In vitro quality parameters of whole blood-derived platelets pooled using two different platelet pooling sets and stored up to 7 days are similar

BACKGROUND

Increasing the number of collections of whole blood-derived platelets (WBDP) and lengthening the allowable storage time may alleviate platelet (PLT) shortages. There is a need for new PLT pooling sets that can provide acceptable quality on Day 7 of storage.

STUDY DESIGN AND METHODS

This pool-and-split study compared WBDP prepared using the platelet-rich plasma method with the novel IMUGARD WB PLT pooling set and a control pooling set. After pooling and filtration, PLT products were tested on Days 1, 5, and 7. Large volume delayed sampling (LVDS) cultures were taken on Day 2.

RESULTS

The median postfiltration residual white blood cell (rWBC) content was 0.18 million per product (maximum 1.26 million; n = 69) with mean PLT recovery of 88.5 ± 2.8% for the new set and median 0.23 million (maximum 1.83 million) rWBC with 87.5 ± 2.5% recovery for the control. Day 5 mean pH22°C were 7.18 ± 0.12 and 7.13 ± 0.10 for the new and control set, respectively. Day 5 in vitro quality parameters were within 20% between the two pooling sets. The new set Day 7 pH22°C was acceptable (7.07 ± 0.17, 100% ≥ 6.3), and most parameters were within 20% of Day 5 values.

CONCLUSION

WBDP quality for the new pooling set is acceptable across a battery of in vitro tests when stored up to 7 days and meets FDA regulatory criteria. The quality parameters were similar between the new pooling set and the control set on Day 5. This new set is compatible with LVDS.

Evaluation of amotosalen and UVA pathogen-reduced apheresis platelets after 7-day storage

BACKGROUND

Amotosalen/UVA pathogen-reduced platelet components (PRPCs) with storage up to 7 days are standard of care in France, Switzerland, and Austria. PRPCs provide effective hemostasis with reduced risk of transfusion-transmitted infections and transfusion-associated graft versus host disease, reduced wastage and improved availability compared with 5-day-stored PCs. This study evaluated the potency of 7-day PRPCs by in vitro characterization and in vivo pharmacokinetic analysis of autologous PCs.

STUDY DESIGN AND METHODS

The in vitro characteristics of 7-day-stored apheresis PRPCs suspended in 100% plasma or 65% platelet additive solution (PAS-3)/35% plasma, thrombin generation, and in vivo radiolabeled post-transfusion recovery and survival of 7-day-stored PRPCs suspended in 100% plasma were compared with either 7-day-stored or fresh autologous conventional platelets.

RESULTS

PRPCs after 7 days of storage maintained pH, platelet dose, in vitro physiologic characteristics, and thrombin generation when compared to conventional 7-day PCs. In vivo, the mean post-transfusion survival was 151.4 ± 20.1 h for 7-day PRPCs in 100% plasma (Test) versus 209.6 ± 13.9 h for the fresh autologous platelets (Control), (T-ΔC: 72.3 ± 8.8%: 95% confidence interval [CI]: 68.5, 76.1) and mean 24-h post-transfusion recovery 37.6 ± 8.4% for Test versus 56.8 ± 9.2% for Control (T-ΔC: 66.2 ± 11.2%; 95% CI: 61.3, 71.1).

DISCUSSION

PRPCs collected in both 100% plasma as well as 65% PAS-3/35% plasma and stored for 7 days retained in vitro physiologic characteristics. PRPCs stored in 100% plasma for 7 days retained in vivo survival. Lower in vivo post-radiolabeled autologous platelet recovery is consistent with reported reduced count increments for allogenic transfusion.

Freeze-dried platelets are a promising alternative in bleeding thrombocytopenic patients with hematological malignancies

Thrombosomes are trehalose-stabilized, freeze-dried group O platelets with a 3-year shelf life. They can be stockpiled, rapidly reconstituted, and infused regardless of the recipient's blood type. Thrombosomes thus represent a potential alternative platelet transfusion strategy. The present study assessed the safety and potential early signals of efficacy of Thrombosomes in bleeding thrombocytopenic patients. We performed an open-label, phase 1 study of single doses of allogeneic Thrombosomes at three dose levels in three cohorts, each consisting of eight patients who had hematologic malignancies, thrombocytopenia, and bleeding. Adverse events, dose-limiting toxicities (DLTs), World Health Organization (WHO) bleeding scores, and hematology values were assessed. No DLTs were reported. The median age was 59 years (24-71). Most patients had AML (58%) or ALL (29%), followed by MDS (8%) and myeloproliferative neoplasm (4%). The WHO scores of 22 patients who were actively bleeding at a total of 27 sites at baseline either improved (n = 17 [63%]) or stabilized (n = 10 [37%]) through day 6. Twenty-four hours after infusion, 12 patients (50%) had a clinically significant platelet count increase. Of eight patients who received no platelet transfusions for 6 days after Thrombosomes infusion, 5 had a clinically significant increase in platelet count of ≥5000 platelets/μL and 2 had platelet count normalization. Thrombosomes doses up to 3.78 × 10⁸ particles/kg demonstrated safety in 24 bleeding, thrombocytopenic patients with hematological malignancies. Thrombosomes may represent an alternative to conventional platelets to treat bleeding. A phase 2 clinical trial in a similar patient population is underway.

