It has long been recognized that interferon therapy of chronic hepatitis C is associated with a significant reduction in the degree of necroinflammatory change within the liver. It has only recently become apparent that antiviral therapy might also have an impact on the degree of hepatic fibrosis.

Poynard et al (2002) examined pooled individual data from more than 3000 patients with chronic hepatitis C who have participated in four randomized controlled trials with the same industry sponsor (Schering). Patients enrolled in these four trials were subject to 10 possible different treatment regimens combining standard interferon a2b, pegylated (PEG)-interferon a2b and ribavirin.
They assessed the impact of each regimen by determining the percentage of patients with at least one-grade improvement in necrosis and inflammation using the METAVIR score and with at least one-stage worsening of fibrosis and by the annual fibrosis progression rate. Necrosis and inflammation improved with all treatment regimens, but occurred to the greatest degree with higher doses of peginterferon and ribavirin.

The proportion of cases with worsening fibrosis was also lowest in patients treated with this regimen. All treatment regimens were associated with significant reductions in the rate of fibrosis progression assessed in the follow-up liver biopsies. Not only was the rate of progression of fibrosis slowed but reversal of cirrhosis was observed in 75 of 153 (49%) of patients with cirrhosis at baseline.