In high endemic areas of hepatitis B virus (HBV)
infection, the vast majority of
infection is acquired perinatally or during early childhood. The age of the patient is, therefore, almost equivalent to the duration of HBV
infection. The natural history of chronic HBV
infection consists of three chronological phases: immune tolerance, immune clearance and low replicative phases. The prevalence of
hepatitis B e antigen (
HBeAg) in asymptomatic HBV carriers is around 90% before 15 years of age, and decreases remarkably to less than 10% after 40 years of age. The immune clearance phase is characterized by a series of
hepatitis flares and remissions. These will be followed eventually by
HBeAg seroconversion, which is usually accompanied by remission of
liver disease and confers favourable outcome. However, patients with persistent
HBeAg seropositivity over 40 years of age are associated with a significantly higher risk for progression to
cirrhosis than those with
HBeAg seroconversion before 40 years of age, and thus should be considered as patients with 'delayed'
HBeAg seroconversion.
Antiviral or
immunomodulatory therapy should be considered seriously for these patients.