BACKGROUND/AIMS: Possible short-term interferon therapy was investigated in chronic hepatitis C patients with genotype 2a or 2b and low viral-loads. Furthermore, initial changes of hepatic C virus RNA levels in early phase interferon therapy, and the number of pretreatment mutated clones at hypervariable region-1 were determined in order to upgrade interferon therapy efficacy prediction rates. METHODOLOGY: Study subjects were 31 patients with histologically proven chronic hepatitis C, having less than 1 Meq/mL of hepatic C virus RNA levels. Daily dose was defined as 9 MU of interferon; patients with genotype lb were treated for 26 weeks, while those with genotype 2a or 2b were treated for 16 weeks. RESULTS: Sustained response rates showed no difference in efficacy between the 2 groups (66.7% vs. 62.5%). Response rates based on the number of hypervariable region-1 clones indicated that the fewer the number of mutated clones, more significant was the increase in efficacy. Efficacy as hepatic C virus RNA in early phase treatment showed no difference in response rates between negative and positive groups at any time point from day 1. CONCLUSIONS: In a low viral-load group, the number of hypervariable region-1 clones was a critical factor influencing interferon therapy efficacy. Thus, 16-week interferon therapy was effective and economical.
BACKGROUND/AIMS: Possible short-term interferon therapy was investigated in chronic hepatitis Cpatients with genotype 2a or 2b and low viral-loads. Furthermore, initial changes of hepatic C virus RNA levels in early phase interferon therapy, and the number of pretreatment mutated clones at hypervariable region-1 were determined in order to upgrade interferon therapy efficacy prediction rates. METHODOLOGY: Study subjects were 31 patients with histologically proven chronic hepatitis C, having less than 1 Meq/mL of hepatic C virus RNA levels. Daily dose was defined as 9 MU of interferon; patients with genotype lb were treated for 26 weeks, while those with genotype 2a or 2b were treated for 16 weeks. RESULTS: Sustained response rates showed no difference in efficacy between the 2 groups (66.7% vs. 62.5%). Response rates based on the number of hypervariable region-1 clones indicated that the fewer the number of mutated clones, more significant was the increase in efficacy. Efficacy as hepatic C virus RNA in early phase treatment showed no difference in response rates between negative and positive groups at any time point from day 1. CONCLUSIONS: In a low viral-load group, the number of hypervariable region-1 clones was a critical factor influencing interferon therapy efficacy. Thus, 16-week interferon therapy was effective and economical.