Mirasol Pathogen Reduction Technology System Research Articles

Pathogen reduction of monkeypox virus in plasma and whole blood using riboflavin and UV light.

Monkeypox virus has recently emerged from endemic foci in Africa and, since October 20, 2022, more than 73,000 human infections have been reported by the CDC from over 100 countries that historically have not reported monkeypox cases. The detection of virus in skin lesions, blood, semen, and saliva of infected patients with monkeypox infections raises the potential for disease transmission via routes that have not been previously documented, including by blood and plasma transfusions. Methods for protecting the blood supply against the threats of newly emerging disease agents exist and include Pathogen Reduction Technologies (PRT) which utilize photochemical treatment processes to inactivate pathogens in blood while preserving the integrity of plasma and cellular components. Such methods have been employed broadly for over 15 years, but effectiveness of these methods under routine use conditions against monkeypox virus has not been reported. Monkeypox virus (strain USA_2003) was used to inoculate plasma and whole blood units that were then treated with riboflavin and UV light (Mirasol Pathogen Reduction Technology System, Terumo BCT, Lakewood, CO). The infectious titers of monkeypox virus in the samples before and after riboflavin + UV treatment were determined by plaque assay on Vero cells. The levels of spiked virus present in whole blood and plasma samples exceeded 103 infectious particles per dose, corresponding to greater than 105 DNA copies per mL. Treatment of whole blood and plasma units under standard operating procedures for the Mirasol PRT System resulted in complete inactivation of infectivity to the limits of detection. This is equivalent to a reduction of ≥ 2.86 +/- 0.73 log10 pfu/mL of infectivity in whole blood and ≥ 3.47 +/-0.19 log10 pfu/mL of infectivity in plasma under standard operating conditions for those products. Based on this data and corresponding studies on infectivity in patients with monkeypox infections, use of Mirasol PRT would be expected to significantly reduce the risk of transfusion transmission of monkeypox.

Effect of mirasol pathogen reduction technology system on immunomodulatory molecules of apheresis platelets

Pathogen inactivation for platelets by riboflavin system (MIRASOL) efficiently reduces transfusion related pathogen transmission. However little is known about its impact on platelets’ immunomodulatory biochemical profile. We aimed was to assess the effects of MIRASOL treatment on platelet quality parameters and immunomodulatory molecules CD62P, RANTES, and CD40L in Single Donor Platelets (SDPs) resuspended in plasma (SDP-P) or T-PAS and additive solution (SDP-A). Twenty nine SDPs (15 SDP-P and 14 SDP-A) were included in the study. Samples were collected before, after MIRASOL treatment and just before transfusion. P-selectin (CD62P), RANTES, and CD40L were tested by ELISA. Platelet products quality assays were also performed. Platelet count/unit decreased after Mirasol treatment by 13 %. The pH of all units decreased over the 5-day storage period but remained above expected limits and the swirling test was positive throughout storage. P-selectin levels were not different between the three different time points in both SDPs-P and SDPs-A while RANTES levels were found to differ statistically significantly at the three different time points in all units and in the SPD-A subgroup. CD40L levels in all SDP products increased slightly during storage but this was not statistically significant. CD62P, RANTES, and CD40L in all time points were elevated in SDPs-A compared to SDPs-P but not at a statistically significant level. In conclusion MIRASOL treatment apart from RANTES increase does not seem to substantially affect platelets associated other cytokines and immunomodulatory molecules namely P-selectin and sCD40L which are implicated in immune transfusion reactions.

