from the LRFs. MPs were isolated through double-step centrifugation. Dynamic light scattering (DLS), electron microscopy (EM), and flow cytometry were performed for the evaluation of MPs size, morphology, and structural properties respectively. Statistical analyses were carried out to evaluation of differences between test and control groups. a p-value less than 0.05 indicates significant differences. RESULT: DLS analysis showed that the average MP size in the test and control groups was 654.83 nm and 233.68 nm respectively. SEM images showed the spherical, oval, cell fragment, and micro-aggregate particles and TEM images demonstrated the mitochondrial-like body in the MPs. Flow cytometry studies also showed a significant increase in the percent of CD41, and CD14, and a significant decrease in the percent of CD235a in the test group compared to control (P value=0.029, P value=0.035, P value= 0.001 respectively). Moreover, the percentage of CD34 MPs indicated a borderline difference between the two groups (P value= 0.075). Finally count of MPs in the test and control groups was 1202095.34 and 280948.64, respectively and the difference was significant (P value=0.008). CONCLUSION: It is concluded that LRFs are a potential source of the large volume of various cell MPs with different phenotypical and structural properties for animal and human phase studies. Moreover, the investigation of LRFs as a source of different types of exosomes can shed new light on extracellular vesicle studies.

Investigation of the potential of leukoreduction filters in the creation of anti-inflammatory compound.

BACKGROUND: Some viruses such as SARS, SARS-CoV-2, and MERS cause an imbalance in immune responses and leads to an acute inflammatory reaction named cytokine storm. In this situation, an anti-inflammatory component can modulate the immune system and decrease mortality. The aim of this study was investigate the potential of leukoreduction filters (LRFs) in creating an anti-inflammatory compound. MATERIALS AND METHODS: In this experimental study, firstly optimal dose of the anti-inflammatory drug was obtained through LRFs treatment with 0.1 mg, 0.4 mg, 0.6 mg of Betamethasone. Then inflammatory and anti-inflammatory cytokine in gene and protein level was evaluated. In the next step, LRFs were categorized into treatment 1, treatment 2, control assay, and control groups and treated with the optimal dose of the drug. Finally, the obtained compound was investigated for the concentration of IL1, IL6, and TNF-α as inflammatory and IL4, IL1Ra, and IL10 as anti-inflammatory cytokines. RESULTS: The results of the current study showed that the concentration of 0.4 mg of Betamethasone lead to a significant increase of anti-inflammatory cytokine in gene and protein levels. The results also showed that the Betamethasone treated groups (treatment1) causes a significant increase in the secretion of anti-inflammatory cytokine compares to the control while inflammatory cytokine remained at the control level. CONCLUSION: The results showed that under influence of anti-inflammatory drug treatments the production and secretion of anti-inflammatory cytokines can be induced in LRFs.

Minimal impact of anticoagulant on in vitro whole blood quality throughout a 35-day cold-storage regardless of leukoreduction timing.

BACKGROUND: There is increasing interest in leukoreduced whole blood (WB) as a transfusion product for trauma patients. In some jurisdictions, few leukoreduced filters are approved or appropriate for WB leukoreduction and quality information is therefore limited. This study assessed the impact of filtration timing of WB collected in CPDA-1 versus CPD on in vitro quality. STUDY DESIGN AND METHODS: WB was collected in CPDA-1 or CPD and leukoreduction filtered either after 3-8 h (early) or 18-24 h (late) from stop bleed time. In vitro quality was assessed after filtration and throughout 5 weeks of storage at 4°C. Cell count and hemoglobin levels were determined by hematology analyzer, platelet activation and responsiveness to ADP by surface expression of P-selectin by flow cytometry, hemolysis by HemoCue, and metabolic parameters by blood gas analyzer. Hemostatic properties were assessed by rotational thromboelastometry. Plasma protein activities and clotting times were determined by automated coagulation. RESULTS: Although there were some data points which showed statistically significant differences associated with anticoagulant choices or the filtration timing, no general trend in inferiority/performance could be discerned. After 35 days' storage, only clotting time, alpha angle and factor II in the early filtration arm comparing anticoagulants and prothrombin time and factor II in the CPDA-1 study arm comparing filtration timing showed a significant difference. CONCLUSION: In vitro WB quality seems to be independent on the choice of anticoagulant and filtration timing supporting WB hold-times to up to 24 h, increasing operational flexibility for transfusion services.

