title: Assessing subtype and drug-resistance-associated mutations among antiretroviral-treated HIV-infected patients.
abstract: BACKGROUND
  Several studies have reported an increasing number of therapeutic failures with antiretroviral drugs in HIV-infected patients. The emergence of viral-resistant strains is a major problem for the medical management of infected individuals. The aim of this study is to determine viral subtypes and drug-resistance mutations among antiretroviral-treated HIV-infected patients.
  
  
  METHODS
  A total of 42 antiretroviral-treated but still viremic HIV-infected patients were enrolled. The HIV pol regions were amplified and sequenced to determine subtypes and antiretroviral-resistant mutations.
  
  
  RESULTS
  The subtype distribution was 48% A/D recombinants, 43% subtype B, 5% subtype A and 5% CRF01-AE recombinants. Drug-resistant mutations were most common in subtype B (53%) and A/D recombinant strains (44%). Virus samples from 19% of participants had no drug-resistant mutations; 2, 2 and 76% of samples carried one, two and at least three drug-resistant mutations, respectively. The prevalence of nucleoside transcriptase inhibitor mutations was 76%, with M184V and L74V present in 60 and 38% of samples, respectively. The prevalence of nonnucleoside transcriptase inhibitor mutations was 74%, with P225H present in 55% of study specimens. The prevalence of protease inhibitor mutations was 45%, with major mutation L90M seen in 33% and minor mutation A71V in 36% of samples. Of note, the P225H and A71V are 'minor' drug-resistance mutations conferring only minimal drug-resistance phenotypes in the absence of major mutations.
  
  
  CONCLUSIONS
  Our study found a high prevalence of drug-resistant mutations in Iranian HIV-infected patients. Our data support the need for continued surveillance of resistance patterns to help guide therapeutic approaches and limit transmission of these variants.
authors.affiliation: Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Rasool
authors.initials: R
authors.lastname: Hamkar
authors.forename: Minoo
authors.initials: M
authors.lastname: Mohraz
authors.forename: Shima
authors.initials: S
authors.lastname: Lorestani
authors.forename: Arezoo
authors.initials: A
authors.lastname: Aghakhani
authors.forename: Hong-Ha M
authors.initials: HM
authors.lastname: Truong
authors.forename: Willi
authors.initials: W
authors.lastname: McFarland
authors.forename: Mohammad
authors.initials: M
authors.lastname: Banifazl
authors.forename: Ali
authors.initials: A
authors.lastname: Eslamifar
authors.forename: Maryam
authors.initials: M
authors.lastname: Foroughi
authors.forename: Atessa
authors.initials: A
authors.lastname: Pakfetrat
authors.forename: Amitis
authors.initials: A
authors.lastname: Ramezani
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D024882:Drug Resistance, Viral / Q000187:drug effects / Q000235:genetics*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000235:genetics*; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral; D055815:Young Adult
chemical_list: D012367:RNA, Viral