title: Hepatic gene expression during treatment with peginterferon and ribavirin: Identifying molecular pathways for treatment response.
abstract: The reasons for hepatitis C treatment failure remain unknown but may be related to different host responses to therapy. In this study, we compared hepatic gene expression in patients prior to and during peginterferon and ribavirin therapy. In the on-treatment group, patients received either ribavirin for 72 hours prior to peginterferon alpha-2a injection or peginterferon alpha-2a for 24 hours, prior to biopsy. The patients were grouped into rapid responders (RRs) with a greater than 2-log drop and slow responders (SRs) with a less than 2-log drop in hepatitis C virus RNA by week 4. Pretreatment biopsy specimens were obtained from a matched control group. The pretreatment patients were grouped as RRs or SRs on the basis of the subsequent treatment response. Gene expression profiling was performed with Affymetrix microarray technology. Known interferon-stimulated genes (ISGs) were induced in treated patients. In the pretreatment group, future SRs had higher pretreatment ISG expression than RRs. On treatment, RRs and SRs had similar absolute ISG expression, but when it was corrected for the baseline expression with the pretreatment group, RRs showed a greater fold change in ISGs, whereas SRs showed a greater change in interferon (IFN)-inhibitory pathways. The patients pretreated with ribavirin had heightened induction of IFN-related genes and down-regulation of genes involved in IFN inhibition and hepatic stellate cell activation.
  
  
  CONCLUSIONS
  These data suggest that ISG inducibility is important for the treatment response and that ribavirin may improve outcomes by enhancing hepatic gene responses to peginterferon. Collectively, these mechanisms may provide a molecular basis for the improved efficacy of combination therapy.
authors.affiliation: Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Jordan J
authors.initials: JJ
authors.lastname: Feld
authors.forename: Santosh
authors.initials: S
authors.lastname: Nanda
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.forename: Weiping
authors.initials: W
authors.lastname: Chen
authors.forename: Maggie
authors.initials: M
authors.lastname: Cam
authors.forename: Susan N
authors.initials: SN
authors.lastname: Pusek
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Schweigler
authors.forename: Dickens
authors.initials: D
authors.lastname: Theodore
authors.forename: Steven L
authors.initials: SL
authors.lastname: Zacks
authors.forename: T Jake
authors.initials: TJ
authors.lastname: Liang
authors.forename: Michael W
authors.initials: MW
authors.lastname: Fried
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001706:Biopsy; D016022:Case-Control Studies; D016000:Cluster Analysis; D004359:Drug Therapy, Combination; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D020869:Gene Expression Profiling; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology / Q000627:therapeutic use*; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000494:pharmacology / Q000627:therapeutic use*; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins; D012254:Ribavirin / Q000494:pharmacology / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C100416:peginterferon alfa-2a