Optimized simple and affordable procedure for differentiation of monocyte-derived dendritic cells from LRF: An accessible and valid alternative biological source.

Dendritic cells are one of the most popular immune cells, which plays a remarkable role in both immunotherapy and tolerance induction. Due to unwanted side effects of leukocyte presence in donated blood, the policy of blood service is the pre-storage reduction of leukocytes, which today, filtration is the most common method for this purpose. The filtration method has led to diminished access to Buffy coat as a generally used conventional source of biological cells. We developed a simple, affordable, and reproducible method for dendritic cell differentiation from filter-derived monocytes and, the results of the filter study were compared with differentiated DCs from the conventional buffy coat-derived monocytes. The Monocytes were recovered from leukoreduction filter using an optimized protocol with supplemented PBS buffer. Following the adhesion method, CD14+ Monocyte-enriched population with the purity of 94 % was obtained. After cytokine stimulation over a 6-day period and maturation induction by LPS, differentiated DCs were evaluated for morphology, surface markers (CD86, CD40, CD83 and, HLA-DR), antigen uptake potency and IL-12 secretion. Analysis and comparison of the results represented no significant difference between the two groups. Accordingly, we conclude that leukoreduction filters could be introduced as a reliable and research-grade source of monocyte for DC generation in biological research.

Universal or selective irradiation: a comparison of approaches.

Pathological mechanisms proposed for transfusion-associated graft-versus-host diseases (TA-GVHD) include HLA homozygosity in donor cells of the transfusion unit that is shared by the recipient (one-way HLA match) and immunosuppression in the transfusion recipient. Which of these factors is indispensable or to what degree each factor contributes to the development of TA-GVHD has been the issue of debate. In countries like Japan with higher HLA homogeneity, TA-GVHD occurrence was thought to be primarily dependent on the one-way HLA match mechanism regardless of immunosuppression. Accordingly, universal irradiation of blood components has been conducted with no further TA-GVHD cases. In other developed countries, in contrast, TA-GVHD was thought to be a sort of extrapolation of GVHD observed among heavily immunosuppressed patients. Guidelines with the detailed list of diseases with the indication for irradiated components have been established in those countries. Although TA-GVHD occurrence decreased markedly after the introduction of universal leukoreduction, a considerable number of TA-GVHD cases have occurred among immunocompetent patients mostly by the one-way HLA match mechanism. Because one-way HLA matching with donor homozygosity is thought to be a ubiquitous and independent mechanism for TA-GVHD, it could occur in any transfusion setting regardless of immunosuppression. It would be thoughtful to select an area-specific strategy considering the drawbacks of irradiation and the frequency of TA-GVHD in that area. However, if complete abolition of TA-GVHD is required from the perspective of the high fatality of the disorder, universal irradiation of cellular components will be necessary.

Can transfusion-associated graft-versus-host disease (TA-GvHD) be prevented with leukoreduction alone?

Transfusion-associated graft-versus-host disease (TA-GvHD) is a rare but devastating disease with a very high mortality rate. Because of the high mortality and lack of effective treatments, the current state of the art is aimed at preventing TA-GvHD and this can be accomplished via irradiation of all cellular blood products (red blood cells, granulocytes, and platelets). However, given that TA-GvHD is driven by contaminating white blood cells, and the fact that the international transfusion community has largely embraced leukoreduction, this raises the question as to whether the quantitative reduction of leukocytes via filtration can itself prevent TA-GvHD, thus allowing hospitals to skip irradiation steps? In this paper, we review the medical literature to determine how many leukocytes are needed to be removed to prevent TA-GvHD, while providing brief overviews of this entity itself and current irradiation strategies.

[Association of Perioperative Allogeneic Red Blood Cell Transfusion with Postoperative Infections].

