title: Influence of Host and Viral Factors on Patients with Chronic Hepatitis C Virus Genotype 6 Treated with Pegylated Interferon and Ribavirin: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  We conducted a systematic review and meta-analysis of the influence of host and viral factors on the sustained virologic response (SVR) in hepatitis C virus genotype 6 (HCV-6) patients treated with pegylated interferon (PEG-IFN) and ribavirin (RBV).
  
  
  METHODS
  Data were retrieved from Medline, Embase, PubMed and the Cochrane Library for 'genotype 6' studies published up to December 2014 and for abstracts from international scientific meetings. Inclusion criteria were efficacy of PEG-IFN+RBV based on SVR, 24- or 48-week therapy and treatment-naïve patients. Patients with hepatitis B, D and E and HIV coinfection or another concurrent liver disease were excluded. Pooled standard difference, odds ratio and confidence intervals (CIs) were calculated using a random-effect model with STATA 11.
  
  
  RESULTS
  Fourteen studies were included in the meta-analysis. The pooled SVR rate was 80% (95% CI: 0.78-0.83, p < 0.0001; I2 = 71.2%). SVR of the PEG-IFN+RBV-treated HCV-6 patients was markedly higher than that of HCV-1 patients (80.1 vs. 55.3%). The SVR rate was significantly higher for the 48- than the 24-week treatment, but not different among HCV-infected patients with rs12979860 and ss469415590 polymorphisms of the ILFN4 gene (80.6% CC vs. 66.7% non-CC, p = 0.593; 81.1% TT/TT vs. 60% non-TT/TT, p = 0.288). Gender and type of PEG-IFN did not affect SVR rates.
  
  
  CONCLUSIONS
  Treatment outcomes for HCV-6 patients are superior to those for HCV-1 patients and comparable to those of HCV-2 and HCV-3 patients, especially at 48 weeks. The level of fibrosis affects treatment outcome, but SVR rates are not significantly different between genders. IL28B and IFNL4 polymorphisms are not significantly associated with HCV-6 treatment outcome.
authors.affiliation: Center of Excellence in Clinical Virology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Vo Duy
authors.initials: VD
authors.lastname: Thong
authors.forename: Kittiyod
authors.initials: K
authors.lastname: Poovorawan
authors.forename: Pisit
authors.initials: P
authors.lastname: Tangkijvanich
authors.forename: Rujipat
authors.initials: R
authors.lastname: Wasitthankasem
authors.forename: Sompong
authors.initials: S
authors.lastname: Vongpunsawad
authors.forename: Yong
authors.initials: Y
authors.lastname: Poovorawan
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use*; D060085:Coinfection / Q000188:drug therapy; D005838:Genotype; D016174:Hepacivirus / Q000145:classification / Q000235:genetics / Q000276:immunology*; D019698:Hepatitis C, Chronic / Q000276:immunology* / Q000821:virology; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D016898:Interferon-alpha / Q000627:therapeutic use*; D011092:Polyethylene Glycols / Q000627:therapeutic use; D011110:Polymorphism, Genetic / Q000235:genetics*; D012254:Ribavirin / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D007155:Immunologic Factors; D016898:Interferon-alpha; D011092:Polyethylene Glycols; D012254:Ribavirin