Hepatitis B Serology

Key points

• Interpreting hepatitis B serology is a dying art form which still occurs at regular intervals in medical exams. It is important to remember a few key facts:
• surface antigen (HBsAg) is the first marker to appear and causes the production of anti-HBs
• HBsAg normally implies acute disease (present for 1-6 months)
• if HBsAg is present for > 6 months then this implies chronic disease (i.e. Infective)
• Anti-HBs implies immunity (either exposure or immunisation). It is negative in chronic disease