Allogeneic red blood cell transfusion can induce transfusion-related immunomodulation while correcting anemia and improving oxygenation,and thus may be associated with the increased risk of postoperative infections.However,the available studies have conflicting conclusions.Preclinical studies demonstrate transfusion-related immunomodulation is associated with transfusion amounts.Stored red blood cells can cause more significant immunosuppression than fresh blood products,while leukoreduction alleviates the negative effect on immune system.However,clinical studies do not reach agreements on these issues.Recently,accumulating multi-center,large-sample-size,real-world studies have reported significant associations of all ogeneic red blood cell transfusion in cardiac,orthopedic,hepatic,pancreatic,gastrointestinal,and vesical surgeries with postoperative infections.Considering the limitations of previous studies,future research should focus on multiple operations,prolong the time interval between transfusion and surgery,include different infections into outcomes,and define the postoperative infections accurately in the premise of adequate samples.High-quality clinical evidence could help to optimize the utilization of blood products and improve the postoperative outcomes.

Effect of donor and red blood cells concentrate characteristics on recipient hemoglobin increment following red blood cells transfusion in pediatric patients.

Objectives: To determine the effects of donor and red blood cells concentrate characteristics on recipient hemoglobin increment following red blood cells transfusion in pediatric patients. Methods: This cross-sectional study was conducted at The Hematology & Transfusion Medicine Department of The UCHS & The Children's Hospital, Lahore from 23rd December 2020 to 31st July 2021 after Institutional Ethical committee approval. After taking informed consent from parents/guardians, One hundred recipients receiving RBCs unit transfusion studied along with the respective donors. The donor's details were recorded on a pre-designed proforma which included age, gender, Body Mass Index (BMI), CBC analysis (Hemoglobin [Hb] & Hematocrit) and blood group. Components' preparation, storage and modifications details were also recorded. Hb levels of recipient were determined 12 hours prior to transfusion and 12-18 hours after transfusion. The data was analyzed on SPSS version 26. Results: Among recipients, the mean age was 5.25 ±3 years and male to female ratio was 1.16:1. The mean pre-transfusion Hb level of patients was 6.48g/dl (SD: 2.15) and mean post transfusion Hb was 8.824 g/dl (SD: 2.03) with a significant raise after transfusion (p< 0.001). Majority donors (60%) were between 18 to 30 years of age and mean age was 30.7 years (SD: 9.04). The hemoglobin increment was reduced for transfusion of RBC units from donor with greater age. Post- transfusion Hb rise was more in Rh D positive donations than Rh D negative (p< 0.0001). No significance of donors' gender, BMI, Hb and hematocrit was found in relation to Hb increment. Among RBCs concentrate features, washing with normal saline found to have greater Hb increment, particularly in Thalassemia patients (p< 0.0001). Conclusion: Donors' age and Rh blood group and red blood cell concentrates' washing accounts for significant rise in recipient's post-transfusion hemoglobin. These factors may be used to predict changes in recipients' hemoglobin before transfusion.

Laboratory and clinical comparison of the efficacy of prestorage leukoreduction of red cells at cold versus room temperature.

BACKGROUND: The temperature at which filtration takes place has been reported to influence the efficacy of leukoreduction. We aimed to compare the residual leukocyte count (RLC) in red cell units (RCUs) filtered at cold (CT) versus room temperature (RT) and to assess whether this correlates clinically with a difference in the incidence of acute transfusion reactions (ATRs). METHODS AND MATERIALS: In the first part of the study, whole blood units collected were randomly allocated for subsequent filtration at CT and RT, respectively. RLC postfiltration was assessed using flow cytometry. The second part of the study was a nonrandomized clinical trial in which incidence of ATR was compared between RCUs filtered at RT and CT for 6 months each. RESULTS: Thirty-five RCUs each underwent leukofiltration at CT and RT, respectively. The median RLCs in the filtered units at CT and RT were 0.02 × 106 and 0.1 × 106 leukocytes/unit, respectively (p = .0001), with no difference in red blood cell (RBC) recovery (p = .41). During the second part, 3455 RCUs filtered at RT and 3539 RCUs filtered at CT were transfused to patients. The rate of febrile non-hemolytic transfusion reaction (FNHTR) among transfused patients was less with units filtered at CT (1 per 2000 transfusions) in comparison to RT (1 per 588 transfusions). The difference was, however, not significant (p = .14). CONCLUSION: If change in temperature alone can cause significant reduction in leukocytes, then it is a simple way to curtail the rate of this common yet unpleasant reaction and reduce the reaction rate at minimal cost.

Platelet aggregation in whole blood is not impaired by a platelet-sparing leukoreduction filter and instead depends upon the presence of leukocytes.

