title: Drug-resistance mutations in antiretroviral-naïve patients with established HIV-1 infection in Mexico.
abstract: OBJECTIVE
  To describe the prevalence of baseline drug-resistance mutations, resistance to antiretroviral drugs, and the subsequent virological response to therapy in treatment-naïve patients from Mexico with established HIV-1 infection.
  
  
  METHODS
  Resistance testing was performed on plasma samples from antiretroviral-naïve patients. Data on mutations associated with antiretroviral drug resistance were obtained using Stanford software (http://hivdb.stanford.edu).
  
  
  RESULTS
  Ninety-six treatment-naïve individuals were enrolled in the study during 2002-2003. Of these, 83 patients (86%) had at least one resistance mutation and 15 (16%) had drug resistance. At baseline, the mean plasma viral load was 299 834 HIV-1 RNA copies/mL, and at follow-up it was 37 620 copies/mL (P<0.0001). Primary mutations in the reverse transcriptase region were observed in 15% of patients. For nucleoside inhibitors, mutations T215Y/C and F77L (3%) and D67N/S, T69N and M184V (2%), were detected. For nonnucleoside inhibitors, mutations K103N/R (6%), Y181C (3%) and G190A (2%) were detected. Overall, 6% of patients showed resistance to delavirdine and nevirapine, 4% to efavirenz, and 2% to lamivudine and nelfinavir. Twelve patients showed no response to treatment and three of these patients had antiretroviral drug resistance.
  
  
  CONCLUSIONS
  The prevalence of baseline drug-resistance mutations found in this study was similar to that found in previous reports for newly HIV-infected individuals, although access to and management of antiretrovirals in Mexico are different.
authors.affiliation: Laboratory of Immunodeficiencies and Human Retrovirus, Western Biomedical Research Center, Mexican Institute of Social Security, Guadalajara, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Escoto-Delgadillo
authors.forename: E
authors.initials: E
authors.lastname: Vázquez-Valls
authors.forename: M
authors.initials: M
authors.lastname: Ramírez-Rodríguez
authors.forename: A
authors.initials: A
authors.lastname: Corona-Nakamura
authors.forename: G
authors.initials: G
authors.lastname: Amaya-Tapia
authors.forename: N
authors.initials: N
authors.lastname: Quintero-Pérez
authors.forename: A
authors.initials: A
authors.lastname: Panduro-Cerda
authors.forename: B M
authors.initials: BM
authors.lastname: Torres-Mendoza
mesh_terms: D019380:Anti-HIV Agents / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology*; D016333:HIV Protease / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors / Q000235:genetics; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D009154:Mutation; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D054303:HIV Reverse Transcriptase; D016333:HIV Protease