Th1 response during ribavirin and interferon-alpha combination therapy in chronic hepatitis C.

Ribavirin and interferon-alpha induce Th1 polarization of human CD4+ T cells. The study was conducted to investigate the whether cellular immune response during ribavirin/interferon-alpha therapy is associated with viral eradication by examining mRNA expression of molecules relevant to Th1 and Th2 polarization in CD4+ cells of 13 patients with chronic hepatitis C (seven patients with sustained viral response and six with transient response). Peripheral CD4+ T lymphocytes at 0, 4 and 24 weeks of treatment were tested. There were no significant differences in the mRNA levels at each point of time of the treatment between patients with sustained viral response and those with transient response. The percent increase in mRNA level of the IL-12R beta2 chain from the baseline to the end of the treatment was significantly higher in patients with sustained viral response (15.3+/-6.1%) than in those with transient response (-1.6+/-4.7%, p<0.05). There was no significant difference in percent changes in level of IL-12R beta1 chain mRNA between the two groups. In conclusion, the results of this study indicate that the increase of Th1 response is related to the inflammatory activity in the liver and possibly to ribavirin and interferon-alpha therapy. It is also suggested that the measurement of Th1 response has the potential to distinguish patients with relapse from those with sustained virus response.