In vivo survival of apheresis RBCs, frozen with 40-percent (wt/vol) glycerol, deglycerolized in the ACP 215, and stored at 4 degrees C in AS-3 for up to 21 days

The need for rare blood programs is real

See article on page 670–678, in this issue

Frozen Blood Reserves

Frozen blood reserves are an important component in meeting blood needs. The idea behind a frozen blood reserve is twofold: to freeze units of rare blood types for later use by patients with special transfusion needs and for managing special transfusion circumstances. The permeating additive glycerol is used as a cryoprotectant to protect red blood cells (RBCs) from freezing damage. The use of thawed RBCs has been hampered by a 24-h outdating period due to the potential bacterial contamination when a functionally open system is used for addition and removal of the glycerol. The introduction of an automated, functionally closed system for glycerolization and deglycerolization of RBCs improved the operational practice. More importantly, the closed process allowed for extended shelf life of the thawed RBCs. In the current chapter, a cryopreservation procedure for RBCs using a functionally closed processing system is described.

Implications of variability in cell membrane permeability for design of methods to remove glycerol from frozen-thawed erythrocytes

In North America, red blood cells (RBCs) are currently cryopreserved in a solution of 40% glycerol. While glycerol is not inherently toxic to humans, it must be removed prior to transfusion to prevent intravascular osmotic hemolysis. The current deglycerolization procedure requires about 45 min per RBC unit. We previously presented predictions suggesting that glycerol could be safely removed from RBCs in less than 1 min. However, experimental evaluation of these methods resulted in much higher hemolysis than expected. Here we extend our previous study by considering both concentration-dependence of permeability and variability in permeability values in the mathematical optimization algorithm. To establish a model for the concentration dependence of glycerol permeability, we combined literature data with new measurements of permeability in the presence of 40% glycerol. To account for cell-dependent variability we scaled the concentration-dependent permeability model to define a permeability range for optimization. Methods designed using a range extending to 50% of the model-predicted glycerol permeability had a duration of less than 3 min and resulted in hemolysis ranging from 34% to 83%; hemolysis values were highly dependent on the blood donor. Extending the permeability range to 5% of the model-predicted value yielded a 30 min method that resulted in an average hemolysis of 12%. Our results suggest high variability in the glycerol permeability between donors and within a population of cells from the same donor. Such variability has broad implications for design of methods for equilibration of cells with cryoprotectants.

Betaine Combined with Membrane Stabilizers Enables Solvent-Free Whole Blood Cryopreservation and One-Step Cryoprotectant Removal

Cryopreservation of red blood cells (RBCs) is fundamentally important to modern transfusion medicine. Currently, organic solvent glycerol is utilized as the state-of-the-art cryoprotectant (CPA) for RBC cryopreservation. However, glycerol must be removed before RBC transfusion to avoid intravascular hemolysis via a time-consuming deglycerolization process with specialized equipment (e.g., ACP 215), thus limiting the clinical use of frozen RBCs. Herein, we report novel biocompatible CPA formulations combining betaine with membrane stabilizers (disaccharides or amino acids), which can achieve outstanding efficiency for RBC cryopreservation directly using whole blood without any separation process. Most importantly, because of the osmotic regulation capacity of betaine, a simple and fast one-step method can be used for CPA removal, which is significantly superior to the current multistep deglycerolization process. This work offers a promising solution for highly efficient and solvent-free RBC cryopreservation and holds great potential for improving the long-term storage and long-distance distribution of RBCs.

Red blood cell phenotype fidelity following glycerol cryopreservation optimized for research purposes

Intact red blood cells (RBCs) are required for phenotypic analyses. In order to allow separation (time and location) between subject encounter and sample analysis, we developed a research-specific RBC cryopreservation protocol and assessed its impact on data fidelity for key biochemical and physiological assays. RBCs drawn from healthy volunteers were aliquotted for immediate analysis or following glycerol-based cryopreservation, thawing, and deglycerolization. RBC phenotype was assessed by (1) scanning electron microscopy (SEM) imaging and standard morphometric RBC indices, (2) osmotic fragility, (3) deformability, (4) endothelial adhesion, (5) oxygen (O2) affinity, (6) ability to regulate hypoxic vasodilation, (7) nitric oxide (NO) content, (8) metabolomic phenotyping (at steady state, tracing with [1,2,3-13C3]glucose ± oxidative challenge with superoxide thermal source; SOTS-1), as well as in vivo quantification (following human to mouse RBC xenotransfusion) of (9) blood oxygenation content mapping and flow dynamics (velocity and adhesion). Our revised glycerolization protocol (40% v/v final) resulted in >98.5% RBC recovery following freezing (-80°C) and thawing (37°C), with no difference compared to the standard reported method (40% w/v final). Full deglycerolization (>99.9% glycerol removal) of 40% v/v final samples resulted in total cumulative lysis of ~8%, compared to ~12-15% with the standard method. The post cryopreservation/deglycerolization RBC phenotype was indistinguishable from that for fresh RBCs with regard to physical RBC parameters (morphology, volume, and density), osmotic fragility, deformability, endothelial adhesivity, O2 affinity, vasoregulation, metabolomics, and flow dynamics. These results indicate that RBC cryopreservation/deglycerolization in 40% v/v glycerol final does not significantly impact RBC phenotype (compared to fresh cells).

Measuring Post-transfusion Recovery and Survival of Red Blood Cells: Strengths and Weaknesses of Chromium-51 Labeling and Alternative Methods

The proportion of transfused red blood cells (RBCs) that remain in circulation is an important surrogate marker of transfusion efficacy and contributes to predict the potential benefit of a transfusion process. Over the last 50 years, most of the transfusion recovery data were generated by chromium-51 (⁵¹Cr)-labeling studies and were predominantly performed to validate new storage systems and new processes to prepare RBC concentrates. As a consequence, our understanding of transfusion efficacy is strongly dependent on the strengths and weaknesses of ⁵¹Cr labeling in particular. Other methods such as antigen mismatch or biotin-based labeling can bring relevant information, for example, on the long-term survival of transfused RBC. These radioactivity-free methods can be used in patients including from vulnerable groups. We provide an overview of the methods used to measure transfusion recovery in humans, compare their strengths and weaknesses, and discuss their potential limitations. Also, based on our understanding of the spleen-specific filtration of damaged RBC and historical transfusion recovery data, we propose that RBC deformability and morphology are storage lesion markers that could become useful predictors of transfusion recovery. Transfusion recovery can and should be accurately explored by more than one method. Technical optimization and clarification of concepts is still needed in this important field of transfusion and physiology.

From Development to Implementation: Adjusting the Hematocrit of Deglycerolized Red Cell Concentrates to Meet Regulatory Standards

BACKGROUND

Before transfusion, thawed frozen red cell concentrates (RCCs) must be deglycerolized. In order to ensure that these products meet regulatory standards for hematocrit, an approach to manipulate hematocrit post deglycerolization was developed and implemented.

METHODS

Glycerolized and frozen RCCs were thawed and deglycerolized using the COBE 2991 cell processor, and the final product's hematocrit was adjusted by addition of various volumes of 0.9% saline / 0.2% dextrose. The in vitro quality of RCCs (hematocrit, hemolysis, hemoglobin content, volume, recovery, ATP, supernatant potassium, and others) were compared to Canadian Standards Association (CSA) and other standards for deglycerolized RCCs.

RESULTS

Addition of saline/dextrose re-suspension solution in a range of 65-90 g post deglycerolization led to acceptable hematocrits. In the pilot study, this approach resulted in RCCs meeting all CSA standards for deglycerolized RCCs, with stimulation of RBC metabolism demonstrated by increased ATP concentration. In the validation phase, results were similar, although the CSA hemolysis standard was not met. Pre- and post-implementation data confirmed that manipulated RCCs met CSA hematocrit standards.

CONCLUSION

This process was implemented at Canadian Blood Services to provide deglycerolized RCCs that meet the CSA hematocrit standard. However, pre- and post-implementation data reveal that this deglycerolization process is not sufficient to have RCCs consistently meet hemolysis standards.

Gamma-irradiation of deglycerolized red cells does not significantly affect in vitro quality

BACKGROUND AND OBJECTIVES

Red cells frozen with glycerol may require gamma-irradiation after thawing and deglycerolization for transfusion to at-risk patients. Both freezing and irradiation are known to cause red cell damage. However, the effect of irradiation on the quality of deglycerolized red cells and the optimal shelf life of such a component is currently unknown.

MATERIALS AND METHODS

Red cells (<7 days) were pooled, split and glycerolized using an ACP-215 automated cell washer (n = 12 pairs) and frozen at -80°C. Red cells were thawed, deglycerolized and resuspended in SAG-M. One of each pair was gamma-irradiated, while the other served as a control. Products were stored at 2-6°C and sampled for in vitro testing immediately after irradiation, and at 24 and 48 h postirradiation.

RESULTS

Irradiation of deglycerolized red cells led to a >1·5-fold increase in extracellular potassium, compared to control units at 24 and 48 h postirradiation. Other parameters, including haemolysis, were not significantly affected by irradiation postdeglycerolization.

CONCLUSION

Deglycerolized, irradiated red cells had increased supernatant potassium, but remained of acceptable quality for 24 h postirradiation.

Cryopreservation of red blood cells

Cryopreservation of red blood cell concentrates (RBCs) is an important method for maintaining an inventory of rare RBC units and managing special transfusion circumstances. The permeating additive glycerol is used as a cryoprotectant to protect RBCs against freezing damage. The use of thawed RBCs was hampered a 24-h outdating period due to potential bacterial contamination when a functionally open system was used for addition and removal of the glycerol. With the introduction of a functionally closed system for the glycerolization and deglycerolization of RBC units, extended post-thaw storage became possible. Here, we describe the cryopreservation of red blood cells according to the high-glycerol method, using a functionally closed processing system.

In vitro parameters of cryopreserved leucodepleted and non-leucodepleted red blood cells collected by apheresis or from whole blood and stored in AS-3 for 21 days after thawing

BACKGROUND

The aim of the study was to evaluate the in vitro quality of cryopreserved red blood cells obtained from different sources with or without leucodepletion and stored at 4±2 °C in AS-3 for up to 21 days.

MATERIALS AND METHODS

Red blood cells were collected by four methods: double erythrocytapheresis, whole blood collection with buffy coat removal, double erythrocytapheresis with in-line leucofiltration, or whole blood collection with in-line leucofiltration. All four types of red blood cells were frozen in 40% glycerol after collection and stored at a temperature below -65 °C for at least 30 days, thawed, deglycerolised and subsequently reconstituted in AS-3. The in vitro haematological and biochemical properties of the thawed red blood cells were tested on days 0, 7, 14, and 21 after deglycerolisation and reconstitution.

RESULTS

Overall, 72 units were processed. Leucodepletion of cryopreserved red blood cells units reduced haemolysis, lowered ammonia concentration, preserved pH and osmolality and led to sustained higher concentrations of ATP. In contrast, the source of red blood cells (apheresis or whole blood) did not affect their quality.

DISCUSSION

The quality of all investigated red blood cells units was the same as or even better than that of erythrocytes obtained from double erythrocytapheresis with a 24-hour survival of at least 86% after up to 3 weeks of storage in AS-3.

Frozen blood products: clinically effective and potentially ideal for remote Australia

The development of effective cryopreservation techniques for both red blood cells and platelets, which maintain ex vivo biological activity, in combination with frozen plasma, provides for a unique blood banking strategy. This technology greatly enhances the storage life of these products. The rationale and potential advantages of using cryopreservation techniques for the provision of blood products to remote and military environments have been effectively demonstrated in several conflicts over the last decade. Current haemostatic resuscitation doctrine for the exsanguinating patient supports the use of red blood cells, platelets and frozen plasma early in the resuscitation. We believe an integrated fresh-frozen blood bank inventory could facilitate provision of blood products, not only in the military setting but also in regional Australia, by overcoming many logistic and geographical challenges. The processes involved in production and point of care thawing are sufficiently well developed and achievable to make this technology a viable option. The potential limitations of cryopreservation and subsequent product thawing need to be considered if such a strategy is to be developed. A substantial body of international experience using cryopreserved products in remote settings has already been accrued. This experience provides a template for the possible creation of an Australian integrated fresh-frozen blood bank inventory that could conceivably enhance the care of patients in both regional Australia and in the military setting.

A Dilution-Filtration System for Removing Cryoprotective Agents

In most cryopreservation applications, the final concentrations of cryoprotective agents (CPAs) must be reduced to biocompatible levels. However, traditional methods for removing CPAs usually have disadvantages of operation complexity, time consumption, and ease of contamination, especially for the applications involving large volumes of cell suspensions. A dilution-filtration system, which involves pure ultrafiltration for separation, was developed for continuous, automatic, and closed process of removing CPAs. To predict the optimal protocols under given experimental conditions, a theoretical model was established first. Cell-free experiments were then conducted to investigate the variation in CPA concentration during the process, and the experimental data were compared with the theoretical values for the validation of the model. Finally, ten units (212.9 ml/unit±9.5 ml/unit) of thawed human red blood cells (cryopreserved with 40% (w/v) glycerol) were deglycerolized using the theoretically optimal operation protocols to further validate the effectiveness and advantage of the system. In the cell-free experiments, glycerol was continuously removed and the concentration variations fitted the simulated results quite well. In the in-vitro experiments, glycerol concentration in RBC suspension was reduced to 5.57 g/l±2.81 g/l within an hour, and the cell count recovery rate was 91.19%±3.57%, (n=10), which proves that the system is not only safe for removing CPAs, but also particularly efficient for processing large-scale samples. However, the operation parameters must be carefully controlled and the optimal protocols should be specialized and various from case to case. The presented theoretical model provides an effective approach to find out the optimal operation protocols under given experimental conditions and constrains.

The effects of preserved red blood cells on the severe adverse events observed in patients infused with hemoglobin based oxygen carriers

The severe adverse events observed in patients who received hemoglobin based oxygen carriers (HBOCs) were associated with the Ringer's D.L lactate resuscitative solution administered and to the excipient used in the HBOCs containing Ringer's D,L lactate and the length of storage of the preserved RBC administered to the patient at the time that the HBOCs were infused. This paper reports the quality of the red blood cells preserved in the liquid state at 4 degrees C and that of previously frozen RBCs stored at 4 degrees C with regard to their survival, function and safety. Severe adverse events have been observed related to the length of storage of the liquid preserved RBC stored at 4 degrees C prior to transfusion. The current methods to preserve RBC in the liquid state in additive solutions at 4 degrees C maintain their survival and function for only 2 weeks. The freezing of red blood cells with 40% W/V glycerol and storage at -80 degrees C allows for storage at -80 degrees C for 10 years and following thawing, deglycerolization and storage at 4 degrees C in the additive solution (AS-3, Nutricel) for 2 weeks with acceptable 24 hour posttransfusion survival, less than 1% hemolysis, and moderately impaired oxygen transport function with no associated adverse events. Frozen deglycerolized RBCs are leukoreduced and contain less than 5% of residual plasma and non-plasma substances. Frozen deglycerolized RBCs are the ideal RBC product to transfuse patients receiving HBOCs.

Prolonged maintenance of 2,3-diphosphoglycerate acid and adenosine triphosphate in red blood cells during storage

BACKGROUND

Current additive solutions (ASs) for red cells (RBCs) do not maintain a constant level of critical metabolites such as adenosine triphosphate (ATP) and 2,3-diphosphoglycerate acid (2,3-DPG) during cold storage. From the literature it is known that the intracellular pH is an important determinant of RBC metabolism. Therefore, a new, alkaline, AS was developed with the aim to allow cold storage of RBCs with stable product characteristics.

STUDY DESIGN AND METHODS

Whole blood-derived RBCs (leukoreduced) were resuspended in experimental medium phosphate-adenine-guanosine-glucose-gluconate-mannitol (PAGGG-M; pH 8.2) with and without washing in the same medium. During cold storage several in vitro variables, such as intracellular pH, 2,3-DPG, ATP, and hemolysis, were analyzed.

RESULTS

During cold storage, RBCs resuspended in PAGGG-M showed a constant ATP level (approx. 6 mumol/g Hb) and a very limited hemolysis (<0.2%). The 2,3-DPG content showed an increase until Day 21 (150% of initial level), followed by a slow decrease, with at Day 35 still 100 percent of the initial level. RBCs washed in PAGGG-M even showed a continuous increase of 2,3-DPG during 35 days, with a maximum level of 200 percent of the initial value. The effect of PAGGG-M appears to be related to long-lasting effects of the initial intracellular pH shortly after production.

CONCLUSION

Resuspension of RBCs in our alkaline medium PAGGG-M resulted in a RBC unit of high quality during storage for up to at least 35 days, with 2,3-DPG levels of higher than 10 mumol per g Hb, hemolysis of less than 0.2 percent, and ATP levels of higher than 5 mumol per g Hb.

Altered processing of thawed red cells to improve the in vitro quality during postthaw storage at 4 degrees C

BACKGROUND

The use of a functionally closed system (ACP215, Haemonetics) for the glycerolization and deglycerolization of red blood cell (RBC) units allows for prolonged postthaw storage. In this study, the postthaw quality of previously frozen, deglycerolized RBCs resuspended in saline-adenine-glucose-mannitol (SAGM) or additive solution AS-3 was investigated.

STUDY DESIGN AND METHODS

Leukoreduced RBC units were frozen with 40 percent glycerol and stored at -80 degrees C for at least 14 days. The thawed units were deglycerolized with the ACP215, resuspended in SAGM or AS-3, and stored at 2 to 6 degrees C for up to 21 days.

RESULTS

The mean +/- standard deviation in vitro freeze-thaw-wash recovery was 81 +/- 5 percent. During storage, hemolysis of deglycerolized cells remained below 0.8 percent for 2 days in SAGM and for 14 days in AS-3. This difference was explained by the protective effect of citrate, which is present in AS-3. Cells stored in AS-3 showed a lower glycolytic activity and a faster decline in adenosine 5'-triphosphate (ATP) than cells in SAGM. Increasing the internal pH of cells before storage in AS-3 by use of phosphate-buffered saline (PBS) in the deglycerolization procedure resulted in elevated lactate production and better maintenance of intracellular ATP content. After 3 weeks of storage, the ATP content of PBS-washed cells amounted to 2.5 +/- 0.5 micromol per g of hemoglobin (Hb), whereas for saline/glucose-washed cells this value was decreased to 1.0 +/- 0.3 micromol per g of Hb.

CONCLUSIONS

Leukoreduced, deglycerolized RBCs can be stored for 48 hours in SAGM. Improved ATP levels during refrigerated storage can be observed with thawed cells, resuspended in AS-3, when PBS is used as a washing solution.

Successful in vivo recovery and extended storage of additive solution (AS)-5 red blood cells after deglycerolization and resuspension in AS-3 for 15 days with an automated closed system

BACKGROUND

Previously, cryopreserved red blood cell (RBC) units derived from CPD/AS-5 whole-blood (WB) collections have been limited to 24 hours postthaw storage (1-6 degrees C).

