Pathogen reduction: a precautionary principle paradigm

One Health Ethics and the Ethics of Zoonoses: A Silent Call for Global Action

This paper presents a critical review of key issues related to the emergence of new networks for the spread of zoonotic diseases amid the mass extinction of species. Zoonotic and infectious diseases account for approximately 70% of new and existing diseases affecting humans and animals. The initial section argues that the term "zoonoses" should not be confined to single-cause events within veterinary medicine. Instead, zoonoses should be viewed as complex, systemic phenomena shaped by interrelated factors, including environmental, sociocultural, and economic elements, influenced by anthropogenic climate change. The second section presents bioethical principles and potential strategies for those engaged in zoonotic disease prevention. The third section uses the slaughter of animals in disaster settings as a case study to illustrate the need for further clarification of normative and interspecies justice conflicts in One Health ethics. This section concludes with an outlook on "zoonoethics". Section four develops the analysis of the interlinked elements that trigger zoonoses and examines antimicrobial resistance (AMR) from an ethical and political standpoint, concluding with policy recommendations for addressing AMR. Section five offers a critical reflection, integrating contributions from zoonoethics, human ecology, and the ecotheological turn. Finally, section six concludes with a call to action and policy recommendations for an inclusive, intercultural, and gender-sensitive One Health approach.

Routine results of an algorithm for managing the production of blood components

BACKGROUND AND OBJECTIVES

The variability in the number of donations together with a growing demand for platelet concentrates and plasma-derived medicines make us seek solutions aimed at optimizing the processing of blood. Some mathematical models to improve efficiencies in blood banking have been published. The goal of this work is to validate and evaluate an algorithm's impact in the production of blood components in the Blood and Tissues Bank of Aragon (BTBA).

MATERIALS AND METHODS

A mathematical algorithm was designed, implemented and validated through simulations with real data. It was incorporated into the fractionation area, which uses the Reveos® fractionation system (Terumo BCT) to split blood into its components. After 9 months of daily routine validation, retrospective activity data from the Blood Bank and Transfusion Services before and during the use of the algorithm were compared.

RESULTS

Using the algorithm, the outdating rate of platelet concentrates (PC) decreased by 87.8% in the blood bank. The average shelf life remaining of PC supplied to Transfusion Services increased by almost 1 day. As a consequence, the outdating rate in the Aragon Transfusion Network decreased by 33%. In addition, extra 100 litres of plasma were obtained in 9 months.

CONCLUSIONS

The algorithm improves the blood establishment's workflow and facilitates the decision-making process in whole blood processing. It resulted in a decrease in PC outdating rate, increase in PC shelf life and finally an increase in the volume of recovered plasma, leading to significant cost savings.

Transfusion-transmission of hepatitis E virus through red blood cell transfusion but not through platelet concentrates: A case report from Spain

BACKGROUND

Few cases of transfusion-transmitted hepatitis E virus (HEV) have been published in Spain. Here, we describe a well-characterized lookback investigation of a transfusion-transmitted HEV case at the Community Centre for Blood and Tissues of Asturias (Spain).

CASE REPORT

A female patient with chronic myeloid leukemia underwent an allogeneic bone marrow transplant in March 2019 and showed alterations in liver function shortly afterwards. This patient received blood components from 30 different donors in the 3 months before the transplant. Frozen plasma samples from these donations were investigated for the presence of HEV-RNA. One frequent donor was identified as asymptomatic HEV RNA-positive at the time of his whole blood donation. The investigation revealed that this donor's plasma unit, originally intended for the fractionation industry, had a viral RNA concentration of 1.9 × 104 copies/mL. HEV RNA was detected initially in the index patient who received the red cell concentrate from this donor 25 days after the transfusion. HEV RNA isolated from both donor and recipient were identified as subtype 3f. The recipient of platelet concentrate (PC), treated with a riboflavin-based pathogen reduction technology (PRT) was not infected, being negative for the presence of HEV IgM, IgG, and HEV RNA before and after the transfusion.

CONCLUSION

This case study shows that HEV was transmitted through red cell transfusion to a recipient, while the patient who received riboflavin/UV light treated PC did not develop signs of infection. A causal relationship between PRT treatment of the PC and the non-transmission of HEV remains to be established.

