A 30-year-old man presents with a 2-week history of jaundice, malaise, and right upper quadrant discomfort. He reports no alcohol use and takes no medications. Serology shows HBsAg positive, HBeAg positive, IgM anti-HBc positive, and total anti-HBc positive. Which finding best distinguishes acute hepatitis B from reactivation of chronic hepatitis B in this patient?

• A Detection of HBsAg
• B Positivity of HBeAg
• C Elevated serum ALT level
• D Presence of IgM anti-HBc ✓

Explanation

IgM anti-HBc appears early in acute hepatitis B and marks new infection; it is typically absent or at low titre during reactivation of chronic infection, making it the standard discriminator between acute disease and flares of chronic carriage. HBeAg positivity reflects active viral replication and occurs in both settings. HBsAg is positive in acute infection, chronic carriage, and reactivation alike, so it cannot separate them.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.