What is the recommended treatment and prevention for hepatitis B infection?

Hepatitis B Infection: Treatment and Prevention Guidelines

The recommended first-line treatments for chronic hepatitis B infection are entecavir, tenofovir disoproxil fumarate (TDF), or tenofovir alafenamide (TAF) due to their potent viral suppression, high genetic barrier to resistance, and excellent long-term safety profiles. 1

Screening and Diagnosis

Who to Screen

• Pregnant women at first prenatal visit
• Individuals from high-prevalence areas (Asia, Pacific Islands, Africa)
• Household contacts of HBV-infected persons
• Sexual partners of HBV-infected persons
• Men who have sex with men
• Injection drug users
• Healthcare workers with potential blood exposure
• Patients receiving immunosuppressive therapy
• Patients with HIV infection or other liver diseases
• Patients on dialysis or with end-stage renal disease 2

Diagnostic Tests

• HBsAg: Indicates current infection (acute or chronic)
• Anti-HBs: Indicates immunity (from vaccination or resolved infection)
• Anti-HBc: Indicates previous or ongoing infection
• HBeAg and anti-HBe: Help determine disease activity
• HBV DNA: Quantifies viral load
• Liver function tests: Assess liver damage 2, 1

Treatment Approach for Chronic HBV

Treatment Indications

1. HBV DNA >2,000 IU/mL with elevated ALT and/or moderate-to-severe liver inflammation/fibrosis
2. Cirrhosis with any detectable HBV DNA
3. Family history of HCC with HBV DNA >2,000 IU/mL
4. HBeAg-positive patients >30 years with HBV DNA >20,000 IU/mL 2, 1

First-Line Treatment Options

1. Nucleos(t)ide Analogues (NAs):

   • Entecavir: 0.5 mg daily
   • Tenofovir disoproxil fumarate (TDF): 300 mg daily
   • Tenofovir alafenamide (TAF): 25 mg daily 1

2. Pegylated Interferon-α:

   • 48-week course
   • Better suited for younger patients with high ALT, low HBV DNA, and without cirrhosis 1

Treatment Duration

• For HBeAg-positive patients: Continue treatment for at least 12 months after HBeAg seroconversion
• For HBeAg-negative patients: Long-term or indefinite treatment is typically required
• For cirrhotic patients: Indefinite treatment recommended 1

Monitoring During Treatment

• HBV DNA: Every 3 months until undetectable, then every 3-6 months
• ALT/AST: Monthly until normalized, then every 3 months
• HBeAg/anti-HBe: Every 6 months in HBeAg-positive patients
• Renal function: Regular monitoring, especially with tenofovir therapy 1

Special Populations

Pregnant Women

• Screen all pregnant women for HBsAg at first prenatal visit
• Women with HBV DNA >10^6 IU/mL should receive antiviral therapy (tenofovir preferred) starting at 26-28 weeks of gestation through 4 weeks postpartum to prevent vertical transmission
• Monitor closely during pregnancy and postpartum for flares 2

HIV Co-infection

• Treat with tenofovir-containing regimens
• Avoid lamivudine monotherapy due to high resistance rates 1

Immunosuppressed Patients

• Screen all patients before starting immunosuppressive therapy
• For high-risk patients (HBsAg-positive or receiving B-cell depleting agents): Prophylactic antiviral therapy is strongly recommended
• For moderate-risk patients: Antiviral prophylaxis is suggested
• Continue prophylaxis for at least 6 months after discontinuation of immunosuppressive therapy (12 months for B-cell depleting agents) 2

Prevention Strategies

Vaccination

• Universal vaccination of all infants at birth
• Vaccination of unvaccinated children and adults at risk
• Three-dose schedule achieves protective antibody response in >90% of adults and >95% of adolescents 2

Post-exposure Prophylaxis

• Hepatitis B immune globulin (HBIG) plus vaccination for infants born to HBsAg-positive mothers
• HBIG plus vaccination for unvaccinated individuals with recent exposure 2

Managing Resistance

• Viral resistance is defined as an increase in HBV DNA >1 log10 IU/ml from nadir
• If resistance develops, add or switch to a non-cross-resistant agent
• Newer agents (entecavir, tenofovir) have much lower resistance rates compared to lamivudine 3

Common Pitfalls to Avoid

1. Premature discontinuation of therapy: Can lead to severe hepatitis flares; monitor ALT at least monthly for 3 months after stopping treatment

2. Inadequate monitoring: Regular monitoring of HBV DNA and ALT is essential to detect resistance early

3. Using lamivudine as first-line therapy: High resistance rates (up to 70% after 5 years) make it a poor first-line choice

4. Failing to screen for HCC: Patients with chronic HBV require regular HCC surveillance regardless of treatment status

5. Overlooking renal toxicity: Monitor renal function in patients on tenofovir therapy 1, 4

By following these evidence-based guidelines for treatment and prevention of hepatitis B infection, clinicians can significantly reduce morbidity and mortality associated with chronic HBV infection.