Fatal sepsis associated with a storage container leak permitting platelet contamination with environmental bacteria after pathogen reduction.

BACKGROUND: Pathogen reduction technology and enhanced bacterial culture screening promise to significantly reduce the risk of transfusion-associated septic reactions due to contaminated platelets. Recent reports suggest that these interventions lack efficacy for post-collection and processing contamination with environmental organisms if the storage bag integrity is compromised. CASE REPORT: We report a fatal septic transfusion reaction in a 63-year-old patient with chronic kidney and liver disease who received a pathogen reduced platelet transfusion in anticipation of surgery. METHODS: The residual platelet concentrate was cultured, with the detected microorganisms undergoing 16S genotype sequencing. Separate pathogen reduction studies were performed on the recovered bacteria, including assessment for amotosalen photoproducts. The storage container was subjected to pressure testing and microscopic examination. Environmental culture screening was performed at the hospital. RESULTS: Gram negative rods were detected in the platelet unit and cultures of both platelet component and the patient's blood grew Acinetobacter baumannii complex, Leclercia adecarboxylata and Staphylococcus saprophyticus. These strains were effectively inactivated with >7.2, 7.7, and >7.1 log10 kill, respectively. The platelet storage container revealed a leak visible only on pressure testing. Hospital environmental cultures were negative and the contamination source is unknown. A. baumannii complex and S. saprophyticus 16S genotyping sequences were identical to those implicated in a previously reported septic reaction. CONCLUSION: Findings are compatible with post-processing environmental contamination of a pathogen reduced platelet concentrate via a non-visible, acquired storage container leak. Efforts are warranted to actively prevent damage to, and detect defects in, platelet storage containers, and to store and transport components in clean environments.

Effects of Intercept pathogen reduction treatment on extended cold storage of apheresis platelets.

BACKGROUND: Platelets pose the greatest transfusion-transmitted infectious risk among blood products. Refrigeration of platelets can mitigate bacterial contamination and extend platelet shelf life. Implementation of pathogen reduction technologies (PRTs) at blood banks has become increasingly popular to protect against emerging and reemerging infectious diseases. In this study, we sought to evaluate the effects of Intercept PRT on platelets collected on different platforms and cold-stored for up to 21 days in plasma and platelet additive solution (PAS). METHODS: Double-dose apheresis platelets were collected with use of a Trima or Amicus system into either 100% plasma or 65% InterSol PAS/35% plasma and split equally between two bags. One bag served as control, while the other received Intercept PRT treatment. Bags were stored unagitated in the cold and evaluated on Days 1, 7, 14, and 21 to assess platelet metabolism, activation, aggregation, and clot formation and retraction. RESULTS: By Day 14 of storage, lactate levels reached approximately 13 mmol/L for all samples irrespective of Intercept treatment. Mean clot firmness dropped from the 62.2- to 67.5-mm range (Day 1) to the 28.4- to 51.3-mm range (Day 21), with no differences observed between groups. Clot weights of Intercept-treated Trima/plasma samples were significantly higher than control by Day 14 of storage (P = .004), indicating a reduced clot retraction function. Intercept treatment caused a higher incidence of plasma membrane breakdown in plasma-stored platelets (P = .0013; Trima/plasma Day 14 Control vs Intercept). CONCLUSIONS: Intercept treatment of platelets and subsequent cold storage, in plasma or PAS, results in comparable platelet metabolism platelets for up to 14 days of storage but altered clotting dynamics. Pathogen-reduced platelets with an extended shelf life would be beneficial for the deployed setting and would greatly impact transfusion practice among civilian transfusion centers.

The effect of pathogen inactivation on cryoprecipitate: a functional and quantitative evaluation.

BACKGROUND: As a pooled donor blood product, cryoprecipitate (cryo) carries risks of pathogen transmission. Pathogen inactivation (PI) improves the safety of cryoprecipitate, but its effects on haemostatic properties remain unclear. This study investigated protein expression in samples of pathogen inactivated cryoprecipitate (PI-cryo) using non-targeted quantitative proteomics and in vitro haemostatic capacity of PI-cryo. MATERIALS AND METHODS: Whole blood (WB)- and apheresis (APH)-derived plasma was subject to PI with INTERCEPT® Blood System (Cerus Corporation, Concord, CA, USA) and cryo was prepared from treated plasma. Protein levels in PI-cryo and paired controls were quantified using liquid chromatography-tandem mass spectrometry. Functional haemostatic properties of PI-cryo were assessed using a microparticle (MP) prothrombinase assay, thrombin generation assay, and an in vitro coagulopathy model subjected to thromboelastometry. RESULTS: Over 300 proteins were quantified across paired PI-cryo and controls. PI did not alter the expression of coagulation factors, but levels of platelet-derived proteins and platelet-derived MPs were markedly lower in the WB PI-cryo group. Compared to controls, WB (but not APH) cryo samples demonstrated significantly lower MP prothrombinase activity, prolonged clotting time, and lower clot firmness on thromboelastometry after PI. However, PI did not affect overall thrombin generation variables in either group. DISCUSSION: Data from this study suggest that PI via INTERCEPT® Blood System does not significantly impact the coagulation factor content or function of cryo but reduces the higher MP content in WB-derived cryo. PI-cryo products may confer benefits in reducing pathogen transmission without affecting haemostatic function, but further in vivo assessment is warranted.

Inactivation of severe acute respiratory syndrome coronavirus 2 in plasma and platelet products using a riboflavin and ultraviolet light-based photochemical treatment.

BACKGROUND AND OBJECTIVE: Severe acute respiratory distress syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is a member of the coronavirus family. Coronavirus infections in humans are typically associated with respiratory illnesses; however, viral RNA has been isolated in serum from infected patients. Coronaviruses have been identified as a potential low-risk threat to blood safety. The Mirasol Pathogen Reduction Technology (PRT) System utilizes 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 the pandemic virus SARS-CoV-2 when tested in both plasma and platelets units. MATERIALS AND METHODS: Stock SARS-CoV-2 was grown in Vero cells and inoculated into either plasma or platelet units. Those units were then treated with riboflavin and UV light. The infectious titres of SARS-CoV-2 were determined by plaque assay using Vero cells. A total of five (n = 5) plasma and three (n = 3) platelet products were evaluated in this study. RESULTS: In both experiments, the measured titre of SARS-CoV-2 was below the limit of detection following treatment with riboflavin and UV light. The mean log reductions in the viral titres were ≥3·40 and ≥4·53 for the plasma units and platelet units, respectively. CONCLUSION: Riboflavin and UV light effectively reduced the titre of SARS-CoV-2 in both plasma and platelet products to below the limit of detection in tissue culture. The data suggest that the process would be effective in reducing the theoretical risk of transfusion transmitted SARS-CoV-2.

Towards the understanding of the UV light, riboflavin and additive solution contributions to the in vitro lesions observed in Mirasol®-treated platelets.

OBJECTIVES: Pathogen reduction technologies are implemented to increase the safety of blood products. We previously showed that the UVB alone significantly contributes to the storage lesions observed in platelets treated with riboflavin/UVB using a home-made illuminator. The present study aims at confirming these observations using the commercial Mirasol® technology. METHODS: A three-arm study (untreated, UV-, Mirasol®-treated platelets) was conducted to investigate the platelet storage lesions throughout storage (n=4). A two-arm study was then designed to compare Intersol and T-PAS+ additive solutions (n=3). Phenotype and functional platelet characteristics were assessed using flow cytometry, aggregometry, antioxidant assays and metabolic parameters. RESULTS: Mirasol®-treated platelets exhibit enhanced storage lesions compared to controls (increase of activation markers and glycolysis rate, lower hypotonic shock and double-agonist activation responses, and decrease of total antioxidant capacity). Here, we also confirmed that the UV radiation alone is causing platelet lesions. Riboflavin tends to have an intracellular protective role while it decreases the extracellular antioxidant defenses. Furthermore, benefits of platelet additive solutions containing potassium and magnesium were confirmed as it reduces the extent of storage lesions. CONCLUSIONS: The photosensitizer, UV illumination and composition of the platelet additive solutions are key parameters influencing the platelet storage lesion. The clinical relevance of these findings is not fully understood and recent published clinical studies could not show increase in bleeding in patients receiving Mirasol-treated platelets. New developments in storage solutions might help to improve storage conditions of PRT-treated platelets and should be prioritised as research subject in the future.

