Anti-interferon-α neutralizing antibody induced telaprevir resistance under the interferon-α plus telaprevir treatment in vitro

Factors associated with the response to interferon-based antiviral therapies for chronic hepatitis C

Hepatitis C virus (HCV) infection is a major health concern worldwide. Interferon-α (IFN-α) therapy has been the main antiviral treatment for more than 20 years. Because of its established antitumor effects, IFN-based treatments for chronic HCV infection still have a clinical impact, particularly for patients with high risk conditions of developing hepatocellular carcinoma, such as older age and advanced liver fibrosis. As a result of exhaustive research, several viral factors, including NS5A amino acid mutations such as the IFN sensitivity-determining region and the IFN/ribavirin resistance-determining region, and mutations of amino acids in the core protein region (core 70 and 91) were shown to be associated with the response to IFN-α treatment. In addition, among the host factors related to the response to IFN-α treatment, polymorphisms of the interleukin-28B gene were identified to be the most important factor. In this article, we review the factors associated with the efficacy of IFN-α treatment for chronic HCV infection. In addition, our recent findings regarding the possible involvement of anti-IFN-α neutralizing antibodies in a non-response to pegylated-IFN-α treatment are also described.

Natural interferon-beta treatment for patients with chronic hepatitis C in Japan

Chronic hepatitis C virus (HCV) infection can cause liver cirrhosis and hepatocellular carcinoma (HCC). Several studies have demonstrated that the eradication of HCV reduces the occurrence of HCC. In Japan, as many people live to an advanced age, HCV-infected patients are also getting older, and the age at HCC diagnosis has also increased. Although older HCV-infected patients have a risk of developing HCC, the treatment response to peginterferon-alpha plus ribavirin therapy is relatively poor in these patients because of drop-out or discontinuation of this treatment due to adverse events. It is established that the mechanism of action between interferon-alpha and interferon-beta is slightly different. Short-term natural interferon-beta monotherapy is effective for patients with acute hepatitis C and patients infected with HCV genotype 2 and low viral loads. Natural interferon-beta plus ribavirin for 48 wk or for 24 wk are also effective for some patients with HCV genotype 1 or HCV genotype 2. Natural interferon-beta plus ribavirin has been used for certain “difficult-to-treat” HCV-infected patients. In the era of direct-acting anti-virals, natural interferon-beta plus ribavirin may be one of the therapeutic options for special groups of HCV-infected patients. In the near future, signal transduction pathways of interferon-beta will inform further directions.