title: Evaluation of the persistence and characteristics of indeterminate reactivity against hepatitis C virus in blood donors.
abstract: BACKGROUND
  A substantial number of individuals are excluded from blood donation due to indeterminate results in screening tests for hepatitis C virus antibody (anti-HCV). Disclosure of the characteristics of the indeterminate serologic pattern could optimize the testing and the management and care of blood donors.
  
  
  METHODS
  Ninety-two former blood donors deferred from blood donation due to consistent reactivity in anti-HCV enzyme immunoassay and indeterminate HCV recombinant immunoblot assay (RIBA) results were retested for anti-HCV to examine the extent of disappearance of reactivity. In addition, they were screened for selected viral, immunologic, and inflammatory variables to detect possible causes of the test reactivity pattern.
  
  
  RESULTS
  After a median observation time of 75 months, 66 of 92 individuals had persistent indeterminate HCV RIBA results. Reactivity against the nonstructural NS5 antigen was the most frequent finding. A significant association was detected both between indeterminate reactivity in HCV RIBA and against the NS5 antigen independently and detectable antibody against adenovirus. Novel indeterminate reactivity showed increased prevalence during autumn and winter months.
  
  
  CONCLUSIONS
  Indeterminate HCV RIBA reactivity in blood donors persists over years. Increased prevalence during autumn and winter and association to detection of adenovirus antibody indicate that viral infection and cross-reactivity are etiologic factors in indeterminate HCV RIBA reactivity. Further prospective studies are needed to confirm the results.
authors.affiliation: The Blood Bank, the Department of Microbiology and Immunology, the Gade Institute, and the Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway. guro.kristin.melve@helse-bergen.no
authors.forename: Guro Kristin
authors.initials: GK
authors.lastname: Melve
authors.forename: Helge
authors.initials: H
authors.lastname: Myrmel
authors.forename: Geir Egil
authors.initials: GE
authors.lastname: Eide
authors.forename: Tor
authors.initials: T
authors.lastname: Hervig
mesh_terms: D001782:Blood Donors; D006526:Hepatitis C / Q000175:diagnosis*; D018937:Hepatitis C Antibodies; D006801:Humans; D015151:Immunoblotting
chemical_list: D018937:Hepatitis C Antibodies