Chronic hepatitis B virus carriers in the immunotolerant phase of infection: histologic findings and outcome.

Background & Aims: The indication for histologic evaluation of the liver is controversial for patients in the immunotolerant phase of chronic hepatitis B virus (HBV) infection.

Methods: Results of liver biopsy examination and follow-up evaluation were assessed retrospectively in 40 patients who satisfied the following criteria: presence of hepatitis B surface antigen and hepatitis B e antigen, HBV DNA level greater than 10(7) cp/mL, normal alanine aminotransferase level, absence of co-infection with other viruses, and absence of antiviral or immunosuppressive treatment.

Results: On liver biopsy examination, according to the Metavir scoring system, fibrosis was absent in 20 patients, and mild (F1) in 20 patients. During a median follow-up period of 37.7 months in 31 patients, loss of tolerance was observed at a median age of 30.7 years in 12 (38%): 6 had transition to inactive disease, 3 developed chronic hepatitis, and 3 had a transient increase of alanine aminotransferase levels. Among baseline characteristics, only alanine aminotransferase levels were significantly higher in patients with subsequent loss of tolerance.

Conclusions: In patients in the immunotolerant phase of chronic HBV infection, liver biopsy examination shows only minimal changes and probably is unnecessary. Loss of tolerance, occurring at a median age of 30.7 years, is characterized by a rapid transition to an inactive carrier state in two thirds of patients, and to chronic hepatitis in one third of patients.