Characterization and first-in-human clinical dose-escalation safety evaluation of a next-gen human freeze-dried plasma

Background

Early plasma transfusion is life‐saving for bleeding trauma patients. Freeze‐dried plasma (FDP) provides unique formulation advantages for infusion in the prehospital setting. We describe characterization and clinical safety data of the first, next‐generation FDP stored in plastic bags with rapid reconstitution.

Study design and methods

Coagulation and chemistry parameters on 155 pairs of fresh frozen plasma (FFP) and their derivative FDP units were compared. Next, a first‐in‐human, dose‐escalation safety evaluation of FDP, involving 24 healthy volunteers who donated either whole blood or apheresis plasma to create autologous FDP, was performed in three dose cohorts (270, 540, and 810 ml) and adverse events (AEs) were monitored. Cohort 3 was randomized, double‐blind with a cross‐over arm that compared FDP versus FFP using descriptive analysis for AEs, coagulation, hematology, and chemistry parameters.

Results

FDP coagulation factors, clotting times, and product quality (pH, total protein, and osmolality) post‐lyophilization were preserved. FDP infusions, of up to 810 ml per subject, were found to be safe and with no serious AEs (SAEs) related to FDP. The average time to reconstitute FDP was 67 s (range: 43–106). No differences in coagulation parameters or thrombin activation were detected in subjects infused with 810 ml of FDP compared with FFP.

Conclusion

This first next‐generation FDP product preserves the potency and safety of FFP in a novel rugged, compressible, plastic container, for rapid transfusion, allowing rapid access to plasma in resuscitation protocols for therapy in acute traumatic hemorrhage.

See editorial on page 257–260, in this issue

Hypoxic storage of red blood cells improves metabolism and post-transfusion recovery

BACKGROUND

Blood transfusion is a lifesaving intervention for millions of recipients worldwide every year. Storing blood makes this possible but also promotes a series of alterations to the metabolism of the stored erythrocyte. It is unclear whether the metabolic storage lesion is correlated with clinically relevant outcomes and whether strategies aimed at improving the metabolic quality of stored units, such as hypoxic storage, ultimately improve performance in the transfused recipient.

STUDY DESIGN AND METHODS

Twelve healthy donor volunteers were recruited in a two-arm cross-sectional study, in which each subject donated 2 units to be stored under standard (normoxic) or hypoxic conditions (Hemanext technology). End-of-storage measurements of hemolysis and autologous posttransfusion recovery (PTR) were correlated to metabolomics measurements at Days 0, 21, and 42.

RESULTS

Hypoxic red blood cells (RBCs) showed superior PTR and comparable hemolysis to donor-paired standard units. Hypoxic storage improved energy and redox metabolism (glycolysis and 2,3-diphosphoglycerate), improved glutathione and methionine homeostasis, decreased purine oxidation and membrane lipid remodeling (free fatty acid levels, unsaturation and hydroxylation, acyl-carnitines). Intra- and extracellular metabolites in these pathways (including some dietary purines) showed significant correlations with PTR and hemolysis, though the degree of correlation was influenced by sulfur dioxide (SO₂ ) levels.

CONCLUSION

Hypoxic storage improves energy and redox metabolism of stored RBCs, which results in improved posttransfusion recoveries in healthy autologous recipients-a Food and Drug Administration gold standard of stored blood quality. In addition, we identified candidate metabolic predictors of PTR for RBCs stored under standard and hypoxic conditions.

Red blood cells derived from whole blood treated with riboflavin and ultraviolet light maintain adequate survival in vivo after 21 days of storage

BACKGROUND

Pathogen reduction (PR) of whole blood (WB) may increase blood safety when applied before component separation. This study evaluates the in vivo performance of red blood cells (RBCs) derived from WB treated with the riboflavin and ultraviolet (UV) light PR (Mirasol) system.

STUDY DESIGN AND METHODS

This was a prospective, two-center, single-blind, randomized, two-period, crossover clinical trial designed to evaluate autologous ⁵¹ Cr/^99m Tc-radiolabeled recovery and survival of RBCs derived from Mirasol-treated WB compared to untreated WB. RBCs were stored in AS-3 for 21 days at 1 to 6°C. In vitro RBC variables were characterized. Frequency and severity of treatment-emergent adverse event (TEAE) and neoantigenicity were determined.

RESULTS

Twenty-four healthy adult volunteers (n = 12 per site) were evaluated. The Mirasol 24-hr RBC recoveries were 82.5 ± 3.9% with one-sided 95% lower confidence limit of 80.9%, meeting US Food and Drug Administration acceptance criteria, albeit at lower level than controls (91.7 ± 6.8%, p < 0.001). Mean RBC survival and T₅₀ were reduced in the Mirasol group (61 and 23 days, respectively) versus controls (82 and 36 days, respectively; p < 0.001) with a mean area under the curve survival of treated RBCs of 83% of untreated controls. End-of-storage hemolysis in the Mirasol group was 0.22 ± 0.1% (control, 0.15 ± 0.1%; p < 0.001). No neoantigenicity or differences in TEAEs were found.

CONCLUSION

RBCs derived from Mirasol WB and stored for up to 21 days in AS-3 maintained acceptable cell quality and recovery, albeit modestly reduced compared with untreated RBCs. Mirasol WB may represent a valid single WB PR platform that allows manufacture of RBC for storage for up to 21 days.

