During screening of blood donors in a Delhi blood bank, a donor is found to be HBsAg positive. Which is the most common serological marker pattern that would be expected in a chronic hepatitis B carrier?

Question

Accepted Answer

D. HBsAg positive, anti-HBc total positive, anti-HBc IgM negative, anti-HBs negative. ## Chronic Hepatitis B Serology Pattern

**Key Point:** The most common serological pattern in chronic HBV infection is **HBsAg+, anti-HBc total+, anti-HBc IgM−, anti-HBs−**. This reflects persistent antigen with resolved acute phase markers.

### Distinguishing Acute from Chronic HBV

| Marker | Acute HBV | Chronic HBV | Resolved HBV |
|--------|-----------|-------------|---------------|
| **HBsAg** | + | + | − |
| **Anti-HBc IgM** | + | − | − |
| **Anti-HBc total** | + | + | + |
| **Anti-HBs** | − (appears late) | − | + |
| **Duration** | 6 months | > 6 months | Lifelong immunity |

**High-Yield:** The **absence of anti-HBc IgM** in a HBsAg-positive patient is the key discriminator for chronic infection. Anti-HBc IgM disappears after 6 months; if HBsAg persists beyond 6 months without anti-HBc IgM, the infection is chronic.

### Interpretation Logic

1. **HBsAg+** = Active infection (acute or chronic)
2. **Anti-HBc IgM+** = **Acute phase** (< 6 months)
3. **Anti-HBc IgM−** + **HBsAg+** = **Chronic infection** (> 6 months)
4. **Anti-HBc total+** = Exposure to HBV (past or present)
5. **Anti-HBs+** = Immunity (absent in chronic carriers)

**Clinical Pearl:** Chronic HBV carriers remain **HBsAg-positive for life** (unless they clear the virus, which is rare in adults infected as children). They are **anti-HBc IgM negative** because the acute phase has resolved, but **anti-HBc total remains positive** as a marker of past/ongoing infection.

**Mnemonic: CHRONIC = CAT**
- **C** — Chronic: HBsAg+ > 6 months
- **A** — Anti-HBc IgM Absent (key difference from acute)
- **T** — Total anti-HBc present (lifelong marker)

**Warning:** Do NOT confuse chronic HBV (HBsAg+, anti-HBc IgM−) with acute HBV (HBsAg+, anti-HBc IgM+). The **presence or absence of anti-HBc IgM is the critical differentiator**.

[cite:Robbins 10e Ch 18]

Answer

A. HBsAg positive, anti-HBc total negative, anti-HBc IgM negative, anti-HBs negative

Answer

B. HBsAg negative, anti-HBc total positive, anti-HBc IgM negative, anti-HBs positive

Answer

C. HBsAg positive, anti-HBc total positive, anti-HBc IgM positive, anti-HBs positive

During screening of blood donors in a Delhi blood bank, a donor is found to be HBsAg positive. Which is the most common serological marker pattern that would be expected in a chronic hepatitis B carrier?

Explanation

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