Photodynamic inactivation for in vitro decontamination of Staphylococcus aureus in whole blood.

BACKGROUND: Blood can be the target of microbial cells in the human body. Erythrocytes, platelets, and plasma concentrates in blood bags used in hemotherapy for blood transfusion are contamination targets, which can trigger serious diseases in blood. These infections can cause septicemia that can lead to death if not recognized rapidly and treated adequately. The aim of this study was to evaluate the photodynamic inactivation in the in vitro decontamination of Staphylococcus aureus in whole blood, erythrocytes and platelet-rich plasma. METHODS: Photodynamic inactivation using light doses of 10, 15 and 30 J/cm2 at 630 nm and an hematoporphyrin-derivative photosensitizer (Photogem®) solutions at 25 and 50 µg/mL were evaluated. Toxicity of treatment was determined by hemolysis and cell viability assays. RESULTS: The S. aureus reduction in phosphate buffered saline (PBS), whole blood, erythrocytes and platelet-rich plasma at 15 J/cm2 and 50 µg/mL were 7.2, 1.0, 1.3 and 0.4 log CFU/mL, respectively. Quantitative and qualitative analyses were performed in whole blood samples, and Photogem® showed a low risk of hemolysis (10.7%) in whole blood. However, 100% of erythrocytes suffered hemolysis in the absence of plasma. The cell viability assay showed 13.9% of apoptosis in erythrocytes, but normal platelet viability. CONCLUSION: S. aureus inactivation of whole blood samples using 50 µg/mL Photogem® and 15 J/cm2 resulted in better outcomes, providing promising indications for treatment of bacterial contamination of blood, and in this work, alternative possibilities to apply the technique for blood decontamination are discussed.

Amotosalen-inactivated plasma is as equally well tolerated as quarantine plasma in patients undergoing large volume therapeutic plasma exchange.

A retrospective - single center - survey compared tolerance of individual donor therapeutic plasma in a series of 88 patients principally presenting with thrombotic microangiopathy; all patients underwent therapeutic plasma exchange (TPE) performed with more than 90% of either of two types of plasma preparations. One plasma type used in TPE was prepared with pathogen reduction by amotosalen addition and UVA illumination, and the other one was non-manipulated (quarantine plasma). Both types of plasma were single donor. Occurrences of adverse reactions were equally low in either arm (amotosalen: 9 in 4689 bags of ∼200mL [0.019] versus quarantine: 2 in 828 bags [0.024]), confirming the safe use of amotosalen inactivated therapeutic plasma for TPE.

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

BACKGROUND: Middle 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 METHODS: MERS-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). RESULTS: In 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. CONCLUSION: Riboflavin 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.

Riboflavin-ultraviolet light pathogen reduction treatment does not impact the immunogenicity of murine red blood cells.

BACKGROUND: Ultraviolet (UV) illumination/pathogen reduction effectively inactivates white blood cells (WBCs) in whole blood. Given that cotransfused WBCs may impact recipient immune responses, we hypothesized that pathogen reduction of whole blood may alter responses to RBC antigens. STUDY DESIGN AND METHODS: Transgenic mice expressing a model (HOD) antigen, authentic human (hGPA or KEL) antigens, or natural fluorescence (uGFP) on their RBCs were utilized as blood donors. Recipients were transfused with fresh whole blood to which riboflavin had been added or fresh whole blood treated by UV illumination/pathogen reduction treatment after the addition of riboflavin. Posttransfusion RBC recovery, survival, and alloimmunization were measured by flow cytometry. RESULTS: UV illumination/pathogen reduction treatment did not alter RBC antigen expression, and recipients of treated syngeneic RBCs had persistently negative direct antiglobulin tests. Greater than 75% of treated and untreated syngeneic RBCs were recovered 24 hours posttransfusion in all experiments, although alterations in the long-term posttransfusion survival of treated RBCs were observed. Treated and untreated KEL RBCs induced similar recipient alloimmune responses, with all recipients making anti-KEL glycoprotein immunoglobulins (p > 0.05). Alloimmune responses to treated HOD or hGPA RBCs were no different from untreated RBCs (p > 0.05). CONCLUSION: Pathogen inactivation treatment of fresh whole murine blood with riboflavin and UV illumination does not impact the rate or magnitude of RBC alloimmunization to three distinct RBC antigens. Further, UV illumination/pathogen reduction appears safe from an immunohematologic standpoint, with no immunogenic neoantigens detected on treated murine RBCs. Future studies with fresh and stored human RBCs are warranted to confirm these findings.

