Is the patient's hepatitis B infection acute or chronic?

From the Guidelines

The patient's hepatitis B infection is chronic, not acute, as indicated by the persistence of hepatitis B surface antigen (HBsAg) for more than 6 months, which is a key diagnostic criterion for chronic hepatitis B 1. To determine whether a hepatitis B infection is acute or chronic, it is essential to understand the natural history of the infection and the role of serological testing.

• The presence of HBsAg is a critical marker for diagnosing hepatitis B infection.
• Acute hepatitis B infection is typically characterized by the presence of HBsAg and IgM anti-HBc, with the infection usually resolving within 6 months 1.
• In contrast, chronic hepatitis B is defined by the persistence of HBsAg for more than 6 months, indicating an inability of the immune system to clear the virus 1.
• Serological testing, including HBsAg, anti-HBs, and anti-HBc, is crucial for differentiating between acute, chronic, and resolved infections 1.
• The management of chronic hepatitis B involves regular monitoring of liver function tests, HBV DNA levels, and assessment for liver fibrosis, with treatment indicated based on viral load, liver enzyme levels, and evidence of liver damage 1.
• Common antiviral medications for chronic hepatitis B, such as entecavir, tenofovir disoproxil fumarate, or tenofovir alafenamide, typically require long-term or indefinite administration 1.
• The distinction between acute and chronic infection is crucial as it determines the management approach, follow-up schedule, and need for screening family members and close contacts for potential infection.
• According to the most recent guidelines, the main goal of therapy for patients with chronic HBV infection is to improve survival and quality of life by preventing disease progression and HCC development 1. Key considerations in managing hepatitis B infection include:
• Regular monitoring and assessment for liver damage and fibrosis.
• The use of antiviral therapy to suppress HBV replication and prevent disease progression.
• Screening for HCC and other complications of chronic hepatitis B.
• Vaccination against hepatitis A for patients with chronic hepatitis B who are negative for hepatitis A antibodies 1.

From the Research

Determining Acute or Chronic Hepatitis B Infection

To determine whether a patient's hepatitis B infection is acute or chronic, several factors and studies can be considered:

• The duration of the infection: Chronic hepatitis B is defined as an infection that lasts longer than 6 months 2.
• HBV-DNA levels: Chronic hepatitis B patients often have high HBV-DNA levels, although treatment can reduce these levels 2, 3.
• HBsAg status: The presence of HBsAg is a marker of active hepatitis B infection, and its persistence is indicative of chronic infection 4, 3.
• Liver function and disease outcomes: Chronic hepatitis B can lead to liver damage, cirrhosis, and hepatocellular carcinoma (HCC) 2, 5, 6.

Treatment and Prognosis

Treatment with nucleoside/nucleotide analogs (NAs) such as entecavir (ETV) and tenofovir disoproxil fumarate (TDF) can effectively suppress HBV-DNA levels and improve disease outcomes in chronic hepatitis B patients 2, 5, 6.

• TDF has been shown to be associated with a lower risk of HCC recurrence and mortality compared to ETV in some studies 5, 6.
• HBsAg levels can affect the prognosis of patients with HBV-related HCC after liver resection, with TDF treatment being superior to ETV treatment in patients with high HBsAg levels 6.

Diagnostic Considerations

Quantitative HBsAg levels can be used to predict functional cure (HBsAg loss) and low HBsAg levels (<2 log IU/mL) in patients treated with ETV or TDF 3.

• A significant reduction in HBsAg levels is often seen in the first year of treatment, with further stepwise decreases in subsequent years 3.
• Baseline HBsAg levels and the first-year HBsAg reduction are key predictors of functional cure and low HBsAg levels 3.