## Hepatitis B Serological Markers — Temporal Sequence **Key Point:** The order of serological marker appearance in acute HBV infection is: HBsAg → HBeAg → HBV DNA → Anti-HBc IgM → Anti-HBc IgG → Anti-HBe → Anti-HBs. ### Correct Statements | Marker | Significance | Timing | |--------|--------------|--------| | HBsAg | Indicates infection (acute or chronic) | First marker (appears before Anti-HBc IgM) | | HBeAg | Active viral replication, high infectivity | Appears after HBsAg | | Anti-HBc IgM | Acute infection marker, diagnostic window | Appears AFTER HBsAg, NOT first | | Anti-HBs | Immunity, appears after HBsAg clearance | Confers protection | | HBsAg persistence >6 months | Chronic infection definition | Diagnostic criterion | ### Why Option 2 is Incorrect **High-Yield:** HBsAg is the **first serological marker** to appear in acute HBV infection, not Anti-HBc IgM. Anti-HBc IgM appears later during the acute phase, after HBsAg has already been detected. This is a classic NEET PG trap question. **Clinical Pearl:** The "diagnostic window" (when HBsAg has cleared but Anti-HBc IgM is still positive and Anti-HBs has not yet appeared) is a period of 1–2 weeks where Anti-HBc IgM is the only positive marker. However, this does NOT make Anti-HBc IgM the "first" marker overall. ### Mnemonic for HBV Marker Sequence **"HBsAg Before Anti-HBc"** — HBsAg always precedes Anti-HBc IgM in the timeline of acute infection. [cite:Harrison 21e Ch 297]
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.