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

Impacts of papain and neuraminidase enzyme treatment on electrohydrodynamics and IgG-mediated agglutination of type A red blood cells

The stability of native and enzyme-treated human red blood cells of type A (Rh D positive) against agglutination is investigated under conditions where it is mediated by immunoglobuline G (IgG) anti-D antibody binding. The propensity of cells to agglutinate is related to their interphasic (electrokinetic) properties. These properties significantly depend on the concentration of proteolytic papain enzyme and protease-free neuraminidase enzyme that the cells are exposed to. The analysis is based on the interpretation of electrophoretic data of cells by means of the numerical theory for the electrokinetics of soft (bio)particles. A significant reduction of the hydrodynamic permeability of the external soft glycoprotein layer of the cells is reported under the action of papain. This reflects a significant decrease in soft surface layer thickness and a loss in cell surface integrity/rigidity, as confirmed by nanomechanical AFM analysis. Neuraminidase action leads to an important decrease in the interphase charge density by removing sialic acids from the cell soft surface layer. This is accompanied by hydrodynamic softness modulations less significant than those observed for papain-treated cells. On the basis of these electrohydrodynamic characteristics, the overall interaction potential profiles between two native cells and two enzyme-treated cells are derived as a function of the soft surface layer thickness in the Debye-Hückel limit that is valid for cell suspensions under physiological conditions (approximately 0.16 M). The thermodynamic computation of cell suspension stability against IgG-mediated agglutination then reveals that a decrease in the cell surface layer thickness is more favorable than a decrease in interphase charge density for inducing agglutination. This is experimentally confirmed by agglutination data collected for papain- and neuraminidase-treated cells.

Freeze-dried whole plasma: Evaluating sucrose, trehalose, sorbitol, mannitol and glycine as stabilizers

Several groups report stability results for freeze-dried whole plasma intended for use as a transfusion product [Hellstern P, Sachse H, Schwinn H, Oberfrank K. Manufacture and in vitro characterization of a solvent/detergent-treated human plasma. Vox Sang 1992;63:178-185; Trobisch H. Results of a quality-control study of lyophilized pooled plasmas which have been virally inactivated using a solvent detergent method (modified Horowitz procedure). Beitr Infusionsther 1991;28:92-109; Hugler P, Trobish H, Neuman H, Moller, Sirtl C, Derdak M, Laubenthal H. Quality control of three different conventional fresh-frozen plasma preparations and one new virus-inactivated lyophilized pooled plasma preparation. Klin Wochenschr 1991;69:157-161; Krutvacho T, Chuansumrit A, Isarangkura P, Pintadit P, Hathirat P, Chiewsilp P. Response of hemophilia with bleeding to fresh dry plasma. Southeast Asian J Trop Med Public Health 1993;24:169-173; Chuansumrit A, Krasaesub S, Angchaisuksiri P, Hathirat P, Isarangkura P. Survival analysis of patients with haemophilia at the International Haemophilia Training Centre, Bangkok, Thailand. Haemophilia 2004;10:542-549]. Plasma coagulation properties are substantially impaired in these freeze-dried plasmas, while pH levels are close to alkaline. In this work, plasma supplemented with 60mM sucrose, trehalose, mannitol, sorbitol or glycine was freeze-dried. The samples were subjected to forced degradation at 40 degrees C for 10 days in order to quickly evaluate the effectiveness of the different stabilizers. Initial PT, APTT and TT values were 14.4+/-0. 5s, 31.4+/-1.5s and 18.3+/-0.6s, respectively. At the end of the degradation period, PT, APTT and TT were substantially prolonged, and were 19.1+/-0. 5s, 43.1+/-0.6s and 26.1+/-1.0s, respectively. In the presence of glycine, at the end of the degradation period, PT, APTT and TT values remained close to the initial values and were 15.5+/-0. 4s, 35.7+/-0.9s and 19.4+/-0.2s, respectively. Percent activities of the coagulation factors V, VII, VIII, IX, X and the coagulation inhibitors protein C, protein S and antithrombin III were recorded. Factors V and VIII were most prone to degradation. Factor V and VIII activities, in control plasma, were approx. 44+/-3.5% and 58+/-2.3%, at the end of storage. In contrast, much higher factor V and VIII activities were maintained in the lyophilized glycine-supplemented plasma: approx. 60+/-3.5% and 74+/-7.0%, correspondingly. The most stable protein was protein C, which showed no signs of degradation under the testing conditions of this study. All tested stabilizers provided protection. Glycine, however, outperformed all tested polyols, providing superior preservation of plasma clotting properties. Thermograms of 60mM glycine in water and 60mM glycine in plasma show that, in the presence of plasma, glycine does not crystallize. The process of freeze-drying caused a complete loss of plasma pCO(2) (gas) and a substantial increase in plasma pH. Citric acid was found to be a suitable pH adjuster for lyophilized/rehydrated plasma.

