Potassium loss and cellular dehydration of stored erythrocytes following incubation in autologous plasma: role of the KCl cotransport system

Do We Store Packed Red Blood Cells under "Quasi-Diabetic" Conditions?

Red blood cell (RBC) transfusion is one of the most common therapeutic procedures in modern medicine. Although frequently lifesaving, it often has deleterious side effects. RBC quality is one of the critical factors for transfusion efficacy and safety. The role of various factors in the cells’ ability to maintain their functionality during storage is widely discussed in professional literature. Thus, the extra- and intracellular factors inducing an accelerated RBC aging need to be identified and therapeutically modified. Despite the extensively studied in vivo effect of chronic hyperglycemia on RBC hemodynamic and metabolic properties, as well as on their lifespan, only limited attention has been directed at the high sugar concentration in RBCs storage media, a possible cause of damage to red blood cells. This mini-review aims to compare the biophysical and biochemical changes observed in the red blood cells during cold storage and in patients with non-insulin-dependent diabetes mellitus (NIDDM). Given the well-described corresponding RBC alterations in NIDDM and during cold storage, we may regard the stored (especially long-stored) RBCs as “quasi-diabetic”. Keeping in mind that these RBC modifications may be crucial for the initial steps of microvascular pathogenesis, suitable preventive care for the transfused patients should be considered. We hope that our hypothesis will stimulate targeted experimental research to establish a relationship between a high sugar concentration in a storage medium and a deterioration in cells’ functional properties during storage.

The dielectric spectroscopy of human red blood cells during 37-day storage: β-dispersion parameterization

This study exploits dielectric spectroscopy to monitor the kinetics of red blood cells (RBC) storage lesions, focusing on those processes linked to cellular membrane interface known as β-dispersion. The dielectric response of RBC suspensions, exposed to blood-bank cold storage for 37 days, was studied using time-domain dielectric spectroscopy in the frequency range 500 kHz to 200 MHz. The measured dielectric processes are characterized by their dielectric strength (Δε) and their relaxation times (τ). Changes in the dielectric properties of the RBC suspensions, due to storage-related biophysical changes, were evaluated. For a quantitative characterization of RBC vitality, we characterized the shape of fresh and stored RBC and measured their deformability as expressed by their average elongation ratio, which was achieved under a shear stress of 3.0 Pa. During the second week of storage, an increment in the evolution of the relaxation times and in the dielectric permittivity strength of about 25% was observed. We propose that the characteristic increment of ATP, during the second and third weeks of storage, is responsible for the raise of the specific capacitance of cell membrane, which in turn explains the changes observed in the dielectric response when combined with the influence of the shape changes.

Is It Possible to Reverse the Storage-Induced Lesion of Red Blood Cells?

Cold-storage of packed red blood cells (PRBCs) in the blood bank is reportedly associated with alteration in a wide range of RBC features, which change cell storage each on its own timescale. Thus, some of the changes take place at an early stage of storage (during the first 7 days), while others occur later. We still do not have a clear understanding what happens to the damaged PRBC following their transfusion. We know that some portion (from a few to 10%) of transfused cells with a high degree of damage are removed from the bloodstream immediately or in the first hour(s) after the transfusion. The remaining cells partially restore their functionality and remain in the recipient’s blood for a longer time. Thus, the ability of transfused cells to recover is a significant factor in PRBC transfusion effectiveness. In the present review, we discuss publications that examined RBC lesions induced by the cold storage, aiming to offer a better understanding of the time frame in which these lesions occur, with particular emphasis on the question of their reversibility. We argue that transfused RBCs are capable (in a matter of a few hours) of restoring their pre-storage levels of ATP and 2,3-DPG, with subsequent restoration of cell functionality, especially of those properties having a more pronounced ATP-dependence. The extent of reversal is inversely proportional to the extent of damage, and some of the changes cannot be reversed.

Measures of stored red blood cell quality

Blood banking underpins modern medical care, but blood storage, necessary for testing and inventory management, reduces the safety and efficacy of individual units of red blood cells (RBCs). Stored RBCs are damaged by the accumulation of their own waste products, by enzymatic and oxidative injury, and by metabolically programmed cell death. These chemical activities lead to a complex RBC storage lesion that includes haemolysis, reduced in vivo recovery, energy and membrane loss, altered oxygen release, reduced adenosine tri-phosphate and nitric oxide secretion, and shedding of toxic products. These toxic products include lysophospholipids that can cause transfusion-related acute lung injury, free iron that can potentiate infections and cause inflammation, and shed microvesicles that can scavenge nitric oxide and potentiate inflammation and thrombosis. However, most of the obvious negative outcomes of RBC storage are uncommon and appear to be related to exceptionally bad units. Generally, the quality of stored RBCs is highly related to the conditions of storage, so refrigerator temperature, intact bags, residual leucocyte counts and visible haemolysis remain excellent general measures. Specific biochemical measures, such as adenosine 5'-triphosphate (ATP) and 2,3-diphosphoglycerate (DPG) concentrations, calcium and potassium content or lipid breakdown products, require specialized measures that are not widely available, involve destructive testing and generally reflect only a part of the storage lesion. This review describes a number of components of the storage lesion and their measurement and attempts to access the utility of the measures.

Effect of additive solutions on red blood cell (RBC) membrane properties of stored RBCs prepared from whole blood held for 24 hours at room temperature

BACKGROUND

The quality of RBC components is influenced by collection, processing and storage conditions. Regulations require that whole blood (WB) units be refrigerated within 8 hours and processed into RBCs within 24 hours of collection. Overnight room temperature hold of WB has logistical advantages, but the effect on RBC quality has not been fully investigated. RBC additive solutions were compared for their ability to provide improved quality of RBCs prepared from WB held at room temperature for 24 hours.

STUDY DESIGN AND METHODS

Leukocyte-reduced RBCs were prepared from WB held at 20°C on cooling plates for 24 hours prior to processing. RBCs were stored in additive solutions, SAG-M (control), Erythrosol-4, and PAGGSM, under standard blood banking conditions and sampled during 49 days of storage. Stored RBCs were evaluated for RBC shape and microparticle (MP) accumulation using flow cytometry. Osmotic fragility, adhesion of RBCs to endothelium under shear stress conditions (0.5 dyne/cm(2) ), and routine RBC quality parameters were assessed.

RESULTS

RBCs stored in Erythrosol-4 and PAGGSM had decreased cell size, reduced osmotic fragility, and decreased accumulation of glycophorin A-positive MPs and annexin V-binding MPs compared with RBCs stored in SAG-M. RBCs stored in erythrosol-4 had increased adherence to endothelium at days 42 and 49 compared with RBCs stored in SAG-M or PAGGSM.

CONCLUSION

RBCs stored in PAGGSM or Erythrosol-4 had improved retention of RBC membrane and osmotic resilience. The development of new additive solutions may offer improved quality of RBC components prepared from WB held overnight at room temperature.

Rejuvenation treatment of stored red blood cells reverses storage-induced adhesion to vascular endothelial cells

BACKGROUND

Blood banking procedures are associated with elevated adherence of red blood cells (RBCs) to blood vessel wall endothelial cells (ECs), which can introduce a circulatory risk to recipients. This study was undertaken to examine the possibility of repairing this damage by a poststorage "rejuvenation" procedure before transfusion.

STUDY DESIGN AND METHODS

Stored RBCs were treated with rejuvenation solution (Rejuvesol, enCyte Systems, Inc.), and their adhesion to cultured human microvascular ECs was determined as a function of shear stress using a cell flow properties analyzer. The adherence of rejuvenation-treated stored RBCs (stRBCs) was compared to that of untreated stRBCs and of freshly donated RBCs.

