A 34-year-old man presents with 5 days of malaise, right upper quadrant discomfort, and dark urine. Total bilirubin is 6 mg/dL, ALT 1450 IU/L, AST 900 IU/L. Serology shows HBsAg positive, IgM anti-HBc positive, IgG anti-HBc negative, anti-HBs negative. What is the correct interpretation?
- A Chronic hepatitis B infection
- B Resolved hepatitis B infection with immunity
- C Acute hepatitis B infection ✓
- D Immunity from hepatitis B vaccination
Correct answer: C. Acute hepatitis B infection
Explanation
IgM anti-HBc appears early in acute hepatitis C and marks recent infection; combined with HBsAg positivity this confirms acute hepatitis C. Chronic infection shows IgG anti-HBc with HBsAg persistence beyond 6 months. Vaccination produces isolated anti-HBs without anti-HBc, because core antigen is absent from recombinant surface-antigen vaccines. Resolved infection gives IgG anti-HBc with anti-HBs.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.