title: Protease Inhibitor Resistance Remains Even After Mutant Strains Become Undetectable by Deep Sequencing.
abstract: BACKGROUND
  Although treatment-emergent NS3/4A protease inhibitor (PI)-resistant variants typically decrease in frequency after cessation of PI therapy in patients with chronic hepatitis C virus (HCV) infection, HCV susceptibility to PIs in patients who have not responded to previous PI therapy has not been addressed.
  
  
  METHODS
  Patients with chronic HCV genotype 1 infection were treated either with simeprevir plus interferon or with daclatasvir plus asunaprevir. Frequencies of drug-resistant mutations among patients with treatment failure were analyzed by deep sequencing. Human hepatocyte chimeric mice were injected with serum samples obtained from either treatment-naive patients or nonresponders to treatment with daclatasvir plus asunaprevir and then were treated with simeprevir and sofosbuvir.
  
  
  RESULTS
  Virological response to daclatasvir plus asunaprevir treatment was significantly lower in patients with simeprevir treatment failure as compared to those without previous treatment. Deep-sequencing analysis showed that the frequency of PI treatment-emergent NS3-D168 mutations gradually decreased and were completely replaced by wild-type genes after cessation of therapy. However, mice injected with serum obtained from a patient with PI treatment failure rapidly developed NS3-D168 mutations at significantly higher frequencies following either simeprevir or sofosbuvir treatment.
  
  
  CONCLUSIONS
  The virological response to daclatasvir plus asunaprevir treatment was low in patients with simeprevir treatment failure. PI resistance remains even after disappearance of mutant strains by deep sequencing.
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kan
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: Michio
authors.initials: M
authors.lastname: Imamura
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: Takuro
authors.initials: T
authors.lastname: Uchida
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Hiraga
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: C Nelson
authors.initials: CN
authors.lastname: Hayes
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: Masataka
authors.initials: M
authors.lastname: Tsuge
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Abe
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Aikata
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: Grace Naswa
authors.initials: GN
authors.lastname: Makokha
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.
authors.forename: Sajeda
authors.initials: S
authors.lastname: Chowdhury
authors.affiliation: Liver Research Project Center, Hiroshima University.|Laboratory for Digestive Diseases, Center for Genomic Medicine, Institute of Physical and Chemical Research, Hiroshima.
authors.forename: Daiki
authors.initials: D
authors.lastname: Miki
authors.affiliation: Liver Research Project Center, Hiroshima University.|Laboratory for Digestive Diseases, Center for Genomic Medicine, Institute of Physical and Chemical Research, Hiroshima.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Ochi
authors.affiliation: Liver Research Project Center, Hiroshima University.|PhoenixBio, Higashihiroshima, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: Liver Research Project Center, Hiroshima University.|PhoenixBio, Higashihiroshima, Japan.
authors.forename: Chise
authors.initials: C
authors.lastname: Tateno
authors.affiliation: Department of Gastroenterology and Metabolism, Applied Life Sciences, Institute of Biomedical and Health Sciences.|Liver Research Project Center, Hiroshima University.|Laboratory for Digestive Diseases, Center for Genomic Medicine, Institute of Physical and Chemical Research, Hiroshima.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000627:therapeutic use*; D002219:Carbamates; D024882:Drug Resistance, Viral; D016174:Hepacivirus / Q000187:drug effects* / Q000302:isolation & purification; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000821:virology*; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007093:Imidazoles / Q000627:therapeutic use; D007372:Interferons / Q000627:therapeutic use; D007546:Isoquinolines / Q000627:therapeutic use; D016513:Mice, SCID; D011480:Protease Inhibitors / Q000627:therapeutic use*; D011759:Pyrrolidines; D000069616:Simeprevir / Q000627:therapeutic use; D013449:Sulfonamides / Q000627:therapeutic use; D017211:Treatment Failure; D014633:Valine / Q000031:analogs & derivatives
chemical_list: D000998:Antiviral Agents; D002219:Carbamates; D007093:Imidazoles; D007546:Isoquinolines; D011480:Protease Inhibitors; D011759:Pyrrolidines; D013449:Sulfonamides; D007372:Interferons; D000069616:Simeprevir; D014633:Valine; C549273:daclatasvir; C571889:asunaprevir
keywords: NS3/4A protease inhibitor; NS5B polymerase inhibitor; chimeric mouse; direct-acting antiviral agent; drug resistance; hepatitis C virus