title: Clearance of hepatitis C viremia associated with cellular immunity in the absence of seroconversion in the hepatitis C incidence and transmission in prisons study cohort.
abstract: Understanding the earliest virological and immunological events in acute hepatitis C virus (HCV) infection may provide insight into the determinants of protective immunity. Four cases of HCV viremia with subsequent viral clearance, but without biochemical hepatitis or anti-HCV seroconversion, are reported from a prospective cohort study of prison inmates. Two of the subjects who developed sustained viremia were assessed for production of interferon (IFN)- gamma, by use of the enzyme-linked immunospot (ELISPOT) method and by assessment of HCV cytotoxic T lymphocyte (CTL) activity, CD4 lymphocyte proliferative responses, HCV load, and genotype. After 2-6 months of viremia, all 4 subjects cleared serum HCV RNA. Specific cellular responses were detected in both of the subjects who were assessed, and production of IFN- gamma was demonstrated in one subject. All subjects had weak, but consistent, serological reactivity against HCV nonstructural proteins on immunoblot testing, despite repeatedly nonreactive HCV ELISA tests. These cases highlight the potential for cellular immune responses against HCV to facilitate viral clearance, responses that may model those required for effective HCV vaccination.
authors.affiliation: Department of Pathology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia. j.post@unsw.edu.au
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Post
authors.forename: Yong
authors.initials: Y
authors.lastname: Pan
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Freeman
authors.forename: Charles E
authors.initials: CE
authors.lastname: Harvey
authors.forename: Peter A
authors.initials: PA
authors.lastname: White
authors.forename: Patricia
authors.initials: P
authors.lastname: Palladinetti
authors.forename: Paul S
authors.initials: PS
authors.lastname: Haber
authors.forename: George
authors.initials: G
authors.lastname: Marinos
authors.forename: Michael H
authors.initials: MH
authors.lastname: Levy
authors.forename: John M
authors.initials: JM
authors.lastname: Kaldor
authors.forename: Kate A
authors.initials: KA
authors.lastname: Dolan
authors.forename: Rosemary A
authors.initials: RA
authors.lastname: Ffrench
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Lloyd
authors.forename: William D
authors.initials: WD
authors.lastname: Rawlinson
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002455:Cell Division; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000097:blood; D006526:Hepatitis C / Q000453:epidemiology / Q000276:immunology* / Q000635:transmission / Q000821:virology; D006801:Humans; D015994:Incidence; D007371:Interferon-gamma / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D009517:New South Wales / Q000453:epidemiology; D011329:Prisoners; D012367:RNA, Viral / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013602:T-Lymphocytes, Cytotoxic / Q000473:pathology; D014766:Viremia / Q000453:epidemiology / Q000276:immunology* / Q000635:transmission / Q000821:virology
chemical_list: D006508:Hepatitis Antibodies; D012367:RNA, Viral; D007371:Interferon-gamma