Long-term therapeutic efficacy of interferon for patients with chronic hepatitis C.

Interferon is being used for therapy of chronic hepatitis C, but its long-term results have not been reported. We studied 65 patients with this disease who were monitored for at least 2 years after completion of the therapy. Almost all patients who had responded to therapy at 6 months after the end of therapy had normal levels of alanine aminotransferase (ALT) when evaluated later. The level of ALT became normal for the first time in some patients more than 6 months after therapy ended. The level of ALT in many of the patients without HCV RNA had become normal 6 months after the end of the therapy. One of three schedules was employed: three times weekly long-term; daily for two weeks and none for two weeks in a cycle; and daily for several weeks; 57%, 29%, and 17% of the patients on these schedules came to have normal ALT levels. Patients without HCV RNA at six months after completion of therapy tended to have higher responses in terms an increased level of 2',5'-oligoadenylate synthetase of mononuclear cells in vitro before therapy began. However, therapy three times per week was effective even for some patients judged not responsive to IFN by this test. The results showed that IFN therapy was effective for chronic hepatitis C when judged by long-term results.