title: Antiretroviral drug resistance in HIV-infected patients in Colombia.
abstract: BACKGROUND
  Systematically obtained data on antiretroviral (ARV) resistance in Colombia are lacking. Local estimates of resistance are needed to guide testing, therapy, and policy.
  
  
  METHODS
  A cross-sectional study was performed in ARV-naïve individuals and in patients with first ARV failure. Genotypic resistance testing was performed using Viro-seq. Predicted success to first- and second-line regimens recommended by the Colombian HIV treatment guidelines was estimated.
  
  
  RESULTS
  One hundred and three naïve and 77 experienced patients were included. For naïve patients, resistance mutations were detected in 5.8%, with the most common mutations being 103N (n=5; 4.9%) and 184V (n=3; 2.9%). CD4 count <200cells/mm(3) (p=0.04) and Centers for Disease Control and Prevention (CDC) category C (p=0.004) were associated with primary resistance. For experienced individuals, regimens were non-nucleoside reverse transcriptase inhibitor (NNRTI)-based in 57.1%, protease inhibitor (PI)-based in 14.3%, boosted PI-based in 26.0%, and nucleoside reverse transcriptase inhibitor (NRTI)-based in 2.6% of the cases. Resistance mutations were found in 66 patients (85.7%) with failure. The most common mutations were 184V (n=48; 62.3%), 103N (n=37; 48.1%), G190A/S (n=9; 11.7%), and L90M (n=9; 11.7%). Twelve percent had thymidine analogue mutations (TAMs) but only 1% had more than 1 TAM. The predicted success of regimens recommended by the Colombian guidelines was 95% for naïve patients and 84% for experienced patients. Genotyping could increase the success rates to 100% and 94%, respectively.
  
  
  CONCLUSIONS
  The frequency of primary HIV resistance in Colombia is similar to estimates from other countries in Latin America. CD4 count and CDC category C may allow identification of most of the naïve patients who would benefit from resistance testing. Resistance testing could favorably impact therapy modification in about 5% and 10% of naïve and experienced patients, respectively.
authors: Emory University School of Medicine, Atlanta, GA 30303, USA. cdiazgr@emory.edu
authors: Carlos A
authors: CA
authors: DiazGranados
authors: Monica
authors: M
authors: Mantilla
authors: William
authors: W
authors: Lenis
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D003105:Colombia; D003430:Cross-Sectional Studies; D024921:Drug Resistance, Multiple, Viral; D005260:Female; D006678:HIV / Q000254:growth & development*; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012044:Regression Analysis; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents