title: Changes in gene expression during pegylated interferon and ribavirin therapy of chronic hepatitis C virus distinguish responders from nonresponders to antiviral therapy.
abstract: Treating chronic hepatitis C virus (HCV) infection using pegylated alpha interferon and ribavirin leads to sustained clearance of virus and clinical improvement in approximately 50% of patients. Response rates are lower among patients with genotype 1 than with genotypes 2 and 3 and among African-American (AA) patients compared to Caucasian (CA) patients. Using DNA microarrays, gene expression was assessed for a group of 33 African-American and 36 Caucasian American patients with chronic HCV genotype 1 infection during the first 28 days of treatment. Results were examined with respect to treatment responses and to race. Patients showed a response to treatment at the gene expression level in RNA isolated from peripheral blood mononuclear cells irrespective of degree of decrease in HCV RNA levels. However, gene expression responses were relatively blunted in patients with poor viral response (<1.5 log(10)-IU/ml decrease at 28 days) compared to those in patients with a marked (>3.5 log(10)-IU/ml decrease) or intermediate (1.5 to 3.5 log(10)-IU/ml decrease) response. The number of genes that were up- or down-regulated by pegylated interferon and ribavirin treatment was fewer in patients with a poor response than in those with an intermediate or marked viral response. However AA patients had a stronger interferon response than CA patients in general. The induced levels of known interferon-stimulated genes such as the 2'5'-oligoadenylate synthetase, MX1, IRF-7, and toll-like receptor TLR-7 genes was lower in poor-response patients than in marked- or intermediate-response patients. Thus, the relative lack of viral response to interferon therapy of hepatitis C virus infection is associated with blunted interferon cell signaling. No specific regulatory gene could be identified as responsible for this global blunting or the racial differences.
authors.affiliation: Department of Biology, Indiana University, Bloomington, IN 47401, USA. taylor@indiana.edu
authors.forename: Milton W
authors.initials: MW
authors.lastname: Taylor
authors.forename: Takuma
authors.initials: T
authors.lastname: Tsukahara
authors.forename: Leonid
authors.initials: L
authors.lastname: Brodsky
authors.forename: Joel
authors.initials: J
authors.lastname: Schaley
authors.forename: Corneliu
authors.initials: C
authors.lastname: Sanda
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Stephens
authors.forename: Jeanette N
authors.initials: JN
authors.lastname: McClintick
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Edenberg
authors.forename: Lang
authors.initials: L
authors.lastname: Li
authors.forename: John E
authors.initials: JE
authors.lastname: Tavis
authors.forename: Charles
authors.initials: C
authors.lastname: Howell
authors.forename: Steven H
authors.initials: SH
authors.lastname: Belle
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use*; D015415:Biomarkers; D015536:Down-Regulation / Q000187:drug effects*; D004359:Drug Therapy, Combination; D005260:Female; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D011092:Polyethylene Glycols; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins; D012254:Ribavirin / Q000627:therapeutic use*; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012333:RNA, Messenger; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C417083:peginterferon alfa-2b