Quality of red blood cells washed using the ACP 215 cell processor: assessment of optimal pre- and postwash storage times and conditions

Evaluation of stored red blood cell quality after washing using immune indices

Washed red blood cells (RBCs) can be used to treat immune-related diseases. However, whether the washing process changes the quality of RBCs and affects the curative effect of transfusion therapy remains unclear. We retrospectively analysed the clinical data of patients who received blood transfusion. The physiological and biochemical parameters of RBCs were tested on an automated haematology-biochemical analyser. CD47 and phosphatidylserine (PS) plasma membrane expression were analysed using flow cytometry. Morphological changes in RBCs were observed using scanning electron microscopy. The results showed that the curative effect on patients who received washed RBCs was weaker than that on those who received non-washed RBCs. Physiological and biochemical parameters of RBCs were not significantly different. RBC immune indices changed significantly after washing. The expression of "don't eat me" signals was weakened, whereas the intensity of "eat me" signals was enhanced. This study suggests that the current use of physiological and biochemical parameters as indicators to evaluate the quality of RBCs may not be comprehensive and that evaluation of the real status of RBCs requires other effective parameters. Immune molecules in RBCs are expected to become supplementary markers for evaluating RBC quality.

Tangential flow filtration facilitated washing of human red blood cells: A proof-of-concept study

BACKGROUND AND OBJECTIVES

Red blood cell (RBC) units in hypothermic storage degrade over time, commonly known as the RBC storage lesion. These older RBC units can cause adverse clinical effects when transfused, as older RBCs in the unit lyse and release cell-free haemoglobin (Hb), a potent vasodilator that can elicit vasoconstriction, systemic hypertension and oxidative tissue injury after transfusion. In this study, we examined a novel method of washing ex vivo stored single RBC units to remove accumulated cellular waste, specifically cell-free Hb, using tangential flow filtration (TFF) driven by a centrifugal pump.

MATERIALS AND METHODS

The TFF RBC washing system was run under hypothermic conditions at 4°C, at a constant system volume with 0.9 wt% saline as the wash solution. The RBC washing process was conducted on 10 separate RBC units. For this proof-of-concept study, RBC units were expired at the time of washing (60-70 days old). Cell-free Hb was quantified by UV-visible absorbance spectroscopy and analysed via the Winterbourn equations. Pre- and post-wash RBC samples were analysed by Hemox Analyser, Coulter counter and Brookfield rheometer. The RBC volume fraction in solution was measured throughout the wash process by standard haematocrit (HCT) analysis.

RESULTS

No substantial decrease in the HCT was observed during the TFF RBC washing process. However, there was a significant decrease in RBC concentration in the first half of the TFF RBC wash process, with no significant change in RBC concentration during the second half of the TFF cell wash process with an 87% overall cell recovery compared with the total number of cells before initiation of cell washing. Utilization of the extinction coefficients and characteristic peaks of each Hb species potentially present in solution was quantified by Winterbourn analysis on retentate and permeate samples for each diacycle to quantify Hb concentration during the washing process. Significant cell-free Hb reduction was observed within the first four diacycles with a starting cell-free Hb concentration in the RBC unit of 0.105 mM, which plateaus to a constant Hb concentration of 0.01 mM or a total extracellular Hb mass of 0.2 g in the resultant washed unit. The oxygen equilibrium curve showed a significant decrease in P₅₀ between the initial and final RBC sample cell wash with an initial P₅₀ of 15.6 ± 1.8 mm Hg and a final P₅₀ of 14 ± 1.62 mm Hg. Cooperativity increased after washing from an initial Hill coefficient of 2.37 ± 0.19 compared with a final value of 2.52 ± 0.12.

CONCLUSION

Overall, this study investigated the proof-of-concept use of TFF for washing single RBC units with an emphasis on the removal of cell-free Hb from the unit. Compared with traditional cell washing procedures, the designed system was able to more efficiently remove extracellular Hb but resulted in longer wash times. For a more complete investigation of the TFF RBC washing process, further work should be done to investigate the effects of RBC unit storage after washing. The designed system is lightweight and transportable with the ability to maintain sterility between uses, providing a potential option for bedside ex vivo transfusion in clinical applications.

Transfusion-Associated Hyperkalemic Cardiac Arrest in Neonatal, Infant, and Pediatric Patients

Red blood cell (RBC) transfusions are a life-saving intervention, with nearly 14 million RBC units transfused in the United States each year. However, the safety and efficacy of this procedure can be influenced by variations in the collection, processing, and administration of RBCs. Procedures or manipulations that increase potassium (K⁺) levels in stored blood products can also predispose patients to hyperkalemia and transfusion-associated hyperkalemic cardiac arrest (TAHCA). In this mini review, we aimed to provide a brief overview of blood storage, the red cell storage lesion, and variables that increase extracellular [K⁺]. We also summarize cases of TAHCA and identify potential mitigation strategies. Hyperkalemia and cardiac arrhythmias can occur in pediatric patients when RBCs are transfused quickly, delivered directly to the heart without time for electrolyte equilibration, or accumulate extracellular K⁺ due to storage time or irradiation. Advances in blood banking have improved the availability and quality of RBCs, yet, some patient populations are sensitive to transfusion-associated hyperkalemia. Future research studies should further investigate potential mitigation strategies to reduce the risk of TAHCA, which may include using fresh RBCs, reducing storage time after irradiation, transfusing at slower rates, implementing manipulations that wash or remove excess extracellular K⁺, and implementing restrictive transfusion strategies.

Platelet vesicles are potent inflammatory mediators in red blood cell products and washing reduces the inflammatory phenotype

BACKGROUND

Studies suggest that washing red cell concentrates (RCCs) to remove soluble mediators and/or inflammatory components, such as extracellular vesicles (EVs), may lead to better clinical outcomes. This study tested the hypothesis that non-red blood cell (RBC) generated vesicles in RCC are potent inflammatory mediators in vitro and washing RCCs can reduce these vesicles and subsequently decrease the inflammatory activity of RCCs.

STUDY DESIGN AND METHODS

Sixteen RCCs were pooled and split into four groups based on pre-wash storage time (Day 2 or 14; n = 4/group). Each group was tested 24 hours and 7 days post-wash. Characteristics of RBCs and EVs, cytokines released by monocytes, and expression of human umbilical vein endothelial cells (HUVECs) adhesion molecules were assessed.

RESULTS

All RCCs meet quality standards for hemolysis, hematocrit, and hemoglobin. Washing did not remove residual platelets from RCCs but led to a significant reduction in platelet-EV count regardless of the group. Supernatant of RCCs washed on Day 14 and stored for 24 hours had significantly lower concentrations of RBC-EVs and white blood cell EVs compared to unwashed controls. Supernatant of unwashed RCCs showed higher production of inflammatory cytokines/chemokines MCP-1, IL-8, and TNF-α, and heightened expression of HUVEC VCAM-1, which were significantly reduced by washing. Spiking washed RCC supernatants with platelet-EVs showed significant increase in IL-8, MCP-1, VCAM-1, and E-selection in groups washed on Day 14.

CONCLUSIONS

Platelet-EVs in RCCs are associated with pro-inflammatory activity. As washing significantly reduced RCC immunomodulatory activity, implementation of this process may improve transfusion outcomes.

Blood manufacturing methods affect red blood cell product characteristics and immunomodulatory activity

Transfusion of red cell concentrates (RCCs) is associated with increased risk of adverse outcomes that may be affected by different blood manufacturing methods and the presence of extracellular vesicles (EVs). We investigated the effect of different manufacturing methods on hemolysis, residual cells, cell-derived EVs, and immunomodulatory effects on monocyte activity. Thirty-two RCC units produced using whole blood filtration (WBF), red cell filtration (RCF), apheresis-derived (AD), and whole blood-derived (WBD) methods were examined (n = 8 per method). Residual platelet and white blood cells (WBCs) and the concentration, cell of origin, and characterization of EVs in RCC supernatants were assessed in fresh and stored supernatants. Immunomodulatory activity of RCC supernatants was assessed by quantifying monocyte cytokine production capacity in an in vitro transfusion model. RCF units yielded the lowest number of platelet and WBC-derived EVs, whereas the highest number of platelet EVs was in AD (day 5) and in WBD (day 42). The number of small EVs (<200 nm) was greater than large EVs (≥200 nm) in all tested supernatants, and the highest level of small EVs were in AD units. Immunomodulatory activity was mixed, with evidence of both inflammatory and immunosuppressive effects. Monocytes produced more inflammatory interleukin-8 after exposure to fresh WBF or expired WBD supernatants. Exposure to supernatants from AD and WBD RCC suppressed monocyte lipopolysaccharide-induced cytokine production. Manufacturing methods significantly affect RCC unit EV characteristics and are associated with an immunomodulatory effect of RCC supernatants, which may affect the quality and safety of RCCs.

Traditional and emerging technologies for washing and volume reducing blood products

Millions of blood components including red blood cells, platelets, and granulocytes are transfused each year in the United States. The transfusion of these blood products may be associated with adverse clinical outcomes in some patients due to residual proteins and other contaminants that accumulate in blood units during processing and storage. Blood products are, therefore, often washed in normal saline or other media to remove the contaminants and improve the quality of blood cells before transfusion. While there are numerous methods for washing and volume reducing blood components, a vast majority utilize centrifugation-based processing, such as manual centrifugation, open and closed cell processing systems, and cell salvage/autotransfusion devices. Although these technologies are widely employed with a relatively low risk to the average patient, there is evidence that centrifugation-based processing may be inadequate when transfusing to immunocompromised patients, neonatal and infant patients, or patients susceptible to transfusion-related allergic reactions. Cell separation and volume reduction techniques that employ centrifugation have been shown to damage blood cells, contributing to these adverse outcomes. The limitations and disadvantages of centrifugation-based processing have spurred the development of novel centrifugation-free methods for washing and volume reducing blood components, thereby causing significantly less damage to the cells. Some of these emerging technologies are already transforming niche applications, poised to enter mainstream blood cell processing in the not too distant future.

In-droplet microparticle washing and enrichment using surface acoustic wave-driven acoustic radiation force

Washing and enrichment of particles and cells are crucial sample preparation procedures in biomedical and biochemical assays. On-chip in-droplet microparticle washing and enrichment have been pursued but remained problematic due to technical difficulties, especially simultaneous and precise control over the droplet interface and in-droplet samples. Here, we have achieved a breakthrough in label-free, continuous, on-demand, in-droplet microparticle washing and enrichment using surface acoustic waves. When exposed to the acoustic field, the droplet and suspended particles experience acoustic radiation force arising from inhomogeneous wave scattering at the liquid/liquid and liquid/solid interfaces. Based on these acoustophoretic phenomena, we have demonstrated in-droplet microparticle washing and enrichment in an acoustofluidic device. We expect that the proposed acoustic method will offer new perspectives to sample washing and enrichment by performing the operation in microscale droplets.

Centrifugation-free washing: A novel approach for removing immunoglobulin A from stored red blood cells

