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.

O-Aryl-Glycoside Ice Recrystallization Inhibitors as Novel Cryoprotectants: A Structure-Function Study

Low-molecular-weight ice recrystallization inhibitors (IRIs) are ideal cryoprotectants that control the growth of ice and mitigate cell damage during freezing. Herein, we describe a detailed study correlating the ice recrystallization inhibition activity and the cryopreservation ability with the structure of O-aryl-glycosides. Many effective IRIs are efficient cryoadditives for the freezing of red blood cells (RBCs). One effective cryoadditive did not inhibit ice recrystallization but instead inhibited ice nucleation, demonstrating the significance of inhibiting both processes and illustrating the importance of this emerging class of cryoprotectants.

Transfusion-related immunomodulation: review of the literature and implications for pediatric critical illness

Transfusion-related immunomodulation (TRIM) in the intensive care unit (ICU) is difficult to define and likely represents a complicated set of physiologic responses to transfusion, including both proinflammatory and immunosuppressive effects. Similarly, the immunologic response to critical illness in both adults and children is highly complex and is characterized by both acute inflammation and acquired immune suppression. How transfusion may contribute to or perpetuate these phenotypes in the ICU is poorly understood, despite the fact that transfusion is common in critically ill patients. Both hyperinflammation and severe immune suppression are associated with poor outcomes from critical illness, underscoring the need to understand potential immunologic consequences of blood product transfusion. In this review we outline the dynamic immunologic response to critical illness, provide clinical evidence in support of immunomodulatory effects of blood product transfusion, review preclinical and translational studies to date of TRIM, and provide insight into future research directions.

Quantification of Cell-Free DNA in Red Blood Cell Units in Different Whole Blood Processing Methods

Background. Whole blood donations in Canada are processed by either the red cell filtration (RCF) or whole blood filtration (WBF) methods, where leukoreduction is potentially delayed in WBF. Fresh WBF red blood cells (RBCs) have been associated with increased in-hospital mortality after transfusion. Cell-free DNA (cfDNA) is released by neutrophils prior to leukoreduction, degraded during RBC storage, and is associated with adverse patient outcomes. We explored cfDNA levels in RBCs prepared by RCF and WBF and different storage durations. Methods. Equal numbers of fresh (stored ≤14 days) and older RBCs were sampled. cfDNA was quantified by spectrophotometry and PicoGreen. Separate regression models determined the association with processing method and storage duration and their interaction on cfDNA. Results. cfDNA in 120 RBC units (73 RCF, 47 WBF) were measured. Using PicoGreen, WBF units overall had higher cfDNA than RCF units (p = 0.0010); fresh WBF units had higher cfDNA than fresh RCF units (p = 0.0093). Using spectrophotometry, fresh RBC units overall had higher cfDNA than older units (p = 0.0031); fresh WBF RBCs had higher cfDNA than older RCF RBCs (p = 0.024). Conclusion. Higher cfDNA in fresh WBF was observed compared to older RCF blood. Further study is required for association with patient outcomes.

Association of Blood Donor Age and Sex With Recipient Survival After Red Blood Cell Transfusion

IMPORTANCE

While red blood cells (RBCs) are administered to improve oxygen delivery and patient outcomes, they also have been associated with potential harm. Unlike solid organ transplantation, the clinical consequences of donor characteristics on recipients have not been evaluated in transfusion medicine.

OBJECTIVE

To analyze the association of RBC donor age and sex with the survival of transfusion recipients.

DESIGN, SETTING, AND PARTICIPANTS

We established a longitudinal cohort by linking data from a blood collection agency with clinical and administrative data at 4 academic hospitals.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards regression models were fitted to evaluate the risk of donor age and sex on transfusion recipient survival.