Pathogen reduction of platelets: experience of a single blood bank

: Pathogen reduction technology (PRT) has the potential to prevent pathogen transfusion transmission from blood donor to patient by impeding the replication of bacteria, viruses and parasites in blood components. Additionally, PRT can help to guarantee blood safety in challenging situations for blood supply, as in the Ebola or Chikungunya epidemics, or in a scenario full of uncertainties such as the current SARS-CoV-2 pandemic. The Balearic Islands Blood Bank (BIBB) is one of the few blood establishments worldwide with more than 10 years of experience in the routine use of amotosalen/UVA (Intercept Blood System) and riboflavin/UVA-UVB (Mirasol PRT system) for platelets (PLTs), the use of riboflavin/UVA-UVB for plasma and with research experience in riboflavin/UVA-UVB applied to whole blood. Over the years, we have had the opportunity to evaluate PRT from different perspectives, such as clinical and hemovigilance research in adults and children, in vitro studies on PRT effects on PLTs and assessing the financial impact of PRT implementation. PRT methods offer remarkable benefits but also have certain limitations, which are important to bear in mind during the decision-making process for PRT implementation. The purpose of this study is to review the current knowledge on PRT for PLTs drawing on our experience acquired over the last decade.

Pathogen reduction of SARS-CoV-2 virus in plasma and whole blood using riboflavin and UV light.

BackgroundSevere Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has recently been identified as the causative agent for Coronavirus Disease 2019 (COVID-19). The ability of this agent to be transmitted by blood transfusion has not been documented, although viral RNA has been detected in serum. Exposure to treatment with riboflavin and ultraviolet light (R + UV) reduces blood-borne pathogens while maintaining blood product quality. Here, we report on the efficacy of R + UV in reducing SARS-CoV-2 infectivity when tested in human plasma and whole blood products.Study design and methodsSARS-CoV-2 (isolate USA-WA1/2020) was used to inoculate plasma and whole blood units that then underwent treatment with riboflavin and UV light (Mirasol Pathogen Reduction Technology System, Terumo BCT, Lakewood, CO). The infectious titers of SARS-CoV-2 in the samples before and after R + UV treatment were determined by plaque assay on Vero E6 cells. Each plasma pool (n = 9) underwent R + UV treatment performed in triplicate using individual units of plasma and then repeated using individual whole blood donations (n = 3).ResultsRiboflavin and UV light reduced the infectious titer of SARS-CoV-2 below the limit of detection for plasma products at 60–100% of the recommended energy dose. At the UV light dose recommended by the manufacturer, the mean log reductions in the viral titers were ≥ 4.79 ± 0.15 Logs in plasma and 3.30 ± 0.26 in whole blood units.ConclusionRiboflavin and UV light effectively reduced the titer of SARS-CoV-2 to the limit of detection in human plasma and by 3.30 ± 0.26 on average in whole blood. Two clades of SARS-CoV-2 have been described and questions remain about whether exposure to one strain confers strong immunity to the other. Pathogen-reduced blood products may be a safer option for critically ill patients with COVID-19, particularly those in high-risk categories.

Inactivation of Middle East respiratory syndrome coronavirus (MERS-CoV) in plasma products using a riboflavin-based and ultraviolet light-based photochemical treatment.

BACKGROUNDMiddle East respiratory syndrome coronavirus (MERS‐CoV) has been identified as a potential threat to the safety of blood products. The Mirasol Pathogen Reduction Technology System uses riboflavin and ultraviolet (UV) light to render blood‐borne pathogens noninfectious while maintaining blood product quality. Here, we report on the efficacy of riboflavin and UV light against MERS‐CoV when tested in human plasma.STUDY DESIGN AND METHODSMERS‐CoV (EMC strain) was used to inoculate plasma units that then underwent treatment with riboflavin and UV light. The infectious titers of MERS‐CoV in the samples before and after treatment were determined by plaque assay on Vero cells. The treatments were initially performed in triplicate using pooled plasma (n = 3) and then repeated using individual plasma units (n = 6).RESULTSIn both studies, riboflavin and UV light reduced the infectious titer of MERS‐CoV below the limit of detection. The mean log reductions in the viral titers were ≥4.07 and ≥4.42 for the pooled and individual donor plasma, respectively.CONCLUSIONRiboflavin and UV light effectively reduced the titer of MERS‐CoV in human plasma products to below the limit of detection, suggesting that the treatment process may reduce the risk of transfusion transmission of MERS‐CoV.

Hemovigilance survey of pathogen-reduced blood components in the Warsaw Region in the 2009 to 2013 period.

