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Difficulty: EasyGastroenterology and Hepatology

A healthcare clinic evaluates several patients for hepatitis B virus (HBV) exposure and immunity. Match each patient's hepatitis B serologic panel to the most accurate clinical interpretation.

  • HBsAg (negative), Anti-HBs (positive), Anti-HBc IgG (positive)Immunity due to natural infection
  • HBsAg (negative), Anti-HBs (positive), Anti-HBc (negative)Immunity due to vaccination
  • HBsAg (positive), Anti-HBs (negative), Anti-HBc IgM (positive)Acute hepatitis B infection
  • HBsAg (positive), Anti-HBs (negative), Anti-HBc IgG (positive)Chronic hepatitis B infection

Answer

The correct matches map the presence of Anti-HBs alone to vaccination, Anti-HBs with Anti-HBc to resolved natural infection, HBsAg with IgM Anti-HBc to acute infection, and HBsAg with IgG Anti-HBc to chronic infection.
Hepatitis B serologies rely on the chronological appearance of antigens and antibodies. Active infection always presents with positive HBsAg. Its chronicity is determined by the core antibody class: IgM for acute and IgG for chronic. Immunity is denoted by positive Anti-HBs; if acquired naturally, Anti-HBc IgG is also present, whereas vaccine-induced immunity only displays Anti-HBs.

Step-by-Step Solution

1
Evaluate the Hepatitis B surface antigen (HBsAg) and surface antibody (Anti-HBs).
If HBsAg is positive, the patient has an active infection. If Anti-HBs is positive, the patient has immunity.
HBsAg is the first marker to appear and indicates current infection. Anti-HBs indicates clearance and protection.
2
Examine the Hepatitis B core antibody (Anti-HBc) in patients with immunity (positive Anti-HBs).
Positive Anti-HBc indicates natural infection, while negative Anti-HBc indicates vaccination.
The vaccine only contains the surface antigen. Natural infection exposes the immune system to all viral components, producing core antibodies.
3
Examine the subtype of core antibody (IgM vs. IgG) in patients with active infection (positive HBsAg).
IgM predominant indicates acute infection, whereas IgG predominant indicates chronic infection.
IgM is the first antibody produced during the acute phase. A transition to IgG occurs over several months and persists in chronic stages.

Key Concept

Interpretation of Hepatitis B Serologic Profiles
Estimated Time:1m 0s
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Topics

Gastroenterology and Hepatology

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