Interferon-alfa is an accepted treatment for chronic hepatitis C in adults, with a response rate (defined as normalization of alanine aminotransferase [ALT] values) of about 50 percent and a relapse rate in the first year of 50 percent. Jonas and colleagues conducted an open-labeled prospective trial to determine the safety and efficacy of interferon-alfa-2a therapy in children with chronic hepatitis C virus.

A total of 21 children with at least two ALT determinations more than 1.5 times the upper limit for at least six months completed the study. Treatment consisted of 3 million U of interferon-alfa-2a administered subcutaneously three times weekly for six months. Treatment was extended to one year in patients found to be responding at six months.

Four children (19 percent) had complete response to treatment at the end of six months, with normal ALT values and no detectable RNA for hepatitis C virus. An additional eight children (38 percent) were partial responders, with at least a 50 percent improvement in ALT values. Two of the responders who received prolonged therapy remained RNA–negative for hepatitis C virus, with normal ALT values. Three of the partial responders who received 12 months of treatment became complete responders, and this response was sustained. There were no statistically significant factors associated with response; however, the small sample size limited the ability to detect differences in variables. Side effects of treatment included fever and malaise in virtually every child early in the treatment. Seven of the children participating in the study (33 percent) lost HCV RNA and had normalization of ALT; all of these children had sustained response for at least six months, and five had sustained response for 12 months.

The authors conclude that although the response rate of 33 percent for children is less than the 50 percent rate typically reported for adults at one year, treatment with interferon-alfa has some efficacy in children with chronic hepatitis C infection. Children who have complete or partial response at six months should undergo prolonged treatment. Side effects were minimal. The most worrisome side effect was weight loss, which occurred in one half of the children treated. All of these children regained the lost weight after the conclusion of therapy. No long-term effects of interferon-alfa therapy were noted in follow-up of up to 36 months' duration.