Sindbis virus as a tool for quality control of viral inactivation of heated and chemically treated plasma-derived products

Regulatory guidelines for production of plasma-derived products emphasize the need to document methods of viral inactivation and demonstrate the effectiveness of screening methods. Therefore, it is important to evaluate the kinetics of such processes. Togaviridae family virions may be considered as good tools for quality control of haemoderivatives, if they possess large amounts of cholesterol and saturated lipids and high structural lipid/protein ratio in their envelope composition, which give more resistance to classical treatments. The purpose of this study was to evaluate the efficiency of solvent-detergent and heat treatments adopted during the human haemoderivatives processment. Sindbis virus was used as a model for inactivation of enveloped viruses. Semi-processed human factor VIII (FVIII) product experimentally contaminated with Sindbis virus was used to test a solvent-detergent treatment with tri-N-butyl-phosphate (TNBP) and Tween 80. To evaluate thermal inactivation kinetics, lyophilized, and reconstituted samples of Sindbis virus-containing FVIII were incubated up to 30 h at 60 °C. The results showed that treatment with TNBP and Tween 80 reduced the infectivity of virus-contaminated FVIII in ≥5.5 log10 and heat treatment was effective in all samples, although FVIII concentrate had reduced the rate of viral inactivation during a brief period of time.