title: Sustained virological and biochemical responses to lamivudine and adefovir dipivoxil combination in a chronic hepatitis B infection despite mutations conferring resistance to both drugs.
abstract: BACKGROUND
  Sequential monotherapies of nucleotide analogs used in chronic hepatitis B treatment can lead to the selection of a resistance mutation to each antiviral drug.
  
  
  METHODS
  A patient with chronic hepatitis B was successively treated with lamivudine monotherapy, lamivudine-adefovir dual therapy, adefovir monotherapy and again with an adefovir-lamivudine dual therapy. Lamivudine-associated mutations (rtL180M and rtM204V/I) followed by adefovir-associated mutations (rtN236T and rtA181V) emerged during the two monotherapy regimens. Despite the presence of rtM204V/I, rtA181V, and rtN236T mutations at the beginning of the second dual therapy, sustained biochemical and virological responses have been observed thus far after 23 months.
  
  
  CONCLUSIONS
  This case illustrates that rtM204V/I, rtA181V, and rtN236T resistance mutations can coexist in a patient but do not preclude the recycling of lamivudine and adefovir in combination therapy, when no other therapeutic choices are available.
authors.affiliation: Laboratoire de Virologie moléculaire et structurale, CHU de Grenoble BP 217, 38043 Grenoble cedex 09, France. slarrat@chu-grenoble.fr
authors.forename: Sylvie
authors.initials: S
authors.lastname: Larrat
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Hilleret
authors.forename: Raphaele
authors.initials: R
authors.lastname: Germi
authors.forename: Julien
authors.initials: J
authors.lastname: Lupo
authors.forename: Sandrine
authors.initials: S
authors.lastname: Nicod
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Zarski
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Seigneurin
authors.forename: Patrice
authors.initials: P
authors.lastname: Morand