A 34-year-old man presents with fatigue and jaundice of 3 weeks duration. ALT is 1450 U/L. Serology shows HBsAg negative, anti-HBs negative, total anti-HBc positive, IgM anti-HBc strongly positive. Which phase of hepatitis B infection does this represent?

• A False positive serology due to rheumatoid factor
• B Chronic hepatitis B with core escape mutant
• C Resolved hepatitis B infection
• D Window period of acute hepatitis B ✓

Explanation

During recovery from acute hepatitis B there is an interval when HBsAg has been cleared but anti-HBs has not yet appeared. The hallmark of this window period is isolated positivity of IgM anti-HBc, which confirms recent acute infection even though surface antigen is undetectable. Resolved past infection would show total anti-HBc with anti-HBs and no IgM fraction, so the absence of anti-HBs here points squarely to the window period.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.