title: HCV genome-wide genetic analyses in context of disease progression and hepatocellular carcinoma.
abstract: Hepatitis C virus (HCV) is a major cause of hepatitis and hepatocellular carcinoma (HCC) world-wide. Most HCV patients have relatively stable disease, but approximately 25% have progressive disease that often terminates in liver failure or HCC. HCV is highly variable genetically, with seven genotypes and multiple subtypes per genotype. This variation affects HCV's sensitivity to antiviral therapy and has been implicated to contribute to differences in disease. We sequenced the complete viral coding capacity for 107 HCV genotype 1 isolates to determine whether genetic variation between independent HCV isolates is associated with the rate of disease progression or development of HCC. Consensus sequences were determined by sequencing RT-PCR products from serum or plasma. Positions of amino acid conservation, amino acid diversity patterns, selection pressures, and genome-wide patterns of amino acid covariance were assessed in context of the clinical phenotypes. A few positions were found where the amino acid distributions or degree of positive selection differed between in the HCC and cirrhotic sequences. All other assessments of viral genetic variation and HCC failed to yield significant associations. Sequences from patients with slow disease progression were under a greater degree of positive selection than sequences from rapid progressors, but all other analyses comparing HCV from rapid and slow disease progressors were statistically insignificant. The failure to observe distinct sequence differences associated with disease progression or HCC employing methods that previously revealed strong associations with the outcome of interferon α-based therapy implies that variable ability of HCV to modulate interferon responses is not a dominant cause for differential pathology among HCV patients. This lack of significant associations also implies that host and/or environmental factors are the major causes of differential disease presentation in HCV patients.
authors: Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America; Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America.
authors: Maureen J
authors: MJ
authors: Donlin
authors: Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America.
authors: Elena
authors: E
authors: Lomonosova
authors: Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America.
authors: Alexi
authors: A
authors: Kiss
authors: Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America.
authors: Xiaohong
authors: X
authors: Cheng
authors: Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America; Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America.
authors: Feng
authors: F
authors: Cao
authors: New England Research Institutes, Inc., Watertown, Massachusetts, United States of America.
authors: Teresa M
authors: TM
authors: Curto
authors: Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America; Department of Internal Medicine, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America.
authors: Adrian
authors: A
authors: Di Bisceglie
authors: Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America; Saint Louis Liver Center, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America.
authors: John E
authors: JE
authors: Tavis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000821:virology*; D016022:Case-Control Studies; D016384:Consensus Sequence; D018450:Disease Progression; D005260:Female; D014644:Genetic Variation; D016679:Genome, Viral; D016174:Hepacivirus / Q000235:genetics*; D019698:Hepatitis C, Chronic / Q000473:pathology / Q000821:virology*; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000821:virology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA