title: Treatment outcomes amongst previously antiretroviral-naïve HIV-infected patients starting lopinavir/ritonavir-containing antiretroviral regimens at the Royal Free Hospital.
abstract: OBJECTIVE
  To describe outcomes in patients starting first-line antiretroviral regimens including lopinavir/ritonavir (LPV/r) in a routine clinic setting.
  
  
  METHODS
  Previously naïve patients starting LPV/r-containing antiretroviral therapy were included in the study. Virological failure was defined as the first of two viral loads >500 HIV-1 RNA copies/mL more than 6 months after starting LPV/r. Cumulative percentages experiencing virological failure were calculated using Kaplan-Meier methods.
  
  
  RESULTS
  A total of 195 individuals had a median follow-up time of 1.7 years. At 48 weeks, 87.9, 77.4 and 71.6% of patients with pretreatment CD4 counts of <50, 50-200 and >200 cells/microL, respectively, remained on LPV/r. By 48, 72 and 96 weeks, 2.2, 3.0 and 5.0% of patients, respectively, had experienced virological failure, ignoring treatment changes but censoring follow-up at discontinuation of all antiretrovirals; these percentages became 24.0, 33.7 and 42.3% when LPV/r discontinuation was considered as virological failure. Censoring those who stopped LPV/r with a viral load <50 copies/mL and considering as virological failures those who stopped LPV/r with a viral load >50 copies/mL gave 12.1, 14.6 and 17.0% virological failure at 48, 72 and 96 weeks, respectively. Median CD4 count increases at 24, 48 and 72 weeks were 167, 230 and 253 cells/microL, respectively.
  
  
  CONCLUSIONS
  Few patients experienced virological failure whilst on a LPV/r-based regimen, although it was not uncommon for patients in our clinic with higher baseline CD4 counts to discontinue LPV/r.
authors.affiliation: Royal Free Centre for HIV Medicine and Department of Primary Care and Population Sciences, Royal Free and University College Medical School, Rowland Hill Street, London, UK.
authors.forename: C J
authors.initials: CJ
authors.lastname: Smith
authors.forename: A N
authors.initials: AN
authors.lastname: Phillips
authors.forename: M S
authors.initials: MS
authors.lastname: Youle
authors.forename: C A
authors.initials: CA
authors.lastname: Sabin
authors.forename: F C
authors.initials: FC
authors.lastname: Lampe
authors.forename: R
authors.initials: R
authors.lastname: Tsintas
authors.forename: M
authors.initials: M
authors.lastname: Tyrer
authors.forename: M A
authors.initials: MA
authors.lastname: Johnson
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D017320:HIV Protease Inhibitors / Q000627:therapeutic use*; D015497:HIV-1; D006801:Humans; D008131:London; D061466:Lopinavir; D008297:Male; D011744:Pyrimidinones / Q000627:therapeutic use*; D019438:Ritonavir / Q000627:therapeutic use*; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D017320:HIV Protease Inhibitors; D011744:Pyrimidinones; D061466:Lopinavir; D019438:Ritonavir