Antiviral activity of the interferon α family: biological and pharmacological aspects of the treatment of chronic hepatitis C

Introduction: Type I interferons (IFNs) comprise a group of at least 13 structurally related subtypes of IFN-alpha with similar, but not identical, biological activities. Each subtype displays a unique activity profile; only IFN-alpha 2a and IFN-alpha 2b subtypes together with natural IFN-alpha preparations are currently used in the clinical practice, so that the remaining IFN-alpha subtypes are a still unexploited reservoir of opportunity also in the new era of directacting antiviral agents for the treatment of hepatitis C virus (HCV). Areas covered: This paper reviews recent progress in the study of the biology of IFN family, the antiviral action mechanism and the strategies employed by HCV to evade IFN action. Currently available IFN preparations for the treatment of chronic hepatitis C infection are described and what is currently known on the pharmacokinetics, pharmacodynamics and immunogenicity of IFN-alpha preparations used in clinical practice are summarized. Expert opinion: The characterization of multifunctional nature of IFN system together with recent advances in the identification of HCV IFN evasion strategies and the variety of host factors influencing IFN treatment response should be considered to improve HCV and other infectious diseases treatment in the future.