Signal-Specific Activation and Regulation of Human Neutrophil Fcγ Receptors

FcgammaRs with the ITIM domain have been shown to regulate the inflammatory signal delivered by the ITAM-containing FcgammaRs. In this study, we demonstrate that the function of human neutrophil FcgammaR type IIA (CD32A) is regulated in a distinct manner by different cell activation signals at the ligand-binding stage. Activation of neutrophils with fMLP up-regulated the ligand-binding function of CD32A, whereas PMA-mediated activation completely abolished ligand binding without altering CD32A expression. Furthermore, PMA treatment also abolished CD16B-dependent ligand binding irrespective of the level of expression. The effect of PMA was cell type specific, because the ligand-binding function of CD32A expressed on cultured cells such as K562 and CHO-CD32A transfectants was not affected by PMA. Interestingly, phorbol 12,13-dibutyrate, another phorbol ester, and IL-8 up-regulated CD32A-dependent ligand-binding function. These results demonstrate that regulation of CD32A-dependent ligand binding in human neutrophils is not only cell type specific but also activation signal specific. Moreover, these results suggest the possibility that signals delivered to neutrophils by various inflammatory stimuli can exert opposing effects on the function of human FcgammaRs, representing a novel inside-out regulatory mechanism of FcgammaR ligand binding.

Transfer of glycosylphosphatidylinositol-anchored proteins to deficient cells after erythrocyte transfusion in paroxysmal nocturnal hemoglobinuria

In paroxysmal nocturnal hemoglobinuria (PNH), an acquired mutation of the PIGA gene results in the absence of glycosylphosphatidylinositol (GPI)-anchored cell surface membrane proteins in affected hematopoietic cells. Absence of GPI-anchored proteins on erythrocytes is responsible for their increased sensitivity to complement-mediated lysis, resulting in hemolytic anemia. Cell-to-cell transfer of CD55 and CD59, 2 GPI-anchored proteins, by red cell microvesicles has been demonstrated in vitro, with retention of their function. Because red cell units stored for transfusion contain many erythrocyte microvesicles, transfused blood could potentially serve as a source of CD55 and CD59. We examined whether GPI-anchored proteins could be transferred in vivo to deficient cells following transfusions given to 6 patients with PNH. All patients were group A(1) blood type. Each was given transfusions of 3 U of compatible, washed group O blood. Patient group A(1) cells were distinguished from the transfused group O cells by flow cytometry and staining with a labeled lectin, Dolichos biflorus, which specifically binds to group A(1) erythrocytes. Increased surface CD59 was measured on recipient red cells and granulocytes 1, 3, and 7 days following transfusion in all 6 patients. Our data suggest a potential therapeutic role for GPI-anchored protein transfer for severe PNH.

T-complex polypeptide-1 interacts with the erythrocyte cytoskeleton in response to elevated temperatures

Chaperonins are double ring complexes composed of highly conserved 60-kDa protein subunits that are divided into two subgroups. Group II chaperonins are found in archaea and the cytoplasm of eukarya and are believed to function like other chaperonins as part of a protein folding system. We report here that human erythrocytes contain the group II chaperonin T-complex polypeptide 1 (TCP-1) and that this complex translocates from the cytoplasm to the cytoskeleton in response to heat treatment in the absence of overt cell damage. Identification as TCP-1 was determined by immunodetection for TCP-1alpha and corroborated by mass spectroscopy peptide sequencing. Direct visualization by immunofluorescence confirmed peripherally localized TCP-1 in response to heat treatment. Temperatures ranging from 37-50 degrees C were demonstrated to have distinct kinetic profiles of induced translocation. Heat-induced binding was shown by Triton shell analysis to be specifically associated with the cytoskeletal proteins. Furthermore, the binding was reversible following removal of the stimulatory condition. A stabilizing process is hypothesized based on the known interactions of chaperonins.

