What is the interpretation of a Hepatitis B Panel showing a reactive Hepatitis B surface antibody (HBsAb) and non-reactive Hepatitis B core antibody (HEP.B.CORE Ab), and what are the implications for the patient's immune status and risk of transmission?

Interpretation of Hepatitis B Panel Results

The patient's Hepatitis B panel indicates immunity due to vaccination, with a reactive Hepatitis B surface antibody (HBsAb) and non-reactive Hepatitis B surface antigen (HBsAg) and core antibody (anti-HBc). This pattern shows successful immunization against Hepatitis B virus without evidence of past or current infection 1.

Understanding the Serologic Pattern

• HBsAg negative, anti-HBc negative, anti-HBs positive: This pattern specifically indicates immunity acquired through vaccination rather than natural infection 1
• When both anti-HBs and anti-HBc are positive, this would indicate immunity from past natural infection, which is not the case here 1
• The presence of anti-HBs (≥10 mIU/mL) alone generally indicates protective immunity against HBV infection 1

Clinical Implications

• The patient is protected against HBV infection and does not require vaccination 1
• The patient is not infectious and cannot transmit HBV to others 1
• This pattern confirms successful response to previous HBV vaccination 1
• Unlike individuals with isolated anti-HBc positivity, this patient has no risk of HBV reactivation during immunosuppressive therapy 1

Important Considerations

• Anti-HBs levels may wane over time, but immunocompetent individuals typically maintain protection even with declining antibody levels 1
• If the patient requires immunosuppressive therapy in the future (particularly anti-CD20 monoclonal antibodies like rituximab), they remain protected against HBV reactivation due to the absence of anti-HBc 1
• In rare circumstances, anti-HBs could be passively acquired (e.g., recent hepatitis B immune globulin administration), but this is unlikely in the absence of clinical context suggesting this 1, 2

Special Populations Requiring Additional Monitoring

• If the patient were to develop conditions requiring significant immunosuppression (such as cancer treatment or organ transplantation), monitoring anti-HBs levels might be warranted 1
• For patients with chronic liver disease, maintaining protective anti-HBs levels is particularly important, and booster doses may be considered if levels decline below 10 mIU/mL 3
• In transplant recipients or patients on dialysis, anti-HBs titers should be checked periodically as they may decline more rapidly 1, 4

When to Consider Booster Vaccination

• Routine booster doses are not recommended for immunocompetent individuals with documented seroconversion after vaccination 1
• Booster doses should be considered in specific high-risk scenarios:
  • Prior to starting immunosuppressive therapy if anti-HBs levels are low 1
  • In patients with chronic liver disease with declining anti-HBs levels 3
  • Following organ transplantation if anti-HBs levels fall below protective threshold 1, 4

The patient's serologic pattern represents the ideal outcome following hepatitis B vaccination, indicating successful immunization and protection against both infection and transmission of HBV 1.