Red Blood Cell Storage Duration Research Articles

Loss of Oxygen Transport Potency As a Function of RBC Storage Duration

BACKROUND: Red blood cell (RBC) oxygen (O 2) capture/release is regulated via homeostatic modulation of hemoglobin oxygen (Hb-O 2) affinity in a manner that stabilizes O 2 delivery in the setting of reduced O 2 availability (i.e., hypoxia, anemia) or increased O 2 consumption (i.e., exercise, stress, disease). This is achieved via production of allosteric effectors (i.e., 2,3 DPG, ATP) and adjustment of the RBC biochemical milieu (i.e., pH, anion concentration) in response to regional stimuli including temperature and carbon dioxide (CO 2) abundance, encountered during circulatory transit (aka Bohr effect). Blood storage is known to affect Hb-O 2 affinity, because the environment to which the RBCs are exposed affects cellular metabolism, influencing [allosteric effector], pH, and [anion]. In addition, key proteins may either become depleted or impaired during storage, including anion exchange-1 (AE-1 or Band 3) and carbonic anhydrase, the two proteins that enable the Bohr effect. We therefore explored the novel hypothesis that RBC oxygen transport potency is diminished as a function of blood storage duration, due to loss of the Bohr effect. METHODS: Fresh (healthy control) or stored RBCs units (leuko-reduced in AS-1; Impact Life Davenport IA, USA), were analyzed weekly for up to 42 days. Hb-O 2 affinity was determined from the oxygen dissociation curve (ODC), which describes the relationship between the partial pressure of oxygen (pO 2) and the fraction of oxyhemoglobin (FHbO 2). ODCs were constructed at 2 fixed pH values (HEMOX analyzer, TSC Scientific Corp, PA, USA) or 2 fixed CO 2 levels (thin film rotating tonometer; Meon, Graz, Austria, in conjunction with a gas blender; Oxystreamer, Biospherix, Parish, NY, USA, with samples measured by arterial blood gas machine; ABL90Flex, Radiometer, Brea, CA, USA). Analysis included (1) standard p50 determination (i.e., pO 2 at which Hb is 50% saturated with O 2), (2) delta p50 between ODCs at fixed pH 7.6 and 7.2 - HEMOX, or ODCs at fixed pCO 2, eucarbia ~40 mmHg and hypercarbia ~70 mmHg - tonometer), (3) Area between the two curves measured (ABC), as described above. Additional analyses were performed from ODC data, including comparison of blood O 2 content per gram Hb (with SO 2 converted to blood O 2 content assuming 1-gram Hb binds 1.34 ml O 2), and blood O 2 capacitance (βO2), which quantifies the amount of O 2 unloaded for a given arteriovenous pO 2 gradient. RESULTS: As a function of blood storage duration, we found significant (1) reduction in p50 at 2 fixed pHs (HEMOX) and 2 fixed pCO 2s (tonometer) (2) reduction in delta p50 between ODCs at fixed pH 7.6 and 7.2 (HEMOX), or fixed pCO 2; eucarbia ~40 mmHg and hypercarbia ~70 mmHg (tonometer), i.e., significantly reduced Bohr effect (3) reduction in the area between ODC curves at different pH or CO 2 levels (ABC), a more comprehensive representation of the Bohr effect, across the full range of pO 2s encountered during circulatory transit (rather than the single point p50 measurement), (4) reduction in blood oxygen content per gram Hb, and (5) reduction in βO2. SUMMARY: We demonstrate that blood storage significantly impairs the Bohr effect. Consequently, compared to fresh RBCs, the oxygen transport potency of stored RBCs in AS-1 within one week is ~50-60% that of fresh RBCs and by the time the unit is outdated, is down to ~35%. Consequently, 2.86 the number of RBCs from an expiring stored transfusion unit are required to move the same amount of O 2 as a similar number of RBCs in fresh blood.

Exploring the potential harm of varied blood storage on patients undergoing cardiovascular surgery.

Debate exists surrounding the optimal duration of red blood cell (RBC) storage. A hypothesis emerging from previous research suggests that exposure to fresh blood may be harmful to patients undergoing cardiac surgery. This study uses a large transfusion medicine database to explore the association between in-hospital mortality and red cell storage duration. This is an exploratory retrospective cohort study of all adult patients at Hamilton, Canada, over a 14-year period that received at least one allogeneic red cell transfusion during their hospitalization for cardiac surgery requiring bypass. The primary outcome for the study was in-hospital death. Analysis was performed using multivariate Cox regression modelling with time-dependent and time-independent covariates and stratification variables. Five models with varying definitions for short, intermediate and prolonged duration of RBC storage were tested. From March 2004 to December 2017, 11,205 patients met the inclusion criteria and were included in the regression analyses. No significant effect of short-duration red storage on patient mortality was observed in all statistical models, with the red cells stored for the longest duration as the reference group. When patients who received exclusively fresh (hazard ratio [HR] 1.040, 95% confidence interval [CI] 0.588-1.841, p-value = 0.893) and older aged (HR 1.038, 95% CI 0.769-1.1.402, p-value = 0.0801) RBCs were compared with those who received exclusively mid-age red cells as the reference, statistical significance was similarly not reached. Red cells stored for the shortest duration are not associated with increased risk of mortality among cardiac surgery patients.

Standardizing blood dose using body surface area and analyze the effect of blood storage on hemoglobin increment within pediatric patients

Introduction: Pediatric patients exhibit a wide variation in weight which results in diverse transfusion practices. This study aims to standardize red blood cell (RBC) doses according to body surface area (BSA) and to analyze the role of RBC storage in post-transfusion hemoglobin levels. Material and methods: In this original prospective cohort study on hospitalized pediatric patients aged up to 14, we classified patients into transfusion-dependent (n = 31) and non-transfusion-dependent (n = 158). The non-transfusiondependent group was further classified into ≤10 kg (n = 72) or >10 kg (n = 86) according to body weight (bw). We derived a regression equation between BSA and blood dose in non-transfusion-dependent subjects, and modified the equation by fixing blood dose to 15 mL/kg bw for only BSA based blood dose. We measured pre-transfusion and post-transfusion hemoglobin (Hb) levels, and ascertained effects of blood storage ≤15 days (n = 15) and >15 days (n = 16) on posttransfusion Hb. Results: Pediatric patients ≤10 kg and >10 kg bw (n = 158); mean ± standard deviation of weight and BSA were 4.5 ± 3.1 kg; 22.9 ± 10.4 kg; 0.26 ± 0.14 m 2 ; 0.9 ± 0.28) m 2 respectively. The regression equation ≤10 kg and >10 kg bw when adjusted. Blood dose fixed at 15 mL/kg bw adjusted blood dose ≤10 kg; 15 mL/kg bw = −19.12 + 329.69x BSA m 2 . The regression equation >10 kg bw: adjusted blood dose >10 kg bw; 15 mL/kg bw = −158.8 + 563.3x BSA (m 2 ). The adjusted blood dose with BSA did not exceed 20 mL/kg bw. No significant differences were observed in pre and post-transfusion Hb in transfusion-dependent (n = 31) versus non-transfusion-dependent patients (n = 158) due to the RBC storage duration. Conclusions: RBC blood dose can be standardized by regression equation between standardized RBC dosage and BSA. Post-transfusion Hb is not dependent on days of RBC storage at the blood bank.

Red blood cell storage duration and peri-operative outcomes in paediatric cardiac surgery.

Prior research on red blood cell (RBC) storage duration and clinical outcomes in paediatric cardiac surgery has shown conflicting results. The purpose of this study was to evaluate whether blood stored for a longer duration is harmful in these patients. We performed a retrospective cohort study of paediatric patients undergoing cardiac surgery at our institution between January 2011 and June 2015. Patients were stratified based on whether they were transfused RBCs stored for ≤15days (fresher blood) or >15days (older blood). The primary outcome was composite morbidity, with prolonged length of stay (LOS) as a secondary outcome. Subgroup analyses were performed after stratification by RBC transfusion volume (≤2 vs. >2 RBC units). Multivariable logistic regression models were used to assess the impact of RBC storage duration on composite morbidity and prolonged LOS. Of 461 patients, 122 (26·5%) received fresher blood and 339 (73·5%) received older blood. The overall rate of composite morbidity was 18·0% (n=22) for patients receiving fresher blood and 13·6% (n=46) for patients receiving older blood (P=0·24). In the risk-adjusted model, patients receiving older blood did not exhibit an increased risk of composite morbidity (OR: 0·74, 95% CI: 0·37-1·47, P=0·40) or prolonged LOS (OR: 0·72, 95% CI: 0·38-1·35, P=0·30) compared to patients receiving fresher blood. Similar results were seen after stratification by RBC transfusion volume. Transfusing RBCs stored for a longer duration was not associated with an increased risk of morbidity or prolonged LOS in paediatric cardiac surgery patients.

Effect of Red Blood Cell Storage Duration on Outcomes of Isolated Traumatic Brain Injury.

BackgroundThe aim of this study was to investigate the effects of red blood cell (RBC) storage duration on the outcomes of adult isolated traumatic brain injury (iTBI) patients after transfusion.Material/MethodsA total of 1252 adult iTBI patients who received the fresh RBCs (stored for ≤14 days) or old RBCs (stored for >14 days) were finally enrolled in this study. The primary outcome was 90-day mortality. The secondary outcomes were in-hospital mortality, nosocomial infection, and complications.ResultsBy 90 days after RBC transfusion, 89 patients (17.0%) had died in the fresh RBC group, and 107 had died (14.7%) in the old RBC group, with no significant difference in 90-day mortality between the 2 groups (OR=1.192, 95% CI: 0.877–1.620, P=0.261). According to ISS score, no differences were discovered in mild injury (OR=1.079, 95% CI: 0.682–1.707, P=0.746), severe injury (OR=1.055, 95% CI: 0.634–1.755, P=0.838), and more severe injury (OR=1.940, 95% CI: 0.955–3.943, P=0.064). For GCS score, there were no differences in mild injury (OR=1.546, 95% CI: 0.893–2.676, P=0.118), moderate injury (OR=0.965, 95% CI: 0.616–1.513, P=0.877), and severe injury (OR=1.332, 95% CI: 0.677–2.620, P=0.406). We also observed no significant differences in secondary outcomes.ConclusionsUse of old RBCs did not increase the 90-day mortality in adult iTBI patients.

Effect of red blood cell storage duration on major postoperative complications in cardiac surgery: A randomized trial

BackgroundAlthough observational studies suggest an association between transfusion of older red blood cell (RBC) units and increased postoperative risk, randomized trials have not supported this. The objective of this randomized trial was to test the effect of RBC storage age on outcomes after cardiac surgery. MethodsFrom July 2007 to May 2016, 3835 adults undergoing coronary artery bypass grafting, cardiac valve procedures, or ascending aorta repair, either alone or in combination, were randomized to transfusion of RBCs stored for ≤14 days (younger units) or for ≥20 days (older units) intraoperatively and throughout the postoperative hospitalization. According to protocol, 2448 patients were excluded because they did not receive RBC transfusions. Among the remaining 1387 modified intent-to-treat patients, 701 were randomized to receive younger RBC units (median age, 11 days) and the remaining 686 to receive older units (median age, 25 days). The primary endpoint was composite morbidity and mortality, analyzed using a generalized estimating equation (GEE) model. The trial was discontinued midway owing to enrollment constraints. ResultsA total of 5470 RBC units were transfused, including 2783 in the younger RBC storage group and 2687 in the older RBC storage group. The GEE average relative-effect odds ratio was 0.77 (95% confidence interval [CI], 0.50-1.19; P = .083) for the composite morbidity and mortality endpoint. In-hospital mortality was lower for the younger RBC storage group (2.1% [n = 15] vs 3.4% [n = 23]), as was occurrence of other adverse events except for atrial fibrillation, although all CIs crossed 1.0. ConclusionsThis clinical trial, which was stopped at its midpoint owing to enrollment constraints, supports neither the efficacy nor the futility of transfusing either younger or older RBC units. The effects of transfusing RBCs after even more prolonged storage (35-42 days) remains untested.

Red blood cell storage and adhesion to vascular endothelium under normal or stress conditions: An in vitro microfluidic study.

Observational studies have identified an association between duration of red blood cell (RBC) storage and adverse outcomes in trauma. Hemorrhagic shock (HS) leads to impaired tissue perfusion which is associated with endothelial cell glycocalyx (eGC) shedding. Adhesion of stored RBC to the vascular endothelium has been shown to lead to impaired perfusion in the microcirculation and contribute to organ failure and poor outcome. The role of either or both of the EC and RBC glycocalyx in this process is unknown and was studied in an in vitro model. Human umbilical vein endothelial cells were perfused in a microfluidic device with RBC solutions from fresh, less than 14-day or longer than 21-day storage. In some experiments, the HS microenvironment was simulated by hypoxia-reoxygenation (H/R) and epinephrine (Epi) in the perfusion experiments. Measurements obtained included endothelial cell (EC) and RBC glycocalyx and RBC adherence to human umbilical vein endothelial cell monolayers at variable shear rates. Endothelial cell glycocalyx and RBC glycocalyx dimensions were reduced by H/R and Epi and storage duration respectively. Red blood cell adherence to the endothelium was increased by H/R + Epi treatment and duration of RBC storage. Our data may help explain some of the remaining discrepancies regarding the impact of RBC storage duration on outcomes in the trauma population. Consideration of the integrity of the EC and RBC glycocalyx may guide future transfusion strategies in the trauma population. The microfluidic device system platform may offer a high throughput modality to study emerging therapies to mitigate adverse consequence of RBC storage duration on the perfused endothelium in the trauma setting.

Longer storage of red blood cells does not affect mortality in transfused liver transplant recipients.

The characteristics of red blood cell (RBC) products change after 2 weeks of cold storage. It is unclear whether older RBCs affect mortality after liver transplantation. This retrospective cohort study aimed to evaluate the association between the age of transfused RBCs and death after living donor liver transplantation (LDLT). Of 200 recipients who underwent LDLT, 118 who received RBCs with a mean storage duration of less than 10 days (shorter storage group) were compared with 82 with an RBC mean storage duration of more than 14 days (longer storage group). Key exclusion criteria were transfusion of very fresh RBCs stored for less than 4 days and transfusion of old RBCs in recipients of the shorter storage group. The primary outcome was posttransplant overall death. Survival analysis was performed using the Cox model. Mean RBC storage duration was 7 days in the shorter storage group and 17 days in the longer storage group. Death probability at 1, 2, and 5 years posttransplant was 5.1%, 7.6%, and 13.6% in the shorter storage group, respectively, and 6.1%, 8.5%, and 13.5% in the longer storage group. Death risk was comparable between the two groups in univariable (hazard ratio [HR] 1.00, 95% confidence interval [CI], 0.47-2.16, p = 0.991) and multivariable (HR 1.07, 95% CI, 0.46-2.50, p = 0.882) analyses. Graft failure risk was also comparable (HR 1.04, 95% CI, 0.50-2.18, p = 0.916). Hepatocellular carcinoma recurrence probability at 1, 2, and 5 years was 10.8%, 15.4%, and 23.1%, respectively, in the shorter storage group and 11.4%, 15.9%, and 20.7% in the longer storage group (HR 0.84, 95% CI, 0.37-1.89, p = 0.670). No significant differences were observed regarding graft regeneration/function, vascular/biliary complications, acute kidney injury, surgical site infection, or rejection (p > 0.05). No evidence was found that transfusion of old RBCs contributes to death after LDLT.

Duration of storage influences the hemoglobin rising effect of red blood cells in patients undergoing major abdominal surgery.

After transfusion of senescent red blood cells (RBCs) a considerable fraction is rapidly cleared from the recipients' circulation. Thus, transfusion of senescent RBCs may be less effective in terms of increasing hemoglobin concentration (cHb) after transfusion. Data were retrospectively obtained in patients who underwent major abdominal surgery between 2006 and 2012. Patients were eligible if they received RBCs during surgery and had at least two arterial blood gas analyses performed. The primary endpoint was the increase of recipients' cHb related to the transfusion of 1unit of RBCs with respect to different storage periods. Four storage periods were defined according to the distribution of RBC storage of the study population. General estimating equation was used for calculation of the primary endpoint and to adjust for confounding variables. A total of 598 arterial blood gas samples from 120 patients, receiving 429 RBC units, were analyzed. Mean (±SD) RBC storage was 21 (±9) days. RBC storage duration and the increase in recipients' cHb were inversely and gradually related; that is, the older the RBCs, the lower the increase in the recipients' cHb after transfusion (storage<12 days, ΔcHb per unit RBCs +0.82 [95% confidence interval, 0.42-1.21]g/dL, p<0.01; storage 12-20 days, +0.66 [0.46-0.86] g/dL, p<0.01; storage 21-29 days, +0.56 [0.33-0.79] g/dL, p<0.01; storage ≥30 days, +0.39 [0.07 to 0.71] g/dL, p=0.02). Transfusion of senescent RBCs increased cHb less effectively than transfusion of fresher RBCs.

Effect of Red Blood Cell Storage Duration on Outcome After Paediatric Cardiac Surgery: A Prospective Observational Study

Retrospective reviews have found the use of stored packed red blood cells (PRBCs) in priming to be associated with increased risk of postoperative complications. The purpose of study was to prospectively investigate the influence of duration of storage of PRBCs used in priming the cardiopulmonary bypass (CPB) circuit on the metabolic profile of the patients, and postoperative outcome after paediatric cardiac surgery. Between January 2015 and December 2015, 198 consecutive children operated for cardiac surgery using CPB and received blood for priming the circuit were included. Patients were divided into two groups based on the duration of storage of the blood, newer PRBCs group who received blood stored for ≤14days and the older PRBCs group who received blood stored for >14 days. Mean duration of blood storage used for priming in newer PRBCs blood group (n=103) was 8.4±3.7days while it was 21.9±4.5days in older PRBCs group (n=95). Metabolic parameters of the PRBCs improved to physiological limits in both the groups after initiation of CPB. Postoperative hepatic, pulmonary, haematological complications, sepsis and multi-organ failure were more in the old PRBCs group. However, the difference was not significant. Similarly, there was no significant difference in incidence of prolonged mechanical ventilation, intensive care unit stay and hospital stay and mortality between the two groups. Metabolic parameters of the stored blood become normal after initiation of CPB irrespective of duration of storage. In paediatric patients without significant co-morbidity, undergoing cardiac surgery, transfusion of washed stored blood up to 28days in CPB priming is safe especially if lesser amount of transfusion is required.

In premature infants there is no decrease in 24-hour posttransfusion allogeneic red blood cell recovery after 42 days of storage.

Critically ill preterm very-low-birthweight (VLBW) neonates (birthweight ≤ 1.5 kg) frequently develop anemia that is treated with red blood cell (RBC) transfusions. Although RBCs transfused to adults demonstrate progressive decreases in posttransfusion 24-hour RBC recovery (PTR24 ) during storage-to a mean of approximately 85% of the Food and Drug Administration-allowed 42-day storage-limited data in infants indicate no decrease in PTR24 with storage. We hypothesized that PTR24 of allogeneic RBCs transfused to anemic VLBW newborns: 1) will be greater than PTR24 of autologous RBCs transfused into healthy adults and 2) will not decrease with increasing storage duration. RBCs were stored at 4°C for not more than 42 days in AS-3 or AS-5. PTR24 was determined in 46 VLBW neonates using biotin-labeled RBCs and in 76 healthy adults using 51 Cr-labeled RBCs. Linear mixed-model analysis was used to estimate slopes and intercepts of PTR24 versus duration of RBC storage. For VLBW newborns, the estimated slope of PTR24 versus storage did not decrease with the duration of storage (p = 0.18) while for adults it did (p < 0.0001). These estimated slopes differed significantly in adults compared to newborns (p = 0.04). At the allowed 42-day storage limit, projected mean neonatal PTR24 was 95.9%; for adults, it was 83.8% (p = 0.0002). These data provide evidence that storage duration of allogeneic RBCs intended for neonates can be increased without affecting PTR24 . This conclusion supports the practice of transfusing RBCs stored up to 42 days for small-volume neonatal transfusions to limit donor exposure.

Red blood cell storage duration and long-term mortality in patients undergoing cardiac intervention: a Danish register study.

To study the effect of red blood cell (RBC) storage duration on long-term mortality in patients undergoing cardiac intervention. RBCs undergo numerous structural and functional changes during storage. Observational studies have assessed the association between RBC storage duration and patient outcomes with conflicting results. Between January 2006 and December 2014, 82 408 patients underwent coronary angiography. Of these, 1856 patients received one to four RBC units within 30 days after this procedure. Patients were allocated according to length of RBC storage duration: short-term (≤11 days), intermediate (IM)-term (12-23 days) and long-term (≥24 days). The study endpoints were 30-day and long-term all-cause mortality. A total of 4168 RBC units were given to 1856 patients. The mean RBC storage duration was 8.5 ± 2.1, 17.7 ± 3.4 and 29.9 ± 3.4 days in the short-term, IM-term and long-term storage groups, respectively. There was no difference in baseline characteristics between the groups. The long-term storage group received significantly more units (2.4 ± 1.0 units) as compared to the short-term (2.0 ± 1.0 units; P < 0.001) and IM-term storage group (2.2 ± 1.0 units; P < 0.01). In the survival analysis, there was no significant difference in all-cause mortality between the groups (log-rank: 0.509 for 30-days mortality; 0.493 for 5-year mortality). Additional stratified analysis demonstrated no association between RBC storage duration and long-term mortality. This study did not find an association between RBC storage duration and 30-days or long-term mortality in patients undergoing cardiac intervention.

Dendritic Cell Cross Presentation of RBC Antigens in-Vivo Is Not Affected By RBC Storage Duration and Requires Red Pulp Macrophage "Help" in-Vitro

BACKGROUND: Chronic transfusion is associated with an increased risk of bone marrow graft rejection. In prior studies with mouse models, minor histocompatibility antigens in red blood cell (RBC) and platelet products were presented in the context of recipient MHC class I to prime recipient cytotoxic T cells; these represent cross presentation and cross priming, respectively. Once primed in the recipient, these T cells may attack allogeneic bone marrow grafts. Thus, understanding the mechanism of transfusion-induced T cell cross priming may lead to new methods to reduce bone marrow graft rejection in chronically transfused patients. Cross presentation is performed by a specialized subset of antigen presenting cells (APCs) - CD11b lo, XCR1+ dendritic cells (XCR DCs). Transfusion of RBCs after prolonged refrigerated storage induces erythrophagocytosis and pro-inflammatory gene expression in the spleen. Fluorescent tracking of transfused RBCs showed that splenic red pulp macrophages (RPMs) ingest the majority of damaged RBCs, but RPMs are weak APCs. Splenic dendritic cells, including XCR DCs, also display increased uptake of stored vs. fresh RBCs. These data suggested that refrigerated storage may increase cross presentation of RBC antigens, thereby enhancing T cell cross priming.AIMS: To compare T cell cross priming after transfusion of fresh and refrigerator-stored RBCs, a mouse model was used with transgenic OVA-carrying RBCs as the antigen source and transgenic naive MHC class I-restricted (H-2Kb) OVA-specific T cells (OT-1) as responders. In parallel, an in-vitro system was established to determine the cellular elements required for cross presentation of RBC antigens.METHODS: Purified CD8 T cells from OT-1 mice were loaded with the cell proliferation tracking dye Cell Trace Far Red (CTFR) and adoptively transferred (4 x 10e6 per mouse) into cohorts of 8-12 week old C57BL/6 GFP+ mice (n=3 per group). The next day mice were transfused with 400 uL of fresh (<24 hours old), or stored RBCs (14 days old) from transgenic HOD mice (RBCs express surface HEL, OVA, and Duffy antigens). After 96 hours, flow cytometry was used to assess OT-1 cell proliferation by dye dilution and the expression of activation markers CD44, CD122 and CD62L. Control transfusions with non-HOD GFP+ RBCs confirmed the antigen specificity of the response, and transfusions of HOD blood that had undergone RBC lysis ruled out direct antigen presentation by MHC identical white cells in the transfusate. For the in-vitro cross presentation assay, 1x10e5 CTFR-loaded OT-1 cells were plated in U-bottom 96 well plates with all possible combinations of fresh or stored HOD RBCs (50 x 10e6 per well), bone marrow Flt3L-derived C57BL/6 murine dendritic cells (Flt3L-DCs, 5 X 10e4 per well), and magnetically selected BALB/c (H-2Kd) RPMs (5 x 10e4 per well). MHC mismatch rules out antigen presentation by BALB/c RPMs (H-2Kd) to OT-I T cells (H-2Kb).RESULTS: Transfusion of both fresh and stored HOD RBCs induced vigorous proliferation and activation of OT-1 cells. After 4 days, no differences were seen in the proliferation and activation profiles of OT-1 cells in mice receiving fresh (78±4% CD44hi, CTFR diluted) vs. stored (79±5%) HOD RBCs. The in-vitro cross presentation assay showed weak to absent OVA-specific OT-1 proliferation with co-cultures including fresh or stored HOD RBCs alone, and fresh or stored HOD RBCs plus Flt3L-DCs. In contrast, cultures including RPMs and Flt3L-DCs showed enhanced OVA-specific OT-1 proliferation with fresh (29±10% CTFR diluted) and stored (25±2%) HOD RBCs.CONCLUSION: Cross priming by fresh RBCs was stronger than expected based on prior studies showing minimal RBC uptake by XCR DCs after fresh GFP + RBC transfusion. Cross priming in this system may be more sensitive due to the high frequency of antigen specific T cells and, thus, is saturated by the small antigen load delivered by fresh transfusion. It is also possible that direct uptake of RBCs by DCs harms the cross-presentation machinery and offsets the effect of increased RBC antigen delivery. Optimal cross-presentation of RBC antigen may require cooperation with cells functionally specialized for metabolizing RBC by-products. Indeed, the in-vitro study shows RPMs promote DC-mediated cross presentation of antigens on fresh and stored RBCs. Thus, RPMs may share ingested RBC antigen with adjacent DCs and increase DC activation by secreting inflammatory cytokines.. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

The impact of red blood cell storage duration on tissue oxygenation in cardiac surgery

ObjectiveAlthough storage alters red blood cells, several recent, randomized trials found no differences in clinical outcomes between patients transfused with red blood cells stored for shorter versus longer periods of time. The objective of this study was to see whether storage impairs the in vivo ability of erythrocytes to traverse the microcirculation and deliver oxygen at the tissue level. MethodsA subset of subjects from a clinical trial of cardiac surgery patients randomized to receive transfusions of red blood cells stored ≤10 days or ≥21 days were assessed for thenar eminence and cerebral tissue hemoglobin oxygen saturation (StO2) via the use of near-infrared spectroscopy and sublingual microvascular blood flow via side-stream darkfield videomicroscopy. ResultsAmong 55 subjects, there was little change in the primary endpoint (thenar eminence StO2 from before to after transfusion of one unit) and the change was similar in the 2 groups: +1.7% (95% confidence interval, −0.3, 3.8) for shorter-storage and +0.8% (95% confidence interval, −1.1, 2.9) for longer-storage; P = .61). Similarly, no significant differences were observed for cerebral StO2 or sublingual microvascular blood flow. These parameters also were not different from preoperatively to 1 day postoperatively, reflecting the absence of a cumulative effect of all red blood cell units transfused during this period. ConclusionsThere were no differences in thenar eminence or cerebral StO2, or sublingual microcirculatory blood flow, in cardiac surgery patients transfused with red blood cells stored ≤10 days or ≥21 days. These results are consistent with the clinical outcomes in the parent study, which also did not differ, indicating that storage may not impair oxygen delivery by red blood cells in this setting.

A Histologic Approach to Qualify Lung Tissue Damage in a Sheep Model of Transfusion-Related Lung Injury: Role of Red Blood Cell Storage Duration and Heat Treatment

A Histologic Approach to Qualify Lung Tissue Damage in a Sheep Model of Transfusion-Related Lung Injury: Role of Red Blood Cell Storage Duration and Heat Treatment

Perspectives on the impact of storage duration on blood quality and transfusion outcomes.

