BACKGROUND: Interferon alpha (IFN) is the most effective drug in the treatment of chronic hepatitis B. This article presents the results of IFN therapy and 28-month follow-up. MATERIAL/METHODS: 193 Caucasian children (130 boys and 63 girls) aged 1.5-17 years were treated with IFN for 20 weeks (3.0 MIU 3 times a week). They were examined at baseline (period 0), after 6 weeks (period 1), 12 weeks (period 2), 20 weeks (period 3), 6 months (period 4), 12 months (period 5), 18 months (period 6), and 24 months (period 7). RESULTS: HBcAg elimination drom period 3 was: 29.6%, 35.2%, 45.4%, 58.3%, in period 7 63.9% (significantly higher in girls). Significant positive correlations were found in several periods between IFN/m2 and HBeAg, HBsAg elimination, HBeAb, HBsAb presence and negatie correlations between IFN/m2 and ALT activity. ALT activity significantly decreased in girls between periods 0-3, in boys between 0-3 and 4-6. Significant positive correlations between ALT-0 and HBeAg, HBsAg elimination, HBeAb, HBsAb presence was seen in several periods, more frequently in girls. IFN transiently decreased Hb, leukocytes, and thrombocytes, especially in boys. No relationship was found between IFN therapy and bilirubin, protein, albumin and gammaglobulin concentrations. The prothrombin index increased after 6 months of IFN therapy in girls. CONCLUSIONS: The efficacy of IFN therapy is clearer with longer observation, especially in girls. A relationship was found between IFN dose and HBeAg/HbeAb and HBsAg/HBsAb seroconversion. IFN had a transient negative effect on the peripheral blood picture.

Keywords: Alanine Transaminase - blood, Hepatitis B Surface Antigens - blood, Hepatitis B e Antigens - blood, Hepatitis B, Chronic - blood