Update on the use of pathogen-reduced human plasma and platelet concentrates

Human leukocyte antigen alloimmunization prevention mechanisms in blood transfusion

In many fields of clinical medicine and blood transfusion, the human leukocyte antigen (HLA) system is crucial. Alloimmunization happens as a result of an immune response to foreign antigens encountered during blood transfusion. This gives rise to alloantibodies against red blood cells (RBCs), HLA, or human platelet antigen (HPA). HLA alloimmunization following allogeneic transfusion was shown to be a result of contaminating white blood cells (WBCs) present in the product. It is a common complication of transfusion therapy that leads to difficulties in clinical intolerance and refractoriness to platelet transfusion during patient management. Single-donor platelets, prophylactic HLA matching, leukoreduction, and irradiation of cellular blood products are some of the mechanisms to prevent HLA alloimmunization during a blood transfusion. Now, the best approach to reduce the occurrence of primary HLA alloimmunization is the removal of WBCs from the blood by filtration.

New ultraviolet C light-based method for pathogen inactivation of red blood cell units

BACKGROUND

Pathogen inactivation (PI) technologies for platelet concentrates and plasma are steadily becoming more established, but new PI treatment options for red blood cells (RBCs), the most commonly used blood component, still need to be developed. We present a novel approach to inactivating pathogens in RBC units employing ultraviolet C (UVC) light.

METHODS

Whole blood-derived leukoreduced RBCs suspended in PAGGS-C, a third generation additive solution, served as test samples, and RBCs in PAGGS-C or SAG-M as controls. Vigorous agitation and hematocrit reduction by diluting the RBCs with additional additive solution during illumination ensured that UVC light penetrated and inactivated the nine bacteria and eight virus species tested. Bacterial and viral infectivity assays and in vitro analyses were performed to evaluate the system's PI capacity and to measure the RBC quality, metabolic, functional, and blood group serological parameters of UVC-treated versus untreated RBCs during 36-day storage.

RESULTS

UVC treatment of RBCs in the PAGGS-C additive solution did not alter RBC antigen expression, but significantly influenced some in vitro parameters. Compared to controls, hemolysis was higher in UVC-treated RBC units, but was still below 0.8% at 36 days of storage. Extracellular potassium increased early after PI treatment and reached ≤70 mmol/L by the end of storage. UVC-treated RBC units had higher glucose and 2,3-diphosphoglycerate levels than controls.

CONCLUSION

As UVC irradiation efficiently reduces the infectivity of relevant bacteria and viruses while maintaining the quality of RBCs, the proposed method offers a new approach for PI of RBC concentrates.

Violet-blue 405-nm Light-based Photoinactivation for Pathogen Reduction of Human Plasma Provides Broad Antibacterial Efficacy Without Visible Degradation of Plasma Proteins

In transfusion medicine, bacterial contamination can occur in ex vivo stored blood plasma, and there are continued efforts to improve blood safety and reduce the risk of transfusion-transmitted infections. Visible 405-nm violet-blue light has demonstrated potential for in situ pathogen reduction in ex vivo stored plasma and platelet concentrates. This study investigates the broad-spectrum antibacterial efficacy and compatibility potential of 405-nm light for treatment of blood plasma. Human plasma seeded with bacteria at a range of densities (10¹ -10³ , 10⁴ -10⁶ , 10⁷ -10⁸  CFU mL^-1 ) was exposed to 360 J cm^-2 405-nm light (1 h at 0.1 W cm^-2 ), with this fixed dose selected based on the initial analysis of inactivation kinetics. One-dimensional protein mobility analysis and measurement of advanced oxidation protein products (AOPP) was conducted to evaluate compatibility of the antimicrobial dose with plasma proteins and, identify upper levels at which protein degradation can be detected. Broad-spectrum antibacterial efficacy was observed with a fixed treatment of 360 J cm^-2 , with 98.9-100% inactivation achieved across all seeding densities for all organisms, except E. coli, which achieved 95.1-100% inactivation. At this dose (360 J cm^-2 ), no signs of protein degradation occurred. Overall, 405-nm light shows promise for broad-spectrum bacterial inactivation in blood plasma, while preserving plasma protein integrity.