Washed red blood cells (RBCs) are indicated for immunoglobulin A (IgA) deficient recipients. Centrifugation-based cell processors commonly used by hospital blood banks cannot consistently reduce IgA below the recommended levels, hence double washing is frequently required. Here, we describe a prototype of a simple, portable, disposable system capable of washing stored RBCs without centrifugation, while reducing IgA below 0.05 mg/dL in a single run. Samples from RBC units (n = 8, leukoreduced, 4-6 weeks storage duration) were diluted with normal saline to a hematocrit of 10%, and then washed using either the prototype washing system, or via conventional centrifugation. The efficiency of the two washing methods was quantified and compared by measuring several key in vitro quality metrics. The prototype of the washing system was able to process stored RBCs at a rate of 300 mL/hour, producing a suspension of washed RBCs with 43 ± 3% hematocrit and 86 ± 7% cell recovery. Overall, the two washing methods performed similarly for most measured parameters, lowering the concentration of free hemoglobin by >4-fold and total free protein by >10-fold. Importantly, the new washing system reduced the IgA level to 0.02 ± 0.01 mg/mL, a concentration 5-fold lower than that produced by conventional centrifugation. This proof-of-concept study showed that centrifugation may be unnecessary for washing stored RBCs. A simple, disposable, centrifugation-free washing system could be particularly useful in smaller medical facilities and resource limited settings that may lack access to centrifugation-based cell processors.

Characteristics of Extracellular Vesicles in Red Blood Concentrates Change with Storage Time and Blood Manufacturing Method

Background

Extracellular vesicles (EVs) in blood products are potential effectors of inflammation and coagulation after transfusion. The aim of this study was to assess the impact of different blood manufacturing methods and duration of hypothermic storage on the EV subpopulations in relation to other in vitro quality parameters of red blood cell concentrate (RCC) products.

Methods

RCCs were produced using whole blood filtration (WBF) or red cell filtration (RCF) (n = 12/method), refrigerated for 43 days, and evaluated for EV size profile and concentration, red cell deformability, ATP and 2,3-DPG, hemolysis, and hematological indices.

Results

The total number of EVs increased significantly with storage in both methods, and WBF-RCCs contained the higher numbers of EVs compared to RCF-RCCs. The concentration of small EVs was greater in WBF-RCCs versus RCF-RCCs, with difference between the two methods observed on day 43 of storage (p = 0.001). Throughout storage, significant decreases were identified in ATP, 2,3-DPG, and EI_max, while an increase in hemolysis was observed in both RCC products.

Conclusion

The dynamic shift in the size and concentration of the EV subpopulations is dependent on the blood manufacturing method and length of storage. Better understanding of the potential clinical implications of these heterogeneous populations of EVs are needed.

Raman spectroscopy of stored red blood cell concentrate within sealed transfusion blood bags

Spectral information relevant to the quality of stored blood can be obtained in situ through sealed blood transfusion bags using a commercially available instrument.

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.

Impact of technical and assay variation on reporting of hemolysis in stored red blood cell products

BACKGROUND

Hemolysis of RBCs is an important measure of product quality and is influenced by donor factors, blood component manufacturing and storage. Percent hemolysis is determined using hematocrit (Hct), supernatant Hb (SHb) and total Hb (THb), each of which can be measured using a variety of methods.

METHODS

Sixteen members of an international collaborative were surveyed to understand equipment and procedural variation in hemolysis testing. In a laboratory-based evaluation, we examined how hemolysis was impacted by: measurement of Hct, SHb, THb and number and force of centrifugations for SHb preparation. The number and size of extracellular vesicles (EVs) was also examined.

RESULTS

There was no consensus in equipment or procedures used by international laboratories to measure hemolysis. The centrifugation force used to prepare samples influenced SHb concentration when a single or double (p=0.0001) centrifugation step was used. The number and force of centrifugation related directly to the ability to remove EVs and EV-bound Hb from samples. Hemolysis varied significantly from 0.16% to 0.32% (mean of 0.22%) depending on the combination of methods or centrifugation conditions used to test expired samples.

CONCLUSION

Method and preparative procedures have a critical impact on measurement of hemolysis in RCC.

Quality Assessment of Established and Emerging Blood Components for Transfusion

Blood is donated either as whole blood, with subsequent component processing, or through the use of apheresis devices that extract one or more components and return the rest of the donation to the donor. Blood component therapy supplanted whole blood transfusion in industrialized countries in the middle of the twentieth century and remains the standard of care for the majority of patients receiving a transfusion. Traditionally, blood has been processed into three main blood products: red blood cell concentrates; platelet concentrates; and transfusable plasma. Ensuring that these products are of high quality and that they deliver their intended benefits to patients throughout their shelf-life is a complex task. Further complexity has been added with the development of products stored under nonstandard conditions or subjected to additional manufacturing steps (e.g., cryopreserved platelets, irradiated red cells, and lyophilized plasma). Here we review established and emerging methodologies for assessing blood product quality and address controversies and uncertainties in this thriving and active field of investigation.

