Inactivation of parvovirus B19 in human platelet concentrates by treatment with amotosalen and ultraviolet A illumination
ABSTRACT 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.
B19 inactivation was measured by a novel enzyme-linked immunosorbent spot (ELISPOT) erythroid progenitor cell infectivity assay and by inhibition of long-range (up to 4.3 kb) polymerase chain reaction (PCR), under conditions where the whole coding region of the viral genome was amplified. B19-infected plasma was used to test whether incubation of amotosalen with virus before PCT enhanced inactivation compared to immediate PCT.
Inactivation of up to 5.8 log of B19 as measured by the infectivity assay, or up to 6 logs as measured by PCR inhibition can be achieved under non-limiting conditions. Inactivation efficacy was found to increase with incubation prior to UVA illumination. Without incubation prior to illumination 2.1 +0.4 log was inactivated as determined by infectivity assay. When measured by PCR inhibition, inactivation varied inversely with amplicon size. When primers that spanned the entire coding region of the B19 genome were used, maximum inhibition of PCR amplification was demonstrated.
Under defined conditions, PCT with amotosalen combined with UVA light can be used to inactivate B19, a clinically significant virus that can be transmitted through blood transfusion, and heretofore has been demonstrated to be refractory to inactivation.
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ABSTRACT: Biological warfare and bioterrorism is an unpleasant fact of 21st century life. Highly infectious and profoundly virulent diseases may be caused in combat personnel or in civilian populations by the appropriate dissemination of viruses, bacteria, spores, fungi or toxins. Dissemination may be airborne, waterborne, or by contamination of food or surfaces. Countermeasures may be directed toward destroying or neutralizing the agents outside the body before infection has taken place, by destroying the agents once they have entered the body before the disease has fully developed, or by immunizing susceptible populations against the effects. A range of light-based technologies may have a role to play in biodefense countermeasures. Germicidal UV (UVC) is exceptionally active in destroying a wide range of viruses and microbial cells, and recent data suggests that UVC has high selectivity over host mammalian cells and tissues. Two UVA mediated approaches may also have roles to play; one where UVA is combined with titanium dioxide nanoparticles in a process called photocatalysis, and a second where UVA is combined with psoralens (PUVA) to produce "killed but metabolically active" microbial cells that may be particularly suitable for vaccines. Many microbial cells are surprisingly sensitive to blue light alone, and blue light can effectively destroy bacteria, fungi, and Bacillus spores and can treat wound infections. The combination of photosensitizing dyes such as porphyrins or phenothiaziniums and red light is called photodynamic therapy (PDT) or photoinactivation, and this approach cannot only kill bacteria, spores, and fungi, but also inactivate viruses and toxins. Many reports have highlighted the ability of PDT to treat infections and stimulate the host immune system. Finally pulsed (femtosecond) high power lasers have been used to inactivate pathogens with some degree of selectivity. We have pointed to some of the ways light-based technology may be used to defeat biological warfare in the future.Virulence 09/2013; 4(8). DOI:10.4161/viru.26475 · 3.32 Impact Factor
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ABSTRACT: 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.Transfusion Clinique et Biologique 08/2011; 18(4):444-462. DOI:10.1016/j.tracli.2011.05.005 · 0.67 Impact Factor
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ABSTRACT: The techniques for inactivation of pathogens in labile blood products (LBP) would appear to be the new strategy which will permit us to increase transfusion safety in the face of the risks of transmission of pathogenic agents by LBP. Various methods are in the course of development or already validated and used in France. The latter only apply however to plasma or platelet concentrates. The mechanisms of action and the efficacy of inactivation and attenuation of pathogenic agents vary with the different techniques. Each of these constitutes a preparative procedure composed of unit steps which have to be fully mastered in order to ensure the quality and transfusion efficacy of the treated product.Transfusion Clinique et Biologique 05/2009; 16(2):179-189. DOI:10.1016/j.tracli.2009.03.022 · 0.67 Impact Factor