In 2009 the Mirasol Pathogen Reduction Technology (PRT) was introduced to the routine blood component production of the Regional Blood Transfusion Center in Warsaw (RBTCW). The goal of this study was to investigate the safety of Mirasol-treated blood components. The accumulated passive hemovigilance data of Mirasol-treated blood components collected at the RBTCW are presented and compared to historical and contemporary data. Furthermore, active hemovigilance data collected from patients with different hematologic disorders transfused with Mirasol-treated or untreated blood components at the Institute of Hematology and Transfusion Medicine (IHTM) are presented and discussed. The adverse reaction (AR) reporting rate by hospitals to the RBTCW after the implementation of the Mirasol technology was 0.39% for Mirasol-treated platelet concentrates (M-PCs) and 0.05% for Mirasol-treated fresh-frozen plasma. When comparing contemporary rates of ARs recorded by RBTCW in the time period 2011 to 2012, no statistical difference was observed between Mirasol-treated and untreated blood components. No serious AR was attributed to Mirasol-treated components. At the IHTM a lower rate of ARs after transfusion of M-PCs was observed than with untreated PCs. Despite the fact that very large amounts of Mirasol-treated plasma have been transfused to patients with congenital or acquired thrombotic thrombocytopenic purpura, no significant increase in AR rates was observed. Treatment of blood components with the Mirasol PRT System has proven to be safe for patients and is not associated with increased rates and grades of adverse events in patients of hospitals in the Warsaw Region.

Efficacy of the Mirasol pathogen reduction technology system against severe fever with thrombocytopenia syndrome virus (SFTSV).

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tickborne virus in the Bunyaviridae family. This virus has recently been found in China, Japan and Korea. The risk of transfusion-transmitted SFTSV infection (TTI-SFTSV) is a concern because person-to-person transmission resulting from contact with SFTSV-contaminated blood has been reported. Therefore, we investigated the efficacy of the Mirasol pathogen reduction technology (PRT) system for inactivating SFTSV in vitro. The Mirasol PRT system achieved a > 4.11 log10 reduction value (LRV) for SFTSV. In conclusion, we showed that the Mirasol PRT system could potentially be used to reduce the risk of TTI-SFTSV.

Pathogen reduction technologies

BackgroundIdeally, pathogen reduction technology (PRT) should provide proactive protection against emerging pathogens, reduce the need to introduce additional testing, minimize bacterial contamination and potentially replace processing steps such as gamma‐irradiation.Material and MethodsAvailable literature regarding technologies currently in use or under development for the treatment of labile blood components during processing was reviewed.ResultsThe INTERCEPT and Mirasol PRT systems are used widely in blood centres in Europe, Asia and the Middle East for the treatment of both platelets and plasma, whereas clinical trials of platelets treated using the THERAFLEX UV‐Platelets system are underway. In vitro data suggest that PRT treatment leads to some loss of platelet function. However, haemovigilance reports from countries where PRT‐treated platelets and plasma are transfused indicate no change in component usage, and indeed a reduction in transfusion‐related adverse events. Animal models are being used to elucidate mechanisms for these observed reductions. A second‐generation S‐303 system for red cells is also under development, as is a Mirasol PRT system for treatment of whole blood. Preliminary data indicate that these technologies may eventually become available.ConclusionThe challenge for blood services is to understand and rationalize the costs, risks and benefits of PRT compared with removing any tests or processes, whilst aiming to provide the highest level of blood safety. Ongoing post‐marketing surveillance and clinical trials are still required for all PRT systems.

Establishment of culture systems for Genotypes 3 and 4 hepatitis E virus (HEV) obtained from human blood and application of HEV inactivation using a pathogen reduction technology system

