title: Presence of multiple genotype-specific antibodies in patients with persistent infection with hepatitis C virus (HCV) of a single genotype: evidence for transient or occult superinfection with HCV of different genotypes.
abstract: OBJECTIVE
  We investigated the significance of multiple genotype-specific antibodies in patients with persistent infection with hepatitis C virus (HCV) of a single genotype.
  
  
  METHODS
  Titers of genotype-specific antibodies to group 1 and 2 HCV polypeptides in the NS4 region of HCV were measured in 53 hemophiliacs and 58 nonhemophiliacs who were persistently infected with HCV of a single genotype. In addition, sequence variability in hypervariable region 1 (HVR1) of HCV was evaluated in these patients.
  
  
  RESULTS
  The presence of antibodies to both group 1 and 2 polypeptides, reflecting a mixture of serotypes, was more frequent in hemophiliacs (11 of 53 patients, 20.8%) than in nonhemophiliacs (two of 58 patients, 3.4%; p = 0.01). HVR1 sequence variability in 13 patients with mixed serotypes was higher than in 87 patients with a single serotype (21.1 +/- 4.3% vs 8.5 +/- 6.3%; p < 0.01).
  
  
  CONCLUSIONS
  A mixture of HCV serotypes was more common in hemophiliacs with persistent HCV infection of a single genotype who were at high risk of exposure to HCV than in nonhemophiliacs, and the sequence variability of the infecting strains was high in these patients. These data are suggestive of the effects of superinfection with HCV of different genotypes. The presence of multiple genotype-specific antibodies to HCV may be evidence of transient or occult superinfection with HCV of different genotypes in patients with persistent infection by HCV of a single genotype.
authors.affiliation: Second Department of Internal Medicine, Nagoya University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Toyoda
authors.forename: Y
authors.initials: Y
authors.lastname: Fukuda
authors.forename: T
authors.initials: T
authors.lastname: Hayakawa
authors.forename: T
authors.initials: T
authors.lastname: Kumada
authors.forename: S
authors.initials: S
authors.lastname: Nakano
authors.forename: J
authors.initials: J
authors.lastname: Takamatsu
authors.forename: H
authors.initials: H
authors.lastname: Saito
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000918:Antibody Specificity / Q000276:immunology*; D005260:Female; D005838:Genotype; D006467:Hemophilia A / Q000276:immunology / Q000821:virology; D016174:Hepacivirus / Q000235:genetics* / Q000276:immunology; D018937:Hepatitis C Antibodies / Q000097:blood*; D019698:Hepatitis C, Chronic / Q000276:immunology* / Q000821:virology; D006801:Humans; D007564:Japan; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000276:immunology; D012703:Serotyping; D015163:Superinfection / Q000276:immunology* / Q000821:virology
chemical_list: D018937:Hepatitis C Antibodies; D010455:Peptides