title: Effect of prolonged administration of pegylated interferon/ribavirin therapy in genotypes 2a and 2b: propensity score-matched analysis.
abstract: OBJECTIVE
  Chronic hepatitis C genotype 2 patients show high susceptibility to pegylated interferon plus ribavirin therapy (PEG/RBV). However, the differences in response to therapy between genotypes 2a and 2b, and the efficacy of prolonged therapy for refractory patients have not been evaluated. We investigated the differences in response to PEG/RBV between each genotype and examined the efficacy of prolonged therapy.
  
  
  METHODS
  A total of 343 chronic hepatitis patients infected with hepatitis C virus (HCV) genotype 2 (2a: n = 195; 2b: n = 148) were enrolled in this study. All patients received PEG/RBV for 24 (24 week group, n = 242) or more weeks (prolonged group, n = 101). We analyzed the differences in virological response between genotypes 2a and 2b. Clinical and virological factors of patients in the 24-week group and the prolonged treatment group were matched using propensity score analysis, and the efficacy of prolonged therapy established by comparing time of serum HCV disappearance for each genotype.
  
  
  RESULTS
  Virological response tended to be higher for genotype 2a compared with genotype 2b; however, there was no significant difference in sustained virological response rates between genotypes (2a: 78.3%; 2b: 70.2%; P = 0.19). After propensity score matching, the adjusted P-value for sustained virological response rate was significantly different for genotype 2b patients with undetectable HCV-RNA between weeks 5 and 8, and for genotype 2a patients with detectable HCV-RNA at week 8.
  
  
  CONCLUSIONS
  Prolonged therapy with PEG/RBV may be effective when serum HCV-RNA is detectable at week 4 and week 8 for genotype 2b and 2a patients, respectively.
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Satoe
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Yoshiiku
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Michio
authors.initials: M
authors.lastname: Imamura
authors.forename: C Nelson
authors.initials: CN
authors.lastname: Hayes
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kohno
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kohno
authors.forename: Keiji
authors.initials: K
authors.lastname: Tsuji
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Aisaka
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Kira
authors.forename: Keitarou
authors.initials: K
authors.lastname: Yamashina
authors.forename: Michihiro
authors.initials: M
authors.lastname: Nonaka
authors.forename: Shoichi
authors.initials: S
authors.lastname: Takahashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Moriya
authors.forename: Mikiya
authors.initials: M
authors.lastname: Kitamoto
authors.forename: Shiomi
authors.initials: S
authors.lastname: Aimitsu
authors.forename: Toshio
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Hiroiku
authors.initials: H
authors.lastname: Kawakami
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000008:administration & dosage*; D004338:Drug Combinations; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics*; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000008:administration & dosage*; D057216:Propensity Score; D012367:RNA, Viral; D011994:Recombinant Proteins / Q000008:administration & dosage; D012254:Ribavirin / Q000008:administration & dosage*; D013997:Time Factors; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D004338:Drug Combinations; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012367:RNA, Viral; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C417083:peginterferon alfa-2b; C100416:peginterferon alfa-2a
keywords: genotype 2a; genotype 2b; hepatitis C; pegylated interferon plus ribavirin therapy; prolonged therapy