Inactivation of SARS-CoV-2 in All Blood Components Using Amotosalen/Ultraviolet A Light and Amustaline/Glutathione Pathogen Reduction Technologies

No cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transfusion-transmitted infections (TTI) have been reported. The detection of viral RNA in peripheral blood from infected patients and blood components from infected asymptomatic blood donors is, however, concerning. This study investigated the efficacy of the amotosalen/UVA light (A/UVA) and amustaline (S-303)/glutathione (GSH) pathogen reduction technologies (PRT) to inactivate SARS-CoV-2 in plasma and platelet concentrates (PC), or red blood cells (RBC), respectively. Plasma, PC prepared in platelet additive solution (PC-PAS) or 100% plasma (PC-100), and RBC prepared in AS-1 additive solution were spiked with SARS-CoV-2 and PR treated. Infectious viral titers were determined by plaque assay and log reduction factors (LRF) were determined by comparing titers before and after treatment. PR treatment of SARS-CoV-2-contaminated blood components resulted in inactivation of the infectious virus to the limit of detection with A/UVA LRF of >3.3 for plasma, >3.2 for PC-PAS-plasma, and >3.5 for PC-plasma and S-303/GSH LRF > 4.2 for RBC. These data confirm the susceptibility of coronaviruses, including SARS-CoV-2 to A/UVA treatment. This study demonstrates the effectiveness of the S-303/GSH treatment to inactivate SARS-CoV-2, and that PRT can reduce the risk of SARS-CoV-2 TTI in all blood components.

Impact of different pathogen reduction technologies on the biochemistry, function, and clinical effectiveness of platelet concentrates: An updated view during a pandemic

Standard platelet concentrates (PCs) stored at 22°C have a limited shelf life of 5 days. Because of the storage temperature, bacterial contamination of PCs can result in life‐threatening infections in transfused patients. The potential of blood components to cause infections through contaminating pathogens or transmitting blood‐borne diseases has always been a concern. The current safety practice to prevent pathogen transmission through blood transfusion starts with a stringent screening of donors and regulated testing of blood samples to ensure that known infections cannot reach transfusion products. Pathogen reduction technologies (PRTs), initially implemented to ensure the safety of plasma products, have been adapted to treat platelet products. In addition to reducing bacterial contamination, PRT applied to PCs can extend their shelf life up to 7 days, alleviating the impact of their shortage, while providing an additional safety layer against emerging blood‐borne infectious diseases. While a deleterious action of PRTs in quantitative and qualitative aspects of plasma is accepted, the impact of PRTs on the quality, function, and clinical efficacy of PCs has been under constant examination. The potential of PRTs to prevent the possibility of new emerging diseases to reach cellular blood components has been considered more hypothetical than real. In 2019, a coronavirus‐related disease (COVID‐19) became a pandemic. This episode should help when reconsidering the possibility of future blood transmissible threats. The following text intends to evaluate the impact of different PRTs on the quality, function, and clinical effectiveness of platelets within the perspective of a developing pandemic.

Improvement of Blood Processing and Safety by Automation and Pathogen Reduction Technology

Introduction

The objective of the present study was to describe the experience of the Blood and Tissues Bank of Aragon with the Reveos® Automated Blood Processing System and Mirasol® Pathogen Reduction Technology (PRT) System, comparing retrospectively routine quality data obtained in two different observation periods.

Methods

Comparing quality data encompassing 6,525 blood components from the period 2007-2012, when the semi-automated buffy coat method was used in routine, with 6,553 quality data from the period 2014-2019, when the Reveos system and subsequently the Mirasol system were implemented in routine.

Results

Moving from buffy coat to Reveos led to decreased discard rates of whole blood units (1.2 to 0.1%), increased hemoglobin content (48.1 ± 7.6 to 55.4 ± 6.6 g/unit), and hematocrit (58.9 ± 6.5% to 60.0 ± 4.9%) in red blood cell concentrates. Platelet concentrates (PCs) in both periods had similar yields (3.5 ×10¹¹). Whereas in the earlier period, PCs resulted from pooling 5 buffy coats, in the second period 25% of PCs were prepared from 4 interim platelet units. The mean level of factor VIII in plasma was significantly higher with Reveos (92.8 vs. 97.3 IU). Mirasol PRT treatment of PCs reduced expiry rates to 1.2% in 2019. One septic transmission was reported with a non-PRT treated PCs, but none with PRT-treated PCs.

Conclusion

Automation contributed to standardization, efficiency, and improvement of blood processing. Released resources enabled the effortless implementation of PRT. The combination of both technologies guaranteed the self-sufficiency and improvement of blood safety.

Transfusion medicine: Overtime paradigm changes and emerging paradoxes

This essay aims to discuss some aspects of blood transfusion in the perspective of the changes that occurred over time as well as modifications of the paradigms that transformed the activities and the organization of blood transfusion services. Without specific knowledge, pioneers envisioned precision and personalized medicine, rendering transfusion medicine operational. Transfusion medicine is like The Picture of Dorian Grey: always young despite being old and sometimes appearing old-fashioned. Over the years, the transfusion medicine discipline has evolved, and major progress has been achieved, despite some troublesome periods (for example, the tainted blood scandal, and—at the time being—the offending plasma market and the selling of human parts). Transfusion medicine has at all times implemented the rapidly developing biomedical technologies to secure blood components. The safety of blood components has now reached an exceptional level in economically wealthy countries, especially compared to other health care disciplines. Strengthening of the safety has mandated that blood donors and recipients are unrelated, an issue which has eased preservation and fractionation practices; blood is no longer arm-to-arm transfused and neither is whole blood, the commonest component. However, it is interesting to note that a revival is occurring as whole blood is back on stage for certain specific indications, which is one among the many paradoxes encountered while studying this discipline.

