Aim: Continuation of pegylated interferon (PEG-IFN) plus ribavirin at the recommended dose is difficult in elderly patients and/or patients with cytopenia or complications. Whether the therapeutic efficacy of low-dose PEG-IFN plus ribavirin therapy could be predicted based on virological response within 2 weeks of therapy initiation was evaluated.
Methods: A total of 106 patients with a high viral load of genotype-1b hepatitis C virus (HCV) underwent low-dose PEG-IFN plus ribavirin therapy. PEG-IFN alpha 2b (0.75 µg/kg per week) and ribavirin (600–800 mg/day) were administered for 48 weeks.
Results: Sustained virological response (SVR) was achieved in 37%, and treatment was discontinued in 9%. On univariate analysis of SVR-contributing factors, significant differences were noted in the white blood cell count, platelet count, fibrosis markers, and viral reduction within 2 weeks from therapy initiation. On multivariate analysis, the platelet count and the reduction in the HCV core antigen level at week 2 were independent factors. The positive predictive value (PPV) and the negative predictive value (NPV) for SVR based on a 1-log or greater HCV-RNA level reduction at week 2 were 65% and 90%, respectively, and those based on HCV core antigen level at week 2 were 64% and 97%, respectively. PPV and NPV based on a 2-log or greater reduction of the RNA level were 86% and 67%, respectively, and those based on the core antigen level were 93% and 69%, respectively.
Conclusion: Evaluation of viral reduction at week 2 after therapy initiation is useful for predicting SVR to low-dose PEG-IFN plus ribavirin therapy.