From the Guidelines
Hepatitis B is diagnosed through blood tests that detect HBV surface antigen (HBsAg), antibodies, and viral DNA, and management depends on whether the infection is acute or chronic, with antiviral therapy often required for chronic cases to prevent progression to cirrhosis and liver cancer, as recommended by the most recent study 1.
Diagnosis
- Blood tests are used to detect HBV surface antigen (HBsAg), antibodies, and viral DNA, with HBsAg immunoassay being a necessary and accurate test for diagnosis of chronic hepatitis B (CHB) 1.
- Acute HBV infection is diagnosed by being HBsAg positive and anti-HBc IgM positive, while chronic HBV infection is characterized by persistence of HBsAg for at least 6 months 1.
Management
- Acute HBV typically resolves spontaneously within 6 months and requires supportive care with rest, hydration, and monitoring.
- Chronic HBV often requires antiviral therapy, with first-line treatments including entecavir (0.5mg daily) or tenofovir disoproxil fumarate (300mg daily), which suppress viral replication with minimal resistance 1.
- Alternative options include tenofovir alafenamide (25mg daily), particularly for patients with renal impairment or bone disease.
- Treatment is generally long-term, often lifelong, as discontinuation can lead to viral rebound.
Prevention
- Vaccination is crucial for prevention, with a standard 3-dose series (0,1, and 6 months) recommended for uninfected individuals.
- All household contacts and sexual partners of infected individuals should be screened and vaccinated if susceptible.
Monitoring
- Patients need regular monitoring of liver function tests, HBV DNA levels, and screening for hepatocellular carcinoma with ultrasound every 6 months.
- Antiviral therapy works by inhibiting HBV DNA polymerase, reducing viral replication and liver inflammation, which helps prevent progression to cirrhosis and liver cancer 1.
From the FDA Drug Label
The safety and efficacy of entecavir were evaluated in three Phase 3 active-controlled trials [see Clinical Studies (14.1,14. 2)] . These studies included 1633 subjects 16 years of age or older with chronic hepatitis B virus infection (serum HBsAg-positive for at least 6 months) accompanied by evidence of viral replication (detectable serum HBV DNA, as measured by the bDNA hybridization or PCR assay). Subjects had persistently elevated ALT levels at least 1. 3 times ULN and chronic inflammation on liver biopsy compatible with a diagnosis of chronic viral hepatitis.
The diagnosis of Hepatitis B (HBV) is based on:
- Serum HBsAg-positive for at least 6 months
- Evidence of viral replication (detectable serum HBV DNA)
- Persistently elevated ALT levels at least 1.3 times ULN
- Chronic inflammation on liver biopsy compatible with a diagnosis of chronic viral hepatitis
The management of HBV includes:
- Entecavir therapy for nucleoside-inhibitor-naïve subjects with compensated liver disease
- Monitoring of hepatic function closely for at least several months after discontinuation of therapy 2
- HAART therapy for subjects co-infected with HBV and HIV 2
From the Research
Diagnosis of Hepatitis B
- Hepatitis B virus (HBV) infection is diagnosed through serological testing for HBsAg and for acute infection, additional testing for IgM hepatitis B core antibody (IgM anti-HBc) 3
- The diagnosis of HBV infection requires the evaluation of the patient's blood for hepatitis B surface antigen, hepatitis B surface antibody, and hepatitis B core antibody 4
- Current laboratory tests for diagnosis of HBV infection include serologic- and molecular-based methods to diagnose acute or chronic HBV infection 5
Symptoms of Hepatitis B
- Acute infection may cause nonspecific symptoms, such as fatigue, poor appetite, nausea, vomiting, abdominal pain, low-grade fever, jaundice, and dark urine 4
- Clinical signs of acute infection may include hepatomegaly and splenomegaly 4
Management of Hepatitis B
- The goals of treatment for chronic HBV infection are to reduce inflammation of the liver and to prevent complications by suppressing viral replication 4
- Treatment options include pegylated interferon alfa-2a administered subcutaneously or oral antiviral agents (nucleotide reverse transcriptase inhibitors) 4
- Pegylated interferon alfa-2a, entecavir, and tenofovir are recommended as first-line treatment options for chronic hepatitis B 6
- Treatment is recommended for patients with cirrhosis or with high HBV DNA levels and active or advanced liver disease 3
Prevention of Hepatitis B
- Universal infant immunisation, including birth dose vaccination is the most effective means to prevent chronic HBV infection 3
- Hepatitis B vaccination is recommended for medically stable infants weighing 2,000 g or more within 24 hours of birth, unvaccinated infants and children, and unvaccinated adults requesting protection from hepatitis B or who are at increased risk of infection 6