Inactivation of SARS-CoV-2 infectivity in platelet concentrates or plasma following treatment with ultraviolet C light or with methylene blue combined with visible light.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unlikely to be a major transfusion-transmitted pathogen; however, convalescent plasma is a treatment option used in some regions. The risk of transfusion-transmitted infections can be minimized by implementing Pathogen Inactivation (PI), such as THERAFLEX MB-plasma and THERAFLEX UV-Platelets systems. Here we examined the capability of these PI systems to inactivate SARS-CoV-2. STUDY DESIGN AND METHODS: SARS-CoV-2 spiked plasma units were treated using the THERAFLEX MB-Plasma system in the presence of methylene blue (~0.8 µmol/L; visible light doses: 20, 40, 60, and 120 [standard] J/cm2 ). SARS-CoV-2 spiked platelet concentrates (PCs) were treated using the THERAFLEX UV-platelets system (UVC doses: 0.05, 0.10, 0.15, and 0.20 [standard] J/cm2 ). Samples were taken prior to the first and after each illumination dose, and viral infectivity was assessed using an immunoplaque assay. RESULTS: Treatment of spiked plasma with the THERAFLEX MB-Plasma system resulted in an average ≥5.03 log10 reduction in SARS-CoV-2 infectivity at one third (40 J/cm2 ) of the standard visible light dose. For the platelet concentrates (PCs), treatment with the THERAFLEX UV-Platelets system resulted in an average ≥5.18 log10 reduction in SARS-CoV-2 infectivity at the standard UVC dose (0.2 J/cm2 ). CONCLUSIONS: SARS-CoV-2 infectivity was reduced in plasma and platelets following treatment with the THERAFLEX MB-Plasma and THERAFLEX UV-Platelets systems, to the limit of detection, respectively. These PI technologies could therefore be an effective option to reduce the risk of transfusion-transmitted emerging pathogens.

Migration of di(2-ethylhexyl) phthalate, diisononylcyclohexane-1,2-dicarboxylate and di(2-ethylhexyl) terephthalate from transfusion medical devices in labile blood products: A comparative study.

BACKGROUND AND OBJECTIVES: Polyvinyl chloride (PVC) plasticized with di(2-ethylhexyl) phthalate (DEHP) is a widely used material for medical transfusion devices. Not covalently bound to PVC, DEHP can migrate into blood products during storage. Recognized as an endocrine disruptor and raising concerns about its potential carcinogenicity and reprotoxicity, DEHP is gradually being withdrawn from the medical device market. Therefore, the use of alternative plasticizers, such as diisononylcyclohexane-1,2-dicarboxylate (DINCH) and di(2-ethylhexyl) terephthalate (DEHT), as potential candidates for the replacement of DEHP in medical transfusion devices has been investigated. The purpose of this study was to evaluate the quantity of PVC-plasticizers in the blood components according to their preparation, storage conditions and in function of the plasticizer. MATERIALS AND METHODS: Whole blood was collected, and labile blood products (LBPs) were prepared by the buffy-coat method with a PVC blood bag plasticized either with DEHP, DINCH or DEHT. DINCH and DEHT equivalent concentrations were quantified in LBPs by liquid chromatography-tandem mass spectrometry or coupled with UV and compared to DEHP equivalent concentrations. RESULTS: The plasticizer equivalent concentration to which a patient is exposed during a transfusion depends on the preparation of LBPs as well as their storage conditions, that is, temperature and storage time. At day 1, for all LBPs, the migration of DEHP is 5.0 and 8.5 times greater than DINCH and DEHT, respectively. At the end of the 49 days storage period, the DEHP equivalent concentration in red blood cells concentrate is statistically higher when compared to DINCH and DEHT, with maximal values of 1.85, 1.13 and 0.86 µg/dm2 /mL, respectively. CONCLUSION: In addition to lower toxicity, transfused patients using PVC-DEHT or PVC-DINCH blood bags are less exposed to plasticizers than using PVC-DEHP bags with a ranging exposure reduction from 38.9% to 87.3%, due to lower leachability into blood components.

