A 22-year-old voluntary blood donor is deferred during routine screening. Investigations show: HBsAg negative, anti-HBs negative, anti-HBc (total) reactive, and serum ALT three times the upper limit of normal. What is the most likely interpretation?
- A Resolved hepatitis B infection in the past
- B Immunity following hepatitis B vaccination
- C Window period of acute hepatitis B infection ✓
- D Chronic hepatitis B carrier state
Correct answer: C. Window period of acute hepatitis B infection
Explanation
In the window period of acute hepatitis B, HBsAg has been cleared but protective anti-HBs has not yet appeared; IgM anti-HBc is the only dependable marker and transaminases remain elevated, so this donor is potentially still infectious. Resolved past infection shows both anti-HBc and anti-HBs positivity, isolated anti-HBs indicates vaccine response, and a chronic carrier requires persistently detectable HBsAg, so none of those serological patterns fit this profile.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.