BACKGROUND: Hepatitis C virus (HCV) is a worldwide common disease. Some predictive factors influencing the response to interferon alpha (IFN-α) therapy have been identified, but the conclusions differ in various counties and areas. The aim of this study was to study the associations between HCV genotypes, HLA-DRB alleles and their response to IFN-α and ribavirin in Chinese patients with chronic hepatitis C in Northeast China.
METHODS: HCV genotypes of 113 patients with HCV were investigated. Gene chips were used to analyze the frequency of HLA-DRB in 25 of these patients and their response to IFN-α and ribavirin. The associations of HCV genotypes, HLA-DRB alleles and their response to IFN-α and ribavirin were also studied.
RESULTS: The response rates differed in several types of HCV, with HCV 2b being the highest (57.78%), HCV 1a and 2a lower (46.15% and 47.62%) and HCV 1b the lowest (11.76%). The response rates to IFN-α and ribavirin in patients with DRB1*07 were higher than those with DRB1*04. Sex, HCV type and HLA-DRB were all related to the response. Most female patients with HCV 2b and HLA-DRB1*07 presented complete response, whereas male patients with HCV 1b and HLA-DRB1*04 usually demonstrated no response. DRB1*07 allele and HCV 2b were the factors closely related to the response. 
CONCLUSIONS: The response rate of HCV 1b may be the lowest even IFN-α and ribavirin are combined in treatment. Not only virus but also the host plays an important role in anti-virus therapy. Thus, it is necessary to adjust the host’s  immune status to accelerate the clearance of HCV.