STUDY DESIGN AND METHODS

Sixty-four leukoreduced (LR) and 54 nonleukoreduced (NLR) AS-5 (n = 118) RBC units from 500-mL WB collections were stored for 6 days, glycerolized, frozen (-70 +/- 5 degrees C) for at least 14 days, thawed, deglycerolized, and stored (1-6 degrees C) for 15 days resuspended in AS-3, using an automated closed-system cell processor (ACP 215, Haemonetics). Frozen units were stored in either ethylene vinyl acetate (EVA) or polyvinylchloride (PVC) bags. In vitro parameters were tested in all units 15 days after deglycerolization. In vivo 24-hour recovery was measured in 77 of 118 donors.

RESULTS

Postdeglycerolization in vitro RBC mass recoveries (mean +/- SD) were 96.8 +/- 5.7 and 94.7 +/- 5.6% for EVA LR and NLR units, respectively, and 97.3 +/- 6.2 and 94.7 +/- 6.2% for PVC LR and NLR units, based on unit weight and hematocrit after sampling for in vitro testing, immediately before glycerolization. Hemoglobin content (g/unit, mean +/- SD) after deglycerolization was 40.4 +/- 5.6 and 42.6 +/- 6.0 for EVA LR and NLR units, respectively, and 40.7 +/- 4.8 and 43.0 +/- 7.7 for PVC LR and NLR units. Hemolysis was 0.61 +/- 0.23 and 0.54 +/- 0.16% for EVA LR and NLR units, and 0.47 +/- 0.14 and 0.43 +/- 0.12% for PVC LR and NLR units. In vivo 24-hour recoveries on Day 15 were 83.0 +/- 6.7% (PVC NLR) up to 86.2 +/- 5.7% (EVA NLR).

CONCLUSION

With processing on the ACP 215 system, CPD/AS-5 LR and NLR thawed RBC units can be stored for up to 14 days after frozen storage at -65 degrees C or colder in EVA or PVC bags with acceptable in vivo and in vitro RBC quality.

In vitro variables of red blood cell components collected by apheresis and frozen 6 and 14 days after collection

BACKGROUND

An automated cell processing system (ACP 215, Haemonetics Corp.) can be used for the glycerolization and deglycerolization of RBC components, but the components must be 6 or fewer days old. Depending on the anticoagulant (CP2D)/additive solution (AS) used, deglycerolized RBCs can be stored at 1 to 6 degrees C for up to 14 days. This study evaluated in vitro variables of apheresis RBC stored for 6 and 14 days at 1 to 6 degrees C before glycerolization and 14 days after deglycerolization.

STUDY DESIGN AND METHODS

Two units of CP2D/AS-3 leukoreduced RBCs were collected by apheresis from seven donors. One unit was glycerolized and frozen 6 days and the other 14 days after collection. All units were deglycerolized with the ACP 215 and stored at 1 to 6 degrees C for 14 days in AS-3. Several in vitro variables were evaluated during postdeglycerolization storage.

RESULTS

All components had postdeglycerolization RBC recoveries greater than 81 percent and osmolalities of less than 400 mOsm per kg. No significant differences were noted in potassium and supernatant hemoglobin after 14 days of postdeglycerolization storage between RBCs frozen at 6 and 14 days after collection. After 14 days of postdeglycerolization storage, however, the pH, lactate, and ATP levels were slightly lower in RBCs frozen after 14 days.

CONCLUSION

The ACP 215 can be used to glycerolize and deglycerolize apheresis RBC components that are up to 14 days of age. It is likely that apheresis components glycerolized at 14 days of age or less can be stored up to 14 days in AS-3 after deglycerolization, but this should be confirmed with in vivo survival studies.

Salvaging of liquid-preserved O-positive and O-negative red blood cells by rejuvenation and freezing

BACKGROUND

The RBC inventory is subject to seasonal highs and lows. When the inventory is high, units may be lost due to outdating and when the inventory is low, elective surgical procedures may have to be postponed until sufficient blood is available. This study was done to determine if universal donor O-positive and O-negative RBC subjected to various methods of transportation could subsequently be rejuvenated and frozen to be used for inventory control with satisfactory results.

MATERIALS AND METHODS

Units of blood were collected at two different military facilities and processed as whole blood (WB) or packed RBC. The liquid stored WB or RBC units were subjected to transportation, with or without air dropping, as part of a military exercise. The units were kept at 4 degrees C with wet ice during transportation to the NBRL for evaluation. The quality of the liquid preserved RBC was evaluated before rejuvenation and freezing and after the freeze-thaw-wash procedure. Following frozen storage at -80 degrees C, the RBC were thawed and deglycerolized using the Haemonetics 115 cell washer. In addition to measurements of freeze-thaw and freeze-thaw-wash recovery, other in vitro assessments of RBC quality were made.

RESULTS

The results demonstrate acceptable quality for RBC subjected to transportation, with or without air dropping, following rejuvenation and freezing.

CONCLUSION

We consider it a prudent practice for liquid preserved O-negative and O-positive RBC collected at various blood collection sites to be sent to a specific facility where the universal donor RBC can be rejuvenated and frozen as a stockpile for inventory control.

The survival and function of baboon red blood cells, platelets, and plasma proteins: a review of the experience from 1972 to 2002 at the Naval Blood Research Laboratory, Boston, Massachusetts

The studies reported in this monograph were performed between 1972 and 2002 when it was possible to study healthy male and female baboons. A colony of baboons was maintained for 30 years without any adverse events observed in these baboons in the numerous studies that were performed. These protocols were reviewed and approved by the institutional animal care and use committees (IACUC) at the sites where the studies were performed and by the veterinarian services of the U.S. Navy's Bureau of Medicine and Surgery, the Office of Naval Research, and the Department of Defense. The physiology of red blood cells (RBCs), platelets (PLTs), and plasma proteins in the baboon was investigated together with the viability and function of preserved RBCs, PLTs, and plasma proteins. These studies in the baboon could not have been performed in normal volunteers and patients. The data obtained have provided critical information to explain the clinical observations reported in normal volunteers and patients after transfusion of fresh and preserved blood products. These studies were supported by the U.S. Navy's Bureau of Medicine and Surgery and the Office of Naval Research. In addition, the support of the late Congressman J. Joseph Moakley from Massachusetts is acknowledged because without his support many of these studies could not have been performed. The authors acknowledge the contributions of the numerous research collaborators identified in the 52 peer-reviewed publications that cite other funding agencies that supported the research that is reported, the editorial assistance of Ms Cynthia Ann Valeri, and the assistance of Ms Deborah Tattersall who prepared the figures and tables reported in this publication.

Experiences with frozen blood products in the Netherlands military

For peacekeeping and peace enforcing missions abroad the Netherlands Armed Forces decided to use universal donor frozen blood products in addition to liquid products. This article describes our experiences with the frozen blood inventory, with special attention to quality control. It is shown that all thawed (washed) blood products are in compliance with international regulations and guidelines. By means of the -80 degrees C frozen stock of red cells, plasma and platelets readily available after thaw (and wash), we can now safely reduce shipments and abandon the backup 'walking' blood bank, without compromising the availability of blood products in theatre.

Up to 21-day banked red blood cells collected by apheresis and stored for 14 days after automated wash at different times of storage

BACKGROUND AND OBJECTIVES

A closed-system technology (ACP-215, Haemonetics, Braintree, MA) enables automated washing and extended storage of frozen red blood cells (RBC). This technology was applied to wash banked RBC for removal of undesirable protein and metabolites before transfusion. We studied protein and metabolite depletion as well as RBC metabolism and viability up to 14 days postwash with regard to various pre-storage times.

MATERIALS AND METHODS

Thirty RBC units were collected by means of apheresis and subdivided into three arms based on prewash storage time period (6 days/group 1, 14 days/group 2, 21 days/group 3). Wash efficacy (protein depletion, IgA), RBC metabolism (pH, lactate, potassium, haemolysis) and cell viability (ATP) were analysed immediately and 14 days after washing.

RESULTS

Total protein and IgA postwash were lowered by automated wash in all groups and uniformly met EC guidelines. Potassium (mmol/l) was below 1.2 mmol/l postwash and significantly below prewash values in all groups, even after 14 days of storage (prewash vs. postwash; P < 0.05). RBCs washed after 14 and 21 days, respectively, showed significantly lower pH values and lower ATP content than RBCs washed after only 6 days of storage. Haemolysis rate remained significantly below 0.8%, the maximum level recommended by the EC guidelines, immediately and 14 days after washing in all units.

CONCLUSION

Our data confirm that RBC units banked up to 21 days can be effectively protein- and potassium-depleted with the ACP-215 independent from prewash storage time. With respect to high ATP levels and pH, postwash storage of 2 weeks should be limited to units not older than 7 days before wash. This new washing technology ensures better standardization in washed RBC and provides blood centres with a logistical alternative to 24-h washed RBC products.

Automation of the glycerolization of red blood cells with the high-separation bowl in the Haemonetics ACP 215 instrument

BACKGROUND

The FDA has approved a closed-system red blood cell (RBC) glycerolization procedure with the ACP 215 (Haemonetics), which requires a centrifuge to prepare RBCs before and after glycerolization. In the study reported here, the Haemonetics high-separation bowl was evaluated in an attempt to automate these two concentration steps.

STUDY DESIGN AND METHODS

Ten units of nonleukoreduced citrate phosphate dextrose (CPD)-anticoagulated whole blood were stored at 4 degrees C for 2 to 6 days before glycerolization and freezing as nonrejuvenated RBCs. Twenty-five units of nonleukoreduced CPD whole blood were stored at 4 degrees C for 2 to 8 days and then biochemically treated with a solution containing pyruvate, inosine, phosphate, and adenine (PIPA) before glycerolization and freezing as indated-rejuvenated RBC. Twenty units of leukoreduced CPD and AS-1 RBCs were stored at 4 degrees C for a mean of 48 days and treated with PIPA solution before glycerolization and freezing as outdated-rejuvenated RBCs. The glycerolized RBCs were frozen for at least 2 weeks at -80 degrees C, deglycerolized in the Haemonetics ACP 215 with the 325-mL bowl, and stored in AS-3 at 4 degrees C for 21 days.

