Greub G Frei PC 2001 BACKGROUND/AIMS 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. CONCLUSION Our results show low anti-HBs production in some of the subjects studied. https://sonar.ch/global/documents/124080 eng info:eu-repo/semantics/altIdentifier/doi/10.1034/j.1600-0676.2001.210603.x info:eu-repo/semantics/altIdentifier/pmid/11903881 Liver. - 2001 Adolescent Adult Aged Epitopes Female Hepatitis B Hepatitis B Antibodies Hepatitis B Core Antigens Hepatitis B Surface Antigens Hepatitis B virus Humans Immunoenzyme Techniques Male Middle Aged Presence of low levels of anti-HBs antibody in so-called 'anti-HBc alone' subjects. http://purl.org/coar/resource_type/c_6501