A 48-year-old woman from Delhi is found to have HBsAg positivity on routine blood screening during a pre-operative workup. She is asymptomatic with normal liver function tests (ALT 32 IU/L, AST 28 IU/L, bilirubin 0.9 mg/dL). Further serology shows: HBsAg positive, anti-HBc positive, IgM anti-HBc negative, anti-HBs negative, HBeAg negative, anti-HBe positive. What is the most likely diagnosis?

Explanation

## Interpretation of Chronic Hepatitis B Serology ### Clinical Context Asymptomatic patient with incidental HBsAg positivity, normal liver enzymes, and serological markers consistent with chronic HBV infection. ### Serological Marker Analysis | Marker | Result | Interpretation | |--------|--------|----------------| | HBsAg | Positive | Chronic infection (present >6 months) | | Anti-HBc | Positive | Exposure to HBV | | **IgM anti-HBc** | **Negative** | **Rules out acute infection** | | Anti-HBs | Negative | No clearance of virus | | **HBeAg** | **Negative** | **Low viral replication phase** | | **Anti-HBe** | **Positive** | **Seroconversion from HBeAg** | ### Key Diagnostic Features **Key Point:** The combination of HBsAg(+), anti-HBc(+), IgM anti-HBc(−), HBeAg(−), and anti-HBe(+) defines **HBeAg-negative chronic hepatitis B**, also called the "low-replicative phase" or "anti-HBe phase." **High-Yield:** Chronic HBV infection has two main phases: 1. **Immune-tolerant phase:** HBsAg(+), HBeAg(+), high HBV DNA, normal or mildly elevated ALT 2. **Low-replicative phase:** HBsAg(+), HBeAg(−), anti-HBe(+), low HBV DNA, normal ALT (as in this case) ### Why Not Other Options? **Clinical Pearl:** HBeAg-negative chronic HBV can have variable outcomes. Some patients remain stable with low viral load and normal enzymes (as here), while others develop HBeAg-negative hepatitis with active inflammation despite low HBeAg. Quantitative HBV DNA testing would help stratify risk. ### Mnemonic: CHRONIC HBV PHASES **CHRONIC** = - **C**arrier phase (immune-tolerant): HBeAg(+), high DNA, normal ALT - **H**epatitis phase (immune-clearance): HBeAg(+), high DNA, elevated ALT - **R**emission phase (low-replicative): HBeAg(−), low DNA, normal ALT - **O**ccult phase: HBsAg(−), anti-HBc(+), low/undetectable DNA - **N**ew reactivation: HBeAg(−) hepatitis with active inflammation - **I**mmune recovery: Anti-HBe(+), anti-HBs may appear - **C**learance: HBsAg(−), anti-HBs(+)