A 45-year-old man with a 15-year history of intravenous drug use presents with fatigue, jaundice, and abdominal pain. He reports multiple episodes of acute hepatitis in the past. On examination: hepatomegaly, ascites, and spider angiomas. Laboratory findings: ALT 180 IU/L, AST 320 IU/L (AST > ALT), bilirubin 6.5 mg/dL, albumin 2.8 g/dL, PT prolonged (INR 2.1). Serology: HBsAg positive, anti-HBc IgG positive, anti-HBe positive, HBeAg negative, anti-HDV positive, anti-HCV positive. What is the most likely diagnosis?

Explanation

## Diagnosis: Chronic Hepatitis B with Hepatitis D Superinfection and Concurrent Hepatitis C ### Serological Interpretation | Marker | Finding | Interpretation | |--------|---------|----------------| | HBsAg | Positive | Active HBV infection (chronic, given duration) | | Anti-HBc IgG | Positive | Past or ongoing HBV infection (not acute) | | HBeAg | Negative | Low viral replication phase (or late chronic disease) | | Anti-HBe | Positive | Correlates with HBeAg negativity | | Anti-HDV | Positive | Hepatitis D virus exposure/infection | | Anti-HCV | Positive | Hepatitis C virus exposure/infection | **Key Point:** The presence of **anti-HBc IgG (not IgM)** and **persistent HBsAg** indicates chronic HBV, not acute infection. In acute HBV, anti-HBc IgM would be present. ### Clinical Context: Why Chronic, Not Acute 1. **15-year history of IVDU** — ample time for HBV acquisition and chronification 2. **Cirrhotic features** — ascites, spider angiomas, hypoalbuminemia, prolonged PT → advanced liver disease 3. **AST > ALT** — pattern typical of cirrhosis (fibrosis-induced enzyme release) 4. **Preserved anti-HBc IgG, absence of anti-HBc IgM** — excludes acute HBV ### Hepatitis D (Delta) Virus: Defective Virus Dependency **High-Yield:** HDV is a defective RNA virus that requires HBsAg for replication. It can occur as: - **Coinfection:** simultaneous HBV + HDV (rare, usually self-limited) - **Superinfection:** HDV acquired in a patient with chronic HBV (this case) — causes more severe disease **Clinical Pearl:** Superinfection with HDV accelerates progression to cirrhosis and increases risk of hepatocellular carcinoma. The presence of anti-HDV in a chronic HBsAg-positive patient indicates HDV superinfection. ### Why This Patient Has Severe Disease 1. **Chronic HBV** (15 years) → cirrhosis 2. **HDV superinfection** → accelerated fibrosis 3. **Concurrent HCV** → additive hepatotoxicity **Mnemonic: "HDV needs HBV"** — Delta virus cannot replicate without hepatitis B surface antigen. ### Pathophysiology of Cirrhosis ```mermaid flowchart TD A[Chronic HBV for 15 years]:::outcome --> B[Progressive hepatic fibrosis] B --> C[HDV superinfection]:::urgent C --> D[Accelerated cirrhosis] D --> E[Portal hypertension] E --> F[Ascites, varices, spider angiomas]:::outcome G[Concurrent HCV]:::outcome --> D D --> H[Decompensation: low albumin, prolonged PT]:::urgent ``` **Key Point:** The combination of three hepatotropic viruses (HBV, HDV, HCV) in a single patient with IVDU history is not uncommon and results in accelerated liver disease.