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Difficulty: MediumInterpreting Laboratory Results

Review the following viral hepatitis serologic testing panels obtained during routine outpatient screening. Connect each specific laboratory profile to its most accurate clinical interpretation.

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

Answer

The correct mapping aligns acute infection with HBsAg/IgM anti-HBc, chronic infection with HBsAg/IgG anti-HBc, past natural infection immunity with anti-HBs/IgG anti-HBc, and vaccine immunity with isolated anti-HBs.
Matching viral serology requires a systematic approach. HBsAg determines active disease versus no active disease. Anti-HBc determines if the patient has ever encountered the actual virus (IgM for acute, IgG for past/chronic). Anti-HBs determines immunity. Together, these markers create distinct, non-overlapping profiles for acute infection, chronic infection, natural immunity, and vaccine-induced immunity.

Step-by-Step Solution

1
Analyze the HBsAg (surface antigen) status.
Positive HBsAg indicates current active infection (either acute or chronic). Negative HBsAg indicates the absence of active infection (either resolved or uninfected/vaccinated).
HBsAg is the primary marker of active viral replication and presence in the bloodstream.
2
Evaluate the anti-HBc (core antibody) testing.
IgM anti-HBc points to a recent, acute infection. IgG anti-HBc points to a past exposure (which may be chronic if HBsAg remains positive, or resolved if HBsAg is negative).
The core antigen is not present in the vaccine, so anti-HBc is only produced during a true natural viral infection. The IgM-to-IgG transition marks the passage of time.
3
Check the anti-HBs (surface antibody) status.
Positive anti-HBs indicates immunity. When combined with negative anti-HBc, it proves vaccination. When combined with positive anti-HBc IgG, it proves recovery from natural infection.
Anti-HBs is the neutralizing antibody that provides long-term immunity.

Key Concept

Interpretation of Hepatitis B Serologic Markers
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Topics

Interpreting Laboratory Results

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