Study of coagulation function in thawed apheresis plasma for photochemical treatment by amotosalen and UVA

Preservation of neutralizing antibody function in COVID-19 convalescent plasma treated using a riboflavin and ultraviolet light-based pathogen reduction technology

Background and objectives

Convalescent plasma (CP) has been embraced as a safe therapeutic option for coronavirus disease 2019 (COVID‐19), while other treatments are developed. Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is not transmissible by transfusion, but bloodborne pathogens remain a risk in regions with high endemic prevalence of disease. Pathogen reduction can mitigate this risk; thus, the objective of this study was to evaluate the effect of riboflavin and ultraviolet light (R + UV) pathogen reduction technology on the functional properties of COVID‐19 CP (CCP).

Materials and methods

COVID‐19 convalescent plasma units (n = 6) from recovered COVID‐19 research donors were treated with R + UV. Pre‐ and post‐treatment samples were tested for coagulation factor and immunoglobulin retention. Antibody binding to spike protein receptor‐binding domain (RBD), S1 and S2 epitopes of SARS‐CoV‐2 was assessed by ELISA. Neutralizing antibody (nAb) function was assessed by pseudovirus reporter viral particle neutralization (RVPN) assay and plaque reduction neutralization test (PRNT).

Results

Mean retention of coagulation factors was ≥70%, while retention of immunoglobulins was 100%. Starting nAb titres were low, but PRNT₅₀ titres did not differ between pre‐ and post‐treatment samples. No statistically significant differences were detected in levels of IgG (P ≥ 0·3665) and IgM (P ≥ 0·1208) antibodies to RBD, S1 and S2 proteins before and after treatment.

Conclusion

R + UV PRT effects on coagulation factors were similar to previous reports, but no significant effects were observed on immunoglobulin concentration and antibody function. SARS‐CoV‐2 nAb function in CCP is conserved following R + UV PRT treatment.

Maintaining plasma quality and safety in the state of ongoing epidemic - The role of pathogen reduction

In the field of transfusion medicine, many pathogen reduction techniques (PRTs) are currently available, including those based on photochemical (PI) and photodynamic inactivation (PDI). This is particularly important in the face of emerging viral pathogens that may pose a threat to blood recipients, as in the case of the COVID-19 pandemic. However, PRTs have some limitations, primarily related to their adverse effects on coagulation factors, which should be considered before their intended use. A comprehensive search of PubMed, Wiley Online Library and Science Direct databases was conducted to identify original papers. As a result, ten studies evaluating fresh plasma and frozen-thawed plasma treated with different PI/ PDI methods and evaluating concentrations of coagulation factors and natural anticoagulants both before and after photochemical treatment were included in the review. The use of PI and PDI is associated with a significant decrease in the activity of all analysed coagulation factors, while the recovery of natural anticoagulants remains at a satisfactory level, variable for individual inactivation methods. In addition, the published evidence reviewed above does not unequivocally favour the implementation of PI/PDI either before freezing or after thawing as plasma products obtained with these two approaches seem to satisfy the existing quality criteria. Based on current evidence, if implemented responsibly and in accordance with the current guidelines, both PI and PDI can ensure satisfactory plasma quality and improve its safety.

Hemostatic properties and protein expression profile of therapeutic apheresis plasma treated with amotosalen and ultraviolet A for pathogen inactivation

BACKGROUND

The INTERCEPT Blood System (IBS) using amotosalen-HCl and ultraviolet (UV)A inactivates a large spectrum of microbial pathogens and white blood cells in therapeutic plasma. Our aim was to evaluate to what extent IBS modifies the capacity of plasma to generate thrombin and induces qualitative or quantitative modifications of plasma proteins.

STUDY DESIGN AND METHODS

Plasma units from four donors were collected by apheresis. Samples were taken before (control [CTRL]) and after IBS treatment and stored at -80°C until use. The activities of plasma coagulation factors and inhibitors and the thrombin generation potential were determined using assays measuring clotting times and the calibrated automated thrombogram (CAT), respectively. The proteomic profile of plasma proteins was examined using a two-dimensional differential in-gel electrophoresis (2D-DIGE) method.

RESULTS

Nearly all of the procoagulant and antithrombotic factors tested retained at least 78% of their initial pre-IBS activity. Only FVII and FVIII displayed a lower level of conservation (67%), which nevertheless remained within the reference range for conventional plasma coagulation factors. The thrombin generation profile of plasma was conserved after IBS treatment. Among the 1331 protein spots revealed by 2D-DIGE analysis, only four were differentially expressed in IBS plasma compared to CTRL plasma and two were identified by mass spectrometric analysis as transthyretin and apolipoprotein A1.

CONCLUSION

The IBS technique for plasma moderately decreases the activities of plasma coagulation factors and antithrombotic proteins, with no impact on the thrombin generation potential of plasma and very limited modifications of the proteomic profile.

Split Blood Products

The last 20 years have seen many advances in transfusion therapy and safety. Blood products are biological products engendering complex interactions with the immune system. Prestorage leukoreduction results in a reduced risk of febrile reactions, CMV transmission, and immune modulation, proving to be safer for patients than non-leuko reduced products.

Simple patient identification issues and clerical error continue to be the primary causes of ABO-incompatible transfusions. Rigorous donor screening as well as serologic and nucleic acid testing for transfusion transmitted infection have brought the blood supply to a very safe level, although transmission of these agents continues to be a problem in underdeveloped countries. Emerging infectious diseases, beyond current laboratory detection capabilities, combined with global travel, pose unknown imminent risks everywhere. We also briefly discuss the current risks of transfusion-transmitted infections.

We review currently available hemostatic blood products, their compositions, and their clinical indications; we mention product modifications currently in development; and we touch upon the hemostatic properties and drawbacks of whole blood, which is currently gaining popularity as an alternative to split blood products. We conclude with an in-depth overview of the risks associated with transfusion, including incompatibility, hemolytic transfusion reactions, transfusion-associated circulatory overload (TACO), and transfusion-related acute lung injury (TRALI).

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

BACKGROUND

The quality of fresh-frozen plasma is affected by different factors. Factor VIII is sensitive to blood component storage processes and storage as well as pathogen-reduction technologies. The level of fibrinogen in plasma is not affected by the collection processes but it is affected by preparation and pathogen-reduction technologies.

MATERIALS AND METHODS

The quality of plasma from whole blood and apheresis donations harvested at different times and treated with a pathogen-reduction technique, methylene blue/light, was investigated, considering, in particular, fibrinogen and factor VIII levels and recovery.

RESULTS

The mean factor VIII level after methylene blue treatment exceeded 0.5 IU/mL in all series. Factor VIII recovery varied between 78% and 89% in different series. The recovery of factor VIII was dependent on plasma source as opposed to treatment time. The interaction between the two factors was statistically significant. Mean levels of fibrinogen after methylene blue/light treatment exceeded 200 mg/dL in all arms. The level of fibrinogen after treatment correlated strongly with the level before treatment. There was a negative correlation between fibrinogen level before treatment and recovery. Pearson's correlation coefficient between factor VIII recovery and fibrinogen recovery was 0.58.

DISCUSSION

These results show a difference in recovery of factor VIII and fibrinogen correlated with plasma source. The recovery of both factor VIII and fibrinogen was higher in whole blood plasma than in apheresis plasma. Factor VIII and fibrinogen recovery did not appear to be correlated.

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.

Pathogen inactivation in fresh frozen plasma using riboflavin and ultraviolet light: Effects on plasma proteins and coagulation factor VIII

Background/Aim. Riboflavin (vitamin B2) activated by ultraviolet (UV) light, produces active oxygen which damages cell membrane and prevents replication of the carrier of diseases (viruses, bacteria, protozoa) in all blood products. The aim of this study was to establish the influence of the process of photo inactivation in pathogens using riboflavin and UV rays on the concentration of coagulation factor VIII:C (FVIII:C) and proteins in plasma that were treated before freezing. Methods. The examination included 20 units of plasma, separated from whole blood donated by voluntary blood donors around 6 hours from the moment of collection. The units were pooled and separated in to two groups: one consisted of 10 control units and the other of 10 experimental units. Experimental units of the plasma were treated by riboflavin (35 mL) and UV rays (6.24 J/mL, 265-370 nm) on Mirasol aparature (Caridian BCT Biotechnologies, USA) in approximate duration of 6 minutes. Furthermore, 35 mL of saline solution was added to the control plasma. One sample for examining was taken from the control plasma (KG) and two residual were taken from experimental plasma after the addition of riboflavin either before (EG1) or post illumination (EG2). Results. Comparing the mean values of FVIII:C (%) we noticed statistically significantly higher level in the EG1 group than in the EG2 group (65.00 ? 4.52 vs 63.20 ? 4.73; t = 4.323, p = 0.002), while between the KG and experimental groups (EG1 and EG2) there was no statistically significant difference in the concentration of FVIII:C. There was a statistically significant decrease of albumin concentration (g/L) in the EG2 group comparing to the KG (33.35 ? 0.94 vs 31.94 ? 0.84; t = 3.534, p = 0.002), but there was no mentioned difference in albumin concentration between the KG and the EG1, so as between the EG1 and the EG2. Conclusion. Plasma inactivated by riboflavin and UV rays (Mirasol PRT sistem, Caridian BCT, USA) keeps all the characteristics of conventional plasma, so it could be used for the treatment of pathological conditions that demand transfusion of fresh frozen plasma, or in patients with thrombotic thrombocytopenic purpure when we use therapeutic exchange of plasma.