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.

A randomized controlled trial evaluating recovery and survival of 6% dimethyl sulfoxide-frozen autologous platelets in healthy volunteers.

BACKGROUND: Availability of platelets (PLTs) is severely limited by shelf life in some settings. Our objective was to determine and compare to Food and Drug Administration (FDA) criteria the PLT recovery and survival of autologous PLTs cryopreserved at -65°C or less in 6% dimethyl sulfoxide (DMSO) reconstituted with a no-wash method (cryopreserved PLTs [CPPs]) compared to autologous fresh PLTs. STUDY DESIGN AND METHODS: This was a randomized, Phase I study analyzing PLT viability and in vitro function in consenting healthy subjects. Apheresis PLTs (APs) were collected in plasma. APs were suspended in 6% DMSO, concentrated, and placed at not more than -65°C for 7 to 13 days. Frozen CPPs were thawed at 37°C and resuspended into 25 mL of 0.9% NaCl. Control PLTs (fresh autologous) and CPPs were labeled with (111) In or (51) Cr, and recovery and survival after reinfusion were determined using standard methods. A panel of in vitro assays was completed on APs and CPPs. RESULTS: After frozen storage, CPPs retained 82% of AP yield and showed increased PLT associated P-selectin and reduced responses to agonists. CPP 24-hour recovery (41.6 ± 9.7%) was lower than for fresh PLTs (68.4 ± 8.2%; p < 0.0001) and did not meet the current FDA criterion. CPPs had diminished survival compared to fresh PLTs (7.0 ± 2.1 days vs. 8.4 ± 1.2 days, respectively; p = 0.018), but did meet and exceed the FDA criterion for survival. CONCLUSION: While 24-hour recovery does not meet FDA criteria for liquid-stored PLTs, the CPP survival of circulating PLTs was surprisingly high and exceeded the FDA criteria. These data support proceeding with additional studies to evaluate the clinical effectiveness of CPPs.

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.

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.

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.