title: Virological response to salvage therapy in HIV-infected persons carrying the reverse transcriptase K65R mutation.
abstract: BACKGROUND
  The effect of the HIV reverse transcriptase K65R mutation on virological response to salvage therapy has not been clearly defined.
  
  
  METHODS
  From six Italian clinical centres, all consecutive patients starting salvage antiretroviral therapy after virological failure in the presence of the K65R mutation identified by a genotypic resistance test were selected.
  
  
  RESULTS
  Among 145 subjects included over a 197 person-year follow-up, the estimated probability of virological response (VR, defined as reaching HIV RNA < 50 copies/ml after salvage therapy) at 24 and 48 weeks was 36% and 60%, respectively. The strongest independent predictor of VR was the inclusion of a thymidine analogue (TA) in the salvage regimen. The presence of M184V and the introduction of lopinavir/ritonavir as new drug were both marginally associated with better outcome. After 24 weeks of salvage therapy, the median reduction in HIV-1 RNA was -1.36 log10 copies/ml (interquartile range [IQR] 0.10-2.46): at multivariable regression analysis, salvage regimens containing a TA (beta = +0.80; P = 0.02) and lamivudine (beta = +1.21; P = 0.02) as new drug had a positive effect on the reduction of HIV-1 RNA.
  
  
  CONCLUSIONS
  Development of the K65R mutation does not preclude a high rate of virological response to rescue therapy. Inclusion of a TA in the salvage regimen and the presence of a M184V mutation could have a favourable effect on virological outcome.
authors.affiliation: National Institute for Infectious Diseases 'L Spallanzani' IRCCS, Roma, Italy. antinori@inmi.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Antinori
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Trotta
authors.forename: Patrizia
authors.initials: P
authors.lastname: Lorenzini
authors.forename: Carlo
authors.initials: C
authors.lastname: Torti
authors.forename: Nicola
authors.initials: N
authors.lastname: Gianotti
authors.forename: Franco
authors.initials: F
authors.lastname: Maggiolo
authors.forename: Francesca
authors.initials: F
authors.lastname: Ceccherini-Silberstein
authors.forename: Paola
authors.initials: P
authors.lastname: Nasto
authors.forename: Antonella
authors.initials: A
authors.lastname: Castagna
authors.forename: Andrea
authors.initials: A
authors.lastname: De Luca
authors.forename: Cristina
authors.initials: C
authors.lastname: Mussini
authors.forename: Massimo
authors.initials: M
authors.lastname: Andreoni
authors.forename: Carlo Federico
authors.initials: CF
authors.lastname: Perno
mesh_terms: D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology*; D017320:HIV Protease Inhibitors / Q000627:therapeutic use; D054303:HIV Reverse Transcriptase / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007558:Italy; D019259:Lamivudine / Q000627:therapeutic use; D061466:Lopinavir; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011744:Pyrimidinones / Q000627:therapeutic use; D012367:RNA, Viral / Q000097:blood; D012189:Retrospective Studies; D019438:Ritonavir / Q000627:therapeutic use; D016879:Salvage Therapy; D013936:Thymidine / Q000031:analogs & derivatives; D016896:Treatment Outcome
chemical_list: D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D011744:Pyrimidinones; D012367:RNA, Viral; D061466:Lopinavir; D019259:Lamivudine; D054303:HIV Reverse Transcriptase; D019438:Ritonavir; D013936:Thymidine