Hepatitis B Surface Antibody General Clinical Tests

Test NameMethod	Hepatitis B Surface Antibody, Total Anti- HBs, HBsAb
SpecimenRequirements	SerumStable for 7 d at RT and indefinitely at 4° C or – 20°C.
Chemical InterfacesIn Vivo Effects	None Found
Ref. RangeConventional International Recommended Units	Negative Limits of detection: 2-10 IU/L
Diagnostic Information	With naturally occurring Hepatitis B infections, anti-HBs usually appears in the serum several weeks after disappearance of HBsAg. The presence of of anti-HBs generally means there is protection against Hepatitis B infection. However, convalescent anti-HBs mall fall below limits of detection. A qualitative finding of >10 IU/L for post vaccine testing is the accepted concentration which confers protection.
Remarks	Anti-HBs is now mainly used to assess efficacy of Hepatitis B vaccine but remains an adjunct test along with anti-HBc for determining whether subjects have immunity due to a naturally acquired infection or whether chronic Hepatitis B might exist in an HBsAg negative patient.

References:
Clinical Guide to Laboratory Tests, third edition.