RESULTS

Strong elevation of stRBC/EC adhesion was induced by cold storage and it correlated with translocation of phosphatidylserine (PS) to the RBC surface, a known mediator of RBC/EC adhesion. The role of RBC surface PS in stRBC/EC interaction was confirmed by the suppression of adhesion after the blocking of the stRBC surface PS with annexin V. Concomitantly, RBC storage elevated intracellular levels of reactive oxygen species (ROS) and Ca(2+), the latter known to facilitate PS externalization. Poststorage rejuvenation treatment of stRBCs reversed all the above changes (ROS, Ca(2+), PS), along with complete suppression of the enhanced RBC/EC adhesion, restoring it to that of normal, freshly collected RBCs.

CONCLUSION

Poststorage RBC rejuvenation treatment is effective in reversing the storage-induced RBC/EC interaction. This provides further documentation for the potential clinical benefit of poststorage rejuvenation.

K-Cl cotransport function and its potential contribution to cardiovascular disease

K-Cl cotransport is the coupled electroneutral movement of K and Cl ions carried out by at least four protein isoforms, KCC1-4. These transporters belong to the SLC12A family of coupled cotransporters and, due to their multiple functions, play an important role in the maintenance of cellular homeostasis. Significant information exists on the overall function of these transporters, but less is known about the role of the specific isoforms. Most functional studies were done on K-Cl cotransport fluxes without knowing the molecular details, and only recently attention has been paid to the isoforms and their individual contribution to the fluxes. This review summarizes briefly and updates the information on the overall functions of this transporter, and offers some ideas on its potential contribution to the pathophysiological basis of cardiovascular disease. By virtue of its properties and the cellular ionic distribution, K-Cl cotransport participates in volume regulation of the nucleated and some enucleated cells studied thus far. One of the hallmarks in cardiovascular disease is the inability of the organism to maintain water and electrolyte balance in effectors and/or target tissues. Oxidative stress is another compounding factor in cardiovascular disease and of great significance in our modern life styles. Several functions of the transporter are modulated by oxidative stress, which in turn may cause the transporter to operate in either "overdrive" with the purpose to counteract homeostatic changes, or not to respond at all, again setting the stage for pathological changes leading to cardiovascular disease. Intracellular Mg, a second messenger, acts as an inhibitor of K-Cl cotransport and plays a crucial role in regulating the activity of protein kinases and phosphatases, which, in turn, regulate a myriad of cellular functions. Although the role of Mg in cardiovascular disease has been dealt with for several decades, this chapter is evolving nowadays at a faster pace and the relationships between Mg, K-Cl cotransport, and cardiovascular disease is an area that awaits further experimentation. We envision that further studies on the role of K-Cl cotransport, and ideally on its specific isoforms, in mammalian cells will add missing links and help to understand the cellular mechanisms involved in the pathophysiology of cardiovascular disease.

Blood banking-induced alteration of red blood cell flow properties

BACKGROUND

Blood banking procedures are associated with damage to red blood cell (RBC) membranes, which can impair their flow properties, namely, their deformability, aggregability, and adherence to endothelial cells (ECs) and thus possibly introducing a circulatory risk to recipients. This study was undertaken to comprehensively explore the effect of cold storage and gamma irradiation on RBC flow properties.

STUDY DESIGN AND METHODS

RBC flow properties were monitored as a function of shear stress with a computerized cell flow properties analyzer. Because we had previously studied storage effect on RBC aggregability (Transfusion 1999;39:277-81), here we determined the storage effect on RBC adherence and deformability, by measuring them before (control) and during storage. Gamma irradiation effect on RBC aggregability, adherence, and deformability was determined before (control) and after irradiation.

RESULTS

Cold storage significantly elevated the number of adherent RBCs and the strength of their interaction with ECs, and was marked by decreased RBC deformability as early as 2 weeks into the storage period. The elevation of RBC-EC interaction was well correlated with translocation of phosphatidylserine to the RBC surface. Gamma irradiation induced an immediate and marked increase in the number of rigid cells, but did not affect RBC adherence and aggregability.