Overnight, room temperature hold of whole blood followed by 42-day storage of red blood cells in additive solution-7

BACKGROUND

Overnight, room temperature hold (ONH) of whole blood before component processing offers several benefits. This study evaluated the storage and in vivo recovery characteristics of ONH red blood cells (RBCs) stored in additive solution-7 (AS-7).

STUDY DESIGN AND METHODS

We conducted a three-center, three-arm evaluation of a new blood collection system with AS-7 compared to leukoreduced RBCs processed within 8 hours and stored in AS-1 (control). Whole blood (500 ± 50 mL) from healthy research subjects (n = 240) was held at room temperature 0 to 2 hours, 6 to 8 hours, or ONH (18-24 hr) before component processing and storage at 1 to 6 °C. RBCs were evaluated on Days 42 and 56 with a panel of in vitro assays. Subsets of the AS-7-stored RBCs were evaluated for (51) Cr 24-hour in vivo recovery and long-term survival.

RESULTS

Adenosine triphosphate (ATP) levels in ONH RBCs were not different than AS-7 RBCs prepared within 8 hours. ATP was higher in the ONH group on Day 42 than control, and ATP was maintained in all AS-7 groups through Day 56. ONH units had 0.36 ± 0.14% on Day 42 hemolysis (60/60 < 0.8%), and 0.54 ± 0.22% on Day 56 (10/60 > 0.8%, 2/60 > 1%). In vivo recoveries of stored RBCs were not different between the AS-7 arms at 42 days (p = 0.16; 27/27 ONH units > 75%), but the Day 56 ONH was significantly less than ONH on Day 42 (p = 0.008; 7/28 < 75%).

CONCLUSIONS

Overnight hold of whole blood at room temperature before component processing meets current regulatory requirements when RBCs are stored up to 42 days in AS-7.

The bioequivalence of frozen plasma prepared from whole blood held overnight at room temperature compared to fresh-frozen plasma prepared within eight hours of collection

BACKGROUND

Overnight, room temperature hold of whole blood (WB) before leukoreduction and component processing offers significant logistic and cost advantages over WB processed within 8 hours. Plasma prepared from WB held at room temperature overnight (PF24RT24WB) may result in a degradation of plasma coagulation protein activities compared to plasma frozen within 8 hours of collection. In this study, we intended to evaluate the bioequivalence (BE) of PF24RT24WB prepared using a new WB collection, leukoreduction, and storage system compared to fresh-frozen plasma (FFP) after 12 months of frozen storage.

STUDY DESIGN AND METHODS

We conducted a three-center, three-arm evaluation of the LEUKOSEP HWB-600-XL test system (Hemerus Medical LLC) compared to the RZ2000 control (Fenwal, Inc.). FFP was prepared from WB held at room temperature more than 6 hours and placed at less than -18 °C by 8 hours for control (n = 60) and test (n = 60) arms. PF24RT24WB (n = 60) was prepared with the test system from WB held at room temperature and then filtered and processed 20 to 24 hours postcollection. Frozen plasma was tested at 3, 6, and 12 months using a comprehensive panel of protein and coagulation factor assays.

RESULTS

The test FFP was BE for all coagulation factors and tested proteins at 12 months. As expected, PF24RT24WB had a reduced Factor (F)VIII activity compared to control FFP (87.1%; 90% confidence interval, 79.4%-93.3%) with the lower confidence limit less than 80%. All other factors were within the BE region.

CONCLUSION

Leukoreduced FFP and PF24RT24WB prepared using the LEUKOSEP HWB-600-XL system has been shown to be BE to control leukoreduced FFP with an expected decrease in FVIII activity after overnight hold.

Additive solution-7 reduces the red blood cell cold storage lesion

BACKGROUND

Transfusion of long-stored red blood cells (RBCs) is associated with decreased in vivo RBC recovery, delivery of RBC breakdown products, and increased morbidity and mortality. Reducing the burden of this RBC "storage lesion" is a major challenge in transfusion medicine. Additive solution-7 (AS-7) is a new RBC storage solution designed to improve RBC metabolism by providing phosphate and increasing buffering capacity.

STUDY DESIGN AND METHODS

Storage quality in AS-7 was measured in a prospective, randomized, three-center trial using units of whole blood from healthy human subjects whose RBCs were stored for up to 56 days in AS-7 (n = 120) or for 42 days in the control solution AS-1 (n = 60).

RESULTS

Hemolysis and shedding of protein-containing microvesicles were significantly reduced in RBCs stored in AS-7 for 42 and 56 days compared with RBCs stored in AS-1. Autologous in vivo recoveries of RBCs stored in AS-7 was 88 ± 5% at 42 days (n = 27) and 82 ± 3% at 56 days (n = 27), exceeding recoveries of RBCs stored in currently used solutions.

CONCLUSION

Increasing the phosphate, pH range, and buffer capacity of a RBC storage system allowed RBCs to be stored better and longer than currently approved storage systems. AS-7 ameliorates the long-term storage lesion resulting in significantly increased viability in vitro and in vivo.

Stored red blood cell viability is maintained after treatment with a second-generation S-303 pathogen inactivation process

BACKGROUND

Transfusion-transmitted infections and immunologic effects of viable residual lymphocytes remain a concern in red blood cell (RBC) transfusion. Pathogen reduction technologies for RBC components are under development to further improve transfusion safety. S-303 is a frangible anchor-linker-effector with labile alkylating activity and a robust pathogen reduction profile. This study characterized the viability of RBCs prepared with a second-generation S-303 process and stored for 35 days.

STUDY DESIGN AND METHODS

This was a two-center, single-blind randomized, controlled, crossover study in 27 healthy subjects. S-303 (test) or control RBCs were prepared in random sequence and stored for 35 days, at which time an aliquot of radiolabeled RBCs was transfused. The 24-hour recovery, RBC life span, and in vitro metabolic and viability variables were analyzed.

RESULTS

The mean 24-hour RBC recovery and hemolysis of test RBCs were similar to control RBCs and were consistent with the Food and Drug Administration (FDA) guidance for RBC viability. The mean differences in life span and median life span (T(50) ) of circulating test RBCs were 13.7 and 6.8 days, while the mean difference in the area under the curve of surviving RBCs was 1.38%, in favor of control RBCs. There were no clinically relevant abnormal laboratory values after the infusion of test RBCs. All crossmatch assays of autologous S-303 RBCs were nonreactive.

CONCLUSIONS

RBCs prepared using the S-303 pathogen inactivation process were physiologically and metabolically suitable for transfusion after 35 days of storage, met the FDA guidance criteria for 24-hour recovery, and did not induce antibody formation.

Infusion of P-Capt prion-filtered red blood cell products demonstrate acceptable in vivo viability and no evidence of neoantigen formation

BACKGROUND

Transmission of variant Creutzfeldt-Jacob disease (vCJD) is a major concern in blood transfusion. The P-Capt filter has been shown to remove around 4 log ID(50) prion infectivity from prion-spiked human red blood cells (RBCs).

STUDY DESIGN AND METHODS

Two independent, single-center, randomized, open-label studies were designed to analyze the safety of P-Capt-filtered RBCs. RBCs prepared from leukoreduced whole blood from 43 eligible subjects were randomly assigned to P-Capt filtration and/or storage in plasma or SAGM and stored for 28 or 42 days. Stored RBCs were analyzed for in vivo 24-hour recovery, hemolysis, metabolic variables, blood group antigen expression, neoantigen formation, and safety after autologous infusion.

RESULTS

Mean P-Capt filtration times for leukoreduced RBCs were 41 (SAGM) to 51 (plasma) minutes. Thirteen of 14 subjects receiving P-Capt-filtered RBCs had 24-hour RBC recoveries of 75% or more after 42-day storage, with a mean hemolysis of less than 0.6%. No loss of RBC antigen expression or formation of neoantigens was observed. In both studies, RBCs had white blood cell counts of less than 1 × 10(6)/unit after leukofiltration. P-Capt prion filtration provided an additional greater than 0.8 log leukoreduction. No serious or unexpected adverse events were observed after infusion of P-Capt-filtered full-volume RBC units.

CONCLUSIONS

P-Capt-filtered, stored RBCs demonstrated acceptable viability and no detectable neoantigen expression, immunogenic responses. or safety issues after infusion of a complete unit. The additional filtration time and modest reduction in RBC content are within acceptable levels for implementation in countries with transfusion transmission of vCJD.

In vivo viability of stored red blood cells derived from riboflavin plus ultraviolet light-treated whole blood

BACKGROUND

A novel system using ultraviolet (UV) light and riboflavin (Mirasol System, CaridianBCT Biotechnologies) to fragment nucleic acids has been developed to treat whole blood (WB), aiming at the reduction of potential pathogen load and white blood cell inactivation. We evaluated stored red blood cell (RBC) metabolic status and viability, in vitro and in vivo, of riboflavin/UV light-treated WB (IMPROVE study).

STUDY DESIGN AND METHODS

The study compared recovery and survival of RBCs obtained from nonleukoreduced WB treated using three different UV light energies (22, 33, or 44 J/mL(RBC)). After treatment, WB from 12 subjects was separated into components and tested at the beginning and end of component storage. After 42 days of storage, an aliquot of RBCs was radiolabeled and autologously reinfused into subjects for analysis of 24-hour recovery and survival of RBCs.

RESULTS

Eleven subjects completed the in vivo study. No device-related adverse events were observed. By Day 42 of storage, a significant change in the concentrations of sodium and potassium was observed. Five subjects had a 24-hour RBC recovery of 75% or more with no significant differences among the energy groups. RBC t(1/2) was 24 ± 9 days for the combined three groups. Significant correlations between 24-hour RBC recovery and survival, hemolysis, adenosine triphosphate (ATP), and CO(2) levels were observed.

CONCLUSIONS

This study shows that key RBC quality variables, hemolysis, and ATP concentration may be predictive of their 24-hour recovery and t(1/2) survival. These variables will now be used to assess modifications to the system including storage duration, storage temperature, and appropriate energy dose for treatment.

Multi-institutional randomized control study of haemolysis in stored red cell units prepared manually or by an automated system

BACKGROUND

The haemolysis level at the end of storage is a performance parameter for RBC preparations. In the evaluation of new devices or new processes for processing blood, it is relevant to evaluate whether the haemolysis is linked to (1) specific characteristics of the blood donor, or (2) the nature of the blood-processing methodologies.

