Introduction: Several pretreatment factors have been reported to be useful in predicting patients with a high probability for a sustained response to IFN-alpha treatment, however, predictors of the efficacy of interferonbeta treatment in chronic hepatitis C have not been fully assessed.
Material and methods: To clarify this issue, a prospective study of 52 patients with chronic hepatitis C was conducted. Patients were treated with human natural interferon-beta by drip infusion at doses of 6 MU/day for 8 weeks. The following characteristics were compared between patients with sustained response (SR) and no response (NR): gender, age, source of HCV infection, mean pretreatment serum ALT levels, liver histology, pretreatment serum HCV-RNA levels and HCV genotype.
Results: Seventeen of 52 patients (32.7%) demonstrated SR. The proportion of patients with undetectable HCV-RNA levels determined by branched DNA assay (<0.5 ´ 106 eq/ml) was higher in patients with SR than in those with NR (88.2% vs. 22.9%; p=0.0001). Pretreatment HCV RNA levels determined by multicyclic reverse transcriptase polymerase chain reaction were lower in patients with SR than in those with NR (105.1±1.5 vs. 107.1±1.3 copies/ml; p=0.0001). The rate of SR was higher in patients with genotype 2a or 2b than in genotype 1b (43.8% vs. 15.0%; p=0.0382). Multivariate stepwise logistic regression analysis showed that a younger age and low pretreatment serum levels of HCV RNA were independent predictors of SR to treatment. This prospective study demonstrated that a younger age, low pretreatment viral load and HCV genotype 2a or 2b were factors influencing the SR to interferon-beta treatment, but a younger age and low pretreatment viral load were most important predictors of the efficacy of the treatment.

Keywords: sustained response (SR), HCV-RNA, HCV genotype, IFN-beta