title: HCV genotype 1a shows a better virological response to antiviral therapy than HCV genotype 1b.
abstract: BACKGROUND
  The impact of viral subtype on the rate of sustained virological response (SVR) to antiviral therapy in patients chronically infected with hepatitis C genotype 1 subtype 1a and 1b has not been extensively investigated. The aim of this study is to determine whether the HCV genotype 1 subtypes 1a and 1b respond differently to treatment with PEGylated interferon (PEG-IFN) plus ribavirin.
  
  
  METHODS
  For 48 weeks, 388 "naïve"genotype 1 patients were treated weekly with PEG-IFN α-2a or PEG-INF α-2b combined with daily ribavirin (1000-1200 mg/day). The numbers of patients in whom HCV-RNA was undetectable were compared after 4 (rapid virological response, RVR), 12 (early virological response, EVR), and 48 (end treatment virological response, ETR) weeks of treatment as well as 24 weeks after the last treatment (sustained virological response, SVR).
  
  
  RESULTS
  The rate of SVR was higher in subtype 1a patients than subtype 1b patients (55% vs. 43%; p < 0.02). Multiple logistic regression analysis showed that infection with genotype 1a (odds ratio(OR) : 1.8; 95% confidence interval (CI): 1.4 to 4.1), age < 50 years (OR:7.0; 95% CI 1.1 to 21.2), alanine aminotransferase level (ALT)<100 IU/ml (OR:2.1; 95% CI: 1.3 to3.5), HCV-RNA < 5.6 log10 IU/ml (OR: 3.2; 95% CI: 2.7 to 6.9) and fibrosis score < S3 (OR: 3.8; 95% CI:3.2 to 7.4), were all independent predictors of SVR.
  
  
  CONCLUSIONS
  Dual antiviral therapy is more effective against HCV subtype 1a than against subtype 1b and this difference is independent of other factors that may favour viral clearance.
  
  
  BACKGROUND
  ClinicalTrials.gov Identifier: NCT01342003.
authors.affiliation: Liver Unit Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense, 87 00149, Rome, Italy. adriano.pellicelli@tiscali.it.
authors.forename: Adriano M
authors.initials: AM
authors.lastname: Pellicelli
authors.forename: Mario
authors.initials: M
authors.lastname: Romano
authors.forename: Tommaso
authors.initials: T
authors.lastname: Stroffolini
authors.forename: Ettore
authors.initials: E
authors.lastname: Mazzoni
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Mecenate
authors.forename: Roberto
authors.initials: R
authors.lastname: Monarca
authors.forename: Antonio
authors.initials: A
authors.lastname: Picardi
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Bonaventura
authors.forename: Cristina
authors.initials: C
authors.lastname: Mastropietro
authors.forename: Pascal
authors.initials: P
authors.lastname: Vignally
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Andreoli
authors.forename: Massimo
authors.initials: M
authors.lastname: Marignani
authors.forename: Cecilia
authors.initials: C
authors.lastname: D'Ambrosio
authors.forename: Lucia
authors.initials: L
authors.lastname: Miglioresi
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Nosotti
authors.forename: Olga
authors.initials: O
authors.lastname: Mitidieri
authors.forename: Umberto Vespasiani
authors.initials: UV
authors.lastname: Gentilucci
authors.forename: Claudio
authors.initials: C
authors.lastname: Puoti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Barbaro
authors.forename: Angelo
authors.initials: A
authors.lastname: Barlattani
authors.forename: Caterina
authors.initials: C
authors.lastname: Furlan
authors.forename: Giorgio
authors.initials: G
authors.lastname: Barbarini
mesh_terms: D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D000998:Antiviral Agents / Q000627:therapeutic use*; D001706:Biopsy; D004359:Drug Therapy, Combination; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000187:drug effects* / Q000235:genetics*; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use*; D008103:Liver Cirrhosis / Q000188:drug therapy / Q000473:pathology / Q000821:virology; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D012367:RNA, Viral / Q000097:blood; D011994:Recombinant Proteins / Q000627:therapeutic use; D012254:Ribavirin / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012367:RNA, Viral; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; D000410:Alanine Transaminase; C417083:peginterferon alfa-2b; C100416:peginterferon alfa-2a