MATERIALS AND METHODS

As part of the validation of a new automated whole blood processing system compared to the current manual methods, randomized, paired crossover studies were conducted evaluating measures of blood component quality, including RBC haemolysis over 42 days of storage.

RESULTS

The association between haemolysis and the individual subject was evaluated by modelling haemolysis with independent predictors of treatment (control and test processing) and leucocyte reduction as fixed factors with donor and laboratory as random effects in a mixed-effects ANOVA model. It was found that the day 42 haemolysis values were strongly dependent on the donor subject, with an intraclass correlation coefficient of 0.81.

CONCLUSIONS

The data reported in this study suggest a link between the specific whole blood donor and the haemolysis levels observed in red-blood-cell units stored refrigerated for 42 days. Additional research to identify possible donor characteristics associated with haemolysis during storage is warranted.

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.

Viability of red cells prepared with S-303 pathogen inactivation treatment

BACKGROUND

A nucleic acid-targeted pathogen inactivation process with S-303 was developed to treat red blood cells (RBCs).

STUDY DESIGN AND METHODS

Three studies in healthy subjects investigated posttransfusion recovery, life span, and immunogenic potential of autologous RBCs treated with S-303 and stored for 35 days. A two-arm trial in 42 subjects (1A) examined recovery of 35-day-old S-303 RBCs after a single transfusion. A one-arm study (1B) measured recovery and immune response in 28 subjects after multiple transfusions of S-303 RBCs. A randomized, crossover study (1C) in 29 subjects compared recovery and life span of 35-day-old S-303 RBCs and conventional RBCs.

RESULTS

In Studies 1A and 1B, mean recovery of S-303 RBCs ranged from 78.7 to 84.4 percent. In Phase 1C, the mean 24-hour posttransfusion recoveries of S-303 and untreated RBCs were 81.7 +/- 6.3 and 84.5 +/- 6.2 percent (p = 0.05). The median life spans (t(1/2)) of S-303 and control RBCs were identical (37.4 days, p = 0.98). No antibodies to S-303 RBCs were detected.

CONCLUSION

The mean 24-hour recovery of 35-day-old S-303 RBCs was less than untreated RBCs, but greater than 75 percent. RBCs treated with S-303 and stored for 35 days exhibited median life span not different from that of conventional RBCs.

In vitro and in vivo evaluation of LEUKOSEP HRC-600-C leukoreduction filtration system for red cells

BACKGROUND

Documentation of the benefits of leukoreduction has led to the increased use of this technique and the need for development of efficient and effective techniques for its accomplishment. This study investigated the in vitro properties and in vivo autologous radiolabeled recovery of leukoreduced red cells (RBCs) produced through a leukoreduction filtration system for RBCs (LEUKOSEP HRC-600-C, Hemerus Medical).

STUDY DESIGN AND METHODS

Normal subjects donated 36 units of RBCs that were leukoreduced on Days 0, 3, or 5 through a "hands-off" technique. Biochemical studies were performed before and after filtration and at the end of 42 days of storage. Units leukoreduced on Days 0 or 5 were held until Day 42 and used for autologous radiolabeled return to determine recovery with 51Cr single-label radiolabeling techniques.

RESULTS

Leukoreduction filtration was accomplished in 16.3 +/- 2 minutes on Day 0 at room temperature or 27 to 30 minutes on Days 3 or 5 after refrigeration. Leukoreduction efficiency was 4.6 +/- 0.6 log with a median residual white blood cell (WBC) content of fewer than 3.3 x 10(4) WBCs per unit. RBC recovery was 90 +/- 2 percent. Hemolysis was 0.34 +/- 0.16 percent at the end of 42 days of storage. The in vivo recovery of radiolabeled RBCs 24 hours after autologous return was 80.6 +/- 4.5 percent for RBC units leukoreduced on Days 0 and 5 combined.

CONCLUSION

The LEUKOSEP HRC-600-C WBC reduction filtration system produced leukoreduced RBCs efficiently and effectively with acceptable poststorage biochemical measures and posttransfusion recovery after 42 days of storage.

Buffering and dilution in red blood cell storage

BACKGROUND

Red blood cell (RBC) storage solutions work in a narrow pH range between 7.2 and 6.4. While keeping RBC within that pH range, ATP production can be increased by buffering or dilution.

STUDY DESIGN AND METHODS

In the first study, 12 units of packed CP2D RBCs were pooled in groups of four, re-aliquoted, and added to one of four additive solutions (ASs): AS-3, 110 mL; EAS-61, 170 mL; EAS-78, 170 mL; or EAS-81, 110 mL. EAS-78 and -81 contain bicarbonate. Units were sampled approximately weekly for 10 weeks for biochemical measures. In the second study, 12 volunteers donated RBCs for measures of (51)Cr in vivo recovery after 6 or 8 weeks of storage in EAS-81.

RESULTS

RBCs stored in the higher-volume or buffered ASs had higher RBC ATP concentrations. The combination had an additive effect. Hemolysis was reduced in dilute ASs and less so with buffering. RBCs stored for 8 weeks (n=6) in EAS-81 exhibited 87+/- 2 percent 24-hour (51)Cr in vivo recovery and 0.4+/- 0.2 percent hemolysis.

CONCLUSIONS

It is possible to store RBCs for 8 weeks in buffered conventional volume ASs. Combining buffering and increased AS volume improves stored RBC characteristics further.

Collection of two units of leukoreduced RBCs from a single donation with a portable multiple-component collection system

BACKGROUND

A portable automated component collection system that produces double (2) units of leukoreduced RBCs (DRBCs) from a single donation was evaluated. This study analyzed quality of the collected and final products, the efficacy of automated leukoreduction, and donor safety.

STUDY DESIGN AND METHODS

The system was used to collect 120 DRBCs. WBCs were removed from 90 products with machine-controlled filtration. DRBCs were collected in ACD-A and stored in AS-1 for 42 days at 1 to 6 degrees C. Pre- and postprocedure donor vital signs and hematologic parameters were measured. Procedure time, product characteristics, and adverse events were also recorded. In vitro studies were performed on all products on Day 0 and at end of storage. In vivo recoveries of 28 leukoreduced and 9 nonleukoreduced products were measured on Day 42.

RESULTS

Day 0 mean percentage of hemolysis for leukoreduced and nonleukoreduced units was 0.05 percent. DRBCs had residual WBC counts of less than 1 x 106 cells per unit and mean RBC recovery after filtration of 91.9 +/- 2.7 percent. Mean 24-hour recovery after infusion for leukoreduced units at end of storage was 80.9 +/- 6.9 percent and nonleukoreduced units was 77.6 +/- 5.8 percent (p> 0.05). No clinically significant changes in donor vital signs or serious adverse events were observed.

CONCLUSIONS

The quality of leukoreduced RBCs collected with this portable automated component collection system met or exceeded FDA requirements. This automated system is safe and effective for collection and processing of 2 units of RBCs suitable for transfusion.

Twelve-week RBC storage

BACKGROUND

Better storage can improve RBC availability and safety. Optimizing RBC ATP production and minimizing hemolysis has allowed progressively longer storage.

STUDY DESIGN AND METHODS

In the first study, 24 units of packed CPD RBCs were pooled in groups of four, realiquoted, and added to 300 mL of one of four variants of experimental additive solution 76 (EAS-76) containing 45, 40, 35, or 30 mEq per L NaCl. Units were sampled weekly for 12 weeks for morphologic and biochemical measures. In the second study, 10 volunteers donated 2 units of RBCs for a crossover comparison of Tc/Cr 24-hour in vivo recovery of 6-week storage in AS-1 versus 12-week storage in EAS-76 variant 6 (EAS-76v6) having 30 mEq per L NaCl.

RESULTS

RBCs stored in the lower salt variants of EAS-76 had higher concentrations of RBC ATP with less hemolysis and microvesiculation. RBC 2,3 DPG was preserved for two weeks. RBCs stored for 12 weeks in EAS-76v6 exhibited 78 +/- 4 percent 24-hour in vivo recovery.

CONCLUSIONS

It is possible to store RBCs for 12 weeks with acceptable recovery and 0.6 percent hemolysis and with normal 2,3 DPG concentrations for 2 weeks.

RBC storage for 11 weeks

BACKGROUND

Increasing the length of RBC storage can increase both RBC availability and quality. This work addresses 11-week RBC storage in experimental ASs (EASs).

STUDY DESIGN AND METHODS

Three studies were performed. In the first, 24-hour in vivo recovery of (51)Cr-labeled autologous RBCs was measured in nine volunteers after storage of their RBCs for 11 weeks in EAS 67. In the second study, 4 units of blood were divided and stored in aliquots with an EAS containing 0, 15, 30, or 45 mmol per L of mannitol; then hemolysis, RBC morphology, and microvesicle protein were measured. In the third study, 6 full units were stored for 12 weeks in the EAS containing 30 mmol per L of mannitol, with weekly sampling for morphologic and biochemical measures of RBC quality.

RESULTS

RBCs stored for 11 weeks in EAS-67 had a mean 24-hour in vivo recovery of 79 +/- 5 percent, but the hemolysis was 1.35 +/- 0.68 percent. Increasing mannitol content of the EAS reduced hemolysis but increased microvesiculation. EAS-76, with 30 mmol per L of mannitol allowed 11-week storage with 0.48 +/- 0.10 percent hemolysis at 11 weeks and 0.62 +/- 0.14 percent hemolysis at 12 weeks.

CONCLUSION

It is possible to store RBCs for 11 weeks in EAS with greater than 75 percent recovery and less than 1 percent hemolysis.

The role of electrolytes and pH in RBC ASs

BACKGROUND

Experimental additive solutions (EASs) containing saline, adenine, glucose, mannitol and disodium phosphate can support RBCs for 9 or 10 weeks if used in 200- or 300-mL volumes. The effects of variations in the electrolyte composition and volume of EASs were explored.

STUDY DESIGN AND METHODS

In three four-arm studies, 24 RBC units were pooled in groups of 4 and realiquoted as test units to ensure that all donors were equally represented in each study arm. In Study 1, units were stored for 11 weeks in EAS containing 0, 10, 20, or 30 mmol per L of sodium bicarbonate. In Study 2, units were stored for 9 weeks in EAS containing 26, 50, 100, or 150 mmol per L of sodium chloride. In Study 3, units were stored in 100 or 200 mL of AS-3 or EAS-61. RBC ATP concentrations and hemolysis were measured weekly.

RESULTS

Increasing the sodium bicarbonate content of EASs increased the pH throughout storage and increased RBC ATP concentrations in the later phases of storage, but it had no effect on hemolysis. Increased sodium chloride content of EASs led to lower RBC ATP concentrations and increased hemolysis. In EAS-61, RBC ATP concentrations were increased throughout storage, and hemolysis was lower than that of RBCs stored in AS-3.

CONCLUSION

RBC ATP synthesis is highly dependent on the pH of the AS. Hemolysis is affected by the salt content and volume of the AS.

Successful storage of RBCs for 10 weeks in a new additive solution

BACKGROUND

The effect of storing packed RBCs suspended in 300 mL of an alkaline, experimental additive solution (EAS 64) was explored.

STUDY DESIGN AND METHODS

RBC units prepared from blood collected from healthy donors into CPD were WBC reduced and stored for 10 weeks under blood bank conditions after the addition of 300 mL of EAS 64 (adenine, 2 mM:; dextrose, 50 mM:; mannitol, 20 mM:; NaCl, 75 mM:; Na(2)HPO(4), 9 mM:). For comparison, non-WBC-reduced units from the same donors were stored in a different additive solution (AS-1, Baxter Healthcare) for 6 weeks. Standard methods were used for the in vitro assays. The 24-hour in vivo recoveries were measured by using (51)Cr- and (99m)Tc-labeled RBCs.

RESULTS

Mean recovery in the EAS 64 units after 10 weeks was 84 +/- 8 percent, the same as in the AS-1 units stored for 6 weeks. For EAS 64 and AS-1 units, respectively, the ATP of the RBCs was 85 percent and 64 percent of the initial value, hemolysis was 0.43 percent and 0.63 percent, supernatant potassium was 24 mEq per L and 44 mEq per L, and the morphologic index was 98 and 71.

CONCLUSION

RBCs suspended in 300 mL of EAS 64 can be stored satisfactorily for 10 weeks. Longer RBC storage should reduce outdating, increase availability of transfusions in remote locations, and improve the efficiency of autologous donor programs.

The effects of phosphate, pH, and AS volume on RBCs stored in saline-adenine-glucose-mannitol solutions

BACKGROUND

RBC ATP concentrations are the most important correlate of RBC viability. Tests were performed to determine whether increased AS volume, pH, and phosphate content increased stored RBC ATP concentrations.

STUDY DESIGN AND METHODS

In three studies, packed RBCs were pooled in groups of 3 or 4 units and realiquoted as combined units to reduce intradonor differences. Pooled units were stored in the licensed ASs, AS-1 or AS-5, which contain saline, adenine, glucose, and mannitol (SAGM), or in experimental ASs (EASs) containing SAGM and disodium phosphate. Ten pools were stored in AS-1 at RBC concentrations equivalent to 100, 200, or 300 mL of AS. Six pools were stored in 100, 200, 300, or 400 mL volumes of EAS-61. Ten pools were stored in 100 mL of AS-5, 200 mL of EAS-61, or 300 mL of EAS-64. RBC ATP concentration and other measures of RBC metabolism and function were measured weekly.

RESULTS

RBC ATP concentrations decreased sooner with storage in increasing volumes of AS-1. In EAS-61 and EAS-64, RBC ATP concentrations initially increased and stayed elevated longer with increasing AS volume.

CONCLUSIONS

The addition of disodium phosphate to SAGM AS increases the RBC ATP concentrations. Reducing storage Hct appears to have a separate beneficial effect in reducing hemolysis.

Successful storage of RBCs for 9 weeks in a new additive solution

BACKGROUND

This study explored the effect of storing packed RBCs suspended in 200 mL of an alkaline, hypotonic, experimental additive solution (EAS 61).

STUDY DESIGN AND METHODS

Packed RBC units prepared from RBCs collected from healthy donors in CPD were stored for 8 (n = 10) and 9 (n = 10) weeks under blood bank conditions after the addition of 200 mL of EAS 61 (adenine, 2 mM:; dextrose, 110 mM:; mannitol, 55 mM:; NaCl, 26 mM:; Na(2)HPO(4), 12 mM:). Standard methods were used for in vitro assays. The 24-hour in vivo autologous recoveries were measured with (51)Cr.

RESULTS

Mean +/- SD recoveries at 8 and 9 weeks were 81 +/- 7 and 77 +/- 7 percent. After 9 weeks, the ATP of the RBCs was 81 percent of the initial value, hemolysis was 0.35 percent, supernatant potassium was 46 mEq per L, and the morphologic index was 94.1.

CONCLUSION

Packed RBCs suspended in 200 mL of EAS 61 can be stored satisfactorily for 9 weeks. Longer RBC storage should reduce outdating, increase availability of transfusions in remote locations, and improve the efficiency of autologous donor programs.

A feasibility evaluation of an automated blood component collection system platelets and red cells

BACKGROUND

The purpose of these studies was to evaluate the functional properties of blood components collected with an automated collection system.

STUDY DESIGN AND METHODS

Single-donor platelets (n = 44) and packed red cell (RBC) units (n = 10) were collected. In vitro and in vivo assays were used to assess the function of single-donor platelet components stored for 5 days and of packed RBC units after storage for 42 days at 4 degrees C.