Cold stored platelets - Increasing understanding and acceptance.

Platelet transfusions decreased the risk of morbidity and mortality secondary to thrombocytopenia. This therapy not only ameliorates platelet loss in bleeding patients,but also those with acquired dysfunction of platelets. The current standard of practice worldwide is to provide room temperature platelets (RTPs); however, there are many disadvantages to the use of RTPs such that alternative approaches have been explored. One potential approach is the integration and use of cold stored platelets (CSP), which are platelets stored at 1-6 °C, in clinical settings. CSP research studies show equivalent hemostasis and platelet dysfunction restoration compared to RTPs. In addition, publications have demonstrated advantages of CSP such as reduced bacterial contamination and wastage. Despite its benefits, the production of CSP by blood centers (BCs) and uptake and use of CSP by hospitals has remained relatively low. This review highlights the rationale for CSP production and strategies for overcoming the implementation challenges faced by BCs based on a literature review.Experiences of Consortium for Blood Availability members to integrate CSP in their BCs and clinical practices by providing variance applications are reviewed in this paper. Also, demonstrated in this manuscript are the current indications and opportunities for CSP utilization by healthcare providers.

Beyond COVID-19 and lessons learned in the United States.

The COVID-19 pandemic severely tested the resilience of the US blood supply with wild fluctuations in blood donation and utilisation rates as community donation opportunities ebbed and hospitals post-poned elective surgery. Key stakeholders in transfusion services, blood centres, supply chains and manufacturers reviewed their experiences during the SARS-CoV-2 pandemic as well as available literature to describe successes, opportunities for improvement and lessons learned. The blood community found itself in uncharted territory responding to restriction of its access to donors (approximately 20% decrease) and some supplies; environmental adjustments to address staff and donor concerns about coronavirus transmission; and the development of a new product (COVID-19 convalescent plasma [CCP]). In assuring that the needs of the patients were paramount, the donation process was safe, that clinicians had access to CCP, and vendor relationships aligned, the blood banking community relearned its primary focus: improving patient outcomes.

Buffy coat platelets coming to America: Are we ready?

BACKGROUND: Buffy coat (BC) platelets (PLTs) have been used globally for many years. In 2004 Canadian Blood Services (CBS) made the decision to transition from PLT-rich plasma (PRP) to BC PLTs. We reviewed the benefits and manufacture process of BC and the implementation challenges involved. STUDY DESIGN AND METHODS: A literature review was performed in the following areas: BC efficacy, donor population shifts, production and good stewardship of PLTs, logistic considerations with overnight holds, advantages of the overnight hold, the CBS experience, licensure and standards, and changes needed to produce BC PLTs in the United States. The aim was to analyze current practice and identify possible actions for blood centers and hospitals. RESULTS: Implementation of BC would offer an additional source of PLTs to address the growing elderly population and the declining apheresis donor base. Substantial logistic, operational, and financial benefits were seen when CBS transitioned to BC with overnight hold. CONCLUSIONS: Buffy coat blood products are widely used throughout the world. Recent conversion from PRP to BC by CBS showed that conversion can be accomplished with planning, communication, and partnership from all stakeholders. In conclusion, BC PLTs are worth serious consideration in the United States, but regulatory barriers in the United States will need to be addressed.

Non-phthalate plasticizer DEHT preserves adequate blood component quality during storage in PVC blood bags.

BACKGROUND AND OBJECTIVES: Commercial blood bags are predominantly made of polyvinyl chloride (PVC) plasticized with di(2-ethylhexyl) phthalate (DEHP). DEHP is favourable for storage of red blood cells (RBC). Historically, removal of DEHP from blood bags has been linked to unacceptable haemolysis levels. Oncoming regulatory restrictions for DEHP due to toxicity concerns increase the urgency to replace DEHP without compromising RBC quality. Di(2-ethylhexyl) terephthalate (DEHT) is one suggested substitute. The aim of this study was to compare PVC-DEHT to PVC-DEHP blood bags using additive solutions saline-adenine-glucose-mannitol (SAGM) and phosphate-adenine-glucose-guanosine-saline-mannitol (PAGGSM), to determine whether DEHT can maintain acceptable component quality. MATERIALS AND METHODS: RBC concentrates (N = 64), platelet concentrates (N = 16) and fresh frozen plasma (N = 32) were produced from whole blood collected into either DEHT or DEHP plasticized systems. Using a pool-and-split study design, pairs of identical RBC content were created within each plasticizer arm and assigned either SAGM or PAGGSM. Storage effects were assessed weekly for 49 days (RBC), 7 days (platelets) and before/after freezing (plasma). RESULTS: Though haemolysis was slightly higher in DEHT, all study arms remained below half of the European limit 0·8%. K+ was lower in DEHT than in DEHP independent of additive solution. The metabolic parameters were not influenced by choice of plasticizer. Platelet activation/metabolism and plasma content were similarly preserved. CONCLUSION: Our study demonstrates that the plasticizer DEHT provides adequate blood component quality. We propose DEHT as a strong future candidate for replacement of DEHP in blood bags.

Inactivation of Japanese encephalitis virus in plasma by methylene blue combined with visible light and in platelet concentrates by ultraviolet C light.

Japanese encephalitis virus (JEV) is endemic to tropical areas in Asia and the Western Pacific. It can cause fatal encephalitis, although most infected individuals are asymptomatic. JEV is mainly transmitted to humans through the bite of an infected mosquito, but can also be transmitted through blood transfusion. To manage the potential risk of transfusion transmission, pathogen inactivation (PI) technologies, such as THERAFLEX MB-Plasma and THERAFLEX UV-Platelets systems, have been developed. We examined the efficacy of these two PI systems to inactivate JEV. STUDY DESIGN AND METHODS: Japanese encephalitis virus-spiked plasma units were treated using the THERAFLEX MB-Plasma system (visible light doses, 20, 40, 60, and 120 [standard] J/cm2) in the presence of methylene blue at approximately 0.8 µmol/L and spiked platelet concentrates (PCs) were treated using the THERAFLEX UV-Platelets system (UVC doses, 0.05, 0.10, 0.15, and 0.20 [standard] J/cm2). Samples were taken before the first and after each illumination dose and tested for infectivity using an immunoplaque assay. RESULTS: Treatment of plasma with the THERAFLEX MB-Plasma system resulted in an average of 6.59 log reduction in JEV infectivity at one-sixth of the standard visible light dose (20 J/cm2). For PCs, treatment with the THERAFLEX UV-Platelet system resulted in an average of 7.02 log reduction in JEV infectivity at the standard UVC dose (0.20 J/cm2). CONCLUSIONS: The THERAFLEX MB-Plasma and THERAFLEX UV-Platelets systems effectively inactivated JEV in plasma or PCs, and thus these PI technologies could be an effective option to reduce the risk of JEV transfusion transmission.

Inactivation of three emerging viruses - severe acute respiratory syndrome coronavirus, Crimean-Congo haemorrhagic fever virus and Nipah virus - in platelet concentrates by ultraviolet C light and in plasma by methylene blue plus visible light.

BACKGROUND: Emerging viruses like severe acute respiratory syndrome coronavirus (SARS-CoV), Crimean-Congo haemorrhagic fever virus (CCHFV) and Nipah virus (NiV) have been identified to pose a potential threat to transfusion safety. In this study, the ability of the THERAFLEX UV-Platelets and THERAFLEX MB-Plasma pathogen inactivation systems to inactivate these viruses in platelet concentrates and plasma, respectively, was investigated. MATERIALS AND METHODS: Blood products were spiked with SARS-CoV, CCHFV or NiV, and then treated with increasing doses of UVC light (THERAFLEX UV-Platelets) or with methylene blue (MB) plus increasing doses of visible light (MB/light; THERAFLEX MB-Plasma). Samples were taken before and after treatment with each illumination dose and tested for residual infectivity. RESULTS: Treatment with half to three-fourths of the full UVC dose (0·2 J/cm2 ) reduced the infectivity of SARS-CoV (≥3·4 log), CCHFV (≥2·2 log) and NiV (≥4·3 log) to the limit of detection (LOD) in platelet concentrates, and treatment with MB and a fourth of the full light dose (120 J/cm2 ) decreased that of SARS-CoV (≥3·1 log), CCHFV (≥3·2 log) and NiV (≥2·7 log) to the LOD in plasma. CONCLUSION: Our study demonstrates that both THERAFLEX UV-Platelets (UVC) and THERAFLEX MB-Plasma (MB/light) effectively reduce the infectivity of SARS-CoV, CCHFV and NiV in platelet concentrates and plasma, respectively.

Inactivation of yellow fever virus in plasma after treatment with methylene blue and visible light and in platelet concentrates following treatment with ultraviolet C light.

BACKGROUND: Yellow fever virus (YFV) is endemic to tropical and subtropical areas in South America and Africa, and is currently a major public health threat in Brazil. Transfusion transmission of the yellow fever vaccine virus has been demonstrated, which is indicative of the potential for viral transfusion transmission. An approach to manage the potential YFV transfusion transmission risk is the use of pathogen inactivation (PI) technology systems, such as THERAFLEX MB-Plasma and THERAFLEX UV-Platelets (Macopharma). We aimed to investigate the efficacy of these PI technology systems to inactivate YFV in plasma or platelet concentrates (PCs). STUDY DESIGN AND METHODS: YFV spiked plasma units were treated using THERAFLEX MB-Plasma system (visible light doses: 20, 40, 60, and 120 [standard] J/cm2 ) in the presence of methylene blue (approx. 0.8 µmol/L) and spiked PCs were treated using THERAFLEX UV-Platelets system (ultraviolet C doses: 0.05, 0.10, 0.15, and 0.20 [standard] J/cm2 ). Samples were taken before the first and after each illumination dose and tested for residual virus using a modified plaque assay. RESULTS: YFV infectivity was reduced by an average of 4.77 log or greater in plasma treated with the THERAFLEX MB-Plasma system and by 4.8 log or greater in PCs treated with THERAFLEX UV-Platelets system. CONCLUSIONS: Our study suggests the THERAFLEX MB-Plasma and the THERAFLEX UV-Platelets systems can efficiently inactivate YFV in plasma or PCs to a similar degree as that for other arboviruses. Given the reduction levels observed in this study, these PI technology systems could be an effective option for managing YFV transfusion-transmission risk in plasma and PCs.

Inactivation of Ebola virus and Middle East respiratory syndrome coronavirus in platelet concentrates and plasma by ultraviolet C light and methylene blue plus visible light, respectively.

BACKGROUND: Ebola virus (EBOV) and Middle East respiratory syndrome coronavirus (MERS-CoV) have been identified as potential threats to blood safety. This study investigated the efficacy of the THERAFLEX UV-Platelets and THERAFLEX MB-Plasma pathogen inactivation systems to inactivate EBOV and MERS-CoV in platelet concentrates (PCs) and plasma, respectively. STUDY DESIGN AND METHODS: PCs and plasma were spiked with high titers of cell culture-derived EBOV and MERS-CoV, treated with various light doses of ultraviolet C (UVC; THERAFLEX UV-Platelets) or methylene blue (MB) plus visible light (MB/light; THERAFLEX MB-Plasma), and assessed for residual viral infectivity. RESULTS: UVC reduced EBOV (≥4.5 log) and MERS-CoV (≥3.7 log) infectivity in PCs to the limit of detection, and MB/light decreased EBOV (≥4.6 log) and MERS-CoV (≥3.3 log) titers in plasma to nondetectable levels. CONCLUSIONS: Both THERAFLEX UV-Platelets (UVC) and THERAFLEX MB-Plasma (MB/light) effectively reduce EBOV and MERS-CoV infectivity in platelets and plasma, respectively.

Reduction of Zika virus infectivity in platelet concentrates after treatment with ultraviolet C light and in plasma after treatment with methylene blue and visible light.

BACKGROUND: Zika virus (ZIKV) has emerged as a potential threat to transfusion safety worldwide. Pathogen inactivation is one approach to manage this risk. In this study, the efficacy of the THERAFLEX UV-Platelets system and THERAFLEX MB-Plasma system to inactivate ZIKV in platelet concentrates (PCs) and plasma was investigated. STUDY DESIGN AND METHODS: PCs spiked with ZIKV were treated with the THERAFLEX UV-Platelets system at 0.05, 0.10, 0.15, and 0.20 J/cm2 UVC. Plasma spiked with ZIKV was treated with the THERAFLEX MB-Plasma system at 20, 40, 60, and 120 J/cm2 light at 630 nm with at least 0.8 µmol/L methylene blue (MB). Samples were taken before the first and after each illumination dose and tested for residual virus. For each system the level of viral reduction was determined. RESULTS: Treatment of PCs with THERAFLEX UV-Platelets system resulted in a mean of 5 log reduction in ZIKV infectivity at the standard UVC dose (0.20 J/cm2 ), with dose dependency observed with increasing UVC dose. For plasma treated with MB and visible light, ZIKV infectivity was reduced by a mean of at least 5.68 log, with residual viral infectivity reaching the detection limit of the assay at 40 J/cm2 (one-third the standard dose). CONCLUSIONS: Our study demonstrates that the THERAFLEX UV-Platelets system and THERAFLEX MB-Plasma system can reduce ZIKV infectivity in PCs and pooled plasma to the detection limit of the assays used. These findings suggest both systems have the capacity to be an effective option to manage potential ZIKV transfusion transmission risk.

Dengue and chikungunya viruses in plasma are effectively inactivated after treatment with methylene blue and visible light.

BACKGROUND: Arboviruses, such as dengue viruses (DENV) and chikungunya virus (CHIKV), pose a risk to the safe transfusion of blood components, including plasma. Pathogen inactivation is an approach to manage this transfusion transmission risk, with a number of techniques being used worldwide for the treatment of plasma. In this study, the efficacy of the THERAFLEX MB-Plasma system to inactivate all DENV serotypes (DENV-1, DENV-2, DENV-3, DENV-4) or CHIKV in plasma, using methylene blue and light illumination at 630 nm, was investigated. STUDY DESIGN AND METHODS: Pooled plasma units were spiked with DENV-1, DENV-2, DENV-3 DENV-4, or CHIKV and treated with the THERAFLEX MB-Plasma system at four light illumination doses: 20, 40, 60, and 120 (standard dose) J/cm(2) . Pre- and posttreatment samples were collected and viral infectivity was determined. The reduction in viral infectivity was calculated for each dose. RESULTS: Treatment of plasma with the THERAFLEX MB-Plasma system resulted in at least a 4.46-log reduction in all DENV serotypes and CHIKV infectious virus. The residual infectivity for each was at the detection limit of the assay used at 60 J/cm(2) , with dose dependency also observed. CONCLUSIONS: Our study demonstrated the THERAFLEX MB-Plasma system can reduce the infectivity of all DENV serotypes and CHIKV spiked into plasma to the detection limit of the assay used at half of the standard illumination dose. This suggests this system has the capacity to be an effective option for managing the risk of DENV or CHIKV transfusion transmission in plasma.

Main Properties of the THERAFLEX MB-Plasma System for Pathogen Reduction.

Methylene blue (MB) treated plasma has been in clinical use for 18 years. The current THERAFLEX MB-Plasma has a number of improved features compared with the original Springe methodology. This overview embodies: the biochemical characteristics of MB, the mechanism of the technology, toxicology, pathogen reduction capacity, current position in clinical setting and status within Europe. The THERAFLEX MB (TMB) procedure is a robust, well standardised system lending itself to transfusion setting and meets the current guidelines. The pathogen kill power of the TMB system, like the other available technologies, is not limitless, probably in order of 6 log for most enveloped viruses and considerably less for non-enveloped ones. It does not induce either new antigen or grossly reducing the function and life span of active principle in fresh frozen plasma (FFP). The removal of the residual MB at the end of the process has the beneficial effect of reducing potential toxic impacts. Clinical haemovigilance data, so far, indicate that cell-free MB plasma is effective in all therapeutic setting requiring FFP, besides inconsistent thrombotic thrombocytopenia purpura data, without serious side-effects or toxicity. The current system is in continuous improvement e.g. regarding virus reduction range, illumination device, software used, and process integration in the blood bank setting.

Updates on pathogen inactivation of plasma using Theraflex methylene blue system.

Methylene blue (MB) treated plasma has been in clinical use for 15 years. The current Theraflex MB-Plasma system has a number of improved features compared with the original Springe methodology. This article gives an overview of processing methodology and recent developments, pathogen inactivation capacity, pharmacokinetics and toxicology, effects on plasma proteins and storage stability, clinical experience and future perspectives. Emphasises will be placed on most recent literature and updated information available.

Tropomyosin 4 expression is enhanced in dedifferentiating smooth muscle cells in vitro and during atherogenesis.

Dedifferentiation of smooth muscle cells (SMC) from the contractile to the synthetic phenotype is a key event in atherosclerosis. A comparable phenotypic change from the contractile to the synthetic state is rapidly incurred when SMC are grown in culture. To identify genes that characterize the contractile and synthetic phenotypes, we performed differential display reverse transcription polymerase chain reactions on RNA from porcine arterial contractile SMC obtained directly from medial tissues and from SMC made synthetic by cell culturing. One of the differentially expressed cDNAs we identified encoded tropomyosin 4 (TM4). Whereas basal levels of TM4 existed in contractile SMC, the amount of TM4 transcripts strongly increased in synthetic SMC (33% vs. 86-106%; p < 0.005). Induction of foam cell formation had no additional enhancing effect on the expression of TM4 in cultivated SMC. We also tested whether TM4 expression was correspondingly enhanced during atherogenesis. The number of TM4-expressing SMC increased with plaque development as demonstrated by simultaneous in situ hybridization and immunohistochemistry. We compared the localization patterns of myosin heavy chain isoforms in normal arteries and lesions of increasing severity and determined that TM4 expression was relegated mainly to SMC of the synthetic phenotype in the media and intima during atherogenesis. The present study demonstrates that upregulation of TM4 mRNA is a relevant marker of dedifferentiation in vascular SMC.

Factor VIII and fibrinogen recovery in plasma after Theraflex methylene blue-treatment: effect of plasma source and treatment time.

BACKGROUND: The quality of fresh-frozen plasma is affected by different factors. Factor VIII is sensitive to blood component storage processes and storage as well as pathogen-reduction technologies. The level of fibrinogen in plasma is not affected by the collection processes but it is affected by preparation and pathogen-reduction technologies. MATERIALS AND METHODS: The quality of plasma from whole blood and apheresis donations harvested at different times and treated with a pathogen-reduction technique, methylene blue/light, was investigated, considering, in particular, fibrinogen and factor VIII levels and recovery. RESULTS: The mean factor VIII level after methylene blue treatment exceeded 0.5 IU/mL in all series. Factor VIII recovery varied between 78% and 89% in different series. The recovery of factor VIII was dependent on plasma source as opposed to treatment time. The interaction between the two factors was statistically significant. Mean levels of fibrinogen after methylene blue/light treatment exceeded 200 mg/dL in all arms. The level of fibrinogen after treatment correlated strongly with the level before treatment. There was a negative correlation between fibrinogen level before treatment and recovery. Pearson's correlation coefficient between factor VIII recovery and fibrinogen recovery was 0.58. DISCUSSION: These results show a difference in recovery of factor VIII and fibrinogen correlated with plasma source. The recovery of both factor VIII and fibrinogen was higher in whole blood plasma than in apheresis plasma. Factor VIII and fibrinogen recovery did not appear to be correlated.