title: Lamivudine resistance in immunocompetent chronic hepatitis B. Incidence and patterns.
abstract: BACKGROUND
  Lamivudine is a non-toxic, potent inhibitor of hepatitis B virus replication. Recently, hepatitis B virus resistance to lamivudine has been described in patients using immunosuppressive drugs after liver transplantation.
  
  
  METHODS
  From our cohort of 81 consecutive patients treated with lamivudine, we selected all immunocompetent patients who received lamivudine monotherapy for a period over 26 weeks (n=14).
  
  
  RESULTS
  Lamivudine resistance with the characteristic mutation in the YMDD motif was observed in four patients (actuarial cumulative incidence: 39%). Two patterns of viral resistance were observed: incomplete response (n=2) and viral breakthrough (n=2).
  
  
  CONCLUSIONS
  The observed high frequency of lamivudine resistance may have implications for the concept of long-term virus-suppressive therapy of chronic hepatitis B by lamivudine monotherapy.
authors.affiliation: Department of Internal Medicine II, Erasmus University Hospital Rotterdam, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Honkoop
authors.forename: H G
authors.initials: HG
authors.lastname: Niesters
authors.forename: R A
authors.initials: RA
authors.lastname: de Man
authors.forename: A D
authors.initials: AD
authors.lastname: Osterhaus
authors.forename: S W
authors.initials: SW
authors.lastname: Schalm
mesh_terms: D000293:Adolescent; D000328:Adult; D017931:DNA Primers; D004352:Drug Resistance, Microbial; D016679:Genome, Viral; D006509:Hepatitis B / Q000188:drug therapy* / Q000276:immunology* / Q000821:virology; D006515:Hepatitis B virus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007121:Immunocompetence; D019259:Lamivudine / Q000494:pharmacology / Q000627:therapeutic use*; D016133:Polymerase Chain Reaction; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D017931:DNA Primers; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine