ABSTRACTS: Oral Presentation Abstracts
Introduction: Over 90% of children infected by hepatitis B virus (HBV) before 1 year of age become asymptomatic chronic carriers. Chronic HBV infection is associated with high risk of cirrhosis and cancer in adulthood, related to the duration of anti-HBe seroconversion. Interferon-a (IFNa) induces anti-HBe serocon-version in 20–40% of children with biochemically/histologically active disease and low HBV DNA, but is considered ineffective and contraindicated for children infected in infancy, who become ‘immune tolerant’ to the virus. However, these children, who have mild histological activity, normal transaminases and high HBV DNA, represent the great majority of the infected paediatric population. We aimed at investigating whether combining the anti-viral effect of lamivudine with the immune-boosting action of IFNa2b is effective in HBV ‘tolerant’ children.
Methods: We enrolled 23 children infected during the first year of life [17 Oriental, 21 with normal transaminases, 15 with HBV DNA > 1000pg/ml by hybridisation and all with mild histological changes]. Treatment comprised of lamivudine (3 mg/Kg) for 8 weeks and lamivudine (3 mg/Kg) and IFN-a2b (5Mu/m2, three weekly) for 10 months.
Results: Seventy-eight percent became HBV DNA negative at the end of treatment, 5 (22%) seroconverted to anti-HBe, 4 (17%) of whom achieved complete control of the viral infection becoming persistently HBsAg negative and anti-HBs positive. None of the children developed YMDD mutations.
Conclusion: This study suggests that lamivudine priming followed by a combination of lamivudine and IFNa2b can induce complete viral control in HBV ‘tolerant’ children, hitherto considered poor responders.