GPT and hepatitis B virus infection: Few studies have provided data on the natural course of fibrosis progression in hepatitis B. In a study of 57 patients in the immune-tolerant phase of the disease, the median rate of fibrosis progression was 0 fibrosis units/year in those with normal liver function and 0.21 fibrosis unit/year in patients with high alanine aminotransferase (ALT) levels (progression into the immune clearance phase) [79].