title: Evolution of lamivudine-resistant hepatitis B virus and HIV-1 in co-infected individuals: an analysis of the CAESAR study. CAESAR co-ordinating committee.
abstract: OBJECTIVE
  Lamivudine has potent activity against HIV-1 and hepatitis B virus (HBV). Co-infection with these two viruses is common, and this may therefore influence the choice of antiretroviral therapies. A cohort of co-infected patients treated with lamivudine were studied in order to evaluate the differential effects of lamivudine on the two viral populations within the same individual after 44-52 weeks of therapy.
  
  
  METHODS
  Retrospective virological analysis of an HIV-1/HBV co-infected lamivudine cohort derived from a randomized, placebo-controlled study of lamivudine in HIV infection, the CAESAR study.
  
  
  RESULTS
  Five of thirteen patients with HBV viral load > 10,000 copies/ml after 44-52 weeks of lamivudine therapy had genotypic drug resistance. Four of these five had a rebound of viral replication over the period of study and in one case this was associated with an alanine transaminase serum elevation. Ten of the thirteen patients had a 44-52 week HIV viral load > 1000 copies/ml, all of whom also had HIV reverse transcriptase M184V or M184I mutations.
  
  
  CONCLUSIONS
  Extrapolating these results to the population yields an estimated 1-year incidence of drug-resistant HBV of at least 14% in lamivudine-treated HIV-1/HBV co-infected patients. The clinical and virological benefit of HBV lamivudine monotherapy in co-infected patients should be balanced against the potential for emergence of drug resistance. Further, these data suggest that the determinants of HIV and HBV drug resistance are different and that parallel evolution, rather than co-evolution of HBV and HIV-1 in co-infected individuals occurs.
authors.affiliation: Division of Immunity and Infection, University of Birmingham Medical School, Edgbaston, UK. D.Pillay@bham.ac.uk
authors.forename: D
authors.initials: D
authors.lastname: Pillay
authors.forename: P A
authors.initials: PA
authors.lastname: Cane
authors.forename: D
authors.initials: D
authors.lastname: Ratcliffe
authors.forename: M
authors.initials: M
authors.lastname: Atkins
authors.forename: D
authors.initials: D
authors.lastname: Cooper
mesh_terms: D018791:CD4 Lymphocyte Count; D004352:Drug Resistance, Microbial; D015658:HIV Infections / Q000097:blood / Q000150:complications* / Q000276:immunology; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification; D006509:Hepatitis B / Q000097:blood / Q000150:complications* / Q000821:virology; D006515:Hepatitis B virus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D019259:Lamivudine / Q000494:pharmacology*; D012189:Retrospective Studies; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology; D019562:Viral Load
chemical_list: D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine