title: Genotypic susceptibility score (GSS) and CD4+ T cell recovery in HIV-1 patients with suppressed viral load.
abstract: HIV drug resistance, measured by the genotypic susceptibility score (GSS), has a deleterious effect on the virological outcome of HIV-1-infected patients. However, it is not known if GSS retains any predictive value for CD4 recovery in patients with suppressed viral load.
  
  
  
  Four hundred and six patients on virological failure (>500 copies/mL) with GSS  : <6 months prior to switch therapy who achieved undetectable plasma viral load (<50 copies/mL) within 1 year, remained undetectable >1 year on an unchanged regimen and had CD4 data available during entire follow-up were included. Adjusted and unadjusted analyses of all characteristics at switch related to CD4 recovery were made for three time frames: (i) 'switch-suppression'; (ii) 'suppression-1 year'; and (iii) 'switch-1 year'.
  
  
  
  Higher GSS was associated with a greater CD4 recovery between 'switch' and '1 year' in the unadjusted analysis (P = 0.010); however, the effect of GSS was no longer statistically significant after adjusting for pre-switch clinical (CD4 count and plasma viral load) and demographic variables. Furthermore, only a lower pre-switch CD4 count was associated with increased CD4 recovery in the 'suppression-1 year' period in both unadjusted and adjusted models. The main CD4 recovery occurred in 'switch-suppression' and the variables associated, both unadjusted and adjusted, were CD4 and plasma viral load at switch, maintaining a trend for GSS (P = 0.06).
  
  
  
  In individuals who re-suppressed HIV viraemia after switching therapy, regimens having a higher GSS were associated with improved CD4 recovery only during the period from switch to virological suppression, but, once viral load is re-suppressed, the GSS of the new regimen has no further effect on subsequent CD4 recovery.
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada aglez-serna@cfenet.ubc.ca.|Laboratory of Molecular Immunobiology, Hospital General Universitario Gregorio Maranon, Madrid, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Gonzalez-Serna
authors.affiliation: Virology, Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Arie C
authors.initials: AC
authors.lastname: Glas
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
authors.forename: C J
authors.initials: CJ
authors.lastname: Brumme
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
authors.forename: Art F Y
authors.initials: AF
authors.lastname: Poon
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
authors.forename: Adriana
authors.initials: A
authors.lastname: Nohpal De La Rosa
authors.affiliation: Department of Internal Medicine and Infectious Diseases, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Tania
authors.initials: T
authors.lastname: Mudrikova
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
authors.forename: Viviane
authors.initials: V
authors.lastname: Dias Lima
authors.affiliation: Virology, Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Annemarie M J
authors.initials: AM
authors.lastname: Wensing
authors.affiliation: BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Harrigan
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D024882:Drug Resistance, Viral; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects* / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019562:Viral Load / Q000276:immunology*; D014766:Viremia / Q000276:immunology / Q000821:virology
chemical_list: D019380:Anti-HIV Agents