The present study aimed to investigate alterations in Toll-like receptor 4 (TLR4), interferon regulatory factor 5 (IRF5) and interferon-gamma-inducible protein-10 (IP-10), and evaluate whether these factors may be associated with a sustained virological response (SVR) among patients with hepatitis C virus genotype-1 (HCV-1) who were treated with peginterferon plus ribavirin (PEG-IFN-RBV). A total of 31 Chinese patients infected with HCV-1 were enrolled in the present study and 25 patients obtained SVR. The expression levels of IP-10 declined significantly during PEG-IFN-RBV therapy at the 24 and 48 week time-points, compared with the baseline (P<0.005, 0.001 and 0.001, respectively). In addition, it was observed that IRF5 mRNA expression and the number of TLR4(+) peripheral blood mononuclear cells exhibited similar correlations with IP-10 concentration (R-2=0.0726, P=0.001, R-2=0.1634, P<0.0001, respectively) in the SVR group patients; however, these correlations were not observed to be present in the non-SVR group patients. In conclusion, the results of the present study suggest that marked alterations in IP-10, TLR4 and IRF5 expression may serve as indicators for the development of SVR in patients with HCV-1 treated with PEG-IFN-RBV.