BACKGROUND: Recent studies characterizing in vitro hemostatic properties of whole blood (WB) leukoreduced (LR) with a platelet-sparing filter have described subtle, if any, changes to viscoelastic clotting; however, reductions in platelet (PLT) content and impedance aggregometry (IA) responses have been noted. The effects of filtration of WB (i.e., filter-contact effects, reduction in platelet and leukocyte count) have not been rigorously investigated as to their individual impacts on platelet IA responses. STUDY DESIGN AND METHODS: WB units from healthy donors were collected and characterized to assess the effects of platelet-sparing leukoreduction (LR) upon the in vitro hemostatic measures of platelet IA and thromboelastometry. Further characterization of platelet IA responses was carried out in WB samples to delineate the effects of platelet count and leukocyte presence/absence upon the response. RESULTS: WB filtration reduced the platelet count and IA responses but had no impact on viscoelastic clotting measures in fresh WB. Experiments revealed that IA responses have a linear correlation with platelet count in both apheresis platelets and WB and that passage of platelets through the WB-LR filter has no impact upon the strength of this response. Further experiments in LR WB showed that addition of autologous leukocytes back to the platelets fully restored the platelet aggregation response to pre-filtration levels. CONCLUSION: WB filtration results in platelet count reduction and leukocyte removal; however, platelet IA is not degraded by passage through the filter. Apparent declines in platelet IA responses can be fully attributed to the reduction in platelet count and the removal of leukocytes.

Cold-stored leukoreduced whole blood: Extending the time between donation and filtration has minimal impact on in vitro quality.

BACKGROUND: Leukoreduced whole blood (LR-WB) has received renewed attention as alternative to component-based transfusion in trauma. According to the manufacturer's instructions, leukoreduction should be carried out within 8 h after collection. This study assessed impact of (1) WB collection bag, (2) LR filtration, and (3) timing of filtration on in vitro quality. STUDY DESIGN AND METHODS: WB collected into different vendor bags was held at room temperature for <8 h or >16 h but <24 h prior to LR. In vitro quality was assessed before and after filtration, and throughout 3 weeks of storage at 4°C. Cell count and hemoglobin levels were determined by hematology analyzer, platelet activation, and responsiveness to ADP by surface expression of P-selectin by flow cytometry, hemolysis by HemoCue, and metabolic parameters by blood gas analyzer. Hemostatic properties were assessed by rotational thromboelastometry. Plasma protein activities and clotting times were determined by automated coagulation analyzer or quantitative immunoblotting. RESULTS: Bag type had no impact on WB in vitro quality. LR by filtration had some impact, but is aligned with data in the literature. The time between donation and filtration resulted in some statistically significant differences in metabolic activity, platelet yield, platelet activation, and factor protein activity initially; however, these differences in in vitro quality attributes decreased throughout 21-day cold storage. CONCLUSION: WB hold time showed only a minor impact on WB in vitro quality, so it may be possible for blood processing facilities to explore extended hold times prior to filtration in order to provide greater operational flexibility.

Effect of leukoreduction and temperature on risk of bacterial growth in CPDA-1 whole blood: A study of Escherichia coli.

BACKGROUND: Collection of non-leukoreduced citrate-phosphate-dextrose-adenine (CPDA-1) whole blood is performed in walking blood banks. Blood collected under field conditions may have increased risk of bacterial contamination. This study was conducted to examine the effects of WBC reduction and storage temperature on growth of Escherichia coli (ATCC® 25922™) in CPDA-1 whole blood. METHODS: CPDA-1 whole blood of 450 ml from 10 group O donors was inoculated with E. coli. Two hours after inoculation, the test bags were leukoreduced with a platelet-sparing filter. The control bags remained unfiltered. Each whole blood bag was then split into three smaller bags for further storage at 2-6°C, 20-24°C, or 33-37°C. Bacterial growth was quantified immediately, 2 and 3 h after inoculation, on days 1, 3, 7, and 14 for all storage temperatures, and on days 21 and 35 for storage at 2-6°C. RESULTS: Whole blood was inoculated with a median of 19.5 (range 12.0-32.0) colony-forming units per ml (CFU/ml) E. coli. After leukoreduction, a median of 3.3 CFU/ml (range 0.0-33.3) E. coli remained. In the control arm, the WBCs phagocytized E. coli within 24 h at 20-24°C and 33-37°C in 9 of 10 bags. During storage at 2-6°C, a slow self-sterilization occurred over time with and without leukoreduction. CONCLUSIONS: Storage at 20-24°C and 33-37°C for up to 24 h before leukoreduction reduces the risk of E. coli-contamination in CPDA-1 whole blood. Subsequent storage at 2-6°C will further reduce the growth of E. coli.

In vitro characteristics and in vivo platelet quality of whole blood treated with riboflavin and UVA/UVB light and stored for 24 hours at room temperature.

BACKGROUND: There is a global increase in whole blood usage and at the same time, emerging pathogens give cause for pathogen reduction technology (PRT). The Mirasol PRT has shown promising results for plasma and platelet concentrate products. Treatment of whole blood with subsequent platelet survival and recovery analysis would be of global value. STUDY DESIGN AND METHODS: A two-arm, open-label laboratory study was performed with 40 whole blood collections in four groups: non-leukoreduced non-PRT-treated, non-leukoreduced PRT-treated, leukoreduced non-PRT-treated, and leukoreduced PRT-treated. Leukoreduction and/or PRT-treatment was performed on the day of collection, then all WB units were stored at room temperature for 24 h. Sampling was performed after hold-time and after 24-h storage in RT. If PRT-treatment or leukoreduction, samples were also taken subsequently after treatment. Thirteen healthy volunteer blood donors completed the in vivo study per protocol. All WB units were non-leukoreduced and PRT-treated. Radioactive labeling of platelets from RT-stored, PRT-treated whole blood, sampling of subjects, recovery, and survival calculations were performed according to the Biomedical Excellence for Safer Transfusion Collaborative protocol. RESULTS: In vitro characteristics show that PRT-treatment leads to increased levels of hemolysis, potassium, and lactate, while there are decreased levels of glucose, FVIII, and fibrinogen after 24 h of storage. All values are within requirements for WB. In vivo recovery and survival of platelets were 85.4% and 81.3% of untreated fresh control, respectively. CONCLUSIONS: PRT-treatment moderately reduces whole blood quality but is well within the limits of international guidelines. Recovery and survival of platelets are satisfactory after Mirasol treatment.

Leukoreduction makes a difference: A pair proteomics study of extracellular vesicles in red blood cell units.

Prestorage filtration of blood to remove contaminating donor leukocytes and platelets has substantially increased the safety level of transfusion therapy. We have previously shown that leukoreduction has a mitigating effect on the storage lesion profile by lowering the extent of hemolysis and of RBC aging and removal phenotypes, including surface signaling and microvesiculation. Even though protein composition may determine the fate of EVs in the recipient, the probable effect of leukoreduction on the EV proteome has been scarcely investigated. In the present paired study, we characterized the proteome of EVs released in prestorage leukoreduced (L) and nonleukoreduced (N) RBC units prepared from the same donors, by immunoblotting and qualitative proteomics analyses at two storage intervals. Apart from common proteofrms typically associated with the established EV biogenesis mechanisms, the comparative proteomics analyses revealed that both leukoreduction and storage duration affect the complexity of the EV proteome. Membrane and cytoskeleton-related proteins and regulators, metabolic enzymes and plasma proteins exhibited storage duration dependent variation in L- and N-EVs. Specific proteoforms prevailed in each EV group, such as transferrin in L-units or platelet glycoproteins, leukocyte surface molecules, MHC HLA, histones and tetraspanin CD9 in N-units. Of note, several unique proteins have been associated with immunomodulatory, vasoregulatory, coagulatory and anti-bacterial activities or cell adhesion events. The substantial differences between EV composition under the two RBC preparation methods shed light in the underlying EV biogenesis mechanisms and stimuli and may lead to different EV interactions and effects to target cells post transfusion.

Association between the length of storage of transfused leukoreduced red blood cell units and hospital-acquired infections in critically ill children: A secondary analysis of the TRIPICU study.

OBJECTIVE: Evaluate the association between leukoreduced red blood cell (RBC) storage length and hospital-acquired infection (HAI) incidence rate in critically ill children. BACKGROUND: RBC transfusions are common in critically ill children. Despite their benefits, observational studies suggest an association between them and HAIs. One possible mechanism for increased HAI is transfusion-related immunomodulation due to bioactive substances' release as transfused blood ages. METHODS: In this secondary analysis of the 'Transfusion Requirement in Paediatric Intensive Care Units' (TRIPICU) study, we analysed a subset of 257 participants that received only one pre-storage leukoreduced RBC transfusion. RBC storage length was classified as 1) transfusion of 'fresh' RBCs (≤10 days), 2) transfusion of 'stored' RBCs (21-34 days), and 3) transfusion of 'long-stored' RBCs (≥35 days). All were compared to a 'golden' period (11-20 days), representing the time between 'fresh' and 'stored'. We used quasi-Poisson multivariable regression models to estimate the HAI incidence rate ratio (IRR) and corresponding 95% confidence interval (CI). RESULTS: We found that the association between the length of storage time of leukoreduced RBCs and HAIs was not significant in the 'fresh' group (IRR 1.23; 95% CI 0.55, 2.78) and the 'stored' group (IRR 1.61; 95% CI 0.63, 4.13) when compared to the 'golden' period. However, we observed a statistically significant association between the 'long-stored' group and an increase in the HAI incidence rate (IRR 3.66; 95% CI 1.22, 10.98). CONCLUSION: Transfusion of leukoreduced RBC units stored for ≥35 days is associated with increased HAI incidence rate in haemodynamically stable, critically ill children.

Effect of leukoreduction on transfusion-related immunomodulation in patients undergoing cardiac surgery.

OBJECTIVES: In this study, we aimed to determine the consequences of different amounts of leukocyte transfusion on the outcome of patients undergoing cardiac surgery. DESIGN: This was a prospective, single-blinded cohort study conducted for 1 year from July 2018 to June 2019. SETTING: The study setting was the Department of Transfusion Medicine, along with Cardiac Anaesthesia, Cardiac Surgery and Cardiac biochemistry departments in a tertiary care cardiac centre. PARTICIPANTS: A total of 150 patients undergoing cardiac surgery during the study period were divided into three groups (50 in each): Leukofiltered (LR), Buffy coat depleted (BCD) and Non-leukoreduced (NLR). INTERVENTION: The intervention was intra- and postoperative transfusion of packed red blood cells (PRBCs) having different amounts of leukocytes. MEASUREMENTS AND MAIN RESULTS: Patient details about length of intensive care unit (ICU) and hospital stay, blood usage, inotropic drug duration, mechanical ventilation, urine output and infection were recorded from the patient data sheet, whereas patients were followed up for 30 days post-operation, and any mortality was noted. Haematological parameters and biochemical parameters for renal function test were analysed on pre- and post-surgical days 1, 3, 5 and 7, whereas on postoperative days 1 and 7, cytokine-like FAS ligands, Interleukin-10 (IL-10) and Interferon-γ (INF-γ) were tested. Patients in all three groups received an average of four, two and two units of packed red blood cells, platelets and fresh frozen plasma, respectively. There was a statistically significant (P < .05) rise in total leukocyte, neutrophil and lymphocyte count in all three groups from day 0 to day 3, but it reduced to preoperative level on day 5. There was shorter ICU and hospital stay in the LR group of patients (46 ± 19.9 hours and 7.5 ± 2.4 days) compared to NLR (52.1 ± 24.2 hours and 7.9 ± 4.1 days) and BCD (53.3 ± 26.7 hours and 8.8 ± 3.1 days) group of patients, but it was statistically non-significant. The duration of mechanical ventilation was significantly lesser in LR group patients (10.2 ± 6.2 hours) as compared to NLR group (14.7 ± 12.7 hours). On risk ratio calculation of developing postoperative kidney injury, the NLR group had 1.3 and 2.6 times more risk compared to the BCD and LR groups, respectively. On postoperative days 1 and 7, FAS-L levels significantly increased in all three group of patients, whereas IL-10 increased in the NLR and BCD groups and decreased in the LR group non-significantly. The INF-γ levels decreased on day 1 in the NLR and BCD groups but increased in the LR group, but it was inversed on day 7. CONCLUSION: Depletion of leukocytes decreased Transfusion Related Immunomodulation (TRIM) effects in patients undergoing cardiac surgery, but this also depends on the degree of leukoreduction. As found in our study, leukofiltration is more effective compared to buffy-coat depletion only.