Interferon Therapy of Chronic Hepatitis B

Chronic hepatitis B (CHB) results from the inability of the host’s immune system to control viral replication. Interferon-α (IFN-α) therapy can convert CHB into inactive hepatitis B virus (HBV) infection in 20–30% of the treated patients. In spite of the low response rate, IFN-α therapy has the advantage of having a limited duration and being effective even after therapy, as demonstrated by a much higher incidence of HBsAg clearance in responders to IFN-α than in naturally occurring inactive HBsAg carriers. IFN-α has multiple antiviral, antiproliferative, and immunomodulatory activities and targets: cellular genes (IFN-stimulated genes) activating different pathways of antiviral defense in infected and noninfected cells, HBV replication blocking the RNA-containing core particle formation and accelerating their decay, degrading pregenomic RNA, and modulating the nuclear viral minichromosome (covalently closed circular DNA) activity by targeting its epigenetic regulation and both innate and adaptive immune response. The interference of viral heteroPublished online: July 15, 2014 Maurizia Rossana Brunetto Liver Unit, Reference Centre for Chronic Liver Disease and Hepatocellular Carcinoma of the Tuscany Region, University Hospital of Pisa Via Paradisa 2, IT–56124 Cisanello-Pisa (Italy) E-Mail brunettomaurizia @ gmail.com © 2014 S. Karger AG, Basel 0300–5526/14/0574–0163$39.50/0