title: Significance of isolated hepatitis B core antibody in blood donors.
abstract: BACKGROUND
  About 25% of blood donors who test positive for antibody to hepatitis B core antigen (anti-HBc) have no other positive hepatitis B serologic results. Because of the potential importance and diagnostic uncertainty of this test result, we studied its significance by assessing the serologic response to hepatitis B vaccine in donors with an isolated anti-HBc pattern.
  
  
  METHODS
  Specimens from 300 blood donors that were positive for anti-HBc by enzyme immunoassay were tested for anti-HBc by radioimmunoassay and for antibody to hepatitis B surface antigen (anti-HBs). A subgroup of 37 were further studied after administration of hepatitis B vaccine and compared with 34 similarly vaccinated age- and sex-matched seronegative controls. Measurements of anti-HBs were made at vaccination and 1, 2, 4, 8, 25, and 30 weeks after initial vaccination.
  
  
  RESULTS
  Among 300 donors who tested positive for anti-HBc by enzyme immunoassay, the radioimmunoassay for anti-HBc was negative in 76 (25.3%) and the test for anti-HBs was negative in 104 (34.7%). Significant differences were observed for radioimmunoassay anti-HBc and anti-HBs titers, alanine aminotransferase, and male-female ratios between four distinct serogroups (A through D) defined by the combination (positive/negative) of radioimmunoassay anti-HBc and anti-HBs results. No significant differences between the study and control groups were observed in the magnitude of anti-HBs responses at any of the six postvaccine testing periods.
  
  
  CONCLUSIONS
  Isolated anti-HBc in US blood donors is usually a false-positive result, regardless of the titer.
authors.affiliation: Department of Pathology, Tucson Veterans Affairs Medical Center, AZ.
authors.forename: R B
authors.initials: RB
authors.lastname: Schifman
authors.forename: S L
authors.initials: SL
authors.lastname: Rivers
authors.forename: R E
authors.initials: RE
authors.lastname: Sampliner
authors.forename: J E
authors.initials: JE
authors.lastname: Krammes
mesh_terms: D000328:Adult; D000367:Age Factors; D001130:Arizona; D001771:Blood Banks / Q000706:statistics & numerical data; D001782:Blood Donors / Q000706:statistics & numerical data*; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood*; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000276:immunology; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011863:Radioimmunoassay; D012011:Red Cross
chemical_list: D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines