Outcome in partial early virologic responders to combination therapy with peginterferon and ribavirin in patients infected with hepatitis C virus genotype 1b.

The course and outcome in patients infected with hepatitis C virus (HCV) genotype 1b with partial early virologic response during combination therapy with peginterferon and ribavirin, in whom serum HCV RNA is detectable but has decreased by more than 2 log(10) 12 weeks after the start of the therapy, has not been elucidated sufficiently. The outcome in this group of patients was investigated. Serum HCV RNA levels was measured every 4 weeks in 149 patients with HCV genotype 1b infection who underwent combination therapy for 48 weeks. In patients with partial early virologic response, the time point when serum HCV RNA became undetectable as well as the final virologic response to treatment was determined. Sixty-three patients (42.3%) had partial early virologic response. The time when serum HCV RNA became undetectable ranged from 16 to 48 weeks after the start of therapy. Serum HCV RNA remained detectable in 17 patients. The rates of sustained virologic response decreased with the delay of the time when serum HCV RNA became undetectable; sustained virologic responder was not found in patients in whom HCV RNA was still detectable at 24 weeks after the start of treatment. The degree of decrease in serum HCV RNA levels at 12 weeks corresponded to the rate of sustained virologic response in partial early virologic responders. The outcome of partial early virologic responders varied greatly, and close monitoring of serum HCV RNA is required for predicting the outcome of treatment in these patients.