RESULTS

Between October 25, 2006, and December 31, 2013, a total of 30 503 RBC transfusion recipients received 187 960 RBC transfusions from 80 755 unique blood donors. For recipients receiving an RBC unit from younger donors, the risk of death was increased compared with recipients receiving an RBC unit from a donor 40 to 49.9 years old (adjusted hazard ratio, 1.08; 95% CI, 1.06-1.10; P < .001 for donor age range 17-19.9 years and 1.06; 95% CI, 1.04-1.09; P < .001 for donor age range 20-29.9 years). Receiving an RBC transfusion from a female donor was associated with an 8% statistically significant increased risk of death compared with receiving an RBC transfusion from a male donor (adjusted hazard ratio, 1.08; 95% CI, 1.06-1.09; P < .001).

CONCLUSIONS AND RELEVANCE

Red blood cell transfusions from younger donors and from female donors were statistically significantly associated with increased mortality. These findings suggest that donor characteristics may affect RBC transfusion outcomes.

Testosterone-dependent sex differences in red blood cell hemolysis in storage, stress, and disease

BACKGROUND

Red blood cell (RBC) hemolysis represents an intrinsic mechanism for human vascular disease. Intravascular hemolysis releases hemoglobin and other metabolites that inhibit nitric oxide signaling and drive oxidative and inflammatory stress. Although these pathways are important in disease pathogenesis, genetic and population modifiers of hemolysis, including sex, have not been established.

STUDY DESIGN AND METHODS

We studied sex differences in storage or stress-induced hemolysis in RBC units from the United States and Canada in 22 inbred mouse strains and in patients with sickle cell disease (SCD) using measures of hemolysis in 315 patients who had homozygous SS hemoglobin from the Walk-PHASST cohort. A mouse model also was used to evaluate posttransfusion recovery of stored RBCs, and gonadectomy was used to determine the mechanisms related to sex hormones.

RESULTS

An analysis of predisposition to hemolysis based on sex revealed that male RBCs consistently exhibit increased susceptibility to hemolysis compared with females in response to routine cold storage, under osmotic or oxidative stress, after transfusion in mice, and in patients with SCD. The sex difference is intrinsic to the RBC and is not mediated by plasmatic factors or female sex hormones. Importantly, orchiectomy in mice improves RBC storage stability and posttransfusion recovery, whereas testosterone repletion therapy exacerbates hemolytic response to osmotic or oxidative stress.

CONCLUSION

Our findings suggest that testosterone increases susceptibility to hemolysis across human diseases, suggesting that male sex may modulate clinical outcomes in blood storage and SCD and establishing a role for donor genetic variables in the viability of stored RBCs and in human hemolytic diseases.

Assessing the influence of component processing and donor characteristics on quality of red cell concentrates using quality control data

BACKGROUND AND OBJECTIVES

Quality control (QC) data collected by blood services are used to monitor production and to ensure compliance with regulatory standards. We demonstrate how analysis of quality control data can be used to highlight the sources of variability within red cell concentrates (RCCs).

MATERIALS AND METHODS

We merged Canadian Blood Services QC data with manufacturing and donor records for 28 227 RCC between June 2011 and October 2014. Units were categorized based on processing method, bag manufacturer, donor age and donor sex, then assessed based on product characteristics: haemolysis and haemoglobin levels, unit volume, leucocyte count and haematocrit.

RESULTS

Buffy-coat method (top/bottom)-processed units exhibited lower haemolysis than units processed using the whole-blood filtration method (top/top). Units from female donors exhibited lower haemolysis than male donations. Processing method influenced unit volume and the ratio of additive solution to residual plasma.

CONCLUSIONS

Stored red blood cell characteristics are influenced by prestorage processing and donor factors. Understanding the relationship between processing, donors and RCC quality will help blood services to ensure the safety of transfused products.

Manufacturing method affects mitochondrial DNA release and extracellular vesicle composition in stored red blood cells

BACKGROUND AND OBJECTIVES

Damage-associated molecular patterns (DAMPs) are found in transfusion products, but their potential impacts are not fully understood. We examined the influence of manufacturing method on levels of mitochondrial (mt) DNA and extracellular vesicle (EV) DAMPs in red cell concentrates (RCCs).

MATERIALS AND METHODS

Eighty-seven RCCs were prepared using nine different methods (6-15 units/method), including three apheresis, five whole blood (WB)-derived leucoreduced (LR) and one WB-derived non-LR method. On storage days 5 and 42, levels of mtDNA (by PCR) and number and cell of origin of EVs (by flow cytometry) were assessed in RCC supernatants.

