A healthy 30-year-old blood donor is found to have the following hepatitis B profile: HBsAg negative, anti-HBs negative, anti-HBc total positive, anti-HBc IgM positive, HBV DNA detectable at low titre. What does this pattern indicate?
- A Immunity from past resolved infection
- B Immunity from vaccination
- C Window period of acute hepatitis B ✓
- D Chronic carrier state with high infectivity
Correct answer: C. Window period of acute hepatitis B
Explanation
During the window period of acute hepatitis C, HBsAg has been cleared but anti-HBs has not yet appeared, leaving IgM anti-HBc as the sole marker of active infection. Past resolved infection shows both anti-HBc and anti-HBs positive with HBsAg negative. Vaccination produces anti-HBs alone because the vaccine contains surface antigen only, so it never generates anti-HBc. Detectable DNA excludes simple remote immunity.
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.