Neutralizing antibodies to interferon-α and circulating interferon in patients with chronic hepatitis C non-responding to pegylated interferon plus ribavirin re-treated by pegylated interferon-α-2a and ribavirin (ANRS HC16 GAMMATRI substudy*)

A lack of antiviral response in patients with chronic hepatitis C treated with pegylated (PEG)-interferon (IFN)-α-2a + ribavirin (RIBA) may be explained by neutralizing antibodies to IFN-α-2a. The aim of this study was to assess neutralizing antibodies to IFN-α-2a and IFN levels in non-responder patients who were re-treated by PEG IFN-α-2a and RIBA for 12 weeks. Non-responders to a first-line treatment of PEG IFN-α-2a + RIBA were included for treatment with PEG IFN-α-2a (180 µg/week) + RIBA (1,000 mg/day if