Lab Tests for Hepatitis B Titre
Order a three-test panel consisting of hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc total or IgG), and hepatitis B surface antibody (anti-HBs) to comprehensively determine hepatitis B status and immunity. 1, 2
Core Screening Panel
The complete hepatitis B titre assessment requires all three tests simultaneously, not just HBsAg alone: 1, 2
- HBsAg detects active infection (both acute and chronic) 3, 1
- Anti-HBc (total or IgG) indicates previous or ongoing infection 1, 2
- Anti-HBs indicates immunity from either vaccination or resolved infection 1, 2
This three-test approach is essential because HBsAg testing alone misses past infections, occult infections, and fails to distinguish vaccine-derived immunity from natural immunity. 1, 4
Interpretation of Results
The combination of these three tests provides definitive answers: 1, 2
| Test Pattern | Interpretation |
|---|---|
| HBsAg+, anti-HBc+, anti-HBs− | Active chronic HBV infection [1,2] |
| HBsAg−, anti-HBc+, anti-HBs+ | Resolved past infection with natural immunity [1,2] |
| HBsAg−, anti-HBc−, anti-HBs+ | Vaccine-derived immunity [1,2] |
| HBsAg−, anti-HBc+, anti-HBs− | Isolated core antibody (possible occult HBV) [1,4] |
| HBsAg−, anti-HBc−, anti-HBs− | Susceptible to HBV infection [1,2] |
Additional Testing When HBsAg is Positive
If HBsAg is positive, immediately order the following additional tests to assess disease activity and guide treatment: 3, 2
- HBeAg and anti-HBe to determine viral replication status (HBeAg+ indicates high replication) 3, 1, 2
- Quantitative HBV DNA to measure viral load 3, 2
- Liver function tests including AST/ALT, alkaline phosphatase, bilirubin, albumin, and prothrombin time 3, 2
- Complete blood count and creatinine 3, 2
Confirm chronic infection by documenting HBsAg persistence for at least 6 months or by demonstrating absence of IgM anti-HBc. 3
Special Considerations for Isolated Anti-HBc Positivity
When the pattern shows HBsAg−, anti-HBc+, anti-HBs−, this represents isolated core antibody and requires further evaluation: 1, 4
- Order quantitative HBV DNA testing to rule out occult HBV infection, especially if the patient is immunocompromised or about to start immunosuppressive therapy 1, 4
- Approximately 10% of patients with isolated anti-HBc have detectable HBV DNA, representing occult infection 4
Post-Vaccination Immunity Assessment
For assessing vaccine-induced immunity, measure anti-HBs quantitatively 1-2 months after completing the vaccine series: 3, 5
- Protective immunity is defined as anti-HBs ≥10 mIU/mL 3, 5
- Post-vaccination testing is specifically recommended for healthcare workers, hemodialysis patients, immunocompromised persons, sexual partners of HBsAg-positive individuals, and infants born to HBsAg-positive mothers 5
- Routine post-vaccination testing is not needed for immunocompetent adults 5, 2
Common Pitfalls to Avoid
- Do not order only HBsAg for screening—this misses past infections, occult infections, and immunity status 1, 4
- Do not order IgM anti-HBc for routine screening; reserve this test only when acute hepatitis B is clinically suspected 1
- Do not assume vaccination history eliminates the need for testing, as breakthrough infections can occur and vaccine response varies 1
- Do not interpret isolated anti-HBc as definitively indicating occult infection without confirmatory HBV DNA testing 1, 4
- Do not delay testing before immunosuppressive therapy—this is a critical intervention point to prevent potentially fatal HBV reactivation 1