Background & ObjectivesRed blood cells (RBCs) may be stored up to 42 days before transfusion, per US and EU standards. Although there is ample evidence that RBCs undergo deleterious changes during storage, studies assessing outcomes relative to storage time report conflicting findings. This study investigated RBC storage duration perspectives and practices among blood banking and transfusion professionals.Materials & MethodsA survey was administered at the American Association of Blood Banking annual meeting in October 2014 (N = 69).ResultsOn average, participants believed RBC storage should not exceed 34 days (median: 35; range: 1–52), and estimated that RBCs are typically stored 21 days before transfusion at their institutions (median: 20; range: 10–40). There was 97% agreement that minimizing/reversing changes during RBC storage may produce clinical benefits; however, 80% believed the research does not consistently demonstrate worse outcomes using older blood. Two‐thirds agreed that RBC storage duration is a major concern, but 81% agreed most institutions are not pursuing measures to shorten storage.ConclusionsThis study found that many transfusion professionals believe RBCs should be stored for fewer than the 42 days currently allowed and that further efforts are warranted to abrogate changes in stored RBCs. These findings suggest a need for increased awareness of potential consequences of extended RBC storage and for strategies to maximize transfusion benefits.

Longer Duration of Red Blood Cell Storage Induces Progressively Increased Markers of Extravascular Hemolysis and Hepcidin in Autologously Transfused Healthy Volunteers

Background:Transfusion of stored red blood cells (RBCs) results in a variable amount of extravascular hemolysis depending on the extent of RBC damage during storage. Metabolomic studies of RBCs throughout storage in vitro suggest that a shift in the metabolomics profile occurs at 14-21 days of storage; however, the correlation between storage duration in vitro and the extent of hemolysis in vivo is unknown.Aims:This study examined the relationship between storage duration and laboratory evidence of hemolysis in human recipients after autologous RBC transfusion.Methods:We recruited 30 healthy adults who met the standards for allogeneic blood donation. Each volunteer was randomized to receive a transfusion of one autologous RBC unit after 1, 2, 3, 4, 5, or 6 weeks of storage. Each RBC unit was transfused over 1 hour and blood samples were collected before, and at 0, 2, 4, 8, 10, 12, 14, and 20 hours after transfusion to measure various analytes. Serum hepcidin was measured by ELISA, plasma free hemoglobin by the cyanomethemoglobin method, and all other parameters by standard clinical laboratory assays. For each analyte, the Pearson correlation coefficient was used to determine the strength of the linear association between storage duration and changes in analyte levels at specific times post-transfusion.Results:At each time evaluated between 0 and 8 hours after transfusion, indirect bilirubin, a marker of extravascular hemolysis, progressively and linearly increased proportionally with RBC storage duration, with the maximal regression coefficient observed 2 hours post-transfusion (R2 = 0.44; p<0.0001). Furthermore, at all times evaluated between 0 and 14 hours post-transfusion, serum iron increased proportionally with storage duration (see Figure); the strongest regression coefficient was observed 6 and 8 hours post-transfusion (R2 = 0.67; p<0.0001). In conjunction with the increases in serum iron, hepcidin, the master regulator of iron homeostasis, increased proportionally with storage duration at all times between 6 and 12 hours post-transfusion with a maximal regression coefficient at 8 hours post-transfusion (R2 = 0.25; p<0.007). In contrast, no linear associations were found between RBC storage duration and indicators of intravascular hemolysis, including plasma free hemoglobin, lactate dehydrogenase, and haptoglobin.Conclusion:Altogether, these results suggest that, as storage duration increases, there is a progressive increase in post-transfusion extravascular hemolysis. Furthermore, this is the first report of an effect of stored RBC transfusions on serum hepcidin concentrations. In particular, progressive increases in hepcidin levels, associated with increased storage duration, are observed starting at 6 hours post-transfusion. Nonetheless, the strengths of correlation coefficients between markers of extravascular hemolysis and RBC storage duration suggest that substantial donor/recipient variability exists. The clinical consequences of the progressive increase in extravascular hemolysis with greater durations of RBC storage remain to be determined.Median with interquartile range for changes in serum iron levels from baseline (i.e., pre-transfusion) to 20 hours post-transfusion for each randomized week of RBC storage (N=30). Serum iron increased between 0 and 14 hours post-transfusion, with a maximum peak at 6-8 hours post-transfusion. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Effects of packed red blood cell storage duration on post-transfusion clinical outcomes: a meta-analysis and systematic review.

There is substantial conjecture regarding the clinical significance of packed red blood cell (PRBC) changes that occur during in vitro storage. Here, we present a meta- and systematic analysis of adult studies published between 1994 and 2015 with the aim of updating existing quantitative reviews and providing a comprehensive cover of the six most commonly studied outcomes-mortality, infection, renal dysfunction, multiple organ dysfunction syndrome (MODS), thrombotic complications and prolonged hospital length of stay. Computerised searches of Pubmed and EMBASE identified publications that reported target outcomes and PRBC storage duration prior to transfusion. Bibliographies of relevant literature were manually searched to incorporate missed studies. Randomised controlled trial (RCT) data was meta-analysed using a random effects model with Cochrane Collaboration Review Manager (RevMan) version 5.1 software. Observational investigations were systematically reviewed. Sixty-four papers were selected covering 462,581 patients with the majority of studies being observational in nature. Meta-analysis of eight RCTs demonstrated a trend towards decreased mortality with stored PRBC transfusion; albeit this effect was not statistically significant (OR 0.91, 95 % CI 0.78-1.05, p = 0.20). In a small subset of intensive care unit (ICU), cardiac surgery and trauma patients; observational studies suggested that prolonged storage may be correlated with increased mortality. Trauma and cardiac surgery patients appeared to be most susceptible to the potential infectious complications of stored PRBCs. Stored PRBCs were unlikely to affect thrombotic complications or hospital length of stay. There were inadequate data to determine whether stored PRBCs had clinically relevant effects on renal dysfunction and MODS. Although literature presents a concerning picture of potential storage complications, current findings are too inconsistent to drive changes in clinical practice. Results from current RCTs will likely play a role in PRBC age guidelines for cardiac surgery and ICU patients. However, these studies may be less efficacious at detecting small effects that are limited to specific subpopulations.

Effect of Red Blood Cell Transfusion on Unfavorable Neurologic Outcome and Symptomatic Vasospasm in Patients with Cerebral Aneurysmal Rupture: Old versus Fresh Blood

Red blood cell (RBC) transfusion, especially with "old" blood, is associated with adverse clinical outcomes. We compared the effects of fresh blood versus old blood transfusion on poor neurologic outcomes and symptomatic vasospasm in patients with ruptured cerebral aneurysms. In this retrospective study, 211 patients with aneurysmal rupture were divided into 3 groups: nontransfusion (n = 136), fresh blood (RBC storage ≤ 14 days) transfusion (n = 39), and old blood (RBC storage >14 days) transfusion (n = 36). Unfavorable neurologic outcomes (modified Rankin Scale score ≥ 3) and symptomatic cerebral vasospasm were assessed. The incidence of unfavorable neurologic outcomes was significantly higher in the fresh blood and old blood transfusion groups compared with the nontransfused group (71.8% and 58.3% vs. 21.3%; P < 0.01); the incidence of symptomatic vasospasm was significantly higher in the old blood group compared with the fresh blood and nontransfusion groups (57.1% vs. 26.7% and 22.2%; P < 0.05). On binary logistic regression, old age, Hunt and Hess grade 3-4, high postoperative C-reactive protein level, RBC transfusion, delayed infarction, and hydrocephalus were independent predictors of unfavorable neurologic outcomes. Young age, Fisher grade 3-4, old RBC transfusion, and surgical clipping were independent predictors of postoperative symptomatic vasospasm. RBC transfusion itself, regardless of the duration of RBC storage, was associated with unfavorable neurologic outcomes in patients with ruptured cerebral aneurysms. Also, old blood transfusion, but not fresh blood transfusion, was associated with increased symptomatic cerebral vasospasm.

Transfusion of 1 and 2 units of red blood cells does not increase mortality and organ failure in patients undergoing isolated coronary artery bypass grafting.

In cardiac surgery, the association between red blood cell (RBC) transfusion and clinical outcome is elusive. We investigated in a large cohort of patients who underwent isolated coronary artery bypass grafting (CABG) the effect of transfusion of 1-2 units of leucocyte-depleted RBCs on mortality and multiorgan failure. The investigation included all patients from July 2009 to June 2014 who underwent CABG at our institution and received no (n = 1478) or 1-2 units of RBCs (n = 1528). The primary end-point was 30-day mortality; secondary end-points were major organ dysfunction. A subgroup analysis assessed the effect of the duration of RBC storage on patient outcome. Statistical analysis was performed using propensity score (PS) adjustment. The 30-day mortality rate was 0.3% in the RBC- group and 0.2% in the RBC+ group. Compared with the RBC- group, PS-adjusted odds ratio (OR) of 30-day mortality in the RBC+ group was 0.29 [95% confidence interval (CI): 0.06-1.50; P = 0.14]. PS-adjusted OR of a 'prolonged intensive care unit (ICU) stay' (>48 h) was significantly higher in the RBC+ group than in the RBC- group [OR 1.49 (95% CI: 1.14-1.95); P = 0.004], but major clinical complications such as low cardiac output syndrome, stroke, haemofiltration, wound infection and prolonged mechanical ventilator support (>24 h) did not differ significantly between groups. Duration of blood storage was not independently associated with clinical outcome. Our data do not indicate a transfusion-related increase in mortality and multiorgan failure in patients undergoing isolated CABG.