Hepatitis C treatment response kinetics and impact of baseline predictors.

The optimal duration of treatment for hepatitis C virus (HCV) infections is highly variable but critical for achieving cure (sustained virological response, SVR). We prospectively investigated the impact of age, fibrosis, baseline viraemia and genotype on the early viral kinetics and treatment outcome. Patients treated with peginterferon alfa-2a and ribavirin in standard dosing were included: 49 with genotype 1 treated for 48weeks and 139 with genotype 2 or 3 treated for 24weeks. The reduced SVR rates in patients older than 45years, with severe liver fibrosis or pretreatment viraemia above 400,000IU/mL were strongly associated with slower second phase declines of HCV RNA. Genotype 2/3 infections responded more rapidly than genotype 1, reaching week 4 negativity (RVR) in 59%vs 22%. We conclude that baseline response predictors such as age, fibrosis and viral load were well reflected by the early viral kinetics as assessed by repeated HCV RNA quantifications. The kinetic patterns and the high relapse rate in genotype 2/3 patients without RVR suggest that this group might benefit from treatment durations longer than 24weeks.