title: Induction of hepatitis C virus (HCV)-specific T cells by needle stick injury in the absence of HCV-viraemia.
abstract: BACKGROUND
  The risk of hepatitis C virus (HCV) infection after occupational exposure is low with seroconversion rates between 0 and 5%. However, factors associated with natural resistance against HCV after needle stick injury are poorly defined. HCV-specific T-cell responses have been described in cross-sectional studies of exposed HCV-seronegative individuals.
  
  
  METHODS
  In this study, we prospectively followed 10 healthcare professionals who experienced an injury with an HCV-contaminated needle. Blood samples were taken on the day or the day after the event and at different time points during follow-up for up to 32 months. HCV-specific T-cell responses were investigated directly ex vivo and in T-cell lines.
  
  
  RESULTS
  None of the individuals became positive for HCV-RNA in serum tested with the highly sensitive transcription-mediated amplification (TMA)-assay or in peripheral blood mononuclear cells (PBMC). All of them remained anti-HCV negative throughout follow-up. At the time of injury, HCV-specific CD4+ T-cell responses were already detectable in two individuals and became detectable thereafter in three additional persons. Transient HCV-specific CD8+ T-cell responses developed in two HLA-A2 positive patients, which became negative until the most recent follow-up after 5 and 17 months, respectively.
  
  
  CONCLUSIONS
  We demonstrate the development of HCV-specific T cells in HCV-exposed individuals after needle stick injury indicating subinfectious exposure to HCV. T-cell immunity against HCV may contribute to the low prevalence of HCV in medical healthcare professionals in Western countries.
authors.affiliation: Department of Gastroenterology, Hannover Medical School, Hannover, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Kubitschke
authors.forename: M J
authors.initials: MJ
authors.lastname: Bahr
authors.forename: N
authors.initials: N
authors.lastname: Aslan
authors.forename: C
authors.initials: C
authors.lastname: Bader
authors.forename: H L
authors.initials: HL
authors.lastname: Tillmann
authors.forename: C
authors.initials: C
authors.lastname: Sarrazin
authors.forename: T
authors.initials: T
authors.lastname: Greten
authors.forename: J
authors.initials: J
authors.lastname: Wiegand
authors.forename: M P
authors.initials: MP
authors.lastname: Manns
authors.forename: H
authors.initials: H
authors.lastname: Wedemeyer
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006526:Hepatitis C / Q000635:transmission*; D006801:Humans; D017758:Infectious Disease Transmission, Patient-to-Professional / Q000379:methods*; D008297:Male; D016602:Needlestick Injuries / Q000150:complications*; D018570:Risk Assessment; D013601:T-Lymphocytes; D014766:Viremia / Q000209:etiology