Biochemical stabilization enhances red blood cell recovery and stability following cryopreservation

Glycerolized red blood cells (RBC) are approved for long-term cryopreservation. However, the need to remove the glycerol cryoprotectant prior to transfusion has limited the usefulness of this cryopreservation method. This report describes using non-cryoprotectant biochemical stabilization techniques to substitute for the standard glycerol cryoprotectant. The glycerolized RBC method was compared to a newly developed LC-V method that combines transfusable cryoprotectants (hydroxyethyl starch and dextran) and specific non-cryoprotectant biochemical stabilizers (nicotinamide, nifedipine, and flurbiprofen). Results demonstrate that the biochemical stabilizers significantly reduce cryopreservation-induced hemolysis compared to cryopreservation in their absence and that thaw hemolysis levels approach those of standard 40% (w/v) glycerolized RBC (3.1+/-0.2% for 40% glycerol compared to 8.7+/-0.9% for the LC-V protocol). Furthermore, LC-V cryopreserved RBC exhibit a significantly enhanced post-thaw stability compared to glycerolized RBC as determined by osmotic fragility index (0.557+/-0.034 for 40% glycerol compared to 0.478+/-0.016 for the LC-V protocol). Analysis of biochemically stabilized RBC proteins revealed a transient translocation of carbonic anhydrase to the membrane fraction. However, the enhanced RBC recovery and stability could not be attributed to this event. Finally, DSC analysis demonstrated that the biochemical stabilizers of the LC-V process were not functioning as surrogate cryoprotectants in that they did not affect the quantity or quality of ice formed. Overall, this work demonstrates that cryopreservation-induced RBC damage may be corrected or prevented through specific biochemical stabilization and represents a significant step toward a directly transfusable cryopreserved RBC product.

Hypertonic resuscitation and blood coagulation: in vitro comparison of several hypertonic solutions for their action on platelets and plasma coagulation

Resuscitation with hypertonic saline (HS) appears to aggravate bleeding in a model of uncontrolled hemorrhage [J. Trauma 28 (1988) 751; J. Trauma 29 (1989) 79; Arch. Surg. 127 (1992) 93]. This property may be related to the anticoagulant effects of HS on plasma clotting factors and platelets [J. Trauma 31 (1991) 8]. The hypothesis in this study is that a hypertonic solution can be developed that would not disturb the blood coagulation mechanism and could be used as an alternative to hypertonic saline.HS and four different 2400 mosM solutions containing monosaccharides and/or glycine were screened for their in vitro effects on plasma clotting times and platelets. Significant prolongations falling outside the normal range were detected in prothrombin time (PT) and thrombin rime (TT) when only 5% of the volume of normal plasma is HS. Platelet function as measured by extent of shape change (ESC) induced by ADP and aggregation induced by thrombin were also critically impaired by HS at a 5% dilution. All alternative solutions-hypertonic glucose, sorbitol, glycine, glucose/glycine, glucose/mannitol/glycine, sorbitol/glycine-caused a significantly reduced impairment in platelet function and the plasma coagulation system. Hypertonic glycine showed a unique ability to fully preserve the function and integrity of the plasma coagulation system. Considering the pre-deposition of the trauma patient to coagulopathy, administration of HS which clearly is a potent anticoagulant and anti-platelet risks further aggravating the coagulopathy. In contrast, hypertonic glycine preserves the blood coagulation mechanism and exhibits the potential for numerous therapeutic applications. Therefore, prompt evaluation of hypertonic glycine as a resuscitative fluid is highly desirable.

Alkaline CPD and the preservation of RBC 2,3-DPG

BACKGROUND

Concentrations of 2,3-DPG decline rapidly in the first week of RBC storage because of the low pH of conventional storage solutions. Alkaline additive solutions, which can preserve RBCs for up to 11 weeks, still do not preserve 2,3-DPG because the starting pH is below 7.2.

STUDY DESIGN AND METHODS

Alkaline CPD (pH=8.7) was made with trisodium citrate, dextrose, and disodium phosphate. Twelve units of whole blood were collected into heparin and pooled in groups of four units. Each pool was then aliquoted into four units; 63 mL of CPD with pH 5.7, 6.5, 7.5, or 8.7 was added to one unit of each pool, and 300 mL of the alkaline experimental additive solution-76 was added. In Study 2, 12 units were collected into alkaline CPD, pooled in groups of four, aliquoted as described, and stored in four variants of experimental additive solution-76 containing 0, 9, 18, and 27 mM of disodium phosphate. RBC ATP and 2,3-DPG concentrations, intracellular and extracellular pH and phosphate concentrations, hemolysis, and other measures of RBC metabolism and function were measured weekly.

RESULTS

RBCs stored in more alkaline conditions made 2,3-DPG, but at the expense of ATP. Concentrations of 2,3-DPG decreased after 2 weeks storage, but ATP concentrations never fully recovered. Providing more phosphate both increased the duration of 2,3-DPG persistence and raised ATP concentrations in the later stages of storage.

CONCLUSIONS

Maintaining both 2,3-DPG and ATP requires both high pH and high concentrations of phosphate.

Recombinant CD16A-Ig forms a homodimer and cross-blocks the ligand binding functions of neutrophil and monocyte Fcgamma receptors

Receptors for the Fc region of IgG (FcgammaR) are expressed as membrane-bound and soluble forms in inflammatory cells. These receptors mediate a variety of immunoregulatory functions. FcgammaR-bearing neutrophils and macrophages play a major role in mediating immune complex induced inflammatory diseases and antibody-mediated tissue injury in autoimmune diseases. To delineate the biological role of the soluble FcgammaR, a recombinant soluble CD16A (CD16A-Ig) was expressed and characterized. CD16A-Ig is secreted as a disulfide-linked homodimer of 70kDa. The purified CD16A-Ig bound to human IgG1 and IgG3 immobilized onto ELISA plates and on IgG1- and IgG3-coated erythrocytes. Saturation binding studies and Scatchard plot analysis showed that immune complex bound to the purified CD16A-Ig with high avidity. Moreover, CD16A-Ig competitively blocked the binding of cell surface-expressed CD16A-CHO cells to IgG-coated plates. The dimeric CD16A-Ig also efficiently cross-blocked the binding of IgG-coated target cells to other FcgammaR expressed on neutrophils and monocytes. These results demonstrate that CD16A-Ig forms a high avidity dimer and is capable of blocking cell-cell interactions mediated by inflammatory cells expressing FcgammaR and IgG-coated target cells. These findings suggest that the dimeric FcgammaR molecules could be used therapeutically for the intervention of immune complex-mediated inflammatory disease.

Red blood cell stabilization reduces the effect of cell density on recovery following cryopreservation

The relationship between red blood cell hematocrit and hemolysis during cryopreservation has been examined. Cells were frozen with glycerol, thawed, and deglycerolized in a model system based on the protocols used in transfusion medicine. Analysis included determination of hemolysis following thaw (Thaw) and deglycerolization (Overall) and osmotic fragility of the final cell suspensions. Results demonstrate that thaw hemolysis decreased with increasing hematocrit at all glycerol levels tested. Overall hemolysis increased with increasing hematocrit at low (15% w/v) glycerol and decreased with increasing hematocrit at high (40% w/v) glycerol levels. These results were paralleled by changes in the fragility index. Furthermore, these results indicate a distinction between freeze/thaw lysis and damage which leads to lysis during postthaw processing. To examine this further, a biochemical stabilizing solution, having no cryoprotective effects itself, was added to suboptimal glycerol concentrations. This addition resulted in hemolysis levels and fragility indices comparable to those using high (40% w/v) glycerol levels. Thus, the damage observed with increasing hematocrit is not necessarily a function of the packing on the volume of the ice-free zone, but rather an expression of cell damage. Furthermore, this damage is, in part, biochemical in nature and may be protected against through specific cellular stabilization prior to cryopreservation.

A hypotonic storage solution did not prolong the viability of RBCs

BACKGROUND

Hypotonic storage solutions and WBC filtration are both reported to improve RBC viability. This study tested the ability of an investigational hypotonic storage solution (AS-24, Medsep Corp.) to extend the viability of liquid-stored RBCs to 8 weeks.

STUDY DESIGN AND METHODS

In a pair of crossover trials, 11 RBC units, WBC-reduced by filtration and stored in AS-24 for 8 weeks, were compared with units from the same donors that were stored for 6 weeks in AS-3, and 13 RBC units, WBC-reduced by filtration and stored in AS-3 for 8 weeks, were compared with units from the same donors that were stored for 6 weeks in AS-3. Viability was measured by the (51)Cr/(99m)Tc double-isotope method.

RESULTS

RBC viability at 8 weeks averaged 64 +/- 3 percent in the AS-24 units and 67 +/- 2 percent in the AS-3 units. It was equal at 77 +/- 3 percent and 77 +/- 2 percent after 6 weeks' storage in AS-3 in both trials.

CONCLUSIONS

Prestorage WBC reduction and storage in AS-24 did not extend RBC viability to 8 weeks. The improved viability previously demonstrated with storage of dilute suspensions of RBCs in hypotonic solutions is probably caused by factors other than the hypotonicity.