title: Presence of low levels of anti-HBs antibody in so-called 'anti-HBc alone' subjects.
abstract: OBJECTIVE
  The 'anti-Hbc alone' pattern could sometimes be that of subjects who produced anti-HBs after recovery, but at a lower level than that detectable using commercial assays. This study aimed to test this hypothesis.
  
  
  METHODS
  A total of 104 'anti-HBc alone' serum samples, i.e.positive for the anti-HBc antibody but not for HBsAg nor for anti-HBs antibody, were recruited when routine testing a broad population of employees, patients and pregnant women from a university hospital. A possible subliminal anti-HBs production, that would have escaped detection by commercial EIAs, was investigated by comparing the optical densities (ODs) obtained in vaccinees (commercial anti-HBs EIA) to those of a control group of 100 nonimmunised and nonvaccinated subjects.
  
  
  RESULTS
  The median OD was significantly higher (p<0.0001) in the 'anti-HBc alone' subjects (OD=0.035) than in the controls (OD=0.023). Thirty-six percent of the 'anti-HBc alone' subjects had an anti-HBs OD higher than the median OD of the controls+2SD. 'Anti-HBc alone' subjects with anti-HBe antibody had higher anti-HBs ODs (0.041) than had those without anti-HBe (0.029). In 'anti-HBc alone' subjects, the anti-HBs ODs, although under the cut-off value of the EIA, were found to be higher than in the controls.
  
  
  CONCLUSIONS
  Our results show low anti-HBs production in some of the subjects studied.
authors.affiliation: Division d'Immunologie et d'Allergie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland. greub@wanadoo.fr
authors.forename: G
authors.initials: G
authors.lastname: Greub
authors.forename: P C
authors.initials: PC
authors.lastname: Frei
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000939:Epitopes; D005260:Female; D006509:Hepatitis B / Q000276:immunology*; D006510:Hepatitis B Antibodies / Q000032:analysis*; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D006515:Hepatitis B virus / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged
chemical_list: D000939:Epitopes; D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens