Efficacy of Interferon Monotherapy for Chronic Hepatitis C : Investigation of appropriate treatment with respect to histologic and virologic factors, and usefulness of twice-daily interferon-β administration as induction therapy

[Abstract] In order to determine the most appropriate interferon (IFN) therapy according to patient background and to evaluate the efficacy of twice-daily IFN-β induction therapy (β2 therapy), 320 patients with chronic hepatitis C who underwent various IFN monotherapy regimens were retrospectively analyzed. Sustained virological response (SVR) and biochemical response (BR) rates were calculated with respect to HCV serogroup (SG), pretreatment viral load, histological stage, total IFN dose, and IFN regimen (Low, Medium, High, and β2 therapy). The total IFN dose in β2 therapy was almost equal to that in the High group. The SVR rate for β2 therapy in patients with stage F0-2 was as follows: SG 1 infection and high viral load 27%, SG 1 infection and low viral load 80%, and SG 2 infection and high viral load 78%, and was higher than that for the other regimens. The combined efficacy rate, including BR, for β2 therapy was the highest among all regimens, indicating that this should be the first choice of treatment for the above types of patients. The SVR rate for β2 therapy in patients with SG2 infection and low viral load was 90%, and was 70% even in the Low group (total dose: about 300 MU), and thus the initial therapy for these patients could be short-term. Among patients with stage F3/4 the overall SVR rate for patients with low viral load was 41% (11/27), which suggests that IFN therapy should be actively considered.