Reduction of biological response modifiers in the supernatant of washed paediatric red blood cells

BACKGROUND

Washing of red blood cells (RBC) can reduce unwanted biological response modifiers (BRMs) that can mediate transfusion complications in infants. The aim of this study was to examine the in vitro quality and the changes in BRMs following washing in paediatric RBC units.

MATERIALS AND METHODS

A pool and split design was used to prepare RBC (either 1 or 4 days old; n = 26 pairs). One unit was washed with 0·9% saline by centrifugation and then resuspended in SAG-M, while the other remained unwashed. Each RBC unit was divided to produce four units of paediatric-sized components. Samples were taken after 3 h and subsequently on days 1, 2, 7 and 14 post-wash.

RESULTS

Washing of RBC resulted in some red cell loss, with a minor increase in haemolysis. Washing effectively reduced supernatant potassium and IgA, as well as cytokines and complement proteins. RBC microparticles were significantly reduced in RBC washed at 1, but not 4 days post-collection. Incubation with supernatant from unwashed but not washed RBC led to endothelial cell activation, with increased cell surface expression of CD62E (E-selectin) and CD106 (VCAM).

CONCLUSION

Although washing affected some aspects of the in vitro quality of RBC, it effectively reduced the concentration and activity of BRMs in the supernatant of RBC. Such a reduction may be clinically beneficial in selected patient groups.

Modifications to Blood Components: When to Use them and What is the Evidence?

Blood component modifications can be performed by the hospital blood bank for select clinical indications. In general, modification of blood components increases costs and may delay availability of the blood component because of the additional time required for some modification steps. However, the benefit of blood product modification may outweigh these concerns. Common modifications include leukoreduction, irradiation, volume reduction, splitting, and washing. Modification availability and selection practice may vary from hospital to hospital. In this article, available blood component modifications are described along with the benefits, drawbacks, and specific clinical indications supporting their use.

Quality of red blood cells washed using a second wash sequence on an automated cell processor

BACKGROUND

Washed red blood cells (RBCs) are indicated for immunoglobulin (Ig)A-deficient recipients when RBCs from IgA-deficient donors are not available. Canadian Blood Services recently began using the automated ACP 215 cell processor (Haemonetics Corporation) for RBC washing, and its suitability to produce IgA-deficient RBCs was investigated.

STUDY DESIGN AND METHODS

RBCs produced from whole blood donations by the buffy coat (BC) and whole blood filtration (WBF) methods were washed using the ACP 215 or the COBE 2991 cell processors and IgA and total protein levels were assessed. A double-wash procedure using the ACP 215 was developed, tested, and validated by assessing hemolysis, hematocrit, recovery, and other in vitro quality variables in RBCs stored after washing, with and without irradiation.

RESULTS

A single wash using the ACP 215 did not meet Canadian Standards Association recommendations for washing with more than 2 L of solution and could not consistently reduce IgA to levels suitable for IgA-deficient recipients (24/26 BC RBCs and 0/9 WBF RBCs had IgA levels < 0.05 mg/dL). Using a second wash sequence, all BC and WBF units were washed with more than 2 L and had levels of IgA of less than 0.05 mg/dL. During 7 days' postwash storage, with and without irradiation, double-washed RBCs met quality control criteria, except for the failure of one RBC unit for inadequate (69%) postwash recovery.

CONCLUSION

Using the ACP 215, a double-wash procedure for the production of components for IgA-deficient recipients from either BC or WBF RBCs was developed and validated.

Buffy coat (top/bottom)- and whole-blood filtration (top/top)-produced red cell concentrates differ in size of extracellular vesicles

BACKGROUND AND OBJECTIVES

The influence that blood component separation methods have on changes to the red blood cell membrane during storage is not well understood. In Canada, red cell concentrates (RCCs) are produced using the buffy coat (BC, top/bottom) and the whole-blood filtration (WBF, top/top) methods, and this study aimed at comparing their influence on the characteristics of the extracellular vesicles (EV) which accumulated in the respective products during storage.

MATERIALS AND METHODS

Using flow cytometry, dynamic light scattering and mass spectrometry, we assessed RCC EVs for concentration, size, lipid composition and correlation with supernatant haemoglobin (Hb).

RESULTS

Accumulation of RBC EVs (CD235a(+) ) with storage time was similar in WBF and BC RCCs. The size of the EVs changed from <100 nm at d5 to near 200 nm by d42, with the EVs from WBF being smaller (P < 0·001) than BC RCCs at all storage times. The amount of EV-bound Hb in the WBF and BC units was similar (about 10% of total supernatant Hb). WBF EVs and BC EVs displayed similar lipid composition.

CONCLUSION

Haemolysis and EVs increase in BC and WBF RCCs during storage. Differences in the size characteristics of the EVs in WBF and BC RCCs suggest that non-RBC EVs are more prevalent in WBF products. Understanding the impact that manufacturing has on the characteristics of the different populations of EVs in RCCs will aid quality improvement efforts.

The effect of processing method on the in vitro characteristics of red blood cell products

BACKGROUND AND OBJECTIVES

While the clinical impact of differences in red blood cell (RBC) component processing methods is unknown, there are concerns they may be confounding variables in studies such as the ongoing 'age of blood' investigations. Here, we compare the in vitro characteristics of red cell concentrates (RCCs) produced by several different processing methods.

MATERIALS AND METHODS

Nine processing methods were examined: three apheresis methods (Alyx, MCS+ and Trima), as well as leucoreduced whole blood-derived RCCs produced by buffy coat and whole blood filtration and non-leucoreduced RCCs. RCCs were stored in saline-adenine-glucose-mannitol or additive solutions (AS) 1 or 3 for 42 days, with quality tested on day 5 and day 42.

RESULTS

Many significant product differences were observed both early in and at the end of storage. Mean haemoglobin (Hb) ranged from 52 to 71 g/unit and mean Hct from 59·5 to 64·8%. Most RCC passed regulated quality control criteria according to Canadian Standards Association guidelines, although there were some failures relating to Hb content and residual WBC counts.

CONCLUSION

Processing method impacts RCC characteristics throughout storage; better understanding of these differences and reporting of processing method details is critical.

In vitro evaluation of the quality of blood products collected and stored in systems completely free of di(2-ethylhexyl)phthalate-plasticized materials

BACKGROUND

The plasticizer di(2-ethylhexyl)phthalate (DEHP) is a common component in blood bags. DEHP is noncovalently bound to polyvinylchloride (PVC) polymer and can leach into the blood product. There are public concerns that exposure to DEHP might induce developmental and reproductive toxicity in humans. The aim of this study was to evaluate an alternative plasticizer, di(isononyl) cyclohexane-1,2-dicarboxylate (Hexamoll DINCH, BASF SE), for its use in blood bags.

STUDY DESIGN AND METHODS

Whole blood (WB) was collected into DEHP-containing and DEHP-free collection systems. After overnight hold, WB was centrifuged and separated in plasma, buffy coat, and red blood cells (RBCs). Buffy coats and plasma were used to make platelet (PLT) concentrates in DEHP-free systems. After addition of additive solution (AS), SAG-M, PAGGS-M, AS-3, or PAGGG-M, RBCs were leukoreduced and analyzed for in vitro characteristics and plasticizer levels during storage.

RESULTS

The use of DINCH-based systems had no effect on WB composition, blood processing, and plasma quality. PLT in vitro quality variables were maintained during storage in DEHP-free systems. During storage in SAG-M, hemolysis was significantly higher in DINCH-PVC while potassium leakage and adenosine triphosphate content were comparable. During storage in alternative ASs, hemolysis was reduced compared to storage in SAG-M.

CONCLUSIONS

The complete absence of DEHP in the collection system had no effect on WB composition, processing, or plasma and PLT quality. During storage in SAG-M, the absence of DEHP resulted in increased hemolysis. With alternative ASs like PAGGS-M, AS-3, or PAGGG-M, the absence of DEHP had no effect on hemolysis. Leakage of DINCH into the blood product was less pronounced than that of DEHP.

A quality monitoring program for red blood cell components: in vitro quality indicators before and after implementation of semiautomated processing

BACKGROUND

Canadian Blood Services has been conducting quality monitoring of red blood cell (RBC) components since 2005, a period spanning the implementation of semiautomated component production. The aim was to compare the quality of RBC components produced before and after this production method change.

STUDY DESIGN AND METHODS

Data from 572 RBC units were analyzed, categorized by production method: Method 1, RBC units produced by manual production methods; Method 2, RBC units produced by semiautomated production and the buffy coat method; and Method 3, RBC units produced by semiautomated production and the whole blood filtration method. RBC units were assessed using an extensive panel of in vitro tests, encompassing regulated quality control criteria such as hematocrit (Hct), hemolysis, and hemoglobin (Hb) levels, as well as adenosine triphosphate, 2,3-diphosphoglycerate, extracellular K(+) and Na(+) levels, methemoglobin, p50, RBC indices, and morphology.

RESULTS

Throughout the study, all RBC units met mandated Canadian Standards Association guidelines for Hb and Hct, and most (>99%) met hemolysis requirements. However, there were significant differences among RBC units produced using different methods. Hb content was significantly lower in RBC units produced by Method 2 (51.5 ± 5.6 g/unit; p < 0.001). At expiry, hemolysis was lowest in Method 2-produced RBC units (p < 0.05) and extracellular K(+) levels were lowest in units produced by Method 1 (p < 0.001).

CONCLUSION

While overall quality was similar before and after the production method change, the observed differences, although small, indicate a lack of equivalency across RBC products manufactured by different methods.

Coinfusion of dextrose-containing fluids and red blood cells does not adversely affect in vitro red blood cell quality

BACKGROUND

Transfusion guidelines advise against coinfusing red blood cells (RBCs) with solutions other than 0.9% saline. We evaluated the impact of coinfusion with dextrose-containing fluids (DW) on markers of RBC quality.

STUDY DESIGN AND METHODS

A pool-and-split design was used to allow conditions to be tested on each pool within 2 hours of irradiation. Three pools at each storage age (5, 14, and 21 days) were created for each phase. In Phase 1, samples were infused through a neonatal transfusion apparatus alone or with treatment solutions: D5W, D10W, D5W/0.2% saline, and 0.9% saline. In Phase 2, samples were incubated alone or in a 1:1 ratio with treatment solutions and tested after 5, 30, and 180 minutes. Hemolysis, supernatant potassium, RBC indices, morphology, and deformability were measured on all samples.

RESULTS

In Phase 1, RBCs transfused alone through the apparatus had higher (p<0.01) hematocrit, total hemoglobin, and supernatant potassium compared to all other groups. No statistical differences were identified between groups for other measured variables. In Phase 2, mean corpuscular volume of all samples containing DW increased with incubation length and were higher (p<0.01) than RBCs incubated alone or with 0.9% saline after 30 and 180 minutes. RBCs incubated with D5W and D5W/0.2% saline had greater (p<0.05) hemolysis than RBCs alone after 180 minutes.

CONCLUSION

In vitro characteristics of RBCs coinfused with 0.9% saline or D10W were not adversely impacted. When developing clinical studies in neonates, we recommend use of D10W and a transfusion apparatus that minimizes the contact volume of the coinfusate with the RBC.

Washing older blood units before transfusion reduces plasma iron and improves outcomes in experimental canine pneumonia

In a randomized controlled blinded trial, 2-year-old purpose-bred beagles (n = 24), with Staphylococcus aureus pneumonia, were exchanged-transfused with either 7- or 42-day-old washed or unwashed canine universal donor blood (80 mL/kg in 4 divided doses). Washing red cells (RBC) before transfusion had a significantly different effect on canine survival, multiple organ injury, plasma iron, and cell-free hemoglobin (CFH) levels depending on the age of stored blood (all, P < .05 for interactions). Washing older units of blood improved survival rates, shock score, lung injury, cardiac performance and liver function, and reduced levels of non-transferrin bound iron and plasma labile iron. In contrast, washing fresh blood worsened all these same clinical parameters and increased CFH levels. Our data indicate that transfusion of fresh blood, which results in less hemolysis, CFH, and iron release, is less toxic than transfusion of older blood in critically ill infected subjects. However, washing older blood prevented elevations in plasma circulating iron and improved survival and multiple organ injury in animals with an established pulmonary infection. Our data suggest that fresh blood should not be washed routinely because, in a setting of established infection, washed RBC are prone to release CFH and result in worsened clinical outcomes.

Segments from red blood cell units should not be used for quality testing

BACKGROUND

Nondestructive testing of blood components could permit in-process quality control and reduce discards. Tubing segments, generated during red blood cell (RBC) component production, were tested to determine their suitability as a sample source for quality testing.

STUDY DESIGN AND METHODS

Leukoreduced RBC components were produced from whole blood (WB) by two different methods: WB filtration and buffy coat (BC). Components and their corresponding segments were tested on Days 5 and 42 of hypothermic storage (HS) for spun hematocrit (Hct), hemoglobin (Hb) content, percentage hemolysis, hematologic indices, and adenosine triphosphate concentration to determine whether segment quality represents unit quality.

RESULTS

Segment samples overestimated hemolysis on Days 5 and 42 of HS in both BC- and WB filtration-produced RBCs (p < 0.001 for all). Hct and Hb levels in the segments were also significantly different from the units at both time points for both production methods (p < 0.001 for all). Indeed, for all variables tested different results were obtained from segment and unit samples, and these differences were not consistent across production methods.

CONCLUSION

The quality of samples from tubing segments is not representative of the quality of the corresponding RBC unit. Segments are not suitable surrogates with which to assess RBC quality.

Rejuvenation of ATP during storage does not reverse effects of the hypothermic storage lesion

BACKGROUND

Hypothermic storage (HS) of red blood cells (RBCs) leads to a progressive deterioration of cell quality. Mitigating these deleterious changes could allow maintenance or even an improvement of RBC in vitro quality. The aim was to determine the effect of a cold rejuvenation treatment of RBCs and in particular to assess the connection between ATP levels, RBC deformability, and morphology during RBC storage.

STUDY DESIGN AND METHODS

A pool-and-split design of leukoreduced CPD-saline-adenine-glucose-mannitol-packed RBC units was used to generate three groups: untreated controls, sham-treated units, and units treated with a cold (1-6 °C) rejuvenation solution on Day 28, 35, or 42 of cold storage. Units were followed until Day 49 of storage and assessed for ATP concentration, morphology, deformability, and other in vitro quality variables including hemolysis, pH, and supernatant potassium levels.

RESULTS

At every treatment time, rejuvenation was associated with a significant increase in intracellular ATP (p < 0.01). On Day 28, rejuvenation was accompanied by a significant decrease in deformability 1 week after treatment (p < 0.01). Rejuvenation on Day 28, but not Day 35 or 42, was also associated with a significant change in morphology (p < 0.01). Of the in vitro quality variables measured, most changed during cold storage, but differences among treatment groups were not observed.

CONCLUSION

The results of our study demonstrate a cold rejuvenation of RBCs during HS increases intracellular ATP, but that this change does not ameliorate, or exacerbate, the metabolic or biochemical symptoms of the storage lesion.