title: Polymorphism rtQ215H in primary resistance to adefovir dipivoxil in hepatitis B virus infection: a case report.
abstract: The benefit of lamivudine (LAM) in hepatitis B virus (HBV) infection is compromised by the progressively increasing emergence of drug-resistant mutant strains. Although the addition of adefovir dipivoxil (ADV) usually induces complete suppression of viral replication, primary non-response to ADV in LAM resistant patients has been reported in a variable percentage of cases. Here we report a case of a patient with HBV infection and hepatocellular carcinoma who started LAM therapy and subsequently developed virological breakthrough. The patient was given ADV, but HBV-DNA negativisation was not reached. However, HBV clearance was obtained when the patient was switched from ADV to tenofovir. Virological evaluations showed two well-known LAM-related mutations (rtL180M and rtM204I) in addition to reverse-transcriptase rtQ215H. This is the first case suggesting that this mutation may have an impact on viral replication. Finally, we also report that rtQ215H is responsive to tenofovir.
authors.affiliation: University of Bologna, Clinical Medicine, via Massarenti 9, Bologna 40138, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Micco
authors.forename: Sirio
authors.initials: S
authors.lastname: Fiorino
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Loggi
authors.forename: Stefania
authors.initials: S
authors.lastname: Lorenzini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vitale
authors.forename: Carmela
authors.initials: C
authors.lastname: Cursaro
authors.forename: Anna
authors.initials: A
authors.lastname: Riili
authors.forename: Mauro
authors.initials: M
authors.lastname: Bernardi
authors.forename: Pietro
authors.initials: P
authors.lastname: Andreone