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Zorluk: ZorGastroenterology and Hepatology

Match the following Hepatitis B serologic profiles obtained during routine screening or acute evaluation to their most accurate clinical interpretation.

  • HBsAg negative, Anti-HBs positive, Anti-HBc IgG positiveNatural immunity from prior infection
  • HBsAg positive, Anti-HBs negative, Anti-HBc IgM positive, HBeAg positiveAcute viral hepatitis B infection
  • HBsAg positive, Anti-HBs negative, Anti-HBc IgG positive, HBeAg negative, normal ALTInactive chronic hepatitis B carrier
  • HBsAg negative, Anti-HBs negative, Anti-HBc IgM positive"Window period" of acute hepatitis B infection
  • HBsAg negative, Anti-HBs positive, Anti-HBc negativeImmunity secondary to vaccination

Cevap

Profile 1 matches natural immunity; Profile 2 matches acute infection; Profile 3 matches inactive carrier; Profile 4 matches the window period; Profile 5 matches vaccination immunity.
Accurate interpretation of Hepatitis B serology requires stepwise analysis: HBsAg identifies active disease, Anti-HBc distinguishes acute (IgM) from chronic/resolved (IgG) exposure, and Anti-HBs identifies immunity. The absence of HBsAg and Anti-HBs with positive Anti-HBc IgM defines the window period. Isolated Anti-HBs defines vaccination.

Adım Adım Çözüm

1
Evaluate the HBsAg status for each profile.
Positive HBsAg indicates active infection (acute or chronic). Negative HBsAg indicates immunity, resolution, or the window period.
HBsAg is the hallmark of active viral presence.
2
Differentiate between sources of immunity in HBsAg-negative profiles.
Profile 5 has isolated Anti-HBs, indicating vaccination. Profile 1 has both Anti-HBs and Anti-HBc IgG, indicating natural immunity from prior exposure.
Vaccines only contain surface antigen, while natural infection exposes the host to both surface and core antigens.
3
Differentiate acute versus chronic states in HBsAg-positive profiles.
Profile 2 has Anti-HBc IgM, marking acute infection. Profile 3 has Anti-HBc IgG with normal ALT and negative HBeAg, marking an inactive chronic carrier.
IgM is an acute phase reactant, whereas IgG indicates a chronic state (persisting >6 months).
4
Identify the pattern lacking both HBsAg and Anti-HBs.
Profile 4 only shows Anti-HBc IgM, which is classic for the 'window period'.
During this phase, surface antigen has been cleared, but surface antibodies are still forming and bound in complexes, leaving Anti-HBc IgM as the sole marker.

Anahtar Kavram

Interpretation of Hepatitis B Serologic Markers
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Konular

Gastroenterology and Hepatology

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