Efficacy and safety of interferon alpha therapy in children with chronic hepatitis B: A long-term follow-up cohort study from China

Interferon-alpha (IFN-α) is currently the preferred antiviral treatment for children with chronic hepatitis B (CHB) aged >1-year-old. However, the evidence regarding the exact efficacy and safety in the real world is not sufficient. This study aimed to investigate the efficacy of IFN-α therapy in children with CHB and to provide a theoretical basis for practically identifying ideal antiviral therapies for CHB children. Clinical manifestations, baseline characteristics, related laboratory tests, and adverse events were retrospectively analyzed in children with CHB who visited the Children's Hospital of Fudan University, were treated with IFN-α and were followed up from January 2003 to October 2018. A total of 18 immune-active patients without advanced fibrosis were enrolled, and their average age at the start of treatment was 4.45 ± 2.75 years old. IFN α-2b was administered subcutaneously by body surface area (BSA) category, based on 3 MU/m(2), for a median 48 weeks. Before treatment, the alanine aminotransferase (ALT) range was 81 to 409 U/L (median 158 U/L). The median hepatitis B virus (HBV)-DNA load was 9.89 × 10(7) IU/mL, and the HBV-DNA load varied from 3.10 × 10(4) to 4.56 × 10(8) IU/mL. The ALT levels of 17 children became normal at an average of 12 weeks during treatment, and those of 1 child became normal at 6 weeks after IFN-α withdrawal. Sixteen (88.9%, 16/18) children became HBV-DNA negative (<10(3) IU/mL) at an average of 24 weeks during treatment, while 1 became negative at 96 weeks after IFN-α withdrawal and 1 remained HBV-DNA positive. HBV e antigen (HBeAg) seroconversion occurred in 13 of 14 (92.9%, 13/14) HBeAg-positive patients at an average of 12 weeks during treatment. HBV s antigen (HBsAg) loss or seroconversion occurred in 4 (22.2%, 4/18) patients at an average of 21 weeks during treatment. Only mild flu-like symptoms and transient neutropenia appeared in some children at the early treatment stage. No severe abnormal results were observed in other laboratory parameters. The antiviral monotherapy of 48 weeks of IFN-α was well tolerated and good responded, which was associated with higher rates of HBeAg seroconversion and HBsAg clearance in the children in this study than in previously reported adults and pediatric patients.