From the Guidelines
A positive Hepatitis B core IgG (anti-HBc IgG) result indicates past or chronic Hepatitis B virus (HBV) infection, but by itself doesn't determine if the infection is resolved or ongoing. This antibody develops during acute infection and typically persists for life. Treatment recommendations depend on additional test results, particularly HBsAg (surface antigen) and HBV DNA levels.
Key Considerations
- If HBsAg is positive, indicating chronic infection, treatment may include antiviral medications such as entecavir (0.5mg daily), tenofovir disoproxil fumarate (300mg daily), or tenofovir alafenamide (25mg daily) 1.
- These medications are typically long-term, often lifelong treatments that suppress viral replication but rarely cure the infection.
- For patients with high viral loads, elevated liver enzymes, or evidence of liver damage, treatment is strongly recommended.
- Regular monitoring of liver function tests, HBV DNA levels, and ultrasound screening for hepatocellular carcinoma every 6 months is necessary for those with chronic infection.
Special Situations
- If HBsAg is negative but anti-HBc IgG is positive, this usually indicates resolved infection with immunity, requiring no specific treatment.
- However, immunosuppressive therapy can reactivate dormant HBV, so prophylactic antiviral therapy may be needed in such situations, as recommended by the 2021 American College of Rheumatology guideline for the treatment of rheumatoid arthritis 1.
- The persistence of anti-HBc IgG results from the immune system's continued response to viral core proteins even after the active infection has been controlled.
Recent Guidelines
- The 2020 ASCO provisional clinical opinion update recommends that all patients anticipating systemic anticancer therapy should be tested for HBV and that patients with chronic HBV receiving any systemic anticancer therapy should receive antiviral prophylactic therapy through and for a minimum of 12 months following anticancer therapy 1.
From the Research
Hepatitis B Core IgG Positive Result
A Hepatitis B core IgG (Immunoglobulin G) positive result indicates that an individual has been exposed to the Hepatitis B virus (HBV) in the past and has developed immunity to the virus. This can occur after a person has recovered from an acute HBV infection or after vaccination.
Interpretation of Results
- A positive Hepatitis B core IgG result, in the absence of Hepatitis B surface antigen (HBsAg) or Hepatitis B surface antibody (anti-HBs), can be an indication of a past HBV infection 2.
- The presence of Hepatitis B core IgG can also indicate that an individual is at risk of HBV reactivation, particularly if they are undergoing immunosuppressive therapy or have a compromised immune system 3.
- In some cases, a positive Hepatitis B core IgG result can be an isolated finding, and the individual may not have any symptoms or active infection 2.
Treatment Recommendations
- Individuals with a positive Hepatitis B core IgG result should be screened for other HBV markers, such as HBsAg and anti-HBs, to determine their current infection status 3.
- Those with a history of HBV infection or exposure should be monitored for signs of HBV reactivation, particularly if they are undergoing immunosuppressive therapy or have a compromised immune system 3.
- Vaccination against HBV can help prevent infection in individuals who are at risk, and response to vaccination can help elucidate the cause of an isolated positive Hepatitis B core antibody result 2.
Additional Considerations
- The presence of IgM antibody to Hepatitis B core antigen (anti-HBc IgM) can indicate an acute HBV infection, while the presence of IgG antibody (anti-HBc IgG) can indicate a past infection 4, 5, 6.
- The determination of anti-HBc IgM and IgG can be useful in predicting the outcome of chronic HBV infection and in diagnosing acute HBV infection in HBsAg-negative patients 4, 5, 6.