[Virological breakthrough in treating hepatitis B with entecavir: it means resistance?]

A 45 year-old married man, with several sexual partners, initiated symptoms with nodosum erythema and in August 2008, is diagnosed of chronic hepatitis due to hepatitis B virus (HBV). Later he was diagnosed of Child A cirrhosis and hepatocarcinoma. He began HBV treatment with Entecavir 0.5 mg; then he underwent a V segment hepatectomy. In February 2009 he presented a relapse with a tumor of 14 mm on VI segment with AFP values of 68 ng/dl, so he underwent an ethanolization with good evolution. During the follow up, he has not presented evidence of relapse of hepatocarcinoma and continued with Entecavir 0.5 mg/d. In April 2010, after 72 weeks of therapy with good compliance, the patient presented a virological breakthrough (viral load 646 UI/dl) and Tenofovir was added to his therapy. Nowadays the patient is receiving double therapy for HBV and his last viral load, April 2012, was negative. This could be the first case in our country of a probable resistance to Entecavir; complementary tests are needed in order to rule out this suspicion.