CONCLUSION

RBC flow properties appear to be especially sensitive to cold storage and gamma irradiation because they are impaired long before the expiration date. Because impaired RBC flow properties facilitate circulatory disorders, the potential circulatory risk of transfusion RBC with blood banking-impaired rheology should be considered.

Cellular properties of human erythrocytes preserved in saline-adenine-glucose-mannitol in the presence of L-carnitine

L-Carnitine (LC) in the preservation medium during storage of red blood cells (RBC) can improve the mean 24-hr percent recovery in vivo and increase RBC life-span after reinfusion. The purpose of the study was to investigate the differences in the biochemical properties of RBCs stored in the presence or absence of LC, and the cell-age related responses to storage conditions and to LC. RBC concentrates in saline-adenine-glucose-mannitol (SAG-M) were stored in the presence or absence of 5 mM LC at 4 degrees C for up to 8 weeks. RBC subpopulations of different densities were prepared by centrifugation on Stractan density gradient. Cells were sampled at 0, 3, 6, and 8 weeks, and hematological and cellular properties analyzed (MCV, MCHC, 4.1a/4.1b ratio as a cell age parameter, intracellular Na(+) and K(+)). After 6 weeks, MCV of RBC stored in the presence of LC was lower than that of controls (6 weeks MCV: controls 95.4 +/- 1.8 fl; LC 91.5 +/- 2.0 fl; n = 6; P < 0.005). This was due to swelling of control cells, and affected mainly older RBCs. LC appeared to reduce or retard cell swelling. Among the osmotically active substances whose changes during storage could contribute to cell swelling, only intracellular Na(+) and K(+) differed between stored control RBCs and LC-treated cells. LC reduces the swelling of older cells during storage at 4 degrees C in SAG-M, possibly by acting on the permeability of cell membrane to monovalent cations.

Regulation of K-Cl cotransport: from function to genes

This review intends to summarize the vast literature on K-Cl cotransport (COT) regulation from a functional and genetic viewpoint. Special attention has been given to the signaling pathways involved in the transporter's regulation found in several tissues and cell types, and more specifically, in vascular smooth muscle cells (VSMCs). The number of publications on K-Cl COT has been steadily increasing since its discovery at the beginning of the 1980s, with red blood cells (RBCs) from different species (human, sheep, dog, rabbit, guinea pig, turkey, duck, frog, rat, mouse, fish, and lamprey) being the most studied model. Other tissues/cell types under study are brain, kidney, epithelia, muscle/smooth muscle, tumor cells, heart, liver, insect cells, endothelial cells, bone, platelets, thymocytes and Leishmania donovani. One of the salient properties of K-Cl-COT is its activation by cell swelling and its participation in the recovery of cell volume, a process known as regulatory volume decrease (RVD). Activation by thiol modification with N-ethylmaleimide (NEM) has spawned investigations on the redox dependence of K-Cl COT, and is used as a positive control for the operation of the system in many tissues and cells. The most accepted model of K-Cl COT regulation proposes protein kinases and phosphatases linked in a chain of phosphorylation/dephosphorylation events. More recent studies include regulatory pathways involving the phosphatidyl inositol/protein kinase C (PKC)-mediated pathway for regulation by lithium (Li) in low-K sheep red blood cells (LK SRBCs), and the nitric oxide (NO)/cGMP/protein kinase G (PKG) pathway as well as the platelet-derived growth factor (PDGF)-mediated mechanism in VSMCs. Studies on VSM transfected cells containing the PKG catalytic domain demonstrated the participation of this enzyme in K-Cl COT regulation. Commonly used vasodilators activate K-Cl COT in a dose-dependent manner through the NO/cGMP/PKG pathway. Interaction between the cotransporter and the cytoskeleton appears to depend on the cellular origin and experimental conditions. Pathophysiologically, K-Cl COT is altered in sickle cell anemia and neuropathies, and it has also been proposed to play a role in blood pressure control. Four closely related human genes code for KCCs (KCC1-4). Although considerable information is accumulating on tissue distribution, function and pathologies associated with the different isoforms, little is known about the genetic regulation of the KCC genes in terms of transcriptional and post-transcriptional regulation. A few reports indicate that the NO/cGMP/PKG signaling pathway regulates KCC1 and KCC3 mRNA expression in VSMCs at the post-transcriptional level. However, the detailed mechanisms of post-transcriptional regulation of KCC genes and of regulation of KCC2 and KCC4 mRNA expression are unknown. The K-Cl COT field is expected to expand further over the next decades, as new isoforms and/or regulatory pathways are discovered and its implication in health and disease is revealed.

Blood bank conditions and RBCs: the progressive loss of metabolic modulation

BACKGROUND

Human RBC metabolism is modulated by the cell oxygenation state. Among other mechanisms, competition of deoxyhemoglobin and some glycolytic enzymes for the cytoplasmic domain of band 3 is probably involved in modulation. This metabolic modulation is connected to variations in intracellular NADPH and ATP levels as a function of the oxygenation state of the cell, and, consequently, it should have physiologic relevance. The present study investigates the effect of storage on this metabolic modulation and its relationship with the alteration of membrane protein composition.

STUDY DESIGN AND METHODS

RBCs stored in CPD-saline-adenine-glucose-mannitol were assayed for glucose uptake and partition between glycolysis and the pentose phosphate pathway at high and low oxygen saturation by nuclear magnetic resonance spectroscopy after 1, 14, 21, 35, and 42 days of storage. Membrane protein composition was determined by SDS-PAGE on Days 1, 14, 35, and 42. Metabolic values and 2,3 DPG concentration were also measured after rejuvenation for 1 hour at 37 degrees C with pyruvate-inosine-phosphate-adenine solution on Day 21.

RESULTS

Metabolic differences between RBCs incubated at high and low oxygen saturation decreased during storage, and, on Day 35, the two groups did not have significant differences (p = 0.111). SDS-PAGE showed that membrane protein composition was concurrently modified. The percentage of unmodified band 3 decreased during storage, principally between Days 14 and 35. In rejuvenated RBCs, oxygen-dependent modulation was not restored.

CONCLUSIONS

RBCs stored in CPD-saline-adenine-glucose-mannitol do show a progressive loss of oxygen-dependent metabolic modulation, which is not restored after rejuvenation and which seems partly related to modifications in membrane proteins, mainly band 3.

The effect of hypotonicity, glutamine, and glycine on red cell preservation

BACKGROUND

Red cells (RBCs) stored in hypo-osmolar additive solutions with the same concentrations of adenine, dextrose, mannitol, and sodium chloride and varied amounts of ammonium, phosphate, glycerol, and glutamine were better preserved than RBCs in the standard additive solution (Adsol). Cell swelling occurred in all the experimental additives. This observation prompted the evaluation of glutamine and glycine alone, as well as a combination of glutamine and glycine, all of which have been described as producing swelling of rat liver cells.

STUDY DESIGN AND METHODS

Aliquots of RBCs were stored at 4 degrees C in Adsol or experimental additive solutions (EASs) all containing adenine, 2 mM; dextrose, 110 mM; mannitol, 55 mM; and sodium chloride, 50 mM. EAS 42 had, in addition, glutamine, 10 mM; glycine 5 mM, and phosphate, 20 mM. EAS 43 had glutamine, 10 mM; glycine, 10 mM; and phosphate 20 mM. EAS 44 had glutamine, 10 mM; EAS 45 had glutamine, 10 mM, and phosphate, 20 mM, and EAS 46 had only glycine, 10 mM. At intervals, measurements were made of mean corpuscular volume, mean corpuscular hemoglobin concentration, morphology, ATP, hemolysis, supernatant potassium, ammonia, pH, and microvesicles shed.

