No abstract

Interferon (IFN) is effective in treating adults as well as children with chronic hepatitis C. We investigated the efficacy of IFN therapy in 13 children with underlying acute leukemia who had chronic hepatitis C (age range, 5 to 17 years; mean age, 9.9 years). Natural IFN- alpha was administered at a dose of 0.1 mega unit (MU)/kg (maximum dose, 6.0 MU) daily for 2 weeks and then three times per week for an additional 22 weeks (total dose, 8 MU/kg). IFN treatment was initiated at least 2 years after the completion of treatment for acute leukemia. A complete response was obtained in 5 children (38%). The serum level of anti- hepatitis C virus core antibody was closely related to the response to IFN. IFN therapy was well tolerated by all but 1 of the children, who developed mild transient heart failure 4 months after the initiation of therapy. IFN therapy for children with chronic hepatitis C who had underlying acute leukemia was beneficial. However, further trials are required to confirm the safety and improve the dosage schedule of IFN therapy.

A low serum titre of HCV RNA and a significant decrease in the serum titre of anti-HCV core were associated with spontaneous remission in children with chronic hepatitis C. Intrahepatic HCV RNA assessment is necessary to confirm complete remission.

To evaluate the long-term protection provided by hepatitis B (HB) vaccine in a high-risk environment, we followed 50 infants born to mothers with hepatitis B e (HBe) antigen. These infants were immunized with a three-dose regimen of plasma-derived HB vaccine and were followed for up to 10 years. Two infants (4%) acquired hepatitis B virus (HBV) infection before 1 year of age. The 48 other infants remained hepatitis B surface (HBs) antigen-negative during the follow-up period. The geometric mean titers of serum antibody to HBs antigen rapidly decreased during the first 4 years but remained at protective levels throughout the follow-up period. These data suggest that protection against significant HBV infection lasts for at least 10 years. We conclude that the long-term protection afforded by plasma-derived HB vaccine is satisfactory and that a routine booster dose before 10 years of age is not necessary.

A region associated with sensitivity to interferon (IFN) has been identified previously in the nonstructural protein 5A (NS5A) of hepatitis C virus (HCV) genotype 1b. A study was undertaken to determine whether the presence of mutations in the NS5A2209-2248 sequence could serve as a predictor of response to IFN therapy in children and adolescents with chronic HCV-1b infection. Sixteen children (M/F ratio = 11:5; mean age 11.7 years, range 5 to 19 years) with chronic HCV-1b infection who received IFN-alpha for 6 months (total dose: 8 MU/kg) were enrolled in this study. Twelve of the children (75%) had an underlying malignant disease. Pretreatment NS5A gene sequences were detected by reverse transcription-nested polymerase chain reaction (RT-nested PCR). PCR products were subjected to direct sequencing by the dideoxy chain termination method. The amino acid sequences of NS5A2209-2248 were compared with the published NS5A2209-2248 sequences of HCV-J. The NS5A2209-2248 sequences were detected in 10(63%) of the 16 children. Eight patients had the wild-type sequences, with no amino acid changes; and two patients had the intermediate type, with only one amino acid change. Four (25%) of the 16 patients responded completely to IFN therapy. Three of the four patients had the wild-type sequences, while none of the patients with the mutant type had a complete response. Serum HCV RNA levels in children with the wild type did not differ from those in patients with the mutant type. This study shows that there is no significant correlation between response to IFN and mutations in NS5A2209-2248. The amino acid sequences in NS5A2209-2248 in young patients with chronic HCV-1b infection appear to be conserved.