Treatment of chronic hepatitis C with alpha-interferon.

BACKGROUND/AIMS The present analysis evaluates whether the type, dose, and duration of interferon treatment affect its short- and long-term responses, and also analyzes whether the presence of liver cirrhosis predicts response rates. MATERIAL AND METHODS The present review analyzes 52 randomized clinical trials of a-interferon in chronic NANB and C hepatitis. Normalization of serum ALT during and 3-6 months after interferon treatment served to assess short- and long-term response rates. RESULTS Interferon initially induced ALT normalization in 1499/2927 patients (51.2%); due to a high relapse rate (> 50%), only 482/2218 patients (21.7%) still had normal ALT values three months after interferon therapy had been stopped. Nevertheless, ALT normalization was increased more than 8-fold by a-interferon treatment (21.7%) when compared with the spontaneous normalization rate in untreated or placebo-treated controls (22/822 controls; 2.7%)(chi 2 = 156.1; p < or = 10(-15). The long-term response rate significantly increased with increasing weekly doses and with the duration of interferon therapy (r = 0.25 and 0.38 with p < 0.01, respectively). Correspondingly, the response rate was correlated most closely with the total dose of interferon given (r = 0.49, p < 0.001). Total interferon doses > 240 M.U. resulted in a threefold higher long-term response when compared with doses < 240 M.U. (X2 = 103.3; p < or = 10(-15). The presence of cirrhosis markedly reduced the response rate to almost 1/3 of noncirrhotic patients (chi 2 = 12.1; p = 0.00013). The response rate did not depend on the type of interferon used. CONCLUSIONS The present data strongly suggest that future studies which evaluate effects of a-interferon in chronic hepatitis C should focus on higher doses and longer duration of therapy, preferably in noncirrhotic patients.