RESULTS

It took approximately 50 minutes to glycerolize the nonrejuvenated and rejuvenated RBCs. After freezing, deglycerolization, and postwash storage at 4 degrees C in AS-3 for 2 weeks, the quality was similar to that of RBCs processed by the current FDA-approved method.

CONCLUSION

Processing time and need for technical expertise were significantly reduced with the completely automated functionally closed glycerolization procedure with the high-separation bowl in the Haemonetics ACP 215 instrument.

Chronic red blood cell exchange to prevent clinical complications in sickle cell disease

We tracked the results of 394 manual or automatic red blood cell exchanges done with a cell separator in 20 sickle cell patients at high risk for recurrent complications. Over an average of 6 years, none of the patients developed complications related to the procedure or to the increased blood use. It was safe and effective in preventing complications of sickle cell disease, and if done automatically, reduced iron overload. Ferritin levels also decreased in patients treated with automatic red blood cell exchange. Furthermore, using Single Donor Red Blood Cell units (SDRC) we reduced the potential exposure to transfusion transmitted infectious diseases (TTI).

Extended storage of AS-1 and AS-3 leukoreduced red blood cells for 15 days after deglycerolization and resuspension in AS-3 using an automated closed system

BACKGROUND

The utilization of cryopreserved red blood cell (RBC) units had been limited by a maximum postdeglycerolization storage of 24 hours at 1 to 6 degrees C until the recent development of a closed system for the glycerolization and deglycerolization process.

STUDY DESIGN AND METHODS

Sixty leukoreduced additive solution (AS), AS-1 (n = 30) and AS-3 (n = 30) RBC units from 500-mL whole blood (WB) collections were stored for 6 days, glycerolized, frozen at -70 +/- 5 degrees C for at least 14 days, thawed, deglycerolized, and stored for 15 days at 1 to 6 degrees C. Glycerolization and deglycerolization were performed with the ACP 215. In-vitro variables were tested before glycerolization, on Day 0, and Day 15 after deglycerolization storage. Forty donors were assessed for double-label 24-hour percent recovery, and T1/2 survival time was measured for 20 donors.

RESULTS

Postdeglycerolization mean +/- standard deviation in-vitro RBC mass recoveries were 93 +/- 5 percent for AS-1 and 95 +/- 4 percent for AS-3. Mean hemoglobin +/- standard deviation after deglycerolization was 50.5 +/- 5.5g for AS-1 and 50.1 +/- 3.5g for AS-3. Mean hemolysis (Day 15) was 0.36 +/- 0.11 percent for AS-1 and 0.38 +/- 0.13 percent for AS-3. Double-label 24-hour in-vivo recoveries were 82.5 +/- 7.8 percent for AS-1 and 81.4 +/- 7.1 percent for AS-3. The 51Cr T1/2 value was 41.8 +/- 3.97 for AS-1 and 40.6 +/- 7.11 for AS-3. Other in-vitro variables were as expected.

CONCLUSION

Leukoreduced AS-1 and AS-3 RBCs after frozen storage at -70 +/- 5 degrees C can be stored for up to 14 days when processing is performed with the ACP 215 system with resuspension of deglycerolized RBCs in AS-3.

The in vitro quality of red blood cells frozen with 40 percent (wt/vol) glycerol at −80°C for 14 years, deglycerolized with the Haemonetics ACP 215, and stored at 4°C in additive solution-1 or additive solution-3 for up to 3 weeks

BACKGROUND

Red blood cells (RBCs) frozen with 40 percent (wt/vol) glycerol, stored at -80 degrees C (mean temperature; range, -65 to -90 degrees C) for 14 years, deglycerolized in the Haemonetics automated cell processor (ACP) 215 with the 325-mL disposable bowl, and stored at 4 degrees C in additive solution (AS)-1 or AS-3 for 21 days were evaluated.

STUDY DESIGN AND METHODS

A total of 106 units of citrate phosphate dextrose adenine-1 RBCs were frozen with 40 percent (wt/vol) glycerol in the original 800-mL polyvinylchloride plastic bag and stored in corrugated cardboard boxes at -80 degrees C for 14 years. The thawed units were deglycerolized with the ACP 215 with a 325-mL disposable bowl and stored in AS-1 or AS-3 at 4 degrees C for 21 days.

RESULTS

The freeze-thaw recovery value was 94 +/- 4 percent (mean +/- SD), the freeze-thaw-wash recovery value was 80 +/- 7 percent, and there was no breakage. Thirty-eight units were processed as 19 pairs. Two units of ABO-matched units were thawed, pooled, divided equally into two units, and deglycerolized. One unit was stored in AS-1 and the other in AS-3 at 4 degrees C for 21 days. Units stored in AS-1 exhibited significantly greater hemolysis than those stored in AS-3.

