title: Virological and immunological characteristics of HIV treatment failure.
abstract: BACKGROUND
  Resistance to antiretroviral treatment is prevalent. There is limited knowledge of the determinants of disease evolution in subjects infected with multidrug-resistant HIV (MDR-HIV).
  
  
  METHODS
  Infectivity, replication, chemokine receptor usage, and env, gag, protease and reverse transcriptase sequence analysis was performed for MDR-HIV isolates from 14 HIV-infected individuals and compared to wild-type HIV isolates from individuals naive to antiretroviral treatment. Expression of CD45RO/RA, Ki67 and interferon-gamma and CD4 proliferative response to various antigens was determined for individuals infected with MDR-HIV and compared to that in individuals with optimal suppression of viral replication.
  
  
  RESULTS
  Infectivity and replication are diminished for various MDR-HIV isolates, usually in the context of an increase in CD4 and CD4+CD45RA+ T-cell counts. However, a number of MDR-HIV isolates are associated with high in vivo viraemia and pronounced immunosuppression, and display in vitro levels of infectivity and replication comparable to those of wild-type strains. No specific genetic sequence or chemokine receptor usage predicted the fitness of an MDR isolate.
  
  
  CONCLUSIONS
  Despite the biological diversity of resistant viruses and the range of host responses observed, our descriptive analysis indicates that viral factors play a role in determining the degree of immune damage observed in the context of MDR-HIV infection.
authors.affiliation: Division of Infectious Diseases, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Kaufmann
authors.forename: M
authors.initials: M
authors.lastname: Muñoz
authors.forename: G
authors.initials: G
authors.lastname: Bleiber
authors.forename: S
authors.initials: S
authors.lastname: Fleury
authors.forename: B
authors.initials: B
authors.lastname: Lotti
authors.forename: R
authors.initials: R
authors.lastname: Martinez
authors.forename: W
authors.initials: W
authors.lastname: Pichler
authors.forename: P
authors.initials: P
authors.lastname: Meylan
authors.forename: A
authors.initials: A
authors.lastname: Telenti
mesh_terms: D000328:Adult; D000368:Aged; D018791:CD4 Lymphocyte Count; D018432:Drug Resistance, Multiple / Q000276:immunology* / Q000502:physiology; D005260:Female; D005434:Flow Cytometry; D006678:HIV / Q000187:drug effects* / Q000235:genetics / Q000276:immunology; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology; D017320:HIV Protease Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D017211:Treatment Failure; D019562:Viral Load; D014779:Virus Replication / Q000276:immunology*
chemical_list: D017320:HIV Protease Inhibitors