title: Identification of serologically silent occult hepatitis C virus infection by detecting immunoglobulin G antibody to a dominant HCV core peptide epitope.
abstract: OBJECTIVE
  Occult HCV infection has been described among anti-HCV-HCV RNA-negative individuals with abnormal transaminase values in whom HCV RNA is detected in liver.
  
  
  METHODS
  IgG antibody to an HCVcore-derived peptide (anti-HCVcore) was investigated in 145 patients with serologically silent occult HCV infection.
  
  
  RESULTS
  At the time of the diagnostic biopsy 45/145 (31%) occult HCV-infected patients tested IgG anti-HCVcore-positive but none of the 140 patients with HCV-unrelated liver disease (P<0.001). Among 23 IgG anti-HCVcore-positive patients at baseline, 22 remained antibody-reactive (one became antibody-negative). Similarly, 17/31 baseline anti-HCVcore-negative patients remained non-reactive whereas 14 seroconverted to IgG anti-HCVcore (although transiently in 10 patients). Thus, a total of 59/145 (40.7%) patients with occult HCV infection showed IgG anti-HCVcore reactivity at any time point analyzed, including 14 initially non-reactive patients. By supplemental immunoblot assay 16 sera reacted weakly with an HCVcore-peptide band (indeterminate result) of which 10 (62.5%) reacted in the IgG anti-HCVcore assay. Occult HCV-infected patients who tested anti-HCVcore-positive showed more frequently signs of necro-inflammation (P=0.035) and greater percentages of HCV RNA-positive hepatocytes (P=0.004) compared with those anti-HCVcore-negative.
  
  
  CONCLUSIONS
  This work documents that IgG anti-HCVcore testing identifies occult HCV infection among seronegative, non-viremic patients using screening tests and may be useful in tracking anti-HCV-negative infections.
authors.affiliation: Fundación para el Estudio de las Hepatitis Virales, Guzman el Bueno, 72 28015 Madrid, Spain.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Quiroga
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Castillo
authors.forename: Silvia
authors.initials: S
authors.lastname: Llorente
authors.forename: Javier
authors.initials: J
authors.lastname: Bartolomé
authors.forename: Guillermina
authors.initials: G
authors.lastname: Barril
authors.forename: Vicente
authors.initials: V
authors.lastname: Carreño
mesh_terms: D000328:Adult; D000918:Antibody Specificity; D005260:Female; D006526:Hepatitis C / Q000175:diagnosis*; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D016056:Immunodominant Epitopes; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged; D014758:Viral Core Proteins / Q000276:immunology*
chemical_list: D018937:Hepatitis C Antibodies; D016056:Immunodominant Epitopes; D007074:Immunoglobulin G; D014758:Viral Core Proteins