The first group is treated with high-dose interferon alfa (IFN-A) administered subcutaneously twice a week for 12 weeks. If the alanine aminotransferase (ALT) level has normalized, the IFN-A dose is decreased in a stepwise fashion. If the ALT level decreases by more than 50%, IFN-A is continued at the same dose until week 24 or the ALT normalizes. If the ALT level decreases by less than 50%, treatment is discontinued.