%0 Journal Article %T Antiviral therapy in acute viral hepatitis B: why and when %A Giuseppe Morelli %A Alessandro Perrella %A Costanza Sbreglia %A Pasquale Bellopede %A Vincenzo Riccio %A Oreste Perrella %J Infectious Agents and Cancer %D 2009 %I BioMed Central %R 10.1186/1750-9378-4-2 %X Therefore there are elderly patients with severe acute HBV hepatitis caractherized by high serum bilirubin levels >15 mmole/dl, international normalized ratio (INR) with value more than 1.6; these patients are caractherized by a severe outcome of HBV infection.As known, outcome of infection and the pathogenesis of liver diseases are determined by viral and host factors, such as T reg lymphocytes.T regs may be associated with a negative immune response such as an inhibition of gamma- IFN secretion.The impact of viral load on antiviral T cell responses may play a critical role in thaese patients, influencing disease persistence and immune response.Antiviral drugs could be useful in these patients determing a possible down -regulation of T regs.Dear Editor,Acute viral hepatitis B is cleared in more than 95% of patients, while the remainder ones may develop either chronic HBV infection or, rarely, fulminant hepatitis. [1] The role of antivirals, such as lamivudine or entecavir, in acute HBV infection, has not been evaluated in controlled trials.Lamivudine administration shows an antiviral efficacy in patients with HbeAg positive and HbeAg negative.Among the patients with acute infection there are elderly subjects with severe course and severe outcome of HBV hepatitis.A logical hypothesis for these patients is that a rapid decrease in the HBVDNA levels trough the use of antiviral agents could result in a less intense host response against HBV virus.Today, increased knowledge of the virological and immunological events to HBV infection permits to define the mechanisms involved in viral clearance, persistence and disease severity.Outcome of infection and the pathogenesis of liver disease are determined by viral and host factors. [1]The impact of viral load on antiviral T-cell responses has been precisely characterized in animal models of viral infections: a sustained presence of viral antigens leads to virus specific T cell deletion [2].In HBV infection the frequency and f %U http://www.infectagentscancer.com/content/4/1/2