Effective interferon therapy for chronic hepatitis C patients with low viral loads.
OBJECTIVE
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.


METHODS
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.
Fujiyama
Shigetoshi
S
Third Department of Internal Medicine, Kumamoto University School of Medicine, 1-1, Honjo 1-chome, Kumamoto 860-8556, Japan. shfujiya@kaiju.medic.kumamoto-u.ac.jp
Chikazawa
Hideto
H
Honda
Yoshikazu
Y
Tomita
Kimio
K
D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000008:administration & dosage*; D001706:Biopsy; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000187:drug effects / Q000235:genetics; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000473:pathology / Q000821:virology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage* / Q000009:adverse effects; D008099:Liver / Q000473:pathology; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D012367:RNA, Viral / Q000097:blood; D011994:Recombinant Proteins; D016896:Treatment Outcome; D014759:Viral Envelope Proteins / Q000235:genetics; D019562:Viral Load; D014764:Viral Proteins / Q000235:genetics
D000998:Antiviral Agents; C400562:HVR1 protein, Hepatitis C virus; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012367:RNA, Viral; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C091015:glycoprotein E2, Hepatitis C virus