Hepatitis A and B Titer Testing Guidelines

Introduction to Hepatitis Testing

The American Association for the Study of Liver Diseases recommends testing for total (IgG) anti-HAV antibodies to determine immunity to Hepatitis A 3
A positive IgG anti-HAV result indicates either past infection or successful vaccination, according to the American Association for the Study of Liver Diseases 3
For suspected acute infection, IgM anti-HAV should be ordered, as suggested by the Clinical and Molecular Hepatology journal 1

The Centers for Disease Control and Prevention indicates that immunity from vaccination is confirmed by a positive anti-HBs, negative anti-HBc, and negative HBsAg result 2
The American Association for the Study of Liver Diseases states that immunity from past infection is confirmed by a positive anti-HBs, positive anti-HBc, and negative HBsAg result 1, 2
Chronic infection is indicated by a positive HBsAg for more than 6 months, positive anti-HBc, and negative anti-HBs, as reported by the Clinical and Molecular Hepatology journal 1, 3
Acute infection is confirmed by a positive HBsAg and positive IgM anti-HBc, according to the MMWR Recommendations and Reports 1, 4

The American Association for the Study of Liver Diseases recommends sequential testing for patients with indeterminate results (isolated anti-HBc) with repeat testing in 3-6 months 1
Patients with chronic HBV should be tested for HAV immunity and vaccinated if negative for anti-HAV, as suggested by the Clinical and Molecular Hepatology journal 3
For patients with occupational exposure or healthcare workers, both anti-HBs and anti-HBc should be tested to distinguish between vaccine-induced and infection-induced immunity, according to the MMWR Recommendations and Reports and the Clinical Gastroenterology and Hepatology journal 2, 4

False negative anti-HBs can occur in immunocompromised patients despite immunity, as reported by the Clinical Gastroenterology and Hepatology journal 2
The "window period" during acute HBV infection may show negative HBsAg but positive IgM anti-HBc, according to the Clinical and Molecular Hepatology journal and the MMWR Recommendations and Reports 1, 4
Isolated anti-HBc requires careful interpretation and may necessitate HBV DNA testing to rule out occult HBV infection, as suggested by the Clinical and Molecular Hepatology journal and the Clinical Gastroenterology and Hepatology journal 1, 2
Anti-HBs levels may decline over time after vaccination but most individuals retain immune memory, according to the Clinical Gastroenterology and Hepatology journal 2