It has been demonstrated that the hepatitis E virus (HEV) can be transmitted via blood transfusion, and the risk of HEV transmission via transfusion has become a major global concern. An HEV culture system for blood-derived HEV has been sought to obtain valuable knowledge of the virus and the risk of HEV infection through blood products. We endeavored to establish an HEV culture system using RNA-positive blood specimens for Genotypes (G) 3 and 4 and applied this system to evaluate tissue culture infectious dose (TCID). We applied this method to investigate the potential of the Mirasol pathogen reduction technology (PRT) system (Terumo BCT) to inactivate live HEV in contaminated platelet samples (PLTs). PLTs were spiked with cultured HEV G3 or G4 and then treated with the Mirasol PRT system. PLTs were examined before and after the treatment for HEV load using TCID titration. We successfully established two strains for HEV production: the JRC-HE3 strain for G3 and the UA1 strain for G4. The Mirasol PRT system expressed more than 3 log inactivation for JRC-HE3 and more than 2 log inactivation for UA1. The Mirasol PRT system inactivated greater than 2 to 3 logs of live HEV in PLTs and can potentially be used to lower the possibility of blood-borne HEV transmission. The G3 and G4 HEV inocula identified in this study and the hepatoma cell culture system provide a new means to assess HEV infectious titer and to evaluate other pathogen reduction strategies.

Pathogen reduction treatment alters the immunomodulatory capacity of buffy coat–derived platelet concentrates

Storage of platelet concentrates (PCs) after Mirasol pathogen reduction technology (PRT) treatment changes platelet (PLT) surface marker expression and secretion of immunomodulatory factors. Given that PLTs are known to participate in immune function, PRT may alter the way PLTs interact with the immune cells of a recipient upon transfusion. As such, the aim of this study was to assess the effects of PRT treatment on the functional ability of PLTs to interact with peripheral blood mononuclear cells (PBMNCs). Buffy coat-derived PCs were pooled and split to obtain matched pairs. One unit was treated using the Mirasol PRT system, while the control PC remained untreated. After 5 days of storage, either the PLTs or the PLT supernatants from the PCs were cocultured with PBMNCs, with or without lipopolysaccharide (LPS). The immunomodulatory factors secreted into culture medium after coculture were examined. PRT-treated PLTs and PLT supernatant significantly increased the interleukin (IL)-8 concentration, which was manifested only in the presence of LPS. Conversely, PRT-treated PLTs secreted less soluble P-selectin (sCD62P) upon coculture with PBMNCs. PRT-treatment induced differential secretion of IL-8 and sCD62P during coculture, which may be attributed to either bioactive substances present in PLT supernatant or as a result of cell-cell interactions.

Hazard assessment of sodium nitrite high level in some meat products

Treatment of fresh frozen plasma (FFP) by riboflavin (RB) and ultraviolet (UV) light inhibits nucleic acid replication, leading to inactivation of white blood cells (WBCs) and pathogens. The goal of this study was to compare the effects of pathogen reduction technology (PRT) treatment on the plasma protein content based on biochemical, immune and hemostatic characteristics in “typical” pre-storage vs. post-storage PRT-treatment setting.Following whole blood centrifugation, separated plasma units were: (a) inactivated and frozen (pre-storage setting or control group [CG]) or (b) immediately frozen (post-storage setting or study group [SG]) afterward thawed, inactivated and stored at −40 ± 5 °C (cryostorage). Plasma units were inactivated by the Mirasol PRT system (TerumoBCT, USA). Using multi-laboratory techniques and equipments, biochemistry (Advia 1800; Siemens, Germany), IgM, IgG and IgA, complement components C3 and C4 (BNA II nefelometer analyzer; Siemens, Germany), as well as CH50 activity (Behring coagulation timer; Siemens, Germany) were investigated. Procoagulant and inhibitor factors, such as antithrombin-III (AT-III), and protein C (PC) were determined by BCS XP Coagulation system (Siemens, Germany). There were neither significant changes in final protein levels, nor any differences in plasma immunoglobulin levels investigated. In the final samples CH50 activity was reduced in both investigated groups. The plasma concentration of the complement C3 following post-storage treatment was significantly (p < 0.05) higher than in pre-storage setting. There was a trend of depletion of procoagulant activities in both, pre-storage and post-storage PRT-treatment (initial vs. final values), but there were no significant differences between two groups. Results confirmed that AT-III was significantly higher after post-storage inactivation.In conclusion, this study confirmed that there were not clinically relevant intergroup (pre-storage vs. post-storage PRT-treatment) differences in plasma constituent levels. Post-storage treated FFP remains, protein quantity, and activity well, and therefore can be used in clinical practice. Previously cryostored or quarantine FFP units (despite the reduced quarantine period after NAT/PCR testing) could be safely and effectively inactivated, directly prior to clinical application.