RESULTS

Adverse events observed in the 44 study subjects were minor. The mean 24-hour recovery value for the packed RBC units stored for 42 days was 83.6 +/- 5.4 percent, with a mean percentage of hemolysis on Day 42 at 0.46 +/- 0.19 percent. The 25 patients receiving platelet components achieved a mean corrected count increment of 15.1 +/- 10.4 x 10(3). All platelet concentrates had less than 1 x 10(6) total white cells.

CONCLUSION

Both in vitro and in vivo testing for the packed RBCs collected and stored for 42 days met the standards for both hemolysis and percentage of 51Cr 24-hour RBC recovery. The in vitro results and transfusion data on white cell-reduced platelet components transfused to thrombocytopenic patients were comparable to those on available platelet components.

The effect of hypotonicity, glutamine, and glycine on red cell preservation

BACKGROUND

Red cells (RBCs) stored in hypo-osmolar additive solutions with the same concentrations of adenine, dextrose, mannitol, and sodium chloride and varied amounts of ammonium, phosphate, glycerol, and glutamine were better preserved than RBCs in the standard additive solution (Adsol). Cell swelling occurred in all the experimental additives. This observation prompted the evaluation of glutamine and glycine alone, as well as a combination of glutamine and glycine, all of which have been described as producing swelling of rat liver cells.

STUDY DESIGN AND METHODS

Aliquots of RBCs were stored at 4 degrees C in Adsol or experimental additive solutions (EASs) all containing adenine, 2 mM; dextrose, 110 mM; mannitol, 55 mM; and sodium chloride, 50 mM. EAS 42 had, in addition, glutamine, 10 mM; glycine 5 mM, and phosphate, 20 mM. EAS 43 had glutamine, 10 mM; glycine, 10 mM; and phosphate 20 mM. EAS 44 had glutamine, 10 mM; EAS 45 had glutamine, 10 mM, and phosphate, 20 mM, and EAS 46 had only glycine, 10 mM. At intervals, measurements were made of mean corpuscular volume, mean corpuscular hemoglobin concentration, morphology, ATP, hemolysis, supernatant potassium, ammonia, pH, and microvesicles shed.

RESULTS

The initial mean corpuscular volumes were larger in all EASs than in Adsol, but the greatest difference was between EASs 44 and 46 (108 fL) and Adsol (86 fL) (p < 0.001). The morphology scores were significantly better in all the EASs (p < 0.04). The ATPs were significantly greater in all the EASs (p < 0.001), and highest in those with phosphate. potassium leakage and hemolysis were less in the EASs (p < 0.001). The ammonia levels higher in all the EASs than in Adsol, with the exception of EAS 46. During storage, the extracorpuscular and intracorpuscular pH levels were essentially identical. The shedding of microvesicles was greatly reduced in all the EASs.

CONCLUSION

Cell swelling induced in RBCs after collection appears to improve preservation. Ammonia and phosphate enhance RBC ATP maintenance. Glycine decrease the formation of ammonia by RBCs stored in a hypotonic medium.

Studies in red blood cell preservation 10. 51Cr recovery of red cells after liquid storage in a glycerol-containing additive solution

The purpose of the present study was to compare the 24-hour recovery of red blood cells stored for 9 weeks in a hypoosmolar additive solution containing 150 mM glycerol to cells stored in Adsol. Seven units of packed red cells were split into 2 aliquots. To one sample, 100 ml of the experimental additive solution (EAS 25) was added, and to the other, 50 ml of Adsol. At the end of the storage period the cells were labeled with 51Cr. A double chromium technique was used to make it possible to perform comparative autologous studies in the same donor. The 24-hour 51Cr recovery value for EAS 25 was 73.0 +/- (SD) 4.2% and for Adsol 60.9 +/- 7.1. At 9 weeks the adenosine triphosphate levels were not significantly better compared to Adsol but the other in vitro measurements were better. New approaches to the study of red cell preservation are suggested.

Studies in red blood cell preservation: 9. The role of glutamine in red cell preservation

Previous studies have demonstrated that an additive solution containing ammonium chloride (NH4+) and phosphate (Pi) in addition to adenine, glucose and mannitol would support red blood cell (RBC) in vitro characteristics and in vivo 24-hour viability after storage for 9 weeks. The purpose of the present study was to determine if NH4+ generated by the action of glutaminase on glutamine could be substituted for added NH4+ salts. Packed RBCs were stored with equal volumes of adenine, glucose, mannitol, and citrate containing additive solutions with 10 mM glutamine (EAS 31) or with 10 mM glutamine and either 10 (EAS 36) or 20 mM (EAS 37) Pi. One aliquot was stored with Adsol. The mean ATP levels of the RBCs stored in the glutamine plus phosphate EASs were 132 (10 mM Pi) and 144% (20 mM Pi) of the initial levels at 28 days, and at 84 days remained at 48 and 56%, respectively. The ATP levels of the RBC stored in Adsol were 105 and 25% at 28 and 84 days of storage, respectively. Percentage hemolysis and vesiculation was significantly lower (p < 0.01) for RBCs stored in glutamine and glutamine plus phosphate as compared to RBCs stored in Adsol. The levels of NH4+ were 22 to 34% higher in the EASs than in Adsol at the end of 84 days of storage, suggesting that glutamine is broken down by glutaminase to generate NH4+. The mean corpuscular volumes (MCVs) of RBCs in EASs 36 and 37 were substantially higher than in Adsol throughout the course of storage (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)