[Predicting factors for the response to interferon therapy against hepatitis C virus infection: HCV genotyping].

The predictive factors in the efficacy of interferon therapy were analyzed on the patients with chronic hepatitis C by multivariate analysis, and HCV genotype and histological diagnosis were found useful for predicting the response to interferon therapy. Of the patients, 57% were found to be infected with HCV II, 27% were with HCV III, and 3% were with HCV IV. HCV I was not found in our patients. The complete response rate of the patients with HCV II (21%) was significantly lower than that of HCV III (63%). The concentration of HCV RNA was significantly larger in the patients with HCV II than in those with HCV III. When the patients with equal concentrations of HCV RNA were compared, the complete response rate was also significantly lower in the patients with HCV II than in those with HCV III. On histological diagnosis, the patients with mild disease were significantly more responsive than those with severe disease. The complete response rate of the patients with HCV II who have severe histological lesions (severe CAH) was 7%. On the other hand, the complete response rate of the patients with HCV III and a histological diagnosis of mild disease (CPH or mild CAH) was 80%. Our findings suggest that the outcome of interferon therapy can be predicted to some degree from the pretreatment data.