[Interferon in hepatitis B]

Abstract

Hepatitis B virus (HBV) infection is a worldwide public health problem. There are an estimated 350 million persons with chronic HBV infection that could progress to cirrhosis and hepatocarcinoma with nearly one million deaths per year. In the last few years the therapeutic options in chronic hepatitis B have increased and currently six treatments are authorized: standard interferon (IFN)-alpha, pegylated interferon-alpha (PEG-IFNalpha), lamivudine, adefovir, entecavir, and telbivudine. For the last 25 years, conventional IFNalpha has been used as the treatment of chronic hepatitis B (CHB) and currently PEG-IFNalpha is indicated due to its greater effectiveness. Both drugs are first line options for HBeAg(+) and HBeAg(-) CHB. The advantages of IFNalpha and PEG-IFNalpha are that these drugs are administered for a limited time period, they achieve a higher sustained response rate and do not induce HBV mutants with antiviral resistance. These drugs achieve greater HBeAG and HBsAG clearance due to their antiviral and immunomodulatory activity. PEG-IFNalpha induces sustained biochemical and virological response in approximately one third of patients with HBeAg(+) CHB. The best response to IFNalpha and PEG-IFNalpha is obtained in patients with elevated transaminase levels, moderate viral load and HBV genotypes A and B. The disadvantages of IFNalpha and PEG-IFNalpha are their adverse effects and contraindications. These drugs cannot be administered in patients with decompensated cirrhosis. The combination of nucleos(t)ide analogs with PEG-IFNalpha could achieve much higher sustained response rates; however, which treatment constitutes the most suitable therapeutic strategy requires investigation.