title: Clinical utility of genotyping resistance test on determining the mutation patterns in HIV-1 CRF01_AE and subtype B patients receiving antiretroviral therapy in Hong Kong.
abstract: BACKGROUND
  HIV-1 genotypic resistance test (GRT) has been widely used to monitor HIV infection but only few reports revealed the mutation patterns of non-B HIV-1 subtypes.
  
  
  OBJECTIVE
  To evaluate the concordance of GRT and clinical treatment outcomes on different HIV-1 subtypes and monitor the mutation patterns and frequencies.
  
  
  METHODS
  Pre- and post-treatment plasma samples from 123 patients (39 treatment naïve and 84 treatment experienced) were tested by ViroSeq HIV-1 Genotyping System followed by analysis using the Stanford HIV database. The mutation patterns and frequencies developed in the pol gene were compared among subtypes.
  
  
  RESULTS
  HIV-1 subtypes among patients in Hong Kong were mainly subtype B and CRF01_AE. Primary mutation was not detected among all pre-treatment samples. For post-treatment samples, primary mutations were only detected in the treatment failure group. The mutation patterns and frequencies were similar between CRF01_AE and subtype B viruses. However, the frequencies of L74V/I and K103N in the reverse transcriptase region were different between CRF01_AE and subtype B viruses. VirtualPhenotype was unable to analyze an in-frame insertion of arginine and isoleucine at protease codon 35 of one CRF01_AE isolate.
  
  
  CONCLUSIONS
  This is the first report to demonstrate the high degree of concordance of longitudinal genotyping data and clinical treatment outcome in patients harboring different HIV-1 subtypes. Our findings shed light to the emergence of resistance mutations and its testing in CRF01_AE, which is relevant to other prevailing places in Asia.
authors.affiliation: Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong Special Administrative Region, China. wcyam@hkucc.hku.hk
authors.forename: W C
authors.initials: WC
authors.lastname: Yam
authors.forename: J H K
authors.initials: JH
authors.lastname: Chen
authors.forename: K H
authors.initials: KH
authors.lastname: Wong
authors.forename: K
authors.initials: K
authors.lastname: Chan
authors.forename: V C C
authors.initials: VC
authors.lastname: Cheng
authors.forename: H Y
authors.initials: HY
authors.lastname: Lam
authors.forename: S S
authors.initials: SS
authors.lastname: Lee
authors.forename: B J
authors.initials: BJ
authors.lastname: Zheng
authors.forename: K Y
authors.initials: KY
authors.lastname: Yuen
mesh_terms: D000465:Algorithms; D023241:Antiretroviral Therapy, Highly Active; D024882:Drug Resistance, Viral / Q000235:genetics*; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000187:drug effects* / Q000235:genetics; D006723:Hong Kong; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009154:Mutation; D011933:Reagent Kits, Diagnostic; D017211:Treatment Failure; D016896:Treatment Outcome
chemical_list: D011933:Reagent Kits, Diagnostic