RESULTS

There was a 100-fold difference in mtDNA levels among methods, with highest levels in non-LR, followed by MCS+ and Trima apheresis RCCs. There was a 10-fold difference in EV levels among methods. RBC-derived CD235a+ EVs were found in fresh RCCs and increased in most during storage. Platelet-derived CD41a+ EVs were highest in non-LR and Trima RCCs and did not change during storage. WBC-derived EVs were low in most RCCs; CD14+ EVs increased in several RCCs during storage.

CONCLUSION

DAMPs in RCCs vary by manufacturing method. MtDNA and EV could be informative quality markers that may be relevant to RCC immunomodulatory potential.

Dengue virus persists and replicates during storage of platelet and red blood cell units

BACKGROUND

Dengue virus (DENV) is a transfusion-transmissible arbovirus that threatens blood donor systems with approximately 200 million high-titer asymptomatic infections occurring annually. Here we investigated the viability of DENV during storage of donor-derived platelet (PLT) and red blood cell (RBC) units. While purified PLTs have been shown to generate viable DENV, RBCs are replication incompetent. Combined with different storage criteria, distinct virus persistence profiles were anticipated in PLT and RBC units.

STUDY DESIGN AND METHODS

Mimicking the virus titer of asymptomatic donors, purified DENV was spiked (10(5) -10(6) infectious units/mL) into PLT or RBC units produced and stored according to blood bank operating procedures. DENV was measured by infectious plaque-forming assays and by quantitative reverse transcription-polymerase chain reaction.

RESULTS

In both PLT (7 days, 20-24°C) and RBC (42 days, 1-6°C) units, infectious DENV persisted throughout storage despite logarithmic decay. In buffer alone, DENV infectivity was insignificant by Day 1 at 20 to 24°C or 14 days at 1 to 6°C. Infectious virus production was identified in stored PLT units using a translation inhibitor and supported by virus genome replication. Surprisingly, DENV was also produced in RBC units, implying the involvement of cells other than RBCs.

CONCLUSION

Both virus propagation and effects independent of cell function mitigate the intrinsic lability of DENV. Nevertheless, the overall rapid storage decay suggests that aged PLT and RBC units may be safer. These data raise awareness to the possible persistence of other conceivably more robust RNA viruses during the storage of cellular blood products.

The Grand Challenges of Organ Banking: Proceedings from the first global summit on complex tissue cryopreservation

The first Organ Banking Summit was convened from Feb. 27 - March 1, 2015 in Palo Alto, CA, with events at Stanford University, NASA Research Park, and Lawrence Berkeley National Labs. Experts at the summit outlined the potential public health impact of organ banking, discussed the major remaining scientific challenges that need to be overcome in order to bank organs, and identified key opportunities to accelerate progress toward this goal. Many areas of public health could be revolutionized by the banking of organs and other complex tissues, including transplantation, oncofertility, tissue engineering, trauma medicine and emergency preparedness, basic biomedical research and drug discovery - and even space travel. Key remaining scientific sub-challenges were discussed including ice nucleation and growth, cryoprotectant and osmotic toxicities, chilling injury, thermo-mechanical stress, the need for rapid and uniform rewarming, and ischemia/reperfusion injury. A variety of opportunities to overcome these challenge areas were discussed, i.e. preconditioning for enhanced stress tolerance, nanoparticle rewarming, cyroprotectant screening strategies, and the use of cryoprotectant cocktails including ice binding agents.

An investigation of red blood cell concentrate quality during storage in paediatric-sized polyvinylchloride bags plasticized with alternatives to di-2-ethylhexyl phthalate (DEHP)

BACKGROUND AND OBJECTIVES

Di-2-ethylhexyl phthalate (DEHP) is a blood bag plasticizer. It is also a toxin, raising concerns for vulnerable populations, for example, neonates and infants. Here, the in vitro quality of red cell concentrates (RCC) stored in paediatric bags formulated with alternative plasticizers to DEHP was compared.

