The timing of gamma irradiation and its effect on cell-free and microvesicle-bound hemoglobin. The BEST collaborative study.

BACKGROUND: Gamma irradiation of red cell concentrates (RCCs) is regularly used to prevent transfusion-associated graft-versus-host disease (TA-GvHD) in at-risk patients. While studies have indicated that irradiated RCCs exhibit increased hemolysis, there have been no efforts to differentiate between free- and microvesicle (MV)-bound hemoglobin (Hb). As an increase in the proportion of free-Hb in irradiated RCCs could alter vascular function, we sought to characterize differences in the state of extracellular Hb based on the timing of irradiation. STUDY DESIGN AND METHODS: Four separate pools of seven CPD/SAGM leukoreduced RCCs were produced and split into four sets of seven identical units. The units from each set were subject to irradiation (25 Gy) at six different points during storage, with one unit serving as a nonirradiated control. All testing was performed immediately following unit expiry on day 43. RESULTS: The earlier in storage that units were irradiated, the higher the hemolysis and the lower the proportion of MV-bound Hb. Units irradiated earlier in storage (1-8 days post collection) additionally had lower membrane rigidity (KEI ), lower mean corpuscular Hb concentrations (MCHC), and higher mean corpuscular fragility (MCF). Morphology indices, mean cell volume (MCV), mean corpuscular Hb (MCH), phosphatidylserine (PS) expression, as well as MV production and size did not however differ significantly between groups based on the timing of irradiation. CONCLUSIONS: Our findings indicate that irradiation timing can alter the state of extracellular Hb, with "early" irradiation promoting an increased proportion of cell-free Hb as well as mechanical damage to the RBC membrane.

Closed system processing variables affect post-thaw quality characteristics of cryopreserved red cell concentrates.

BACKGROUND: Differences in manufacturing conditions using the Haemonetics ACP 215 cell processor result in cryopreserved red cell concentrates (RCCs) of varying quality. This work studied the effect of processing method, additive solution, and storage duration on RCC quality to identify an optimal protocol for the manufacture of cryopreserved RCCs. MATERIALS AND METHODS: RCCs were pooled-and-split and stored for 7, 14, or 21 days before cryopreservation. Units were glycerolized with the ACP 215 using a single or double centrifugation method. After thawing, the RCCs were deglycerolized, suspended in AS-3, SAGM, ESOL, or SOLX/AS-7, and stored for 0, 3, 7, 14, or 21 days before quality testing. Quality assessments included hemoglobin content, hematocrit, hemolysis, adenosine triphosphate (ATP), supernatant potassium, and mean cell volume. RESULTS: Both glycerolization methods produced RCCs that met regulatory standards for blood quality. Dual centrifugation resulted in higher hemoglobin content, fewer processing alerts, and a shorter deglycerolization time than single centrifugation processing. Units processed with AS-3 and ESOL met regulatory standards when stored for up to 21 days pre-cryopreservation and 21 days post-deglycerolization. However, ESOL demonstrated superior maintenance of ATP over RBCs in AS-3. Some RCCs suspended in SAGM and SOLX exceeded acceptable hemolysis values after 7 days of post-deglycerolization storage regardless of pre-processing storage length. CONCLUSIONS: When manufacturing cryopreserved RCCs using the ACP 215, dual centrifugation processing with AS-3 or ESOL additive solutions is preferred, with storage periods of up to 21 days both pre-processing and post-deglycerolization.

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.

Introduction of a closed-system cell processor for red blood cell washing: postimplementation monitoring of safety and efficacy.

BACKGROUND: After introduction of a closed-system cell processor, the effect of this product change on safety, efficacy, and utilization of washed red blood cells (RBCs) was assessed. STUDY DESIGN AND METHODS: This study was a pre-/postimplementation observational study. Efficacy data were collected from sequentially transfused washed RBCs received as prophylactic therapy by ß-thalassemia patients during a 3-month period before and after implementation of the Haemonetics ACP 215 closed-system processor. Before implementation, an open system (TerumoBCT COBE 2991) was used to wash RBCs. The primary endpoint for efficacy was a change in hemoglobin (Hb) concentration corrected for the duration between transfusions. The primary endpoint for safety was the frequency of adverse transfusion reactions (ATRs) in all washed RBCs provided by Canadian Blood Services to the transfusion service for 12 months before and after implementation. RESULTS: Data were analyzed from more than 300 RBCs transfused to 31 recipients before implementation and 29 recipients after implementation. The number of units transfused per episode reduced significantly after implementation, from a mean of 3.5 units to a mean of 3.1 units (p < 0.005). The corrected change in Hb concentration was not significantly different before and after implementation. ATRs occurred in 0.15% of transfusions both before and after implementation. CONCLUSION: Safety and efficacy of washed RBCs were not affected after introduction of a closed-system cell processor. The ACP 215 allowed for an extended expiry time, improving inventory management and overall utilization of washed RBCs. Transfusion of fewer RBCs per episode reduced exposure of recipients to allogeneic blood products while maintaining efficacy.

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.

Quality of red blood cells washed using an automated cell processor with and without irradiation.

BACKGROUND: Sterile washing of red blood cells (RBCs) and use of an additive solution permits longer postwash storage. The effect of irradiation during this extended storage time is unclear. STUDY DESIGN AND METHODS: RBCs were washed 14 days after collection using an automated cell processor and stored in saline-adenine-glucose-mannitol. To determine how long washed and irradiated RBCs could be stored, units were irradiated 1, 4, 5, and 7 days after washing and in vitro quality was assessed. Determined limits of postwash storage time for washed and washed and irradiated RBCs were validated. Quality assessment included percent recovery, hemoglobin (Hb), hemolysis, extracellular K(+) , and adenosine triphosphate. Immunoglobulin (Ig)A levels were measured in the nonirradiated arm. RESULTS: RBCs irradiated 1 and 4 days after washing had unacceptably high hemolysis by Day 7 postwash, not meeting the acceptance criterion (<0.8% hemolysis in 98% of units with 95% confidence). Therefore, a 48-hour maximum storage time after irradiation was chosen. Storage limits tested in the validation phase were as follows: washing on Day 14 and subsequent storage for 7 days (washed RBCs) and washing on Day 14, irradiation on Day 19, and subsequent storage for 48 hours (washed and irradiated RBCs). All units met criteria for Hb, hematocrit, hemolysis, and sterility for washed RBCs. However, RBCs were washed with less than 2 L of saline, and IgA levels in 27 of 40 units were too high to be suitable for transfusion to IgA-deficient recipients. CONCLUSION: The extended expiry for washed and washed and irradiated RBCs met requirements for all indications except transfusion to IgA-deficient recipients.

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.

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.

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

BACKGROUND: Washing of red blood cell concentrates (RCCs) is required for potassium-sensitive transfusion recipients, including neonates in need of large-volume transfusions. When open, nonsterile washing systems are used, postwash outdate time is limited to 24 hours, often leading to problems providing the component to the patient before expiry. STUDY DESIGN AND METHODS: A closed, automated cell processor, the ACP 215 from Haemonetics Corporation, was used to wash RCCs and determine optimal pre- and postwash storage times. Two postwash storage solutions, additive solution (AS)-3 and saline-adenine-glucose-mannitol (SAGM), were compared. The in vitro quality of leukoreduced RCCs, prepared from citrate-phosphate-dextrose-anticoagulated whole blood, was determined postwash and compared to existing guidelines for RCC quality (hemoglobin content, hematocrit, and hemolysis) and predetermined criteria for ATP and supernatant potassium levels. A criterion for visual hemolysis was also applied. RESULTS: The prewash storage time, postwash storage time, and the postwash resuspension solution all contributed to RCC quality postwash. Levels of hemolysis were greater when washed RCCs were resuspended in SAGM (p = 0.01), while AS-3 proved worse at maintaining ATP levels postwash (p < 0.01). Immediately postwash, all units had supernatant K+ levels below the detection limit of the instrument (<1 mmol/L), but these increased to above acceptable levels within 14 days. CONCLUSION: Based on all acceptance criteria, a maximum 14-day prewash storage period and 7-day postwash storage period in SAGM preservative was found to be optimal. The longer outdate time postwashing should help lessen challenges in providing components to patients before expiry.