Effect of Mirasol pathogen reduction technology system on in vitro quality of MCS+ apheresis platelets

Reducing the risk of pathogen transmission to transfusion recipients is one of the great concerns in transfusion medicine. Important among the measures suggested to minimise pathogen transmission is pathogen reduction technology (PRT) systems. The present study examined the effects of Mirasol PRT system on MCS+ apheresis platelets in vitro quality measures during a seven-day storage period at 22°C. Statistical analysis indicated no significant difference in platelet concentrations between the control and treated platelet concentrates (PCs) during the storage period. Glucose and lactate levels were measured to determine metabolic activities of control and treated platelets. In both control and treated platelets, the amount of glucose consumed and lactate produced increased significantly with storage time, but glucose consumption and lactate production rates were significantly higher in treated platelets compared with control platelets. The mean pH of treated PCs was decreased at all time points relative to control PCs but remained within acceptable limits. The expression of P-selectin was also higher in Mirasol PRT treated platelets throughout the storage period, but differences were not statistically significant on Days 1 and 4. Finally, visual inspection of swirling indicated that Mirasol PRT treatment of platelets is associated with platelet shape change. Overall, our results show that MCS+ apheresis platelets treated with Mirasol PRT can preserve adequate in vitro properties for at least 5days of storage.

Plasma constituent integrity in pre-storage vs. post-storage riboflavin and UV-light treatment – A comparative study

Treatment of fresh frozen plasma (FFP) by riboflavin (RB) and ultraviolet (UV) light inhibits nucleic acid replication, leading to inactivation of white blood cells (WBCs) and pathogens. The goal of this study was to compare the effects of pathogen reduction technology (PRT) treatment on the plasma protein content based on biochemical, immune and hemostatic characteristics in "typical" pre-storage vs. post-storage PRT-treatment setting. Following whole blood centrifugation, separated plasma units were: (a) inactivated and frozen (pre-storage setting or control group [CG]) or (b) immediately frozen (post-storage setting or study group [SG]) afterward thawed, inactivated and stored at -40 ± 5°C (cryostorage). Plasma units were inactivated by the Mirasol PRT system (TerumoBCT, USA). Using multi-laboratory techniques and equipments, biochemistry (Advia 1800; Siemens, Germany), IgM, IgG and IgA, complement components C3 and C4 (BNA II nefelometer analyzer; Siemens, Germany), as well as CH50 activity (Behring coagulation timer; Siemens, Germany) were investigated. Procoagulant and inhibitor factors, such as antithrombin-III (AT-III), and protein C (PC) were determined by BCS XP Coagulation system (Siemens, Germany). There were neither significant changes in final protein levels, nor any differences in plasma immunoglobulin levels investigated. In the final samples CH50 activity was reduced in both investigated groups. The plasma concentration of the complement C3 following post-storage treatment was significantly (p<0.05) higher than in pre-storage setting. There was a trend of depletion of procoagulant activities in both, pre-storage and post-storage PRT-treatment (initial vs. final values), but there were no significant differences between two groups. Results confirmed that AT-III was significantly higher after post-storage inactivation. In conclusion, this study confirmed that there were not clinically relevant intergroup (pre-storage vs. post-storage PRT-treatment) differences in plasma constituent levels. Post-storage treated FFP remains, protein quantity, and activity well, and therefore can be used in clinical practice. Previously cryostored or quarantine FFP units (despite the reduced quarantine period after NAT/PCR testing) could be safely and effectively inactivated, directly prior to clinical application.

Pathogen Reduction Technologies: The Best Solution for Safer Blood?

Although it is generally accepted that blood has never been safer than today, transfusion-associated side effects, particularly infective, still occur. Unlike screening strategies, pathogen reduction technologies offer a new approach to increase blood safety by actively/directly targeting possible, also emerging pathogens or donor leukocytes. Advanced technologies for cellular blood products like the psoralen-based INTERCEPT BLOOD SYSTEM or the riboflavin-based Mirasol pathogen reduction technology system have extensively been examined and are on the way to enter the blood bank routine. However, as with any medical treatment, the transfusion of pathogen reduced blood products is not completely risk-free. Due to possible impairment of the treated blood cells the transfusion success is significantly lower as compared to untreated blood products. Long-term side effects concerning the photosensitizers and their photoproducts still remain a matter of debate. This paper outlines current pathogen reduction technologies but also focuses on ethical concerns associated with the employment of these techniques.

Photochemical inactivation of chikungunya virus in plasma and platelets using the Mirasol pathogen reduction technology system

Chikungunya virus (CHIKV) is a reemerging mosquito-borne virus that has been responsible for a number of large-scale epidemics as well as imported cases covering a wide geographical range. As a blood-borne virus capable of mounting a high-titer viremia in infected humans, CHIKV was included on a list of risk agents for transfusion and organ transplant by the AABB Transfusion-Transmitted Diseases Committee. Therefore, we evaluated the ability of the Mirasol pathogen reduction technology (PRT) system (CaridianBCT Biotechnologies) to inactivate live virus in contaminated plasma and platelet (PLT) samples. Plasma, PLTs, and phosphate-buffered saline controls were spiked with CHIKV and treated with riboflavin and varying doses of ultraviolet (UV) light using the Mirasol PRT system. Samples were tested before and after treatment for cytotoxicity, interference, and virus titer by titration and quantitative real-time reverse transcription-polymerase chain reaction. A significant reduction in CHIKV titer of greater than 99% was recorded after treatment of plasma or PLTs with the Mirasol PRT system, and the titer reduction was directly proportional to the UV dose delivered to the samples. No cytotoxicity of interference was observed in any sample at any treatment dose. These data indicate that the Mirasol PRT system efficiently inactivated live CHIKV in plasma and PLTs and could therefore potentially be used to prevent CHIKV transmission through the blood supply.

Prevention of Alloimmunization and Induction of Partial Tolerance Following Transfusion with Pathogen Reduced Platelets in Mice

Abstract 718 Introduction:The presence of donor white blood cells (WBC) in transfused blood products can induce alloimmunization, and reducing or eliminating this response may prove to be of clinical benefit. The use of a pathogen reduction method based on UV light illumination in the presence of riboflavin has been shown to induce changes in WBCs that result in a failure to bind to, or induce proliferation of allogeneic PBMCs in vitro. In addition, a study in rats has shown a reduction in alloimmunization in vivo using this treatment. Transfusion of cells illuminated with UV light at other doses without riboflavin has been shown to induce some degree of tolerance with a reduced antibody response to subsequent allogeneic transfusions. We sought to assess both the degree of alloimmunization in mice given pathogen reduced versus untreated allogeneic platelets, as well as determine if cells from mice given pathogen reduced platelets exhibited signs of tolerance ex vivo. Methods:Peripheral blood was collected from C57Bl/6 and Balb/cJ mice into CPDA-1, and platelet rich plasma (PRP) was prepared by gentle centrifugation. WBCs were isolated from the remainder of the blood and were added back to a portion of the PRP to generate either WBC-enriched or WBC-poor PRP. These products were either left untreated or pathogen reduced using the Mirasol pathogen reduction technology system, which uses a combination of riboflavin and UV illumination. These products were transfused via tail vein injection into Balb/cJ mice. Two weeks after transfusion the treated mice were sacrificed, and peripheral blood and spleens were collected. Serum levels of circulating alloantibodies were measured by flow cytometry. Splenocytes were cultured for 48 hours in the presence or absence of C57Bl/6 splenocytes, and levels of secreted cytokines were measured in culture supernatants using multiplexing techniques. Groups were compared using one-way ANOVA with Tukey’s multiple comparison post-test, α=0.05. Results:Mice given allogeneic PRP transfusions had significantly elevated levels of alloantibodies compared with non-transfused control mice, whereas mice given syngeneic PRP or pathogen reduced PRP did not. Mice given either the WBC-enriched PRP or WBC-poor PRP generated alloantibodies, though higher levels of antibodies were observed with WBC-enriched PRP. Levels of IFN-γ, TNF-α, IL-10 and GM-CSF were significantly higher following secondary allogeneic challenge of cells from mice given untreated allogeneic PRP compared with those given no transfusion or syngeneic PRP, but not with those given pathogen reduced PRP. Levels of IL-1β, IL-4, IL-5, IL-6, IL-12(p70), and IL-13 were significantly reduced following secondary allogeneic challenge of cells from mice given pathogen reduced allogeneic PRP compared with those given no transfusion or syngeneic PRP. Conclusions:Treatment of allogeneic PRP with riboflavin and UV light prior to transfusion blocks alloimmunization in mice. Furthermore, secondary cytokine responses to allogeneic cells ex vivo are reduced, in some cases bellow the levels observed in cells from mice without prior exposure, suggesting induction of tolerance. Disclosures:Marschner:CaridianBCT Biotechnologies: Employment. Goodrich:CaridianBCT Biotechnologies: Employment. Norris:CaridianBCT Biotechnologies: Consultancy, Research Funding.

