title: Cellular immune response to hepatitis C virus (HCV) in nonviremic blood donors with indeterminate anti-HCV reactivity.
abstract: BACKGROUND
  Blood donors with indeterminate hepatitis C virus antibody (anti-HCV) reactivity are rejected from blood donation. As they are mostly nonviremic, the source of these reactions remains unclear. Reasons for such findings can be resolved HCV infections as well as unspecific antibody reactions. The aim of this study was to investigate HCV-specific T-cell response in blood donors to determine the reason for the weak antibody detection.
  
  
  METHODS
  Anti-HCV reactivity was tested in 72 blood donors initially diagnosed with an indeterminate HCV result by enzyme-linked immunosorbent assay and immunoblot. Cellular immune response was measured by proliferation assay and enzyme-linked immunosorbent spot analysis after stimulation with viral proteins core, NS3, and NS4.
  
  
  RESULTS
  In 56% of donors anti-HCV reactivity was detectable in the screening assay whereas 72% had a reaction in the confirmation immunoblot. Forty-six percent of donors had a cellular immune response against HCV proteins. The response was most frequent to NS3 protein.
  
  
  CONCLUSIONS
  In almost half of donors the indeterminate result in serologic testings could be explained by a previous resolved HCV infection as the pattern of T-cell response was similar to these patients. These findings indicate that HCV-specific antibodies disappear more rapidly after resolved infection than HCV-specific T cells. These results are important for counseling blood donors and patients with indeterminate serologic results.
authors.affiliation: Institute of Virology, University Hospital Essen, Virchowstrasse 179, Essen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Hitziger
authors.forename: Michael
authors.initials: M
authors.lastname: Schmidt
authors.forename: Volkmar
authors.initials: V
authors.lastname: Schottstedt
authors.forename: Holger
authors.initials: H
authors.lastname: Hennig
authors.forename: Alexandra
authors.initials: A
authors.lastname: Schumann
authors.forename: Stefan
authors.initials: S
authors.lastname: Ross
authors.forename: Mengji
authors.initials: M
authors.lastname: Lu
authors.forename: Erhard
authors.initials: E
authors.lastname: Seifried
authors.forename: Michael
authors.initials: M
authors.lastname: Roggendorf
mesh_terms: D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay; D016174:Hepacivirus / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000276:immunology*; D018936:Hepatitis C Antigens / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D014758:Viral Core Proteins / Q000276:immunology
chemical_list: D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D014758:Viral Core Proteins