Whole blood treated with riboflavin and ultraviolet light: quality assessment of all blood components produced by the buffy coat method.

BACKGROUND: Pathogen inactivation (PI) technologies are currently licensed for use with platelet (PLT) and plasma components. Treatment of whole blood (WB) would be of benefit to the blood banking community by saving time and costs compared to individual component treatment. However, no paired, pool-and-split study directly assessing the impact of WB PI on the subsequently produced components has yet been reported. STUDY DESIGN AND METHODS: In a "pool-and-split" study, WB either was treated with riboflavin and ultraviolet (UV) light or was kept untreated as control. The buffy coat (BC) method produced plasma, PLT, and red blood cell (RBC) components. PLT units arising from the untreated WB study arm were treated with riboflavin and UV light on day of production and compared to PLT concentrates (PCs) produced from the treated WB units. A panel of common in vitro variables for the three types of components was used to monitor quality throughout their respective storage periods. RESULTS: PCs derived from the WB PI treatment were of significantly better quality than treated PLT components for most variables. RBCs produced from the WB treatment deteriorated earlier during storage than untreated units. Plasma components showed a 3% to 44% loss in activity for several clotting factors. CONCLUSION: Treatment of WB with riboflavin and UV before production of components by the BC method shows a negative impact on all three blood components. PLT units produced from PI-treated WB exhibited less damage compared to PLT component treatment.

The effect of riboflavin and ultraviolet light on the infectivity of arboviruses.

BACKGROUND: Arboviruses are an emerging threat to transfusion safety and rates of infection are likely to increase with the increased rainfall associated with climate change. Arboviral infections are common in Australia, where Ross River virus (RRV), Barmah Forest virus (BFV), and Murray Valley encephalitis virus (MVEV), among others, have the potential to cause disease in humans. The use of pathogen reduction technology (PRT) may be an alternative approach for blood services to manage the risk of arboviral transfusion transmission. In this study, the effectiveness of the Mirasol PRT (Terumo BCT) system at inactivating RRV, BFV, and MVEV in buffy coat (BC)-derived platelets (PLTs) was investigated. STUDY DESIGN AND METHODS: BC-derived PLT concentrates in additive solution (SSP+) were spiked with RRV, BFV, or MVEV and then treated with the Mirasol PRT system. The level of infectious virus was determined before and after treatment, and the reduction in viral infectivity was calculated. RESULTS: Treatment with PRT (Mirasol) reduced the amount of infectious virus of all three arboviruses. The greatest level of inactivation was observed for RRV (2.33 log; 99.25%), followed by BFV (1.97 log; 98.68%) and then MVEV (1.83 log; 98.42%). CONCLUSION: Our study demonstrates that treatment of PLT concentrates with PRT (Mirasol) reduces the infectious levels of RRV, BFV, and MVEV. The relevance of the level of reduction required to prevent disease transmission by transfusion has not been fully defined and requires further investigation. In the face of a changing climate, with its associated threat to blood safety, PRT represents a proactive approach for maintaining blood safety.

Riboflavin and ultraviolet light for pathogen reduction of murine cytomegalovirus in blood products.

BACKGROUND: Two studies were performed to test the effectiveness of riboflavin and ultraviolet (UV) light treatment (Mirasol PRT, Terumo BCT) against murine cytomegalovirus (MCMV). The first study utilized immune-compromised mice to measure the reduction of cell-free MCMV. A second study used a murine model to evaluate the ability of Mirasol PRT to prevent transfusion-transmitted (TT)-MCMV infection. STUDY DESIGN AND METHODS: Human plasma was inoculated with MCMV and then treated with Mirasol PRT. The viral titer was measured using an infectious dose 50% assay in nude mice. Mice were euthanized on Day 10 posttransfusion, and their spleens were tested for the presence of MCMV DNA using polymerase chain reaction (PCR). Mirasol PRT was also evaluated to determine its effectiveness in preventing TT-MCMV in platelets (PLTs) stored in PLT additive solution. PLTs were inoculated with either cell-associated MCMV or cell-free MCMV and then treated with Mirasol PRT. Mice were transfused with treated or untreated product and were euthanized 14 days posttransfusion. Blood and spleens were assayed for MCMV DNA by real-time-PCR. RESULTS: Using nude mice to titer MCMV, a modest 2.1-log reduction was observed in plasma products after Mirasol PRT treatment. TT-MCMV was not observed in the mouse transfusion model when either cell-free or cell-associated MCMV was treated with Mirasol PRT; MCMV transmission was uniformly observed in mice transfused with untreated PLTs. CONCLUSIONS: These results suggest that using riboflavin and UV light treatment may be able to reduce the occurrence of transmission of human CMV from infectious PLTs and plasma units.

The effectiveness of riboflavin photochemical-mediated virus inactivation and changes in protein retention in fresh-frozen plasma treated using a flow-based treatment device.

BACKGROUND: A flow-based treatment device using riboflavin and ultraviolet (UV) light was developed to inactivate viruses in fresh-frozen plasma (FFP). The objective of this study was to evaluate the in vitro effectiveness of virus inactivation and changes in protein quality in FFP treated with this device. STUDY DESIGN AND METHODS: FFP-contaminating viruses were treated with riboflavin and UV light using a one-pass linear flow device. The infectivity of viruses was measured using established biologic assays. Real-time polymerase chain reaction (PCR) was performed to detect damage to viral nucleotides after treatment. Treated plasma was analyzed using standard coagulation assays. RESULTS: FFP treated at the UV dose of 3.6 J/cm(2) (J) exhibited a mean reduction of virus titer of more than 4 logs. The effectiveness increased significantly at higher doses. Real-time PCR showed that the cycle threshold values for both complete inactivation and virus recultivation were higher than that of the untreated sample. At doses of 3.6, 5.4, and 7.2 J, the protein recovery rates were 60.2 ± 8.6, 46.6 ± 9.4, and 28.0 ± 1.0% for fibrinogen; 67.0 ± 3.1, 57.3 ± 8.0, and 49.2 ± 3.8% for Factor VIII; 93.6 ± 2.8, 89.6 ± 6.1, and 86.5 ± 5.3% for antithrombin-III; and 72.1 ± 5.6, 59.8 ± 14.2, and 49.2 ± 8.4% for Protein C, respectively. CONCLUSION: The effectiveness of virus inactivation was enhanced, but total activity of plasma factors was reduced, in a UV dose-dependent manner.

In vitro function of platelets treated with ultraviolet C light for pathogen inactivation: a comparative study with nonirradiated and gamma-irradiated platelets.

BACKGROUND: During storage of platelet concentrates (PCs) replication of contaminating pathogens might occur, which can be prevented by various pathogen inactivation (PI) methods using photoactive substances in combination with ultraviolet (UV) light. A new method uses only UVC light for PI without photoactive substances. This study evaluates the in vitro function, including hemostatic properties (clot formation and elasticity), of platelets (PLTs) treated with UVC light. STUDY DESIGN AND METHODS: A PC with 35% plasma and 65% PLT additive solution (SSP+) was prepared from five buffy coats. Three PCs were pooled and divided into 3 units. One unit was used as a nonirradiated control, the second was a gamma-irradiated control, and the third unit was treated with UVC light. In vitro variables including analysis of coagulation by free oscillation rheometry were analyzed on Days 1, 5, and 7 of storage. Ten units in each group were investigated. RESULTS: Swirling was well preserved, and the pH level was higher than the reference limit (6.4) during storage of PLTs in all groups. Glycolysis and PLT activation were higher for UVC-treated PLTs but the clot-forming capacity was unaffected. However, immediately after UVC treatment, the clot elastic properties were slightly affected. Hypotonic shock response decreased immediately after UVC treatment but recovered partly during the storage period. CONCLUSION: UVC treatment affected the in vitro properties, but PLT quality and storage stability were well preserved for up to 7 days, and the in vitro hemostatic capacity of UVC-treated PLTs was only minimally altered. The clinical relevance of these changes needs to be evaluated in controlled trials.

Pathogen reduction in human plasma using an ultrashort pulsed laser.

Pathogen reduction is a viable approach to ensure the continued safety of the blood supply against emerging pathogens. However, the currently licensed pathogen reduction techniques are ineffective against non-enveloped viruses such as hepatitis A virus, and they introduce chemicals with concerns of side effects which prevent their widespread use. In this report, we demonstrate the inactivation of both enveloped and non-enveloped viruses in human plasma using a novel chemical-free method, a visible ultrashort pulsed laser. We found that laser treatment resulted in 2-log, 1-log, and 3-log reductions in human immunodeficiency virus, hepatitis A virus, and murine cytomegalovirus in human plasma, respectively. Laser-treated plasma showed ≥70% retention for most coagulation factors tested. Furthermore, laser treatment did not alter the structure of a model coagulation factor, fibrinogen. Ultrashort pulsed lasers are a promising new method for chemical-free, broad-spectrum pathogen reduction in human plasma.

Development of a mitochondrial DNA real-time polymerase chain reaction assay for quality control of pathogen reduction with riboflavin and ultraviolet light.

BACKGROUND AND OBJECTIVES: Transfusion is associated with a risk of infection and alloimmunization. Pathogen reduction using riboflavin and UV light (Mirasol treatment) inactivates pathogens and leucocytes. With increasing adoption of the technology in clinical use, regulatory agencies have recommended the introduction of quality control measures to monitor pathogen reduction efficacy. We sought to develop a real-time PCR-based assay to document the impact of pathogen reduction on the mitochondrial genome in blood components. MATERIALS AND METHODS: DNA was extracted from platelet and plasma components before and after treatment with riboflavin and UV light. Inhibition of PCR amplification of mitochondrial DNA (mtDNA) in short- and long-amplicon target regions, ranging from under 200 base pairs (bp) to over 1800 bp, was measured in treated relative to untreated components. RESULTS: Pathogen reduction of platelets using riboflavin and UV light resulted in inhibition of PCR amplification of long-amplicon mtDNA targets, demonstrating approximately 1 log reduction of amplification relative to untreated products. Amplification of short-amplicon mtDNA targets was not affected by treatment. Evaluation of 110 blinded platelet samples from the PREPAReS clinical trial resulted in prediction of treatment status with 100% accuracy. Pathogen reduction of plasma components resulted in similar levels of PCR inhibition, while testing of 30 blinded plasma samples resulted in prediction of treatment status with 93% accuracy. CONCLUSION: A differential sized amplicon real-time PCR assay of mitochondrial DNA effectively documents nucleic acid damage induced by Mirasol treatment of platelets. The use of the assay for plasma product pathogen reduction requires further investigation.

Implementation and public acceptability: lessons from food irradiation and how they might apply to pathogen reduction in blood products.

BACKGROUND AND OBJECTIVES: The issues around food irradiation (FI) have both similarities and differences to pathogen reduction (PR) in blood products. We performed a systematic search of the FI literature to identify lessons that could help to inform the implementation of pathogen reduction technology for blood products. METHODS: A comprehensive literature search was performed in EMBASE. MEDLINE, PSYCHINFO, CINAL and Physiological Abstracts for articles related to FI that met predefined eligibility criteria. A coding scheme was developed by the investigators, and relevant information from the articles was coded using NVivo 9. Reports for each code were generated and summarized. RESULTS: One thousand two hundred and sixty-six articles were identified by the broad search, and 50 met the study eligibility criteria for inclusion. The implementation of FI was slow and has been met by significant controversy, sparked by concerns from the public and social groups about the acceptability of irradiated food. Numerous factors influenced public acceptability including: demographic factors; perceptions of safety and risk; endorsement of and trust in the FI industry and social institutions that serve as opinion leaders; knowledge and the provision of scientific information including benefits and cost; and the availability of choice. CONCLUSION: There are a number of lessons from the FI literature that may be generalizable to the implementation of PR of blood products. Based on findings from this study, six recommendations are made to facilitate public implementation of this new technology.

Oxygen removal during pathogen inactivation with riboflavin and UV light preserves protein function in plasma for transfusion.

BACKGROUND AND OBJECTIVE: Photochemical pathogen inactivation technologies (PCT) for individual transfusion products act by inhibition of replication through irreversibly damaging nucleic acids. Concern on the collateral impact of PCT on the blood component's integrity has caused reluctance to introduce this technology in routine practice. This work aims to uncover the mechanism of damage to plasma constituents by riboflavin pathogen reduction technology (RF-PRT). METHODS: Activity and antigen of plasma components were determined following RF-PRT in the presence or absence of dissolved molecular oxygen. RESULTS: Employing ADAMTS13 as a sentinel molecule in plasma, our data show that its activity and antigen are reduced by 23 ± 8% and 29 ± 9% (n = 24), respectively, which corroborates with a mean decrease of 25% observed for other coagulation factors. Western blotting of ADAMTS13 shows decreased molecular integrity, with no obvious indication of additional proteolysis nor is riboflavin able to directly inhibit the enzyme. However, physical removal of dissolved oxygen prior to RF-PRT protects ADAMTS13 as well as FVIII and fibrinogen from damage, indicating a direct role for reactive oxygen species. Redox dye measurements indicate that superoxide anions are specifically generated during RF-PRT. Protein carbonyl content as a marker of disseminated irreversible biomolecular damage was significantly increased (3·1 ± 0·8 vs. 1·6 ± 0·5 nmol/mg protein) following RF-PRT, but not in the absence of dissolved molecular oxygen (1·8 ± 0·4 nmol/mg). CONCLUSIONS: RF-PRT of single plasma units generates reactive oxygen species that adversely affect biomolecular integrity of relevant plasma constituents, a side-effect, which can be bypassed by applying hypoxic conditions during the pathogen inactivation process.

Human platelets pathogen reduced with riboflavin and ultraviolet light do not cause acute lung injury in a two-event SCID mouse model.

BACKGROUND: Pathogen reduction technologies (PRTs) can induce platelet (PLT) lesions that reduce PLT survival and recovery from circulation and may be associated with acute lung injury (ALI). STUDY DESIGN AND METHODS: Human PLTs (hPLTs) in plasma with or without single or multiple Mirasol PRT treatments were assessed in vitro by aggregation and percentage of P-selectin expression. In vivo studies included PLT recovery in SCID mice and assessment of ALI in a two-event mouse model in which the sensitizing event was lipopolysaccharide injection and the second event was infusion of Mirasol-treated hPLTs. RESULTS: A single-dose Mirasol treatment (5 J/cm(2) ) did not induce any change in aggregation in response to adenosine 5'-diphosphate (ADP) while a five-times-repeat Mirasol treatment (5×) increased aggregation response to low concentration of ADP. Mirasol PLTs (1×-5×) had increased percentage of P-selectin-positive PLTs after treatment and decreased aggregation with TRAP as the agonist. In vivo recovery in SCID mice was reduced extensively with Mirasol treatments (1× and 5×). In the two-event model of ALI, only the 5× Mirasol PLTs accumulated in the lung and this was not accompanied by changes in lung histology or increases in MIP-2 levels in bronchoalveolar lavage fluid. CONCLUSIONS: Mirasol PRT treatment induced PLT activation and reduced in vivo recovery in a SCID mouse model of transfusion. In our two-event mouse model of ALI, the 5× Mirasol hPLTs accumulated in the lung, but did not cause signs of ALI. The 1× Mirasol treatment did not lead to PLT lung accumulation or ALI in this model.