Adonis Stassinopoulos

Inactivation of parvovirus B19 in human platelet concentrates by treatment with amotosalen and ultraviolet A illumination.

BACKGROUND: The human erythrovirus B19 (B19) is a small (18‐ to 26‐nm) nonenveloped virus with a single‐stranded DNA genome of 5.6 kb. B19 is clinically significant and is also generally resistant to pathogen inactivation methods. Photochemical treatment (PCT) with amotosalen and ultraviolet A (UVA) inactivates viruses, bacteria, and protozoa in platelets (PLTs) and plasma prepared for transfusion. In this study, the capacity of PCT to inactivate B19 in human PLT concentrates was evaluated.

Quantification of Viral Inactivation by Photochemical Treatment with Amotosalen and UV A Light, Using a Novel Polymerase Chain Reaction Inhibition Method with Preamplification

Abstract Background. In evaluating a photochemical treatment process for inactivating parvovirus B19, there lacked simple culture methods to measure infectivity. The recently developed enzyme‐linked immunospot (ELISpot) infectivity assay uses late‐stage erythropoietic progenitor cells and is labor intensive and time consuming. We evaluated a novel, efficient polymerase chain reaction (PCR) inhibition assay and examined correlations with reductions in infectivity. Methods. Contaminated plasma was treated with 150 μmol/L amotosalen and 3 J/cm2 ultraviolet A light and then tested for DNA modification using conventional PCR inhibition and a novel preamplification approach. The novel assay subjected the samples to preamplification cycles using long‐template PCR, followed by quantitative PCR (QPCR) inhibition detection. Both approaches were tested for correlations with reductions in viral infectivity by comparing ELISpot assay results of identical samples. Results. The B19 preamplification inhibition assay showed detection ranges of 2–2.5 log and demonstrated quantitative correlation with up to a 5.8‐log reduction in viral infectivity in ELISpot results. Conventional PCR detected a >5 log reduction in amplification, correlated with a 4.4‐log reduction in viral infectivity. A range of 4‐log inhibition of hepatitis B virus DNA amplification was also achieved. Conclusions. The results demonstrated that a novel preamplification QPCR assay is a useful tool for predicting reductions in infectivity after photochemical treatment. This assay was extended to show utility in circumstances where practical in vitro assays are unavailable for the determination of the efficacy of pathogen inactivation.

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

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

Amustaline (S-303) treatment inactivates high levels of Zika virus in red blood cell components

The potential for Zika virus (ZIKV) transfusion‐transmission (TT) has been demonstrated in French Polynesia and Brazil. Pathogen inactivation (PI) of blood products is a proactive strategy to inactivate TT pathogens including arboviruses. Inactivation of West Nile, dengue, Zika, and chikungunya viruses was previously demonstrated by photochemical treatment with amotosalen and ultraviolet A (UVA) illumination. In this study, we evaluated ZIKV inactivation in red blood cell (RBC) components by a chemical approach that uses amustaline (S‐303) and glutathione (GSH).

Inactivation of Zika virus in platelet components using amotosalen and ultraviolet A illumination

Concerned over the risk of Zika virus (ZIKV) transfusion transmission, public health agencies recommended the implementation of mitigation strategies for its prevention. Those strategies included the use of pathogen inactivation for the treatment of plasma and platelets. The efficacy of amotosalen/ultraviolet A to inactivate ZIKV in plasma had been previously demonstrated, and the efficacy of inactivation in platelets with the same technology was assumed. These studies quantify ZIKV inactivation in platelet components using amotosalen/ultraviolet A.

Assessment of nucleic acid modification induced by amotosalen and ultraviolet A light treatment of platelets and plasma using real-time polymerase chain reaction amplification of variable length fragments of mitochondrial DNA

Pathogen inactivation methods are increasingly used to reduce the risk of infections after transfusion of blood products. Photochemical treatment (PCT) of platelets (PLTs) and plasma with amotosalen and ultraviolet A (UVA) light inactivates pathogens and white blood cells through formation of adducts between amotosalen and nucleic acid that block replication, transcription, and translation. The same adducts block the amplification of nucleic acids using polymerase chain reaction (PCR) in a manner that correlates with the number of adducts formed, providing a direct quality control (QC). Current QC measures for PCT rely on indirect methods that measure the delivered UVA dose or percent residual amotosalen after illumination, rather than directly measuring nucleic acid modification.

Inactivation of Babesia microti in red blood cells and platelet concentrates

With an increasing number of recognized transfusion‐transmitted (TT) babesiosis cases, Babesia microti is the most frequently TT parasite in the United States. We evaluated the inactivation of B. microti in red blood cells (RBCs) prepared in Optisol (AS‐5) using amustaline and glutathione (GSH) and in platelet components (PCs) in 100% plasma using amotosalen and low‐energy ultraviolet A (UVA) light.

Amustaline (S‐303) treatment inactivates high levels of Chikungunya virus in red‐blood‐cell components

Chikungunya virus (CHIKV) infections have been reported in all continents, and the potential risk for CHIKV transfusion‐transmitted infections (TTIs) was demonstrated by the detection of CHIKV RNA‐positive donations in several countries. TTIs can be reduced by pathogen inactivation (PI) of blood products. In this study, we evaluated the efficacy of amustaline and glutathione (S‐303/GSH) to inactivate CHIKV in red‐blood‐cell concentrates (RBCs).

Amotosalen/UVA treatment inactivates T cells more effectively than the recommended gamma dose for prevention of transfusion-associated graft-versus-host disease: T-CELL INACTIVATION IN PLASMA BY AMOTOSALEN/UVA

Transfusion‐associated graft‐versus‐host disease (TA‐GVHD) is a rare complication after transfusion of components containing viable donor T cells. Gamma irradiation with doses that stop T‐cell proliferation is the predominant method to prevent TA‐GVHD. Treatment with pathogen inactivation methodologies has been found to also be effective against proliferating white blood cells, including T cells. In this study, T‐cell inactivation was compared, between amotosalen/ultraviolet A (UVA) treatment and gamma‐irradiation (2500 cGy), using a sensitive limiting dilution assay (LDA) with an enhanced dynamic range.

Pathogen inactivation of Dengue virus in red blood cells using amustaline and glutathione

Dengue virus (DENV) is an arbovirus primarily transmitted through mosquito bite; however, DENV transfusion‐transmitted infections (TTIs) have been reported and asymptomatic DENV RNA–positive blood donors have been identified in endemic countries. DENV is considered a high‐risk pathogen for blood safety. One of the mitigation strategies to prevent arbovirus TTIs is pathogen inactivation. In this study we demonstrate that the amustaline and glutathione (S‐303/GSH) treatment previously found effective against Zika virus in red blood cells (RBCs) is also effective in inactivating DENV.