MATERIALS AND METHODS

RCC were pooled and split into polyvinylchloride (PVC)/DEHP, PVC/1,2-cyclohexanedicarboxylic acid diisononyl ester (DINCH) or PVC/butyryl trihexyl citrate (BTHC) bags. Quality was assessed on storage days 5, 21, 35 and 43.

RESULTS

Metabolism differed among the bags: pCO2 levels were lowest and pO2 were highest in BTHC bags. Glucose consumption and lactate production suggested higher metabolic rates in BTHC bags. ATP levels were best maintained in DINCH bags (day 43 mean level: 2·86 ± 0·29 μmol/g Hb). RCC in BTHC bags had the greatest potassium release (54·6 ± 3·0 mm on day 43). From day 21, haemolysis was higher in BTHC bags (P < 0·01) and by day 43 had exceeded 0·8% (0·85 ± 0·10%). RCC in BTHC bags showed more microparticle formation than RCC in DEHP or DINCH bags.

CONCLUSION

The results suggest that the BTHC formulation used was detrimental to RBC quality. DINCH bags could be a viable alternative to DEHP: they outperformed DEHP bags energetically, with better maintenance of ATP levels.

Determining the Volume of Additive Solution and Residual Plasma in Whole Blood Filtered and Buffy Coat Processed Red Cell Concentrates

BACKGROUND

Residual plasma in transfused red cell concentrates (RCCs) has been associated with adverse transfusion outcomes. Despite this, there is no consensus on the standard procedure for measuring residual plasma volume.

METHODS

The volumes of residual plasma and additive solution were measured in RCCs processed using two separation methods: whole blood filtration (WBF) and buffy coat (BC)/RCC filtration. The concentration of mannitol and albumin in RCC components was measured using colorimetric assays. Mannitol concentration was used to calculate additive solution volume. Residual plasma volume was calculated using two methods.

RESULTS

Calculated RCC supernatant volumes were much lower in BC-processed components compared to WBF-processed components (BC = 97 ± 6 ml, WBF = 109 ± 4 ml; p < 0.05). Calculated additive solution volumes were greater in WBF- than in BC-processed components (BC = 81 ± 4 ml, WBF = 105 ± 2 ml; p < 0.05). Absolute residual plasma volume varied significantly based on the calculation method used.

CONCLUSION

Disparity between plasma volume calculation methods was observed. Efforts should be made to standardize residual plasma volume measurement methods in order to accurately assess the impact of residual plasma on transfusion outcomes.

Blood Bag Plasticizers Influence Red Blood Cell Vesiculation Rate without Altering the Lipid Composition of the Vesicles

BACKGROUND

Polyvinyl chloride (PVC) plasticized with di(2-ethylhexyl) phthalate (DEHP) is commonly used for blood collection and storage. DEHP has protective effects on RBC membranes, but is also a toxin.

METHODS

A paired study was conducted to investigate the influence of DEHP and two alternative plasticizers, 1,2-cyclohexane-dicarboxylic acid diisononyl ester (DINCH) and n-butyryl-tri-n-hexyl citrate (BTHC), on the preservation of RBCs stored for 42 days in PVC pediatric bags. The RBC membrane was evaluated for supernatant hemoglobin (Hb), release of extracellular microvesicles (EVs), osmotic fragility, deformability, and lipid composition.

RESULTS

In BTHC-plasticized bags, the supernatant Hb increase during storage was 2 times greater than in DINCH- and DEHP-plasticized bags. By day 21, EV concentrations had doubled from day-5 levels in DINCH- and DEHP-, and trebled in BTHC-plasticized bags. RBC mean cell volumes were greater in BTHC- than in DINCH- or DEHP-plasticized bags (p < 0.001). Osmotic fragility differed significantly among plasticizers (p < 0.01). After day 21, RBC deformability decreased in all, but to a greater extent in the bags with BTHC. Phospholipid composition of RBCs and EVs was not different among plasticizers.

CONCLUSION

Membrane stabilization capacity differed among the plasticizers. RBC in BTHC bags stored more poorly, while DEHP and DINCH bags offered better protection against vesiculation, osmotic stress, and Hb loss.

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.