title: Antiretroviral drug resistance testing in adults with HIV infection: implications for clinical management. International AIDS Society--USA Panel.
abstract: OBJECTIVE
  To review current knowledge of the biology and clinical implications of human immunodeficiency virus (HIV) resistance to antiretroviral drugs, describe assays for measuring resistance, and assess their use in clinical practice.
  
  
  METHODS
  The International AIDS Society-USA assembled a panel of 13 physicians with expertise in basic science, clinical research, and patient care relevant to HIV resistance to antiretroviral drugs.
  
  
  METHODS
  We reviewed available data from published reports and presented at national and international research conferences. Basic science research, clinical trial results, and expert opinions were used to form the basis of this report. Data on methods for and characteristics of specific genotypic and phenotypic assays were obtained from manufacturers and service providers.
  
  
  METHODS
  The panel met regularly between October 1997 and April 1998. Panel subgroups developed and discussed different sections of the report before discussing them with the entire panel. Conclusions and suggested approaches to the use of resistance testing were determined by group consensus.
  
  
  CONCLUSIONS
  Plasma HIV RNA level and CD4+ cell count are the primary values that should be used to guide the initiation of antiretroviral therapy and subsequent changes in therapy. Possible causes of treatment failure other than development of drug resistance that should be considered are adherence, drug potency, and pharmacokinetic issues. Genotypic and phenotypic testing for HIV resistance to antiretroviral drugs may prove useful for individual patient management. Assays under development need validation, standardization, and a clearer definition of their clinical roles. Possible current roles of resistance testing for choosing an initial regimen or changing antiretroviral therapy, as well as possible implications of the presence or absence of phenotypic resistance and genotypic changes, are discussed.
authors.affiliation: Harvard Medical School, Boston, MA, USA. hirsch.martin@mgh.harvard.edu
authors.forename: M S
authors.initials: MS
authors.lastname: Hirsch
authors.forename: B
authors.initials: B
authors.lastname: Conway
authors.forename: R T
authors.initials: RT
authors.lastname: D'Aquila
authors.forename: V A
authors.initials: VA
authors.lastname: Johnson
authors.forename: F
authors.initials: F
authors.lastname: Brun-Vézinet
authors.forename: B
authors.initials: B
authors.lastname: Clotet
authors.forename: L M
authors.initials: LM
authors.lastname: Demeter
authors.forename: S M
authors.initials: SM
authors.lastname: Hammer
authors.forename: D M
authors.initials: DM
authors.lastname: Jacobsen
authors.forename: D R
authors.initials: DR
authors.lastname: Kuritzkes
authors.forename: C
authors.initials: C
authors.lastname: Loveday
authors.forename: J W
authors.initials: JW
authors.lastname: Mellors
authors.forename: S
authors.initials: S
authors.lastname: Vella
authors.forename: D D
authors.initials: DD
authors.lastname: Richman
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology* / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D004352:Drug Resistance, Microbial / Q000235:genetics; D004359:Drug Therapy, Combination; D005814:Genes, Viral; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy*; D017320:HIV Protease Inhibitors / Q000494:pharmacology; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D009154:Mutation; D010641:Phenotype; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D018894:Reverse Transcriptase Inhibitors