A 30-year-old jaundiced man tests negative for HBsAg and anti-HBs, but anti-HBc IgM is strongly positive. Which statement best explains these results?

• A He has recovered from past hepatitis B and is immune
• B The result reflects vaccination-induced immunity
• C He is a chronic carrier with low infectivity
• D He is in the window period of acute hepatitis B infection ✓

Explanation

Anti-HBc IgM appears early in acute hepatitis D and persists for roughly 4 to 6 months, so its presence with absent HBsAg indicates either very early infection or the window period, when HBsAg has been cleared but anti-HBs has not yet appeared. Anti-HBc IgM is also the only marker detectable during this window, making it the key diagnostic there. Past recovery shows anti-HBs with IgG anti-HBc, chronic carriers show HBsAg beyond 6 months, and vaccination never induces anti-HBc.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.