title: Virological phenotype switches under salvage therapy with lopinavir-ritonavir in heavily pretreated HIV-1 vertically infected children.
abstract: OBJECTIVE
  To investigate the effects of salvage therapy with lopinavir-ritonavir on HIV-1 phenotype in heavily antiretroviral experienced HIV-infected children.
  
  
  METHODS
  Twenty antiretroviral experienced HIV-infected children were studied during a mean of time of 16.1 months from initiation of the treatment with lopinavir-ritonavir.
  
  
  METHODS
  Besides CD4 T cells, viral load and clinical status, we analyzed 91 serial viral isolates to study the phenotype, and biological clones derived from co-cultivation techniques.
  
  
  RESULTS
  We observed an increase in CD4 T cells, a statistically significant decrease in viral load and clinical benefits from 3 months after treatment. Ninety per cent of children had SI/X4 bulk isolates in peripheral blood mononuclear cells at study entry. The viral phenotype changed to non syncitium-inducing (NSI)/R5 in 94% of the children after a mean of 5.7 months (95% confidence interval, 2.1-9.3 months) of salvage therapy. The remaining 10% of children had NSI/R5 isolates at entry and at all follow-up study. Similar results were found at the clonal level. Thus, at study entry in PBMC of three children with bulk syncitium-inducing (SI) phenotype, we recovered 65 biologic clones, 56 being SI and nine NSI. After salvage therapy bulk isolates changed to NSI and of 40 biologic clones recovered only five were SI and the rest were NSI.
  
  
  CONCLUSIONS
  Our data suggest that lopinavir-ritonavir salvage therapy led not only to a viral load decrease but also to a phenotypic change. X4 virus appeared to be preferentially suppressed. Shifts in co-receptor usage may thereby contribute to the clinical efficacy of anti-HIV drugs in vertically infected infants.
authors.affiliation: Laboratorio de Inmuno-Biología Molecular and Servicio de Pediatría, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Galán
authors.forename: José L
authors.initials: JL
authors.lastname: Jiménez
authors.forename: Milagros
authors.initials: M
authors.lastname: González-Rivera
authors.forename: Ma Isabel
authors.initials: MI
authors.lastname: De José
authors.forename: Ma Luisa
authors.initials: ML
authors.lastname: Navarro
authors.forename: José T
authors.initials: JT
authors.lastname: Ramos
authors.forename: Ma José
authors.initials: MJ
authors.lastname: Mellado
authors.forename: Ma Dolores
authors.initials: MD
authors.lastname: Gurbindo
authors.forename: José Ma
authors.initials: JM
authors.lastname: Bellón
authors.forename: Salvador
authors.initials: S
authors.lastname: Resino
authors.forename: Esther
authors.initials: E
authors.lastname: Cabrero
authors.forename: Ma Angeles
authors.initials: MA
authors.lastname: Muñoz-Fernández
mesh_terms: D004338:Drug Combinations; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000635:transmission; D017320:HIV Protease Inhibitors / Q000627:therapeutic use*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D007963:Leukocytes, Mononuclear / Q000821:virology; D061466:Lopinavir; D008297:Male; D010641:Phenotype; D011744:Pyrimidinones / Q000627:therapeutic use*; D019438:Ritonavir / Q000627:therapeutic use*; D016879:Salvage Therapy; D016176:T-Lymphocyte Subsets; D019562:Viral Load; D014779:Virus Replication / Q000187:drug effects
chemical_list: D004338:Drug Combinations; D017320:HIV Protease Inhibitors; D011744:Pyrimidinones; D061466:Lopinavir; D019438:Ritonavir