Historically, red cell concentrates (RCCs) have been manually glycerolized and deglycerolized using an open system (COBE 2991, Terumo). Implementation of a closed system cell processor (ACP-215, Haemonetics) for glycerolization and deglycerolization of RCCs creates a challenge for management of the historic cryopreserved RCC inventory. A study was undertaken to determine whether manually glycerolized frozen RCCs could be deglycerolized using the closed system processor, as the open system processors are being discontinued. Thirteen ABO/Rh matched RCCs were pooled and split to produce six large (approximately 354 mL) and six small (approximately 244 mL) RCCs. All units were stored for 14 days post-collection, manually glycerolized and frozen at ≤ -65°C for ≥72 h. Half of the units of each size were deglycerolized using the COBE 2991 and resuspended in 0.9% saline, and the remaining units were centrifuged, deglycerolized on the ACP-215, and resuspended AS-3. RBC quality was tested at 24 ± 2 h post-deglycerolization. All units deglycerolized on the ACP-215 had significantly lower hemolysis (p < .001) levels than those processed on the COBE2991. Large ACP-215 deglycerolized units had lower hematocrits (p < .05), hemoglobin (p < .01), and recovery (p = .001) than did large units deglycerolized on the COBE 2991. All ACP-215 units met the regulatory standards for hemolysis, hematocrit, hemoglobin, and recovery. The closed-system ACP-215 processor significantly reduced post-deglycerolization hemolysis in all units, and hemoglobin content in large units. The ACP-215, in combination with a centrifugation step, is suitable for processing cryopreserved RCCs that have been manually glycerolized.
Background: Adenosine triphosphate (ATP) levels guide many aspects of the red blood cell (RBC) hypothermic storage lesions. As a result, efforts to improve the quality of hypothermic-stored red cell concentrates (RCCs) have largely centered around designing storage solutions to promote ATP retention. Considering reduced temperatures alone would diminish metabolism, and thereby enhance ATP retention, we evaluated: (a) whether the quality of stored blood is improved at −4°C relative to conventional 4°C storage, and (b) whether the addition of trehalose and PEG400 can enhance these improvements. Study Design and Methods: Ten CPD/SAGM leukoreduced RCCs were pooled, split, and resuspended in a next-generation storage solution (i.e., PAG3M) supplemented with 0–165 mM of trehalose or 0–165 mM of PEG400. In a separate subset of samples, mannitol was removed at equimolar concentrations to achieve a fixed osmolarity between the additive and non-additive groups. All samples were stored at both 4°C and −4°C under a layer of paraffin oil to prevent ice formation. Results: PEG400 reduced hemolysis and increased deformability in −4°C-stored samples when used at a concentration of 110 mM. Reduced temperatures did indeed enhance ATP retention; however, in the absence of an additive, the characteristic storage-dependent decline in deformability and increase in hemolysis was exacerbated. The addition of trehalose enhanced this decline in deformability and hemolysis at −4°C; although, this was marginally alleviated by the osmolarity-adjustments. In contrast, outcomes with PEG400 were worsened by these osmolarity adjustments, but at no concentration, in the absence of these adjustments, was damage greater than the control. Discussion: Supercooled temperatures can allow for improved ATP retention; however, this does not translate into improved storage success. Additional work is necessary to further elucidate the mechanism of injury that progresses at these temperatures such that storage solutions can be designed which allow RBCs to benefit from this diminished rate of metabolic deterioration. The present study suggests that PEG400 could be an ideal component in these solutions.