Pathogen inactivation

Pathogen inactivation

In vitro quality of single‐donor platelets treated with riboflavin and ultraviolet light and stored in platelet storage medium for up to 8 days

The Mirasol pathogen reduction technology system is known to increase the activation and metabolic rate of platelets (PLTs). Storage of Mirasol PLTs in PLT storage medium (PSM) has the potential to slow this accelerated PLT storage lesion. We investigated the quality of Mirasol-treated PLTs stored in either 50% SSP+ or 50% Composol for 8 days. Single-donor double hyperconcentrates were divided between control and Mirasol-treated arms and after treatment were suspended in approximately 50% (vol/vol) SSP+ (n = 8) or Composol (n = 7). In vitro markers of PLT activation and/or apoptosis were measured over an 8-day storage period. Mirasol treatment resulted in increased spontaneous PLT activation and glycolysis and these effects were worsened when PLTs were treated below a certain volume (150 mL). At higher treatment volumes there were no significant differences between treated units stored in either Composol or SSP+. When low-volume units were stored in Composol the median pH fell below 6.4 on Day 5 and bicarbonate was undetectable, whereas in SSP+ the median pH value was greater than 6.9 and bicarbonate remained at detectable levels, despite other markers of in vitro function being similar to those of Composol. Mirasol treatment of PLTs followed by storage in PSM results in increased PLT activation and metabolism to a level similar to that reported for PLTs treated and stored in plasma. Units treated at a low volume (<150 mL) showed poor in vitro quality.

Cesium cessation? An advantage of pathogen reduction treatments

Cesium cessation? An advantage of pathogen reduction treatments

Protein stability of previously frozen plasma, riboflavin and UV light-treated, refrozen and stored for up to 2 years at −30 °C

Background The Mirasol pathogen reduction technology system for plasma is based on a riboflavin and UV light treatment process resulting in pathogen inactivation due to irreversible, photochemically induced damage of nucleic acids. The objective of this study was to evaluate the in vitro protein quality of previously frozen FFP, thawed, Mirasol-treated and refrozen for a final storage period of up to 2 years at −30 °C. Materials and methods All plasma products were held at 4 ± 2 °C, and frozen within 8 h after the start of collection. FFP was stored frozen at −30 °C for eight time intervals before riboflavin and UV light treatment and refrozen to −30 °C and stored for varying time intervals for a total storage period of up to 2 years at −30 °C. Results were compared to paired, untreated units thawed and stored for the same time intervals. Results The overall mean values for all time points in riboflavin and UV light treated plasma samples indicates that all proteins were well preserved following a period of frozen storage for 2 years at −30 °C. Factors V, VII and XI, retained 70%, 65% and 53% activity, respectively. All other protein factors, anticoagulant and inhibitor proteins demonstrated retention between 74% and 100%. Conclusion Riboflavin and UV light-treated FFP maintained both coagulant and anticoagulant in vitro protein quality after double freeze/thaw storage at −30 °C for up to 2 years, a finding that may offer processing flexibility to blood centers.