What is the management plan for a patient who is Hepatitis B surface antigen (HBsAg) positive?

Management of Patients with Positive Hepatitis B Surface Antigen (HBsAg)

All patients who test positive for HBsAg should be referred to a specialist experienced in managing chronic hepatitis B infection for comprehensive evaluation and appropriate treatment. 1

Initial Assessment

Confirmation and Additional Testing

• Retest for HBsAg to verify chronic infection (persistence of HBsAg ≥6 months indicates chronic HBV infection) 1
• Complete the following serological panel:
  • HBeAg and anti-HBe (to determine replication status)
  • HBV DNA quantification (viral load)
  • Anti-HBc (to distinguish acute from chronic infection)
  • Liver function tests (ALT, AST, bilirubin, albumin, PT/INR)
  • Complete blood count
  • Tests for coinfection: HIV, HCV, HDV
  • Anti-HAV (to assess need for hepatitis A vaccination)

Risk Stratification

• Treatment decisions should be based on: 2
  • HBV DNA levels
  • ALT/AST levels
  • HBeAg status
  • Presence of cirrhosis
  • Age and comorbidities

Treatment Indications

HBeAg-Positive Patients

• Treat if:
  • HBV DNA >20,000 IU/mL and ALT >2× upper limit of normal (ULN)
  • Age >30 years with HBV DNA >20,000 IU/mL regardless of ALT 2

HBeAg-Negative Patients

• Treat if:
  • HBV DNA >2,000 IU/mL and ALT >ULN
  • HBV DNA >2,000 IU/mL with significant liver inflammation/fibrosis on biopsy 2

Cirrhotic Patients

• Treat if:
  • Compensated cirrhosis with HBV DNA ≥2,000 IU/mL regardless of ALT
  • Decompensated cirrhosis regardless of HBV DNA or ALT levels 2

Treatment Options

First-Line Antiviral Agents

• Entecavir (0.5 mg daily)
• Tenofovir disoproxil fumarate (300 mg daily)
• Tenofovir alafenamide (25 mg daily) 2

Alternative Options

• Peginterferon alfa-2a (180 μg weekly for 48 weeks) - especially for young patients with high ALT, low HBV DNA, and without cirrhosis 2
• Lamivudine (100 mg daily) - now considered second-line due to high resistance rates
• Adefovir (10 mg daily) - now considered second-line due to renal toxicity concerns 2

Treatment Duration

• HBeAg-positive patients: Minimum 1 year, continue 3-6 months after HBeAg seroconversion
• HBeAg-negative patients: Typically long-term/indefinite due to high relapse rates (80-90%)
• Cirrhotic patients: Long-term/indefinite treatment regardless of HBeAg status 2

Monitoring

During Treatment

• ALT and HBV DNA every 3-6 months
• HBeAg/anti-HBe status every 6-12 months
• Renal function monitoring, especially with tenofovir or adefovir 2

HCC Surveillance

• Ultrasound every 6 months for:
  • Asian men >40 years
  • Asian women >50 years
  • Patients with cirrhosis
  • Family history of HCC
  • African Americans >20 years
  • Carriers >40 years with elevated ALT or HBV DNA >2000 IU/mL 2

Special Populations

Immunosuppressed Patients

• All HBsAg-positive patients should receive antiviral prophylaxis (entecavir, tenofovir, or TAF) before starting immunosuppressive therapy or chemotherapy
• Continue prophylaxis for at least 12 months (18 months for rituximab-based regimens) after completion of immunosuppressive treatment 1

Pregnant Women

• Consider tenofovir in the third trimester for women with high viral load to prevent vertical transmission 2
• Ensure newborns receive hepatitis B vaccine and hepatitis B immune globulin at birth 1

Prevention of Transmission

Counsel HBsAg-positive patients to:

• Notify household, sexual, and needle-sharing contacts for testing and vaccination 1
• Use condoms with non-immune sexual partners until they can be vaccinated 1
• Cover cuts and skin lesions to prevent spread of infectious secretions 1
• Refrain from donating blood, plasma, tissue, or semen 1
• Avoid sharing household items that could be contaminated with blood (toothbrushes, razors, etc.) 1
• Inform healthcare providers of HBsAg status 1

Patient Education

• HBV is not spread by breastfeeding, kissing, hugging, coughing, sharing food/drinks, or casual contact 1
• Patients should not be excluded from school, work, or other settings based on HBsAg status 1
• Limit or avoid alcohol consumption 1
• Consider hepatitis A vaccination if not immune 1
• Support groups may help patients cope with chronic infection 1

Common Pitfalls and Caveats

• Failure to recognize HBV reactivation risk in HBsAg-positive patients receiving immunosuppressive therapy
• Premature discontinuation of antiviral therapy leading to severe flares
• Inadequate monitoring for drug resistance, especially with lamivudine
• Overlooking the need for HCC surveillance in high-risk patients
• Failure to screen and vaccinate household and sexual contacts