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Difficulty: EasyGastroenterology and Hepatology

Match each of the following Hepatitis B serologic profiles with the most appropriate clinical state.

  • HBsAg (+), anti-HBc IgM (+), anti-HBs (-)Acute hepatitis B infection
  • HBsAg (-), anti-HBc IgG (+), anti-HBs (+)Immunity from resolved natural infection
  • HBsAg (-), anti-HBc (-), anti-HBs (+)Immunity from vaccination
  • HBsAg (+), anti-HBc IgG (+), anti-HBs (-)Chronic hepatitis B infection

Answer

Acute hepatitis B infection matches with positive HBsAg and anti-HBc IgM. Chronic infection matches with positive HBsAg and anti-HBc IgG. Natural immunity matches with positive anti-HBs and anti-HBc IgG. Vaccine immunity matches with isolated positive anti-HBs.
Matching these clinical states requires identifying the primary drivers of Hepatitis B serology. Active infections always present with positive HBsAg. Acute infections are characterized by IgM antibodies to the core antigen, whereas chronic infections show IgG to the core antigen. Immunity is defined by the presence of anti-HBs. Natural immunity includes anti-HBc IgG (because the patient was exposed to the whole virus), whereas vaccine-induced immunity only has anti-HBs (because the vaccine only contains surface antigen).

Step-by-Step Solution

1
Assess HBsAg status for each serologic profile.
Profiles with a positive HBsAg have active, circulating virus (either acute or chronic). Profiles with a negative HBsAg do not have active infection.
HBsAg is the primary viral marker of active circulating Hepatitis B virus.
2
Evaluate the type of core antibody (anti-HBc) in HBsAg-positive profiles.
Positive anti-HBc IgM indicates an acute infection. Positive anti-HBc IgG indicates a chronic infection.
IgM is the initial antibody produced during acute infection, which transitions to IgG in chronic stages (longer than 6 months).
3
Evaluate core antibody (anti-HBc) status in HBsAg-negative, anti-HBs-positive profiles.
Presence of anti-HBc IgG indicates natural immunity. Complete absence of anti-HBc indicates vaccine-induced immunity.
The Hepatitis B vaccine consists solely of recombinant surface antigen, meaning it cannot induce antibodies against the core antigen.

Key Concept

Interpretation of Hepatitis B serology panels
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Topics

Gastroenterology and Hepatology

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