Respiratory transfusion reactions represent some of the most severe adverse reactions related to receiving blood products. Of those, transfusion-related acute lung injury (TRALI) is associated with elevated morbidity and mortality. TRALI is characterized by severe lung injury associated with inflammation, pulmonary neutrophil infiltration, lung barrier leak, and increased interstitial and airspace edema that cause respiratory failure. Presently, there are few means of detecting TRALI beyond clinical definitions based on physical examination and vital signs or preventing/treating TRALI beyond supportive care with oxygen and positive pressure ventilation. Mechanistically, TRALI is thought to be mediated by the culmination of two successive proinflammatory hits, which typically comprise a recipient factor (1st hit—e.g., systemic inflammatory conditions) and a donor factor (2nd hit—e.g., blood products containing pathogenic antibodies or bioactive lipids). An emerging concept in TRALI research is the contribution of extracellular vesicles (EVs) in mediating the first and/or second hit in TRALI. EVs are small, subcellular, membrane-bound vesicles that circulate in donor and recipient blood. Injurious EVs may be released by immune or vascular cells during inflammation, by infectious bacteria, or in blood products during storage, and can target the lung upon systemic dissemination. This review assesses emerging concepts such as how EVs: 1) mediate TRALI, 2) represent targets for therapeutic intervention to prevent or treat TRALI, and 3) serve as biochemical biomarkers facilitating TRALI diagnosis and detection in at-risk patients.
One of the greatest concerns in the subzero storage of cells, tissues, and organs is the ability to control the nucleation or recrystallization of ice. In nature, evidence of these processes, which aid in sustaining internal temperatures below the physiologic freezing point for extended periods of time, is apparent in freeze-avoidant and freeze-tolerant organisms. After decades of studying these proteins, we now have easily accessible compounds and materials capable of recapitulating the mechanisms seen in nature for biopreser-vation applications. The output from this burgeoning area of research can interact synergistically with other novel developments in the field of cryobiology, making it an opportune time for a review on this topic.
Abstract Background The ACP 215 automated cell processor is used to glycerolize and deglycerolize red cell concentrates (RCCs). Its primary advantage over the COBE 2991, previously used to cryopreserve RCCs, is that it maintains a closed system enabling extended post‐thaw expiry. However, it was observed that post‐deglycerolization hematocrits (Hct) of units processed with the LN236 kit are markedly lower than those processed using the COBE 2991. Therefore, we intended to determine whether a modified process using a smaller volume deglycerolization kit (LN235) could increase the final Hct with limited deleterious effects on product characteristics. Study Design and Methods Two proof‐of‐concept (POC) studies, conducted to determine the feasibility of using the LN235 processing kit for deglycerolization, identified the necessary modifications to the pre‐ and post‐deglycerolization process, after which a two‐part study characterized the modified protocol. The impact of pre‐cryopreservation storage duration (7–21 days), input red cell mass, and the type of CPD/SAGM RCC production method (red cell filtration and whole blood filtration) were investigated. Results Using the LN235 kit in conjunction with a volume reduction step for RCCs with a red cell mass exceeding 180 mL allowed for an ~8% increase in Hct. As expected, slightly lower recoveries were seen for large RCCs due to volume reduction; however, there were no other detrimental outcomes on product quality. Conclusions Leveraging the LN235 kit, recommended by Haemonetics for units with a red cell mass of ≤180 mL, can be used to increase the post‐deglycerolization Hct of RCCs that exceed this volume.
Transfusion of red blood cells (RBCs) is one of the most valuable and widespread treatments in modern medicine. Lifesaving RBC transfusions are facilitated by the cold storage of RBC units in blood banks worldwide. Currently, RBC storage and subsequent transfusion practices are performed using simplistic workflows. More specifically, most blood banks follow the “first-in-first-out” principle to avoid wastage, whereas most healthcare providers prefer the “last-in-first-out” approach simply favoring chronologically younger RBCs. Neither approach addresses recent advances through -omics showing that stored RBC quality is highly variable depending on donor-, time-, and processing-specific factors. Thus, it is time to rethink our workflows in transfusion medicine taking advantage of novel technologies to perform RBC quality assessment. We imagine a future where lab-on-a-chip technologies utilize novel predictive markers of RBC quality identified by -omics and machine learning to usher in a new era of safer and precise transfusion medicine.
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