Role of endogenous interferon in hepatitis C virus (HCV) infection and in coinfection by HIV and HCV

Recombinant interferon alpha (IFN alpha), widely used in the treatment of chronic hepatitis C, can induce a major decrease in HCV viraemia in good responders. In order to evaluate the possible role of endogenous IFN, using a biological method, we measured the IFN levels in 74 patients infected by HCV and in 73 patients coinfected by HIV and HCV. IFN levels were much higher in the HCV+HIV+ group and were linked to HIV viraemia. In those patients with high IFN levels, the HCV viraemia was lower, but only in the HCV+ group. These data suggest that IFN can partly control the HCV viraemia, but in coinfection by HIV, the response of HCV to endogenous IFN could be lower.