Irradiation of platelets in Transfusion Medicine: risk and benefit judgments

Irradiation of platelet products is generally used to prevent transfusion-associated graft-versus-host disease (TA-GvHD) as well as transfusion-transmitted infections. As an essential prerequisite, gamma-irradiation of blood products prior to transfusion is required in patients who may develop TA-GVHD. Most studies suggest that gamma irradiation has no significant effect on the quality of platelet products; however, more recent studies have shown that the oxidative effects of gamma irradiation can lead to the induction of platelet storage lesion (PSL) and to some extent reduce the efficiency of transfused platelets. As the second widely used irradiation technique, UV-illumination was primarily introduced to reduce the growth of infectious agents during platelet storage, with the advantage that this method can also prevent TA-GvHD. However, the induction of oxidative conditions and platelet pre-activation that lead to PSL is more pronounced after UV-based methods of pathogen reduction. Since these lesions are large enough to clearly affect the post-transfusion platelet recovery and survival, more studies are needed to improve the safety and effectiveness of pathogen reduction technologies (PRTs). Therefore, pointing to other benefits of PRTs, such as preventing TA-GvHD or prolonging the shelf life of products by eliminating the possibility of pathogen growth during storage, does not yet seem to justify their widespread use due to above-mentioned effects. Even for gamma-irradiated platelets, some researchers have suggested that due to decreased 1-hour post-transfusion increments and increased risk of platelet refractoriness, their use should be limited to the patients who may develop TA-GVHD. It is noteworthy that due to the effect of X-rays in preventing TA-GvHD, some recent studies are underway to examine its effects on the quality and effectiveness of platelet products and determine whether X-rays can be used as a more appropriate and cost-effective alternative to gamma radiation. The review presented here provides a detailed description about irradiation-based technologies for platelet products, including their applications, mechanistic features, advantages, and disadvantages.

Molecular validation of pathogen-reduction technologies using rolling-circle amplification coupled with real-time PCR for torquetenovirus DNA quantification

BACKGROUND

Pathogen reduction technologies (PRT) based on nucleic-acid damaging chemicals and/or irradiation are increasingly being used to increase safety of blood components against emerging pathogens, such as convalescent plasma in the ongoing COVID-19 pandemic. Current methods for PRT validation are limited by the resources available to the blood component manufacturer, and quality control rely over pathogen spiking and hence invariably require sacrifice of the tested blood units: quantitative real-time PCR is the current pathogen detection method but, due to the high likelihood of detecting nonviable fragments, requires downstream pathogen culture. We propose here a new molecular validation of PRT based on the highly prevalent human symbiont torquetenovirus (TTV) and rolling circle amplification (RCA).

MATERIALS AND METHODS

Serial apheresis plasma donations were tested for TTV before and after inactivation with Intercept® PRT using real-time quantitative PCR (conventional validation), RCA followed by real-time PCR (our validation), and reverse PCR (for cross-validation).

RESULTS

While only 20% of inactivated units showed significant decrease in TTV viral load using real-time qPCR, all donations tested with RCA followed by real-time PCR showed TTV reductions. As further validation, 2 units were additionally tested with reverse PCR, which confirmed absence of entire circular genomes.

DISCUSSION

We have described and validated a conservative and easy-to-setup protocol for molecular validation of PRT based on RCA and real-time PCR for TTV.

UV light-emitting diode (UV-LED) at 265 nm as a potential light source for disinfecting human platelet concentrates

The risk of sepsis through bacterial transmission is one of the most serious problems in platelet transfusion. In processing platelet concentrates (PCs), several methods have been put into practice to minimize the risk of bacterial transmission, such as stringent monitoring by cultivation assays and inactivation treatment by photoirradiation with or without chemical agents. As another potential option, we applied a light-emitting diode (LED) with a peak emission wavelength of 265 nm, which has been shown to be effective for water, to disinfect PCs. In a bench-scale UV-LED exposure setup, a 10-min irradiation, corresponding to an average fluence of 9.2 mJ/cm2, resulted in >2.0 log, 1.0 log, and 0.6 log inactivation (mean, n = 6) of Escherichia coli, Staphylococcus aureus, and Bacillus cereus, respectively, in non-diluted plasma PCs. After a 30-min exposure, platelet counts decreased slightly (18 ± 7%: mean ± SD, n = 7); however, platelet surface expressions of CD42b, CD61, CD62P, and PAC-1 binding did not change significantly (P>0.005), and agonist-induced aggregation and adhesion/aggregation under flow conditions were well maintained. Our findings indicated that the 265 nm UV-LED has high potential as a novel disinfection method to ensure the microbial safety of platelet transfusion.

Efficacy of UVC-treated, pathogen-reduced platelets versus untreated platelets: a randomized controlled non-inferiority trial

Pathogen reduction (PR) technologies for blood components have been established to reduce the residual risk of known and emerging infectious agents. THERAFLEX UV-Platelets, a novel ultraviolet C (UVC) light-based PR technology for platelet concentrates, works without photoactive substances. This randomized, controlled, double-blind, multicenter, non-inferiority trial was designed to compare the efficacy and safety of UVC-treated platelets to that of untreated platelets in thrombocytopenic patients with hematologic-oncologic diseases. The primary objective was to determine non-inferiority of UVC-treated platelets, assessed by the 1-hour corrected count increment (CCI) in up to eight per-protocol platelet transfusion episodes. Analysis of the 171 eligible patients showed that the defined non-inferiority margin of 30% of UVC-treated platelets was narrowly missed as the mean differences in 1-hour CCI between standard platelets versus UVC-treated platelets for intention-to-treat and per-protocol analyses were 18.2% (95% Confidence Interval [CI]: 6.4-30.1) and 18.7% (95% CI: 6.3-31.1), respectively. In comparison to the control, the UVC group had a 19.2% lower mean 24-hour CCI and was treated with an about 25% higher number of platelet units, but the average number of days to the next platelet transfusion did not differ significantly between both treatment groups. The frequency of low-grade adverse events was slightly higher in the UVC group and the frequencies of refractoriness to platelet transfusion, platelet alloimmunization, severe bleeding events, and red blood cell transfusions were comparable between groups. Our study suggests that transfusion of pathogen-reduced platelets produced with the UVC technology is safe but non-inferiority was not demonstrated. (clinicaltrials gov. Identifier: DRKS00011156).

Blood Safety in SARS-CoV-2 Infection

: SARS-CoV-2 is a novel infectious agent that rapidly spread from a single city in China to all parts of the world. Right now, the world is facing a major pandemic crisis and every infected patient can infect the other two to three persons. The non-specific symptoms at the early stages of coronavirus 2019 (Covid-19) and also the presence of infected asymptomatic patients result in the absence of accurate estimation of infected patients. Although coronaviruses often affect the upper or lower respiratory tract, viral shedding in plasma or serum can occur and therefore, there is a theoretical risk regarding the transmission of these viruses by transfusion. Experience with other viruses from the corona family group (SARS-CoV and MERS-CoV) tells us that Covid-19 might have a significant impact on blood supply. Until now, SARS-CoV-2 has not been identified as a transfusion transmissible virus and viremia has only been diagnosed in serious patients who would not be allowed for blood donation. In this review article, the safety of blood products during the Covid-19 outbreak is discussed.

Coronavirus Disease 2019: Coronaviruses and Blood Safety

With the outbreak of unknown pneumonia in Wuhan, China, in December 2019, a new coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), aroused the attention of the entire world. The current outbreak of infections with SARS-CoV-2 is termed Coronavirus Disease 2019 (COVID-19). The World Health Organization declared COVID-19 in China as a Public Health Emergency of International Concern. Two other coronavirus infections-SARS in 2002-2003 and Middle East Respiratory Syndrome (MERS) in 2012-both caused severe respiratory syndrome in humans. All 3 of these emerging infectious diseases leading to a global spread are caused by β-coronaviruses. Although coronaviruses usually infect the upper or lower respiratory tract, viral shedding in plasma or serum is common. Therefore, there is still a theoretical risk of transmission of coronaviruses through the transfusion of labile blood products. Because more and more asymptomatic infections are being found among COVID-19 cases, considerations of blood safety and coronaviruses have arisen especially in endemic areas. In this review, we detail current evidence and understanding of the transmission of SARS-CoV, MERS-CoV, and SARS-CoV-2 through blood products as of February 10, 2020, and also discuss pathogen inactivation methods on coronaviruses.

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.

The long and winding road to pathogen reduction of platelets, red blood cells and whole blood

Pathogen reduction technologies (PRTs) have been developed to further reduce the current very low risks of acquiring transfusion-transmitted infections and promptly respond to emerging infectious threats. An entire portfolio of PRTs suitable for all blood components is not available, but the field is steadily progressing. While PRTs for plasma have been used for many years, PRTs for platelets, red blood cells (RBC) and whole blood (WB) were developed more slowly, due to difficulties in preserving cell functions during storage. Two commercial platelet PRTs use ultra violet (UV) A and UVB light in the presence of amotosalen or riboflavin to inactivate pathogens' nucleic acids, while a third experimental PRT uses UVC light only. Two PRTs for WB and RBC have been tested in experimental clinical trials with storage limited to 21 or 35 days, due to unacceptably high RBC storage lesion beyond these time limits. This review summarizes pre-clinical investigations and selected outcomes from clinical trials using the above PRTs. Further studies are warranted to decrease cell storage lesions after PRT treatment and to test PRTs in different medical and surgical conditions. Affordability remains a major administrative obstacle to PRT use, particularly so in geographical regions with higher risks of transfusion-transmissible infections.

Gaps in the knowledge of human platelet lysate as a cell culture supplement for cell therapy: a joint publication from the AABB and the International Society for Cell & Gene Therapy

Fetal bovine serum (FBS) is used as a growth supplement in a wide range of cell culture applications for cell-based research and therapy. However, as a xenogenic product, FBS can potentially transmit prions and adventitious viruses as well as induce undesirable immunologic reactions. In addition, the use of bovine fetuses for FBS production raises concerns as society looks for ways to replace animal testing and reduce the use of animal products for scientific purposes, in particular for the manufacture of clinical products intended for human use. Until chemically defined media are available for these purposes, human platelet lysate (hPL) has been introduced as an attractive alternative for replacing FBS as a cell culture supplement. hPL is a human product that can be produced from outdated platelets avoiding ethical, medical and animal welfare concerns. An increasing number of studies demonstrate that hPL can promote cell growth similarly or even better than FBS in specific cell types. Due to increasing interest in hPL, the AABB and the International Society of Cell Therapy (ISCT) established a joint working group to address its potential. With this article, we aim to present an overview of hPL, identifying the gaps in information on how hPL is produced and tested and the barriers to its translational use in the production of clinical-grade cell therapy products.

Hypoplastic thrombocytopenia and platelet transfusion: therapeutic goals

Platelet transfusions consist a major part of the management of hypoplastic thrombocytopenia, the latter occurring mainly among patients with hematological malignancies. Platelet transfusions have led to a reduction of deaths attributable to thrombocytopenia-induced bleeding, despite their possible complications; nonetheless, prophylactic administration of platelets to patients with severe thrombocytopenia or before invasive procedures should be based on specific criteria, as well as therapeutic administration during active bleeding. Recently developed ex-vivo procedures have resulted in producing safer blood products, yet it remains unclear whether these pathogen-inactivated products have sufficient efficacy. What is more, another significant problem that remains to be more effectively addressed is the developing refractoriness to platelet transfusions.

Bacterial inactivation of platelet concentrates with the THERAFLEX UV-Platelets pathogen inactivation system

BACKGROUND

The THERAFLEX UV-Platelets system (Maco Pharma) uses ultraviolet C (UVC) light for pathogen inactivation (PI) of platelet concentrates (PCs) without any additional photoactive compound. The aim of the study was to systematically investigate bacterial inactivation with this system under conditions of intended use.

STUDY DESIGN AND METHODS

The robustness of the system was evaluated by assessing its capacity to inactivate high concentrations of different bacterial species in accordance with World Health Organization guidelines. The optimal use of the PI system was explored in time-to-treatment experiments by testing its ability to sterilize PCs contaminated with low levels of bacteria on the day of manufacture (target concentration, 100 colony-forming units/unit). The bacteria panel used for spiking experiments in this study included the World Health Organization International Repository Platelet Transfusion Relevant Reference Strains (n = 14), commercially available strains (n = 13), and in-house clinical isolates (n = 2).

RESULTS

Mean log reduction factors after UVC treatment ranged from 3.1 to 7.5 and varied between different strains of the same species. All PCs (n = 12/species) spiked with up to 200 colony-forming units/bag remained sterile until the end of storage when UVC treated 6 hours after spiking. UVC treatment 8 hours after spiking resulted in single breakthrough contaminations with the fast-growing species Escherichia coli and Streptococcus pyogenes.

CONCLUSION

The UVC-based THERAFLEX UV-Platelets system efficiently inactivates transfusion-relevant bacterial species in PCs. The comprehensive data from this study may provide a valuable basis for the optimal use of this UVC-based PI system.

Ultraviolet C light efficiently inactivates nonenveloped hepatitis A virus and feline calicivirus in platelet concentrates

BACKGROUND

Nonenveloped transfusion-transmissible viruses such as hepatitis A virus (HAV) and hepatitis E virus (HEV) are resistant to many of the common virus inactivation procedures for blood products. This study investigated the pathogen inactivation (PI) efficacy of the THERAFLEX UV-Platelets system against two nonenveloped viruses: HAV and feline calicivirus (FCV), in platelet concentrates (PCs).

STUDY DESIGN AND METHODS

PCs in additive solution were spiked with high titers of cell culture-derived HAV and FCV, and treated with ultraviolet C at various doses. Pre- and posttreatment samples were taken and the level of viral infectivity determined at each dose. For some samples, large-volume plating was performed to improve the detection limit of the virus assay.

RESULTS

THERAFLEX UV-Platelets reduced HAV titers in PCs to the limit of detection, resulting in a virus reduction factor of greater than 4.2 log steps, and reduced FCV infectivity in PCs by 3.0 ± 0.2 log steps.

CONCLUSIONS

THERAFLEX UV-Platelets effectively inactivates HAV and FCV in platelet units.

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.

The Role of Plasma Transfusion in Massive Bleeding: Protecting the Endothelial Glycocalyx?

Massive hemorrhage is a leading cause of death worldwide. During the last decade several retrospective and some prospective clinical studies have suggested a beneficial effect of early plasma-based resuscitation on survival in trauma patients. The underlying mechanisms are unknown but appear to involve the ability of plasma to preserve the endothelial glycocalyx. In this mini-review, we summarize current knowledge on glycocalyx structure and function, and present data describing the impact of hemorrhagic shock and resuscitation fluids on glycocalyx. Animal studies show that hemorrhagic shock leads to glycocalyx shedding, endothelial inflammatory changes, and vascular hyper-permeability. In these animal models, plasma administration preserves glycocalyx integrity and functions better than resuscitation with crystalloids or colloids. In addition, we briefly present data on the possible plasma components responsible for these effects. The endothelial glycocalyx is increasingly recognized as a critical component for the physiological vasculo-endothelial function, which is destroyed in hemorrhagic shock. Interventions for preserving an intact glycocalyx shall improve survival of trauma patients.

Red blood cells treated with the amustaline (S-303) pathogen reduction system: a transfusion study in cardiac surgery

BACKGROUND

Nucleic acid-targeted pathogen inactivation technology using amustaline (S-303) and glutathione (GSH) was developed to reduce the risk of transfusion-transmitted infectious disease and transfusion-associated graft-versus-host disease with red blood cell (RBC) transfusion.

STUDY DESIGN AND METHODS

A randomized, double-blind, controlled study was performed to assess the in vitro characteristics of amustaline-treated RBCs (test) compared with conventional (control) RBCs and to evaluate safety and efficacy of transfusion during and after cardiac surgery. The primary device efficacy endpoint was the postproduction hemoglobin (Hb) content of RBCs. Exploratory clinical outcomes included renal and hepatic failure, the 6-minute walk test (a surrogate for cardiopulmonary function), adverse events (AEs), and the immune response to amustaline-treated RBCs.

RESULTS

A total of 774 RBC unis were produced. Mean treatment difference in Hb content was -2.27 g/unit (95% confidence interval, -2.61 to -1.92 g/unit), within the prespecified equivalence margins (±5 g/unit) to declare noninferiority. Amustaline-treated RBCs met European guidelines for Hb content, hematocrit, and hemolysis. Fifty-one (25 test and 26 control) patients received study RBCs. There were no significant differences in RBC usage or other clinical outcomes. Observed AEs were within the spectrum expected for patients of similar age undergoing cardiovascular surgery requiring RBCs transfusion. No patients exhibited an immune response specific to amustaline-treated RBCs.

CONCLUSION

Amustaline-treated RBCs demonstrated equivalence to control RBCs for Hb content, have appropriate characteristics for transfusion, and were well tolerated when transfused in support of acute anemia. Renal impairment was characterized as a potential efficacy endpoint for pivotal studies of RBC transfusion in cardiac surgery.

Cost-utility and budget impact of methylene blue-treated plasma compared to quarantine plasma

BACKGROUND

Methylene blue and visible light treatment and quarantine are two methods used to reduce adverse events, mostly infections, associated with the transfusion of fresh-frozen plasma. The objective of this study was to estimate and compare the budget impact and cost-utility of these two methods from a payer's perspective.

MATERIALS AND METHODS

A budget impact and cost-utility model simulating the risks of hepatitis B virus, hepatitis C virus, cytomegalovirus, a West Nile virus-like infection, allergic reactions and febrile non-haemolytic transfusion reactions achieved using plasma treated with methylene blue and visible light (MBP) and quarantine plasma (QP) was constructed for Spain. QP costs were estimated using data from one blood centre in Spain and published literature. The costs of producing fresh-frozen plasma from whole blood, apheresis plasma, and multicomponent apheresis, and separately for passive and active methods of donor recall for QP were included. Costs and outcomes over a 5-year and lifetime time horizon were estimated.

RESULTS

Compared to passive QP, MBP led to a net increase of € 850,352, and compared to active QP, MBP led to a net saving of € 5,890,425 over a 5-year period. Compared to passive QP, MBP increased the cost of fresh-frozen plasma per patient by € 7.21 and had an incremental cost-utility ratio of € 705,126 per quality-adjusted life-year. Compared to active QP, MBP reduced cost by € 50.46 per patient and was more effective.

DISCUSSION

Plasma collection method and quarantine approach had the strongest influence on the budget impact and cost-utility of MBP. If QP relies on plasma from whole blood collection and passive quarantine, it is less costly than MBP. However, MPB was estimated to be more effective than QP in all analyses.

Mitochondrial DNA multiplex real-time polymerase chain reaction inhibition assay for quality control of pathogen inactivation by ultraviolet C light in platelet concentrates

BACKGROUND

Several ultraviolet (UV) light-based pathogen inactivation (PI) technologies for platelet (PLT) products have been developed or are under development. Upon implementation of PI technologies, quality control measures are required to ensure consistent efficiency of the treatment process. Previous reports showed that amotosalen/UVA and riboflavin/UV-based PI technologies induce modifications of the PLT-derived mitochondrial DNA (mtDNA) that can be detected by polymerase chain reaction (PCR) inhibition assays. In this study, we sought to establish a PCR inhibition assay to document the impact of ultraviolet C (UVC) treatment with the THERAFLEX UV-Platelets system on the mitochondrial genome in PLT concentrates (PCs).

STUDY DESIGN AND METHODS

A multiplex real-time PCR inhibition assay with simultaneous short-amplicon (143 bp) and long-amplicon (794 bp) amplification was developed to detect mtDNA modifications in PLTs after UVC treatment. Assay performance was tested in UVC-treated and untreated, plasma-reduced pooled PCs, and apheresis PCs and challenged using PCs manufactured for a clinical trial under routine-like conditions.

RESULTS

UVC illumination of PLTs resulted in dose-dependent inhibition of mtDNA amplification for the larger amplicon. Amplification of the shorter amplicon was not affected by UVC treatment. Evaluation of 283 blinded apheresis and pooled PLT samples from routine-like PC production resulted in prediction of UVC treatment status with 100% accuracy.

CONCLUSION

The proposed dual-amplicon size real-time mtDNA PCR assay effectively detects nucleic acid damage induced by UVC illumination of PLTs and could be useful as an informative indicator of PI quality of the THERAFLEX UV-Platelets system.

Pathogen Inactivation of Cellular Blood Products-An Additional Safety Layer in Transfusion Medicine

In line with current microbial risk reduction efforts, pathogen inactivation (PI) technologies for blood components promise to reduce the residual risk of known and emerging infectious agents. The implementation of PI of labile blood components is slowly but steadily increasing. This review discusses the relevance of PI for the field of transfusion medicine and describes the available and emerging PI technologies that can be used to treat cellular blood products such as platelet and red blood cell units. In collaboration with the French medical device manufacturer Macopharma, the German Red Cross Blood Services developed a new UVC light-based PI method for platelet units, which is currently being investigated in clinical trials.

Pathogen reduction/inactivation of products for the treatment of bleeding disorders: what are the processes and what should we say to patients?

Patients with blood disorders (including leukaemia, platelet function disorders and coagulation factor deficiencies) or acute bleeding receive blood-derived products, such as red blood cells, platelet concentrates and plasma-derived products. Although the risk of pathogen contamination of blood products has fallen considerably over the past three decades, contamination is still a topic of concern. In order to counsel patients and obtain informed consent before transfusion, physicians are required to keep up to date with current knowledge on residual risk of pathogen transmission and methods of pathogen removal/inactivation. Here, we describe pathogens relevant to transfusion of blood products and discuss contemporary pathogen removal/inactivation procedures, as well as the potential risks associated with these products: the risk of contamination by infectious agents varies according to blood product/region, and there is a fine line between adequate inactivation and functional impairment of the product. The cost implications of implementing pathogen inactivation technology are also considered.

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.

A New Proof of Concept in Bacterial Reduction: Antimicrobial Action of Violet-Blue Light (405 nm) in Ex Vivo Stored Plasma

Bacterial contamination of injectable stored biological fluids such as blood plasma and platelet concentrates preserved in plasma at room temperature is a major health risk. Current pathogen reduction technologies (PRT) rely on the use of chemicals and/or ultraviolet light, which affects product quality and can be associated with adverse events in recipients. 405 nm violet-blue light is antibacterial without the use of photosensitizers and can be applied at levels safe for human exposure, making it of potential interest for decontamination of biological fluids such as plasma. As a pilot study to test whether 405 nm light is capable of inactivating bacteria in biological fluids, rabbit plasma and human plasma were seeded with bacteria and treated with a 405 nm light emitting diode (LED) exposure system (patent pending). Inactivation was achieved in all tested samples, ranging from low volumes to prebagged plasma. 99.9% reduction of low density bacterial populations (≤10³ CFU mL⁻¹), selected to represent typical “natural” contamination levels, was achieved using doses of 144 Jcm⁻². The penetrability of 405 nm light, permitting decontamination of prebagged plasma, and the nonrequirement for photosensitizing agents provide a new proof of concept in bacterial reduction in biological fluids, especially injectable fluids relevant to transfusion medicine.

Evaluation of Mirasol pathogen reduction system by artificially contaminating platelet concentrates with Staphylococcus epidermidis: A pilot study from India

BACKGROUND AND OBJECTIVES

This study was conducted to assess the efficacy of Mirasol pathogen reduction system for platelets aimed at preventing bacterial regrowth by spiking buffy coat pooled platelets (BCPP) with clinically relevant load of Staphylococous epidermidis.

MATERIALS AND METHODS

BCPP units were prepared using Teruflex BP-kit with Imugard III-S-PL (Terumo BCT, Tokyo, Japan). Two BCPP units were pooled, of which 40 ml of negative control (NC) was removed. The remaining volume of the platelet unit was inoculated with clinically relevant load of bacteria (total of 30 CFU of S. epidermidis in 1 ml); following this the platelet unit was split into two parts. One part served as positive control (PC) and the other part was subjected to pathogen reduction technique (Mirasol PRT, CaridianBCT Biotechnologies, Lakewood, CO, USA). Bacterial detection was performed using BacT/ALERT system, controls after day 1 and day 7 following inoculation of bacteria and on day 7 for Mirasol-treated unit.

RESULTS

Of the 32 treatment cycles, 28 were valid and 4 were invalid. No regrowth was observed in 96.4% (27 of 28) after treatment with Mirasol pathogen reduction system. Of four invalid tests, on two instances the NC showed growth, whereas in other 2 no regrowth was detected in 7(th) day PC. Bacterial screening of PCs by BacT/ALERT after 24 h of incubation was 28.6%, whereas the effectiveness increased to 100% when incubated for 7 days.

CONCLUSIONS

Mirasol system was effective in inactivating S. epidermidis when it was deliberately inoculated into BCPP at clinically relevant concentrations. Such systems may significantly improve blood safety by inactivating traditional and emerging transfusion-transmitted pathogens.

The infectious risks in blood transfusion as of today - A no black and white situation

Transfusion has been tainted with the risk of contracting an infection - often severe - and fears about this risk are still prevailing, in sharp contrast with the actual risk in Western countries. Those actual risks are rather immunological, technical (overload) or metabolic. Meanwhile, in developing countries and particularly in Africa, transfusion transmitted infections (TTIs) are still frequent, because of both the scarcity of volunteer blood donors and resources and the high incidence and prevalence of infections. Global safety of blood components has been declared as a goal to be attained everywhere by the World Heath Organization (WHO). However, this challenge is difficult to meet because of several intricate factors, of which the emergence of infectious agents, low income and breaches in sanitation and hygiene. This review aims at encompassing the situation of TTIs in different settings and means that can be deployed to improve the situation where this can possibly be.

Improved proliferation and osteogenic differentiation of human mesenchymal stem cells on a titanium biomaterial grafted with poly(sodium styrene sulphonate) and coated with a platelet-rich plasma proteins biofilm

In order to replace damaged or lost bone in the human body, it is necessary to produce ‘spare body parts’ which are dependent on the use of biomaterial and stem cells and are referred to as ‘tissue engineering’. Surface modification and stem cell interaction of orthopaedic implants offer a promising approach and are investigated here specifically to improve osseointegration of the biomaterial. Osseointegration of titanium implants used in orthopaedic surgery requires that osseo-progenitor cells attach and adhere to the surface, proliferate, then differentiate into osteoblasts and, finally, produce a mineralised matrix. The surface modification of titanium with anionic polymer combined with coating of platelet-rich plasma is provided to create a favourable environment to promote early and strong fixation of implants. The ability of progenitor cells to attach to the surface during early stages is important in the development of new tissue structures; therefore, we developed in our laboratory a strategy involving the grafting of titanium implants with a polymer of sodium styrene sulphonate (poly(sodium styrene sulphonate)) and a biofilm coating of platelet-rich plasma which enables human mesenchymal stem cell interactions. The resulting biomaterial, titanium-poly(sodium styrene sulphonate) and coating of platelet-rich plasma, Ti-poly(sodium styrene sulphonate)–platelet-rich plasma was developed in order to further improve the biomaterial. In this work, we studied and characterised the ‘in vitro’ response of human mesenchymal stem cells to titanium biomaterial grafted with poly(sodium styrene sulphonate) bioactive polymer and coated with platelet-rich plasma proteins (Ti-poly(sodium styrene sulphonate)–platelet-rich plasma). This study shows an increased cell proliferation with Ti-poly(sodium styrene sulphonate)–platelet-rich plasma compared to foetal calf serum and an enhancement of the Ti-poly(sodium styrene sulphonate)–platelet-rich plasma effects on osteoblast differentiation. The results suggest that Ti-poly(sodium styrene sulphonate)–platelet-rich plasma would be a suitable scaffold for bone tissue engineering.

Platelet lysate as a substitute for animal serum for the ex-vivo expansion of mesenchymal stem/stromal cells: present and future

The use of fetal bovine serum (FBS) as a cell culture supplement is discouraged by regulatory authorities to limit the risk of zoonoses and xenogeneic immune reactions in the transplanted host. Additionally, FBS production came under scrutiny due to animal welfare concerns. Platelet derivatives have been proposed as FBS substitutes for the ex-vivo expansion of mesenchymal stem/stromal cells (MSCs) since platelet-derived growth factors can promote MSC ex-vivo expansion. Platelet-derived growth factors are present in platelet lysate (PL) obtained after repeated freezing–thawing cycles of the platelet-rich plasma or by applying physiological stimuli such as thrombin or CaCl₂.

PL-expanded MSCs have been used already in the clinic, taking advantage of their faster proliferation compared with FBS-expanded preparations. Should PL be applied to other biopharmaceutical products, its demand is likely to increase dramatically. The use of fresh platelet units for the production of PL raises concerns due to limited availability of platelet donors. Expired units might represent an alternative, but further data are needed to define safety, including pathogen reduction, and functionality of the obtained PL. In addition, relevant questions concerning the definition of PL release criteria, including concentration ranges of specific growth factors in PL batches for various clinical indications, also need to be addressed. We are still far from a common definition of PL and standardized PL manufacture due to our limited knowledge of the mechanisms that mediate PL-promoting cell growth. Here, we concisely discuss aspects of PL as MSC culture supplement as a preliminary step towards an agreed definition of the required characteristics of PL for the requirements of manufacturers and users.

Neonatal Plasma Transfusion: An Evidence-Based Review

Several clinical scenarios for plasma transfusion are repeatedly identified in audits, including treatment of bleeding in association with laboratory evidence of coagulopathy, correction of disseminated intravascular coagulation, prevention of intraventricular hemorrhage, management of critically ill neonates (eg, during sepsis or as a volume expander), or correction of markers of prolonged coagulation in the absence of bleeding. The findings of at least one national audit of transfusion practice indicated that almost half of plasma transfusions are given to neonates with abnormal coagulation values with no evidence of active bleeding, despite the limited evidence base to support the effectiveness of this practice. Plasma transfusions to neonates should be considered in the clinical context of bleeding (eg, vitamin K dependent), disseminated intravascular coagulation, and very rare inherited deficiencies of coagulation factors. There seems to be no role for prophylactic plasma to prevent intraventricular hemorrhage or for use as a volume expander.

Health Technology Assessment of pathogen reduction technologies applied to plasma for clinical use

Although existing clinical evidence shows that the transfusion of blood components is becoming increasingly safe, the risk of transmission of known and unknown pathogens, new pathogens or re-emerging pathogens still persists. Pathogen reduction technologies may offer a new approach to increase blood safety. The study is the output of collaboration between the Italian National Blood Centre and the Post-Graduate School of Health Economics and Management, Catholic University of the Sacred Heart, Rome, Italy. A large, multidisciplinary team was created and divided into six groups, each of which addressed one or more HTA domains.Plasma treated with amotosalen + UV light, riboflavin + UV light, methylene blue or a solvent/detergent process was compared to fresh-frozen plasma with regards to current use, technical features, effectiveness, safety, economic and organisational impact, and ethical, social and legal implications. The available evidence is not sufficient to state which of the techniques compared is superior in terms of efficacy, safety and cost-effectiveness. Evidence on efficacy is only available for the solvent/detergent method, which proved to be non-inferior to untreated fresh-frozen plasma in the treatment of a wide range of congenital and acquired bleeding disorders. With regards to safety, the solvent/detergent technique apparently has the most favourable risk-benefit profile. Further research is needed to provide a comprehensive overview of the cost-effectiveness profile of the different pathogen-reduction techniques. The wide heterogeneity of results and the lack of comparative evidence are reasons why more comparative studies need to be performed.

Pathogen-reduced Ebola virus convalescent plasma: first steps towards standardization of manufacturing and quality control including assessment of Ebola-specific neutralizing antibodies

BACKGROUND

Ebola virus disease is a public health emergency of international concern, and enormous efforts are being made in the development of vaccines and therapies. Ebola virus convalescent plasma is a promising anti-infective treatment of Ebola virus disease. Therefore, we developed and implemented a pathogen-reduced Ebola virus convalescent plasma concept in accordance with national, European and global regulatory framework.

MATERIALS AND METHODS

Ebola virus convalescent plasma manufacture and distribution was managed by a collection centre, two medical centres and an expert group from the European Blood Alliance. Ebola virus convalescent plasma was collected twice with an interval of 61 days from a donor recovering from Ebola virus disease in Germany. After pathogen reduction, the plasma was analysed for Ebola virus-specific immunoglobulin G (IgG) antibodies and its Ebola virus neutralizing activity.

RESULTS

Convalescent plasma could be collected without adverse events. Anti-Ebola virus IgG titres and Ebola-specific neutralizing antibodies in convalescent plasma were only slightly reduced after pathogen reduction treatment with S59 amotosalen/UVA. A patient in Italy with Ebola virus disease was treated with convalescent plasma without apparent adverse effects.

DISCUSSION

As proof of principle, we describe a concept and practical implementation of pathogen-reduced Ebola virus convalescent plasma manufacture, quality control and its clinical application to an Ebola virus disease patient.

Solvent/detergent plasma: pharmaceutical characteristics and clinical experience

The solvent/detergent treatment is an established virus inactivation technology that has been industrially applied for manufacturing plasma derived medicinal products for almost 30 years. Solvent/detergent plasma is a pharmaceutical product with standardised content of clotting factors, devoid of antibodies implicated in transfusion-related acute lung injury pathogenesis, and with a very high level of decontamination from transfusion-transmissible infectious agents. Many clinical studies have confirmed its safety and efficacy in the setting of congenital as well as acquired bleeding disorders. This narrative review will focus on the pharmaceutical characteristics of solvent/detergent plasma and the clinical experience with this blood product.

New strategies for effective treatment of vitamin K antagonist-associated bleeding

Vitamin K antagonists have been used as oral anticoagulants in the treatment and prevention of thromboembolic events for over half a century. Although vitamin K antagonists are effective in the management of thromboembolic events, the need for routine monitoring and the associated risk of bleeding has resulted in the development and licensing of direct oral anticoagulants for specific clinical indications. Despite these developments, vitamin K antagonists remain the oral anticoagulants of choice in many clinical conditions. Severe bleeding associated with oral anticoagulation requires urgent reversal. Several options for the reversal of vitamin K antagonist exist, including vitamin K, prothrombin complex concentrates and plasma. In this manuscript, we review current evidence and provide physicians with treatment strategies for more effective management of vitamin K antagonist-associated bleeding.