CONCLUSIONS

Acceptable results were achieved when RBCs frozen at -80 degrees C for 14 years were deglycerolized in the ACP 215. Deglycerolized RBCs in AS-1 exhibited significantly higher hemolysis than those in AS-3 after storage at 4 degrees C for 7 to 21 days.

Comparison of radioisotope methods and a nonradioisotope method to measure the RBC volume and RBC survival in the baboon

BACKGROUND

RBC volume, 24-hour posttransfusion survival, and life span can be measured with radio-isotopes and nonradioactive procedures.

STUDY DESIGN AND METHODS

RBC volume was measured directly with autologous baboon RBCs labeled with biotin-X-N-hydroxysuccinimide (NHS), 51Cr, 99mTc, and 111In-oxine and indirectly from the 125I plasma volume and the total body Hct. Twenty-four-hour posttransfusion survival and life span were measured in autologous fresh baboon RBCs labeled with 51Cr, 111In-oxine, 99mTc, and biotin-X-NHS.

RESULTS

Significantly larger RBC volumes were observed when the fresh autologous RBCs were labeled with 51Cr, 111In-oxine, or 99mTc than when they were labeled with the nonradioactive biotin-X-NHS. Twenty-four-hour posttransfusion survival values were significantly lower in the RBCs labeled with 111In-oxine or 99mTc than in the RBCs labeled with 51Cr.

CONCLUSIONS

The greater in vivo elution of 51Cr, 111In-oxine, and 99mTc than that of biotin-X-NHS influenced the measurements of RBC volume, 24-hour posttransfusion survival, and life span of the fresh baboon RBCs.

Incidence of breakage of human RBCs frozen with 40-percent wt/vol glycerol using two different methods for storage at -80 degrees C

BACKGROUND

We reported previously that the incidence of breakage was 34.2 percent when human RBCs were frozen with 40-percent wt/vol glycerol in polyolefin plastic bags stored in aluminum containers at -80 degrees C and subjected to transportation. When human RBCs were frozen with 40-percent wt/vol glycerol at -80 degrees C in PVC plastic bags placed in polyester plastic bags and stored in rigid corrugated cardboard boxes, transportation resulted in a 2.4-percent incidence of breakage. The present study was done to confirm this incidence of breakage.

STUDY DESIGN AND METHODS

The Meryman- Hornblower freezing method was compared to the Naval Blood Research Laboratory (NBRL) method of freezing for incidence of bag breakage. Human RBCs frozen by the Meryman-Hornblower method with 40-percent wt/vol glycerol with supernatant glycerol and stored in polyolefin plastic bags in aluminum containers at -80 degrees C were stored at the NBRL from 1974 to 2002. With the NBRL method, human RBCs frozen at -80 degrees C without supernatant glycerol in the 800-mL PVC plastic primary bag inside a polyester plastic bag in a rigid corrugated cardboard box were stored at the NBRL from 1984 to 2002.

RESULTS

The incidence of breakage for 532 units of RBCs that had been frozen by the Meryman- Hornblower method and stored in aluminum containers was 47.3 percent for nontransported units. RBCs that had been frozen by the NBRL method and stored in rigid corrugated cardboard boxes exhibited breakage of 2.4 percent for 2424 nontransported units and 6.7 percent for 633 transported units.

DISCUSSION

The incidence of breakage was significantly lower for RBCs frozen by the NBRL method than for the RBCs frozen by the Meryman-Hornblower method.

Stability after thawing of RBCs frozen with the high- and low-glycerol method

BACKGROUND

RBCs can be frozen with either the high-glycerol method (HGM) or the low-glycerol method (LGM). To date, the use of frozen RBCs is hampered by a 24-hour outdating period after thawing. A closed washing system (ACP 215) may solve this problem.

STUDY DESIGN AND METHODS

We compared the effects of high- (40%) and low-glycerol (19%) concentration, with and without freezing (at -80 degrees C for HGM, -196 degrees C for LGM) on the in vitro quality of RBCs after deglycerolization with the closed washing system and during storage at 4 degrees C in SAGM after thawing.

RESULTS

Glycerol treatment by itself induced hemolysis during processing, which was more pronounced in HGM cells. The freeze-thaw-wash process decreased the stability of RBCs, particularly in LGM cells during storage after thawing. In contrast to LGM cells, in HGM cells no additional effect of freeze or thaw on stability of washed cells was seen during the first week of storage after thawing. Changes in osmotic resistance and cellular metabolism could not explain the observed differences in RBC stability.

CONCLUSION

The closed washing system is able to process both high- and low-glycerol-treated RBCs. Stability after washing during cold storage in SAGM, as measured by hemolysis, is better for HGM cells as compared to LGM cells.

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.