Comparative study on the inactivation of MS2 and M13 bacteriophages using energetic femtosecond lasers

Femtosecond (fs) laser irradiation techniques are emerging tools for inactivating viruses that do not involve ionizing radiation. In this work, the inactivation of two bacteriophages representing protective capsids with different geometric constraints, that is, the near-spherical MS2 (with a diameter of 27 nm) and the filamentous M13 (with a length of 880 nm) is compared using energetic visible and near-infrared fs laser pulses with various energies, pulse durations, and exposure times. Intriguingly, the results show that inactivation using 400 nm lasers is substantially more efficient for MS2 compared to M13. In contrast, using 800 nm lasers, M13 was slightly more efficiently inactivated. For both viruses, the genome was exposed to a harmful environment upon fs-laser irradiation. However, in addition to the protection of the genome, the metastable capsids differ in many properties required for stepwise cell entry that may explain their dissimilar behavior after (partial) disassembly. For MS2, the dominant mechanism of fs-laser inactivation was the aggregation of the viral capsid proteins, whereas aggregation did not affect M13 inactivation, suggesting that the dominant mechanism of M13 inactivation was related to breaking of secondary protein links.

Analysis of the mechanism of damage produced by thiazole orange photoinactivation in apheresis platelets

BACKGROUND

Pathogen Reduction Technologies (PRTs) are broad spectrum nucleic acid replication-blocking antimicrobial treatments designed to mitigate risk of infection from blood product transfusions. Thiazole Orange (TO), a photosensitizing nucleic acid dye, was previously shown to photoinactivate several types of bacterial and viral pathogens in RBC suspensions without adverse effects on function. In this report we extended TO treatment to platelet concentrates (PCs) to see whether it is compatible with in vitro platelet functions also, and thus, could serve as a candidate technology for further evaluation.

MATERIAL AND METHODS

PCs were treated with TO, and an effective treatment dose for inactivation of Staphylococci was identified. Platelet function and physiology were then evaluated by various assays in vitro.

RESULTS

Phototreatment of PCs yielded significant reduction (≥4-log) in Staphylococci at TO concentrations ≥20 μM. However, treatment with TO reduced aggregation response to collagen over time, and platelets became unresponsive by 24 hours post-treatment (from >80% at 1 h to 0% at 24 h). TO treatment also significantly increased CD62P expression (<1% CD62P+ for untreated and >50% for TO treated at 1 h) and induced apoptosis in platelets (<1% Annexin V+ for untreated and >50% for TO treated at 1 h) and damaged mitochondrial DNA. A mitochondria-targeted antioxidant and reactive oxygen species (ROS) scavenger Mito-Tempo mitigated these adverse effects.

DISCUSSION

The results demonstrate that TO compromises mitochondria and perturbs internal signaling that activates platelets and triggers apoptosis. This study illustrates that protecting platelet mitochondria and its functions should be a fundamental consideration in selecting a PRT for transfusion units containing platelets, such as PCs.

Contemporary resuscitation of hemorrhagic shock: What will the future hold?

Resuscitation of the critically ill patient with fluid and blood products is one of the most widespread interventions in medicine. This is especially relevant for trauma patients, as hemorrhagic shock remains the most common cause of preventable death after injury. Consequently, the study of the ideal resuscitative product for patients in shock has become an area of great scientific interest and investigation. Recently, the pendulum has swung towards increased utilization of blood products for resuscitation. However, pathogens, immune reactions and the limited availability of this resource remain a challenge for clinicians. Technologic advances in pathogen reduction and innovations in blood product processing will allow us to increase the safety profile and efficacy of blood products, ultimately to the benefit of patients. The purpose of this article is to review the current state of blood product based resuscitative strategies as well as technologic advancements that may lead to safer resuscitation.

Accelerated inactivation of M13 bacteriophage using millijoule femtosecond lasers

Irradiation of femtosecond (fs) pulse lasers in the visible and near-infrared ranges have been proposed as a promising approach for inactivating viruses. However, in order to achieve significant virus inactivation, past works have required relatively long irradiation times (1 hour or longer), even for small volumes. Given its advantages compared with other techniques, there is an urgent need to shorten the time required to inactivate viruses using fs laser technology. In this study, we investigate the inactivation of purified M13 bacteriophage in phosphate-buffered saline with large active volume (1 cm³ ), and short exposure time (several minutes), using lasers with 20 mJ/pulse energy at various wavelengths (800, 400 nm or both 800 and 400 nm combined). For an exposure time of 15 and 2 minute, the use of a 400 nm wavelength laser results in a high load reduction of 5.8 ± 0.3 and 2.9 ± 0.15, respectively, on the log₁₀ scale of viability. We show that virus inactivation using the 400 nm laser is much more efficient compared with that using an 800 nm laser, or the simultaneous irradiation of 400 and 800 nm lasers. Higher pathogen inactivation is observed for lasers with shorter pulse duration, whereas at longer pulse durations, the inactivation is reduced. For millijoule-energy fs laser irradiation, the M13 bacteriophage inactivation, via the reduction of the functionality of M13 bacteriophages, is accompanied with relatively small amounts of genetic damage.

In vitro evaluation of pathogen inactivated platelet quality: An 8 year experience of routine use in Galicia, Spain

BACKGROUND

Platelet concentrates (PCs) treated by the pathogen inactivation technology (PI) using amotosalen and UVA illumination (PI-PCs) can be manufactured in additive solutions (PAS-III and PAS-IIIM) or in 100% Plasma. Quality control (QC) is an integral part of the production. We capitalized on our ongoing QC program to capture 8 years-worth of data on parameters related to the quality of 116,214 PI-PCs produced under different manufacturing methods.

MATERIALS AND METHODS

Selected in vitro parameters of metabolism, activation, and storage were analyzed for the different manufacturing periods to compare PI-PCs versus conventional PCs (C-PCs) resuspended in different PAS.

RESULTS AND DISCUSSION

All BC-PCs met quality standards for pH and dose and residual leucocytes. As expected, storage time correlated with increased lactate, LDH, Annexin V, CD62, sCD40 L levels and decreased glucose and pH. With PAS-IIIM, higher levels of glucose were observed toward the end of shelf life (p < 0.0001) with lower platelet activation markers Annexin V (p = 0.038) and CD62 (p = 0.0006). Following PI implementation, a low expire rate of <0.5% was observed. While a 2.3% mean increase in the production of PCs occurred from 2011 to 2015, the distribution of red blood cell concentrates dropped by 4.4%. A mean incidence of 0.14% for transfusion-related adverse reaction was observed while PI-PCs were distributed, similar to the one observed with C-PCs. Overall, PI-PCs prepared in additive solutions consistently met quality standards. Those prepared in PAS-IIIM appeared to have better retention of in vitro characteristics compared to PAS-III though all demonstrated functionality and clinical effectiveness.

Initial Results of a Prospective Study and Identification of New Strategies to Increase Traceability of Plasma-derived Medicines

Plasma medicine is an innovative and emerging field used in a broad range of medical conditions. The present study focused on consumption and documentation pattern of plasma-derived medicines in a teaching hospital. A two-step study was conducted from October to December 2015. During the first phase, the patient records receiving plasma-derived medicines including Coagulation Factor VIII, IX, Prothrombin Complex Concentrate, Factor VIII/Von Wilberand Complex, Anti-Hepatitis B Immunoglobulin, Intravenous Immunoglobulin, Anti-Tetanus Immunoglobulin, and Albumin were checked to assess recording details of these medications at the time of administration. Adverse events reported with the mentioned products were examined from traceability viewpoint. The second step concentrated on practical strategies to improve documentation status of plasma-derived medicines in the hospital. We proposed national guideline as the first strategy and a new barcoding system to track and identify drug information of plasma medicines. Of the expected drug information, only generic name, dosage from, and strength were recorded after administration. Post-marketing safety surveillance of the plasma products was poor similarly. Unavailability of suitable instructions was the main reason for documentation deficiency. A guideline was designed and implemented to inform healthcare professionals about essentials of appropriate documentation for plasma-derived medicines. Updated results of the ongoing phase will be submitted soon. Our survey highlights the importance of documentation as a key component of plasma-derived medicines surveillance within the hospitals.

The Precautionary Principle and the Tolerability of Blood Transfusion Risks

Tolerance for blood transfusion risks is very low, as evidenced by the implementation of expensive blood tests and the rejection of gay men as blood donors. Is this low risk tolerance supported by the precautionary principle, as defenders of such policies claim? We discuss three constraints on applying (any version of) the precautionary principle and show that respecting these implies tolerating certain risks. Consistency means that the precautionary principle cannot prescribe precautions that it must simultaneously forbid taking, considering the harms they might cause. Avoiding counterproductivity requires rejecting precautions that cause more harm than they prevent. Proportionality forbids taking precautions that are more harmful than adequate alternatives. When applying these constraints, we argue, attention should not be restricted to harms that are human caused or that affect human health or the environment. Tolerating transfusion risks can be justified if available precautions have serious side effects, such as high social or economic costs.

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 inactivation: emerging indications

PURPOSE OF REVIEW

To review data about transfusion-transmitted infections so as to assess potential safety benefits of applying pathogen inactivation technology to platelets.

RECENT FINDINGS

Residual bacterial risk still exists. Multiple arbovirus epidemics continue to occur and challenge blood safety policy makers in nonendemic developed countries. There is new documentation of transfusion transmission of dengue and Ross River viruses, and new or increased concern about chikungunya and Zika viruses. Pathogen inactivation has been shown to inactivate almost all bacterial species and several epidemic arboviruses that pose a transfusion transmission risk. The two available platelet pathogen inactivation technologies show different levels of pathogen inactivation as measured by in-vitro infectivity assays; the clinical significance of this finding is not known.

SUMMARY

Pathogen inactivation can mitigate infectious risk and should do so more completely than other interventions such as donor questioning, donor/component recall, or donor testing. However, pathogen inactivation increases the cost of the pathogen-reduced blood component, which is a significant obstacle in the current healthcare environment. This may inhibit the ability to move forward with an effective new paradigm for blood safety that fulfills the implicit public trust in the blood system.

Reduced alloimmunization in mice following repeated transfusion with pathogen-reduced platelets

BACKGROUND

Allogeneic transfusion can result in alloimmunization, leading to platelet (PLT) refractoriness and rejection of solid organ transplants. Previously we demonstrated that pathogen reduction using UV light and riboflavin (UV + R) eliminates the immunogenicity of white blood cells (WBCs) in vitro, blocks alloimmunization from transfusion in mice, and results in reduced ex vivo cytokine responses to subsequent untreated transfusions. We sought to determine if repeated transfusion with pathogen-reduced PLT-rich plasma (PRP) would eventually cause breakthrough alloimmunization or enhanced tolerance.

STUDY DESIGN AND METHODS

BALB/cJ mice were transfused weekly for 2, 4, or 8 weeks with C57Bl/6J PRP that was either untreated or pathogen reduced with UV + R and leukoreduced or not. Alloimmunization was determined by measuring donor antibody levels, ex vivo cytokine responses, and 24-hour donor PLT recovery. The role of donor antibodies in PLT refractoriness was also assessed by transfer of diluted immune sera into naïve recipients.

RESULTS

Donor antibody levels increased with the number of transfusions, but levels were significantly reduced using either UV + R or leukoreduction, and combining UV + R and leukoreduction gave the best protection. Priming of ex vivo cytokine responses required WBCs and remained suppressed with repeated UV + R-treated transfusion. PLT recovery was reduced with UV + R in naïve mice, and multiply transfused mice had poor PLT recovery even when antibody levels were relatively low. Approximately 1/100 dose of serum from a multiply transfused mouse was sufficient for complete rejection of donor PLTs.

CONCLUSIONS

Pathogen reduction significantly reduces alloimmunization in repeatedly transfused mice and combined with leukoreduction provides a high level of protection from alloimmunization.

Risks associated with red blood cell transfusions: potential benefits from application of pathogen inactivation

BACKGROUND

Red blood cell (RBC) transfusion risks could be reduced if a robust technology for pathogen inactivation of RBC (PI-RBCs) were to be approved.

MATERIALS AND METHODS

Estimates of per-unit and per-patient aggregate infectious risks for conventional RBCs were calculated; the latter used patient diagnosis as a determinant of estimated lifetime exposure to RBC units. Existing in vitro data for the two technologies under development for producing PI-RBCs and the status of current clinical trials are reviewed.

RESULTS

Minimum and maximum per-unit risk were calculated as 0.0003% (1 in 323,000) and 0.12% (1 in 831), respectively. The minimum estimate is for known lower-risk pathogens while the maximal estimate also includes an emerging infectious agent (EIA) and endemic area Babesia risk. Minimum and maximum per-patient lifetime risks by diagnosis grouping were estimated as 1.5 and 3.3%, respectively, for stem cell transplantation (which includes additional risk for cytomegalovirus transmission); 1.2 and 3.7%, respectively, for myelodysplastic syndrome; and 0.2 and 44%, respectively, for hemoglobinopathy.

DISCUSSION

There is potential for PI technologies to reduce infectious RBC risk and to provide additional benefits (e.g., prevention of transfusion-associated graft-versus-host disease and possible reduction of alloimmunization) due to white blood cell inactivation. PI-RBCs should be viewed in the context of having a fully PI-treated blood supply, enabling a blood safety paradigm shift from reactive to proactive. Providing insurance against new EIAs. Further, when approved, the use of PI for all components may catalyze operational changes in blood donor screening, laboratory testing, and component manufacturing.

Riboflavin and UV light treatment of platelets: a protective effect of platelet additive solution?

BACKGROUND

Pathogen reduction technologies (PRTs) increase the safety of the blood supply, but are also associated with cell damage. Our aim was to investigate the effect of Mirasol PRT on platelet (PLT) concentrates stored in plasma and whether the use of a PLT additive solution (PAS) is able to improve in vitro quality.

STUDY DESIGN AND METHODS

Twenty-two buffy coats (BCs) were pooled and split into two equal parts. To one half, 2 units of plasma were added, and to the other, 2 units of SSP+ PAS were added. Each part was equally split in half again (to resemble pooling five BCs) and PLT concentrates were prepared. One plasma PLT concentrate was Mirasol treated, and the other served as control; similarly, one SSP+ PLT concentrate was Mirasol treated, and the other not. PLT concentrates were stored for 8 days (n = 12).

RESULTS

Mirasol PRT led to elevated lactate production in PLT concentrates in plasma, giving lower pH values throughout storage. The use of SSP+ mostly abrogated this effect, and Mirasol-treated PLT concentrates in SSP+ had only slightly higher lactate production rates and annexin A5 binding as control PLT concentrates in plasma. However, irrespective whether plasma or SSP+ was used, Mirasol PRT led to higher CD62P expression and lower hypotonic shock response (HSR) scores.

CONCLUSION

Mirasol treatment leads to higher PLT activation and lower HSR scores both when stored in plasma or SSP+. However, if Mirasol-treated PLTs are stored in SSP+, lactate metabolism and annexin A5 binding are lower, showing that PAS can partly mitigate the effect of PRT. The clinical relevance of this finding needs to be demonstrated.

Das hepatopatias e icterícias às hepatites virais: configuração de um caleidoscópio

As hepatites virais A, B, C, D e E - viroses sistêmicas hepatotrópicas - produzem quadros de hepatite aguda. Dependendo do agente etiológico, da carga viral e de condições do hospedeiro, podem evoluir para hepatite crônica, cirrose, câncer de fígado e formas agudas fulminantes. A versatilidade ecológica desses vírus configura uma natureza espectral e cambiante de transmissão no tempo e no espaço; potencializada pelo curso subclínico por vezes prolongado de grande parte das infecções, constitui-se em desafio epidemiológico. Com base no curso histórico dessas infecções foram descritos cenários e tendências relativas ao seu comportamento socioepidemiológico, apontando para a necessidade de superar modelos, padrões, protocolos e retornar à investigação de cada situação de saúde/doença. Ou seja, assinala para a imprescindível exploração das singularidades no sentido de desenvolver ações gerais modeladas pelas especificidades locais.

[Theses on hepatitis at the Faculdade de Medicina of the Universidade Federal do Rio de Janeiro, 1837-2000]

An inventory of the theses on hepatitis of the Faculdade de Medicina of the Universidade Federal do Rio de Janeiro between 1837 and 2000 is presented. The analysis indicates the potential and limits for discussion of the evolutionary framework of scientific knowledge on these health problems in Brazil. The theories are also discussed in light of their scientific reference points and the technological and social changes that influenced them. The landmarks in medical education and knowledge about hepatitis are identified and categorized, considering that the theses reveal at the very least the state of the art on the subject. The study makes it possible to explore the foundations upon which the scientific knowledge on hepatitis were built and indicate possibilities for research in the reconstruction of scientific knowledge of other health problems.

[Expected limits (and possible consequences) of pathogen inactivation technology]

Pathogen reduction technology, now applicable to platelets and plasma, has limits that are already known, and potential or poorly defined other ones. We can distinguish limitations due to adverse events related to the technology itself or to recipient susceptibility, the limits of effectiveness depending on the target, the technology, organizational, economic and geographical limits.

[Pathogen reduction for platelets: available techniques and recent developments]

The will to reach for blood components a microbiological safety comparable to that of plasma-derived drugs led to the development of numerous pathogen reduction research programs for red blood cells and\or platelets in the 1990s. A consensus conference organized in 2007 allowed to define the main steps and precautions to be taken for the implementation of these processes. In the specific case of platelet concentrates, three processes stay this day in the run, even if they are not at the same development stage. A process using ultraviolet C only is at the stage of preclinical studies. The Mirasol® process, based on the activation of riboflavin by exposure to ultraviolet A and ultraviolet B is CE marked (class IIb), and a clinical study was published in 2010. The Intercept® process, involving the activation of a psoralen molecule by exposure to ultraviolet A, is CE marked (class III) since 2002, and has been licensed in France since 2005, in Germany since 2005 and in Switzerland since 2010. At least 12 clinical studies have been published. In regard to this last pathogen reduction process, the medical and scientific documentation, from in vitro investigations to post-marketing observational studies, is much more developed than the corresponding documentation of some innovative processes at the time of their generalization, such as the SAG-mannitol solution for red cell concentrates in 1979, leukoreduction filters for platelets and red cells concentrates in the 1990s, the solvent detergent therapeutic plasma in 1992 or the methylene blue therapeutic plasma in 2006.

Preclinical pharmacokinetic and toxicology assessment of red blood cells prepared with S-303 pathogen inactivation treatment

BACKGROUND

A system has been developed to inactivate a wide spectrum of blood-borne pathogens in red blood cells (RBCs) before transfusion. The system utilizes S-303 to target nucleic acids of pathogens and white blood cells. The safety of pathogen inactivated RBC was assessed using S-303-treated RBCs (S-303 RBCs) and S-300, the primary degradation product of S-303.

STUDY DESIGN AND METHODS

As part of a preclinical safety evaluation program, intravenous toxicity, safety pharmacology, toxicokinetic, and pharmacokinetic studies were conducted in rats and dogs with S-303 RBCs and S-300.

RESULTS

Single and repeated transfusions of S-303 RBCs were well tolerated in rats and dogs at S-303 concentrations up to five times higher than that used to prepare RBCs for clinical use. For S-300, the doses ranged from the lowest level representative of a clinical exposure from transfusion of 1 unit (0.052 mg/kg/day) to up to the amount of S-300 that would result from exposure to more than 1900 units of RBCs (100 mg/kg/day). There were no related effects of S-303 RBCs or S-300 on mortality, clinical status, body weight, or clinical laboratory assessments and no evidence of organ toxicity. S-300 did not accumulate in the plasma of rats and dogs after repeated transfusions. For all the studies, plasma S-303 was consistently below the limit of quantitation.

CONCLUSION

The level of residual S-303 and S-300 in the treated blood component is well below that at which no adverse effects were observed. These results support further clinical development of S-303 RBCs for prevention of transfusion-transmitted infections.

[Photochemical inactivation of pathogens in platelets and plasma: five years of clinical use in routine and hemovigilance. Towards a change of paradigm in transfusion safety]

The transfusion of labile blood products is vital and essential for patients in absence of alternative treatment. Patients and doctors have always feared transfusion-transmitted infections by blood, blood components and blood-derived drugs. Photochemical inactivation of platelet concentrates and plasma, using a technique associating amotosalen and UVA, has been used for five years in a French region for the whole population and a large spectrum of patients, with efficacy and safety. It would seem wise to introduce labile blood products, submitted to pathogen inactivation by a technique already approved by a regulatory agency and not to wait for a perfect system including red blood cells concentrates. Universal implementation of pathogen inactivation in labile blood products is a major and key step to improve safety against infection in transfusion.

Symptomatic parvovirus B19 infection caused by blood component transfusion

BACKGROUND

Although a risk of transfusion-transmitted human parvovirus B19V (TT-B19V) infection has been a concern, there have been very few reports of clinically relevant TT-B19V caused by the transfusion of a B19V-containing blood component. It has therefore been a matter of debate whether a universal B19V screening with an appropriate sensitivity is required.

STUDY DESIGN AND METHODS

Through the Japanese Red Cross hemovigilance system, clinical reports on possible TT-B19V were collected from 1999 to 2008, during which B19V donor screening (sensitivity, 10(10) IU/mL) was conducted and repository blood samples from donors were available.

RESULTS

Eight patients with TT-B19V caused by component transfusion have been identified. Four patients developed sustained anemia and pure red blood cell (RBC) aplasia and one patient developed pancytopenia. The underlying diseases in these five patients were either hematologic malignancy or hemolytic diseases. The viral loads of the responsible components for these cases ranged from 10(3) to 10(8) IU/mL. Two patients who underwent surgical treatment without any hematologic disorder exhibited only moderate symptoms. The B19V DNA sequence identity between a patient and the linked blood donor was confirmed in five of the eight patients. All of the components responsible for the eight cases were positive for anti-B19V immunoglobulin (Ig)M.

CONCLUSION

Vulnerability to serious B19V-related hematologic disorders depended on the patient's underlying disease state of an enhanced erythropoiesis, not on the viral load of the component transfused. To prevent clinically relevant TT-B19V, a strategy is suggested in which patients at risk of acquiring RBC aplasia or pancytopenia are targeted.

A comparison of methods of pathogen inactivation of FFP

INTRODUCTION

Current methods for pathogen inactivation of plasma involve four major processes using solvent-detergent (SD), methylene blue (MB), amotosalen and riboflavin as additives. Three of these methods involve the use of visible or ultraviolet light.

METHODS

A comparison of the four methods was made using publications in Medline, Pubmed, Embase and Biosis to obtain data on the logistics of use, the quality of the plasma proteins and the effectiveness of pathogen inactivation.

RESULTS

Three of the methods, MB, amotosalen and riboflavin, are designed for use in a blood bank; the SD method is generally applied at a centralized manufacturing centre and involves large plasma pools. All methods result in a reduction in protein values with the per cent retention of FVIII activity in the range of 67-78% and fibrinogen of 65-84%. Protein S and alpha(2)-antiplasmin are lower following solvent-detergent treatment. Alterations in fibrinogen structure have been reported with methylene blue.

DISCUSSION

Three of the methods are designed for small volume use in a blood bank. All four methods have some effect on the coagulant proteins; however, the final concentrations are within regulated limits. While there is variability in the effectiveness against pathogens, direct comparison is difficult because of the methodologies used. Nonetheless, all are effective in inactivating HIV and other lipid-enveloped pathogens. Clinical studies on the effectiveness of these products are surprisingly sparse, and no randomized clinical trials have yet been performed with amotosalen or riboflavin plasmas.

Pathogen Reduction Technology Treatment of Platelets, Plasma and Whole Blood Using Riboflavin and UV Light

Bacterial contamination and emerging infections combined with increased international travel pose a great risk to the safety of the blood supply. Tests to detect the presence of infection in a donor have a 'window period' during which infections cannot be detected but the donor may be infectious. Agents and their transmission routes need to be recognized before specific tests can be developed. Pathogen reduction of blood components represents a means to address these concerns and is a proactive approach for the prevention of transfusion-transmitted diseases. The expectation of a pathogen reduction system is that it achieves high enough levels of pathogen reduction to reduce or prevent the likelihood of disease transmission while preserving adequate cell and protein quality. In addition the system needs to be non-toxic, non-mutagenic and should be simple to use. The Mirasol® Pathogen Reduction Technology (PRT) System for Platelets and Plasma uses riboflavin (vitamin B2) plus UV light to induce damage in nucleic acid-containing agents. The system has been shown to be effective against clinically relevant pathogens and inactivates leukocytes without significantly compromising the efficacy of the product or resulting in product loss. Riboflavin is a naturally occurring vitamin with a well-known and well-characterized safety profile. The same methodology is currently under development for the treatment of whole blood, making pathogen reduction of all blood products using one system achievable. This review gives an overview of the Mirasol PRT System, summarizing the mechanism of action, toxicology profile, pathogen reduction performance and clinical efficacy of the process.

Development of the S-303 Pathogen Inactivation Technology for Red Blood Cell Concentrates

Pathogen inactivation systems are in use in many European countries as routine procedures. However, a pathogen inactivation system for erythrocytes is currently not available. Although significant improvements have been made to decrease the incidence of transfusion-transmitted infections, risks remain for infectious disease agents specific to red blood cell concentrates, such as parasitic infections resulting in babesiosis and malaria. The pathogen inactivation system for erythrocytes utilizes S-303 and glutathione for the treatment of red blood cell concentrates. Preclinical studies to assess the pathogen inactivation efficacy and toxicology as well as preliminary clinical studies have been completed. Preclinical studies have shown log reduction for leukocytes, several viruses and bacteria in excess of 4 to 6 logs. Preclinical toxicology studies were conducted to enable the initiation of two phase III clinical studies in the USA for support of acute and chronic anemia. A second-generation system was developed after observation of an unexpected immune response in two chronic anemia patients. Preclinical pathogen inactivation studies, serological evaluations and a clinical study to evaluate survival of S-303-treated erythrocytes have been completed to support advanced development of the S-303 pathogen inactivation system. A functional system for the inactivation of red blood cell concentrates has been completed and is reaching clinical application.

Pathogen Inactivation of Platelet and Plasma Blood Components for Transfusion Using the INTERCEPT Blood System™

BACKGROUND: The transmission of pathogens via blood transfusion is still a major threat. Expert conferences established the need for a pro-active approach and concluded that the introduction of a pathogen inactivation/reduction technology requires a thorough safety profile, a comprehensive pre-clinical and clinical development and an ongoing hemovigilance program. MATERIAL AND METHODS: The INTERCEPT Blood System utilizes amotosalen and UVA light and enables for the treatment of platelets and plasma in the same device. Preclinical studies of pathogen inactivation and toxicology and a thorough program of clinical studies have been conducted and an active he-movigilance-program established. RESULTS: INTERCEPT shows robust efficacy of inactivation for viruses, bacteria (including spirochetes), protozoa and leukocytes as well as large safety margins. Furthermore, it integrates well into routine blood center operations. The clinical study program demonstrates the successful use for very diverse patient groups. The hemovigilance program shows safety and tolerability in routine use. Approximately 700,000 INTERCEPT-treated products have been transfused worldwide. The system is in clinical use since class III CE-mark registration in 2002. The safety and efficacy has been shown in routine use and during an epidemic. CONCLUSION: The INTERCEPT Blood System for platelets and plasma offers enhanced safety for the patient and protection against transfusion-transmitted infections.