What tests are required to obtain hepatitis B surface antigen, anti‑hepatitis C virus antibody, and quantitative anti‑hepatitis B surface antibody titers?

Laboratory Tests Required for Hepatitis B and C Serology

To obtain HBsAg, anti-HCV, and anti-HBs titers, order the following specific tests: hepatitis B surface antigen (HBsAg) by immunoassay, anti-hepatitis C virus antibody (anti-HCV) by enzyme immunoassay or chemiluminescence immunoassay, and quantitative anti-hepatitis B surface antibody (anti-HBs) measured in mIU/mL.

Hepatitis B Surface Antigen (HBsAg) Testing

Order HBsAg by immunoassay (enzyme immunoassay or chemiluminescence immunoassay) to detect active hepatitis B infection. 1

• HBsAg immunoassay is the necessary and accurate test for diagnosis of chronic HBV infection, detecting both acute and chronic infection. 1
• For repeatedly reactive HBsAg results, samples should be confirmed with an FDA-cleared neutralizing confirmatory test to ensure the result is not false-positive. 1
• HBsAg appears 1-10 weeks after exposure and persists in chronic infection beyond 6 months. 1

Anti-Hepatitis C Virus Antibody (Anti-HCV) Testing

Order anti-HCV screening by enzyme immunoassay (EIA) or enhanced chemiluminescence immunoassay (CIA). 1

• Anti-HCV screening should include use of an antibody screening assay, and for screening test-positive results, a more specific supplemental assay should be performed. 1
• If the anti-HCV screening test is positive, reflex testing with quantitative HCV RNA and HCV genotype is required for confirmation and to guide treatment. 1
• In populations with low (<10%) prevalence of HCV infection, false-positive results occur, making supplemental testing essential. 1
• Supplemental testing can be guided by signal-to-cut-off (s/co) ratios from the screening assay to minimize unnecessary confirmatory tests while ensuring accuracy. 1

Quantitative Anti-Hepatitis B Surface Antibody (Anti-HBs) Titers

Order quantitative anti-HBs measured in milli-international units per milliliter (mIU/mL). 1

• Anti-HBs is produced after resolved infection and is the only HBV antibody marker present after vaccination. 1
• A concentration >10 mIU/mL indicates immunity from vaccination or past infection. 1
• Anti-HBs testing is used for vaccine evaluation only and should not be confused with diagnostic testing for active infection. 1
• For dialysis patients and immunocompromised individuals, annual testing with booster vaccination is needed if anti-HBs falls below 10 mIU/mL. 1

Complete Hepatitis B Panel for Comprehensive Assessment

When ordering hepatitis B testing, the complete panel should include HBsAg, total anti-HBc (or IgG anti-HBc), and anti-HBs to fully characterize infection status. 2

• Hepatitis B core antibody (anti-HBc) total or IgG indicates previous or ongoing infection and is essential for distinguishing vaccine-induced immunity from natural infection. 2
• The three-test panel (HBsAg, anti-HBc, anti-HBs) allows proper interpretation of immune status, past infection, chronic infection, or susceptibility. 2
• Do not order IgM anti-HBc for routine screening; it should only be ordered when acute hepatitis B is suspected, as it indicates acute or recently acquired infection. 1, 2

Additional Testing When Initial Results Are Positive

If HBsAg is positive, order HBeAg, anti-HBe, and quantitative HBV DNA. 1, 2

• HBeAg positivity generally indicates high viral replication, while anti-HBe positivity indicates low-level replication. 1
• Quantitative HBV DNA testing is essential to gauge viral replication and determine treatment eligibility. 3

If anti-HCV is positive, order quantitative HCV RNA and HCV genotype. 1

• Quantitative HCV RNA confirms active infection and guides treatment decisions. 1
• HCV genotype determines optimal antiviral regimen selection. 1

Common Pitfalls to Avoid

• Do not rely solely on HBsAg for comprehensive screening, as it will miss past infections and vaccine-induced immunity. 2
• Do not assume vaccination history eliminates the need for testing, as breakthrough infections can occur and vaccine-induced immunity may wane. 2
• Do not interpret isolated anti-HBc as definitively indicating occult infection without ordering quantitative HBV DNA testing for confirmation. 2
• For anti-HCV testing, do not report a positive screening result without supplemental confirmation, especially in low-prevalence populations where false-positives are common. 1