title: Cyclic changes in gene expression induced by Peg-interferon alfa-2b plus ribavirin in peripheral blood monocytes (PBMC) of hepatitis C patients during the first 10 weeks of treatment.
abstract: OBJECTIVE
  This study determined the kinetics of gene expression during the first 10 weeks of therapy with Pegylated-interferon-alfa2b (PegIntron) and ribavirin (administered by weight) in HCV patients and compared it with the recently completed Virahep C study 12 in which Peginterferon-alfa2a (Pegasys) and ribavirin were administered.
  
  
  METHODS
  RNA was isolated from peripheral blood monocytes (PBMC) from twenty treatment-naïve patients just before treatment (day 1) and at days 3, 6, 10, 13, 27, 42 and 70 days after treatment. Gene expression at each time was measured using Affymetrix microarrays and compared to that of day 1.
  
  
  RESULTS
  The expression of many genes differed significantly (p <or= 0.001 and changed at least 1.5-fold) at days 3 (290 probes) and 10 (255 probes), but the number dropped at days 6 (165) and 13 (142). Most genes continued to be up regulated throughout the trial period. A second group of genes, including CXCL10, CMKLR1 (chemokine receptor 1), TRAIL, IL1Ralpha and genes associated with complement and lipid metabolism, was transiently induced early in treatment. CDKN1C (cyclin kinase inhibitor 1) was induced early but repressed at later times. Genes induced at later times were mostly related to blood chemistry and oxygen transport. By week 10, 11 of the patients demonstrated a positive response to therapy, and the final sustained viral response (SVR) was 35%. The levels of gene induction or decrease was very similar to that previously reported with Pegasys/ribavirin treatment.
  
  
  CONCLUSIONS
  The response to Pegintron/ribavirin was similar to that reported for Pegasys/ribavirin despite some differences in the amount administered. We did not detect major differences at the genomic level between patients responding to treatment or non-responders, perhaps because of limited power. Gene induction occurred in a cyclic fashion, peaking right after administration of interferon and declining between administrations of the drug. Our data suggest that more than once a week dosing might be desirable early during treatment to maintain high levels of response as measured by gene expression.
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: Jeanette N
authors.initials: JN
authors.lastname: McClintick
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Edenberg
authors.forename: Paul
authors.initials: P
authors.lastname: Kwo
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006526:Hepatitis C / Q000188:drug therapy / Q000235:genetics; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use*; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D011092:Polyethylene Glycols / Q000627:therapeutic use; D011994:Recombinant Proteins; D012254:Ribavirin / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C417083:peginterferon alfa-2b; C100416:peginterferon alfa-2a