title: The level of persistent HIV viremia does not increase after successful simplification of maintenance therapy to lopinavir/ritonavir alone.
abstract: OBJECTIVE
  To determine whether the level of persistent HIV-1 viremia is affected by simplifying standard antiretroviral therapy to lopinavir/ritonavir (LPV/r) alone.
  
  
  METHODS
  Measurement of HIV-1 RNA levels < 50 copies/ml in longitudinal plasma samples from 41 of 42 subjects enrolled in the 'Only Kaletra' study that compared maintenance therapy with LPV/r alone to standard of care (SOC) with two nucleoside reverse transcriptase inhibitors (NRTI) and LPV/r.
  
  
  METHODS
  Plasma samples for each subject from study screening to week 48 were tested using a modified Roche Amplicor HIV-1 RNA assay with a quantification limit of 3 copies/ml.
  
  
  RESULTS
  Median plasma HIV-1 RNA values at baseline and weeks 4, 8, 12, 24 and 48 were not significantly different between the LPV/r alone and the SOC arms, being 5.1 versus 3.0 (P = 0.29), 4.5 versus 2.9 (P = 0.44), 3.3 versus 2.9 (P = 0.99), 1.9 versus 1.0 (P = 0.68), 3.7 versus 3.6 (P = 0.49), and 2.8 versus 1.6 copies/ml (P = 0.78), respectively. In the 17 of 21 subjects who maintained virus suppression < 50 copies/ml on LPV/r alone, median HIV-1 RNA values did not increase significantly from baseline at any time point after discontinuing NRTI, in comparison to the three subjects with virologic failure whose median HIV-1 RNA levels began to rise at week 8.
  
  
  CONCLUSIONS
  The level of persistent viremia did not increase after stopping NRTI therapy among subjects who maintained virus suppression < 50 copies/ml on LPV/r alone through 48 weeks. This supports further studies of induction-simplification therapy for treatment of HIV-1 infection including the identification of factors predicting success or failure of simplified therapy.
authors.affiliation: University of Pittsburgh, Pensylvania, USA. mckinnonj@dom.pitt.edu
authors.forename: John E
authors.initials: JE
authors.lastname: McKinnon
authors.forename: José R
authors.initials: JR
authors.lastname: Arribas
authors.forename: Federico
authors.initials: F
authors.lastname: Pulido
authors.forename: Rafael
authors.initials: R
authors.lastname: Delgado
authors.forename: John W
authors.initials: JW
authors.lastname: Mellors
mesh_terms: D024882:Drug Resistance, Viral; D004359:Drug Therapy, Combination; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy*; D017320:HIV Protease Inhibitors / Q000627:therapeutic use*; D015497:HIV-1; D006801:Humans; D008137:Longitudinal Studies; D061466:Lopinavir; D011744:Pyrimidinones / Q000627:therapeutic use*; D012367:RNA, Viral / Q000097:blood; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D019438:Ritonavir / Q000627:therapeutic use*; D017211:Treatment Failure; D019562:Viral Load; D014766:Viremia / Q000188:drug therapy
chemical_list: D017320:HIV Protease Inhibitors; D011744:Pyrimidinones; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D061466:Lopinavir; D019438:Ritonavir