RESULTS

The initial mean corpuscular volumes were larger in all EASs than in Adsol, but the greatest difference was between EASs 44 and 46 (108 fL) and Adsol (86 fL) (p < 0.001). The morphology scores were significantly better in all the EASs (p < 0.04). The ATPs were significantly greater in all the EASs (p < 0.001), and highest in those with phosphate. potassium leakage and hemolysis were less in the EASs (p < 0.001). The ammonia levels higher in all the EASs than in Adsol, with the exception of EAS 46. During storage, the extracorpuscular and intracorpuscular pH levels were essentially identical. The shedding of microvesicles was greatly reduced in all the EASs.

CONCLUSION

Cell swelling induced in RBCs after collection appears to improve preservation. Ammonia and phosphate enhance RBC ATP maintenance. Glycine decrease the formation of ammonia by RBCs stored in a hypotonic medium.

Studies in red blood cell preservation 10. 51Cr recovery of red cells after liquid storage in a glycerol-containing additive solution

The purpose of the present study was to compare the 24-hour recovery of red blood cells stored for 9 weeks in a hypoosmolar additive solution containing 150 mM glycerol to cells stored in Adsol. Seven units of packed red cells were split into 2 aliquots. To one sample, 100 ml of the experimental additive solution (EAS 25) was added, and to the other, 50 ml of Adsol. At the end of the storage period the cells were labeled with 51Cr. A double chromium technique was used to make it possible to perform comparative autologous studies in the same donor. The 24-hour 51Cr recovery value for EAS 25 was 73.0 +/- (SD) 4.2% and for Adsol 60.9 +/- 7.1. At 9 weeks the adenosine triphosphate levels were not significantly better compared to Adsol but the other in vitro measurements were better. New approaches to the study of red cell preservation are suggested.

Red blood cell cation transports in uraemic anaemia: evidence for an increased K/Cl co-transport activity. Effects of dialysis and erythropoietin treatment

This study examines the role of uraemia and the effect of different dialysis treatments on red cell cation transport. We evaluated the main cation transport systems in erythrocytes of non-dialysed end-stage renal disease (ESRD) subjects, of patients undergoing haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD), as well as the changes induced by human recombinant erythropoietin (r-HuEPO) administration. In uraemic undialysed and dialysed patients, we observed an increase in K/Cl co-transport activity and in shrinkage-induced amiloride-sensitive (HMA-sensitive) Na efflux (Na/H exchange) and a decrease in Na/K pump and Na/K/Cl co-transport activity, while Na/Li exchange was increased only in dialysed patients. In uraemic erythrocytes, we showed for the first time an increased K/Cl co-transport activity, which was cell age independent. Generally, the different method of dialysis (CAPD or HD) did not modify the cation transport abnormalities observed. During the treatment with r-HuEPO, all the systems, with the exception of the Na/K pump and Na/K/Cl co-transport, increased their activities following the increase of circulating young red cells. The changes produced under r-HuEPO administration were transient and cation transports returned to the baseline values within 100 days of treatment, indicating a primary and prominent pathogenetic role of uraemia in modulating the red cell membrane cation transport activities.

The quality of red blood cells

The evolving practice of medicine has required a number of changes in red cell product manufacture to ensure that the final product is more specifically tailored to the needs of the individual patient. As a result of the increasing concern over the risks of transfusion pharmaceutical standards of manufacture are now applied to blood component preparation. Studies have been undertaken to define the optimum method of blood processing, and newer technologies are emerging to allow acquisition of a more consistent dose of red cells in a fashion which may minimize the lesion of collection. Use of high efficiency 3+ generation filter technologies reduces leukokine build up during storage and improves the quality and purity of the stored blood product. The combination of new plasticizers for packaging and improved red cell additive solutions should allow the blood center to supply a more functional red cell with longer storage shelf life. Overall these developments should result in the provision of a more consistent dose of fully functional red cells to the recipient who will be less exposed to the undesirable sequelae of transfusion than previously.