Project description:BackgroundPrior studies have suggested that transfusion of stored red blood cells (RBCs) with increased levels of cell-free hemoglobin might reduce the bioavailability of recipient nitric oxide (NO) and cause myocardial strain.MethodsUgandan children (ages 6-60 months) with severe anemia and lactic acidosis were randomly assigned to receive RBCs stored 1-10 days versus 25-35 days. B-type natriuretic peptide (BNP), vital signs, renal function test results, and plasma hemoglobin were measured. Most children had either malaria or sickle cell disease and were thus at risk for reduced NO bioavailability.ResultsSeventy patients received RBCs stored 1-10 days, and 77 received RBCs stored 25-35 days. The median (interquartile range) cell-free hemoglobin was nearly 3 times higher in longer-storage RBCs (26.4 [15.5-43.4] μmol/L) than in shorter-storage RBCs (10.8 [7.8-18.6] μmol/L), P < .0001. Median (interquartile range) BNP 2 hours posttransfusion was 156 (59-650) pg/mL (shorter storage) versus 158 (59-425) pg/mL (longer storage), P = .76. BNP values 22 hours posttransfusion were 110 (46-337) pg/mL (shorter storage) versus 96 (49-310) pg/mL (longer storage), P = .76. Changes in BNP within individuals from pretransfusion to 2 hours (or 22 hours) posttransfusion were not significantly different between the study groups. BNP change following transfusion did not correlate with the concentration of cell-free hemoglobin in the RBC supernatant. Blood pressure, blood urea nitrogen, creatinine, and change in plasma hemoglobin were not significantly different in the 2 groups.ConclusionIn a randomized trial among children at risk for reduced NO bioavailability, we found that BNP, blood pressure, creatinine, and plasma hemoglobin were not higher in patients receiving RBCs stored for 25-35 versus 1-10 days.
Project description:Although a subset of recent studies have suggested that red blood cell (RBC) storage length is associated with adverse patient outcomes, others have shown no such relationship. Adults may be transfused with RBC units of different storage lengths, and existing studies do not take into consideration that fresh RBCs may alter responses to concurrently transfused stored RBCs. To test this possibility, we utilized a murine model and investigated transfusion outcomes of fresh, stored, or fresh-plus-stored RBCs.Fresh, 14-day-stored or fresh plus 14-day-stored leukoreduced RBCs from HOD-transgenic donors (with RBC-specific expression of hen egg lysozyme, ovalbumin, and human Duffy(b)) were transfused into naïve C57BL/6 recipients. Serum cytokines and anti-HOD alloimmunization were evaluated after transfusion.In six of six experiments (n = 90 mice total), a proinflammatory serum cytokine storm of interleukin-6, keratinocyte-derived chemokine/CXCL1, and monocyte chemoattractant protein-1 was observed in transfusion recipients of stored but not fresh RBCs, along with high degrees of anti-HOD alloimmunization. However, concurrent transfusion of fresh HOD RBCs along with stored HOD RBCs significantly decreased these adverse outcomes (p < 0.05).These results are consistent with fresh murine HOD RBCs losing protective properties during storage, and introduce a previously unrecognized variable in RBC storage studies. If translatable to humans, uniform "old blood" groups may be needed in future clinical studies to more accurately investigate the biologic effects of older RBC units.
Project description:Our aim was to study the impact of bleeding and red blood cell (RBC) resuscitation on liver regeneration. We assessed the impact of RBC storage time on liver regeneration following 50% partial hepatectomy (PHx) in rats, and explored possible contributing molecular mechanisms using immunohistochemistry, RNA-Seq, and macrophage depletion.
Project description:Anaerobic red blood cell (RBC) storage reduces oxidative damage, maintains adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (DPG) levels, and has superior 24-hour recovery at 6 weeks compared to standard storage. This study will determine if removal of CO2 during O2 depletion by gas exchange may affect RBCs during anaerobic storage.This is a matched three-arm study (n?=?14): control, O2 and CO2 depleted with Ar (AN), and O2 depleted with 95%Ar/5%CO2 (AN[CO2 ]). RBCs in additives AS-3 or OFAS-3 were evenly divided into three bags, and anaerobic conditions were established by gas exchange. Bags were stored at 1 to 6°C in closed chambers under anaerobic conditions or ambient air, sampled weekly for up to 9 weeks for a panel of in vitro tests. A full metabolomics screening was conducted for the first 4 weeks of storage.Purging with Ar (AN) results in alkalization of the RBC and increased glucose consumption. The addition of 5% CO2 to the purging gas prevented CO2 loss with an equivalent starting and final pH and lactate to control bags (p?>?0.5, Days 0-21). ATP levels are higher in AN[CO2 ] (p?<?0.0001). DPG was maintained beyond 2 weeks in the AN arm (p?<?0.0001). Surprisingly, DPG was lost at the same rate in both control and AN[CO2 ] arms (p?=?0.6).Maintenance of ATP in the AN[CO2 ] arm demonstrates that ATP production is not solely a function of the pH effect on glycolysis. CO2 in anaerobic storage prevented the maintenance of DPG, and DPG production appears to be pH dependent. CO2 as well as O2 depletion provides metabolic advantage for stored RBCs.
Project description:Biochemical changes induced in red blood cells (RBCs) during storage may impair their function upon transfusion. Transfusion-associated stresses may further amplify storage lesion effects including increased phosphatidylserine (PS) exposure at the RBC membrane, microparticle (MP) release, and adhesion to endothelial cells (ECs). RBC stress susceptibility in vitro was investigated in relation to storage time and additive solution.Leukoreduced whole blood donations (n?=?18) were paired, mixed, and resplit before separating the RBCs for storage in saline-adenine-glucose-mannitol (SAGM) or AS-1. Samples were taken after 3, 21, or 35 days. For oxidative stress treatment, RBCs were exposed to 0.5 mmol/L tert-butylhydroperoxide. Transfusion-associated stress was simulated by overnight culture at 37 °C with plasma containing inflammatory mediators. PS exposure and MPs were measured by flow cytometry and adhesion to ECs was tested under flow conditions. PS specificity of adhesion was tested by blocking with PS-containing lipid vesicles.Oxidative stress induced significantly higher PS exposure and adhesion to ECs in RBCs stored for 35 days compared to 3 days (p?<?0.04). PS-containing vesicles blocked RBC-EC adhesion. After overnight culture with or without plasma, PS exposure and EC adhesion were significantly increased (p?<?0.05). MP numbers increased with longer RBC storage and after RBC culture with plasma. Culture conditions influenced MP numbers from Day 35 RBCs. RBCs stored in SAGM had significantly higher PS exposure after stress treatment than AS-1 RBCs (p?<?0.02).Storage for 35 days significantly increased RBC susceptibility to oxidative and in vitro transfusion-associated stresses and was higher for RBCs stored in SAGM compared to AS-1.
Project description:RBCs undergo numerous changes during storage and stored RBCs may induce adverse effects, ultimately resulting in organ injury in transfusion recipients. We tested the hypothesis that the addition of SP to stored RBCs would improve the quality of the stored RBCs and mitigate liver injury after transfusion in a murine model. RBCs were harvested from C57BL/6J mice and stored for 14 days in CPDA-1 containing either a solution of SP in saline or saline alone. Haemolysis, the 24-hour posttransfusion recovery, the oxygen-carrying capacity, and the SOD activity of stored RBCs were evaluated. The plasma biochemistry, hepatic MDA level, MPO activity, IL-6, TNF-? concentrations, and histopathology were measured two hours after the transfusion of stored RBCs. Compared with RBCs stored in CPDA-1 and saline, the addition of SP to stored RBCs restored their oxygen-carrying capacity and SOD activity, reduced the AST activity, BUN concentrations, and LDH activity in the plasma, and decreased the MDA level, MPO activity, and concentrations of IL-6 and TNF-? in the liver. These data indicate that the addition of SP to RBCs during storage has a beneficial effect on storage lesions in vitro and subsequently alleviates liver injury after the transfusion of stored RBCs in vivo.
Project description:Transfusions of RBCs stored for longer durations are associated with adverse effects in hospitalized patients. We prospectively studied 14 healthy human volunteers who donated standard leuko-reduced, double RBC units. One unit was autologously transfused "fresh" (3-7 days of storage), and the other "older" unit was transfused after 40 to 42 days of storage. Of the routine laboratory parameters measured at defined times surrounding transfusion, significant differences between fresh and older transfusions were only observed in iron parameters and markers of extravascular hemolysis. Compared with fresh RBCs, mean serum total bilirubin increased by 0.55 mg/dL at 4 hours after transfusion of older RBCs (P = .0003), without significant changes in haptoglobin or lactate dehydrogenase. In addition, only after the older transfusion, transferrin saturation increased progressively over 4 hours to a mean of 64%, and non-transferrin-bound iron appeared, reaching a mean of 3.2?M. The increased concentrations of non-transferrin-bound iron correlated with enhanced proliferation in vitro of a pathogenic strain of Escherichia coli (r = 0.94, P = .002). Therefore, circulating non-transferrin-bound iron derived from rapid clearance of transfused, older stored RBCs may enhance transfusion-related complications, such as infection.
Project description:Both cardiopulmonary bypass (CPB) and red blood cell (RBC) storage are associated with detrimental changes in RBC structure and function that may adversely affect tissue oxygen delivery. We tested the hypothesis that in cardiac surgery patients, RBC deformability and aggregation are minimally affected by CPB with autologous salvaged blood alone but are negatively affected by the addition of stored allogeneic blood.In this prospective cohort study, 32 patients undergoing cardiac surgery with CPB were divided into 3 groups by transfusion status: autologous salvaged RBCs alone (Auto; n = 12), autologous salvaged RBCs + minimal (<5 units) stored allogeneic RBCs (Auto+Allo min; n = 10), and autologous salvaged RBCs + moderate (?5 units) stored allogeneic RBCs (Auto+Allo mod; n = 10). Ektacytometry was used to measure RBC elongation index (deformability) and critical shear stress (aggregation) before, during, and for 3 days after surgery.In the Auto group, RBC elongation index did not change significantly from the preoperative baseline. In the Auto+Allo min group, mean elongation index decreased from 32.31 ± 0.02 (baseline) to 30.47 ± 0.02 (nadir on postoperative day 1) (P = 0.003, representing a 6% change). In the Auto+Allo mod group, mean elongation index decreased from 32.7 ± 0.02 (baseline) to 28.14 ± 0.01 (nadir on postoperative day 1) (P = 0.0001, representing a 14% change). Deformability then dose-dependently recovered toward baseline over the first 3 postoperative days. Changes in aggregation were unrelated to transfusion (no difference among groups). For the 3 groups combined, mean critical shear stress decreased from 359 ± 174 mPa to 170 ± 141 mPa (P = 0.01, representing a 54% change), with the nadir at the end of surgery and returned to baseline by postoperative day 1.In cardiac surgery patients, transfusion with stored allogeneic RBCs, but not autologous salvaged RBCs, is associated with a decrease in RBC cell membrane deformability that is dose-dependent and may persist beyond 3 postoperative days. These findings suggest that autologous salvaged RBCs may be of higher quality than stored RBCs, since the latter are subject to the so-called storage lesions.
Project description:Human red blood cells (RBCs) can be stored for up to 42 days under controlled conditions. Physical and chemical changes occur during RBC storage, altering their function. This study links stored cell mechanical changes with hemodynamic functional alterations upon transfusion.Mechanical properties of fresh and stored RBCs were evaluated in vitro. Their transfusion effects were evaluated in vivo using intravital microscopy of the rat's cremaster muscle preparation. Rats were hemodiluted to 30% hematocrit, to mimic an anemic state before transfusion, and then exchange-transfused with fresh or stored cells.In vitro studies on rheology and oxygen affinity of stored cells confirmed previously published results. Storage was found to modify static and dynamic RBC mechanic behavior. After transfusion, systemic hemodynamics were similar for fresh and stored cells; however, microvascular hemodynamics were drastically affected by stored cells. Stored cells reduced blood flow and oxygen delivery. Additionally, the presence of stored cells in circulation affected cell-to-cell and cell-to-wall interactions and affected cell hydrodynamics. Stored cells disrupted the RBC cell-free layer and wall shear stress signals.The reduced cell deformability due to RBC "storage lesions" caused pathologic changes in microvascular hemodynamics, endothelial cell mechanotransduction, and RBC dynamics. Thus, the mechanical changes of blood-banked cells can limit transfusion ability to achieve its intended goal.