Entecavir as specific antiviral therapy in selected cases of severe acute hepatitis B.

The role of specific antiviral treatment in severe acute hepatitis B has been subject to debate during the past few years. We present clinical findings in a series of three cases of severe acute hepatitis B and one case of acute hepatitis B treated with entecavir during 2007-2009, with interesting evolution. Entecavir appeared to improve the clinical evolution in the reported cases. Two of the patients displayed HBsAg to HBsAb seroconversion while another patient went into an inactive HBsAg carrier state. In the case of mild acute hepatitis B, the liver enzymes had returned to normal, symptomatology had receded but HBsAg had remained positive. Without data on viral load, we were unable to determine whether the patient had entered an inactive HBsAg carrier state or had continued into the services of another medical unit, for treatment of chronic HBV infection. We also discuss into detail a case which displayed transient initial HBe seroconversion at 1 week, followed by seroreversion to positive HBeAg and negative HBeAb at week 3, and a new seroconversion at week 7. We assess the possible roles of precore mutations, antibody-dependent cellular cytotoxicity, coinfection with Epstein Barr virus and the function of Kupffer cells.