title: Characterization of mutations in CRF01_AE virus isolates from antiretroviral treatment-naive and -experienced patients in Singapore.
abstract: OBJECTIVE
  To determine the frequency of drug resistance mutations among antiretroviral treatment-naive and -experienced patients infected with CRF01_AE virus.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  We recruited antiretroviral-experienced HIV-infected patients with suspected drug resistance and consecutive newly diagnosed drug-naive patients. Viral sequencing was performed using standard methods. Frequencies of mutations in CRF01_AE virus isolates were compared with reference data for subtype B virus.
  
  
  RESULTS
  Sequences were obtained for CRF01_AE virus isolates from 69 patients with treatment exposure and 35 treatment-naive patients. Treatment-naive patients had numerous polymorphisms but no major drug resistance mutations. There were differences between CRF01_AE and subtype B viruses in several drug resistance mutations including the following: D67N, L210F, K101E, V106M, V179I/D, G190A/S/E, and G48V (which were more common in CRF01_AE virus) and M41L, T215Y, and V82A (which were less common in CRF01_AE virus).
  
  
  CONCLUSIONS
  The pattern of treatment-related mutations in CRF01_AE virus differs from that in subtype B virus at a number of positions determining drug resistance. Understanding these differences is important for interpreting results of resistance tests and determining treatment choices.
authors.affiliation: Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore, Singapore.
authors.forename: Li-Yang
authors.initials: LY
authors.lastname: Hsu
authors.forename: Ravathi
authors.initials: R
authors.lastname: Subramaniam
authors.forename: Lee
authors.initials: L
authors.lastname: Bacheler
authors.forename: Nicholas I
authors.initials: NI
authors.lastname: Paton
mesh_terms: D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000627:therapeutic use; D024882:Drug Resistance, Viral / Q000235:genetics; D005260:Female; D005814:Genes, Viral; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011446:Prospective Studies; D012846:Singapore
chemical_list: D019380:Anti-HIV Agents