title: HIV-1 subtypes and response to combination antiretroviral therapy in Europe.
abstract: BACKGROUND
  Combination antiretroviral therapy (cART) may vary in ability to suppress viral load and increase CD4+ T-cell count in people infected with different HIV-1 subtypes, possibly due to differences in resistance development. Antiretroviral drugs have predominantly been developed in Western Europe/North America on the basis of the most prevalent subtype, B. However, non-B subtypes are increasingly spreading worldwide.
  
  
  OBJECTIVE
  To compare virological and immunological response to cART between patients infected with B and non-B subtypes across Europe.
  
  
  METHODS
  EuroSIDA prospective, observational cohort with 11,928 HIV-1-infected patients.
  
  
  METHODS
  Response to cART was analysed in patients with subtypes determined pre-cART, via multivariable logistic regression on the first measurements 6-12 months after starting cART. A virological response was defined as a viral load <500 copies/mi and immunological response as a CD4+ T-cell count increase of > or =100 cells/mm(3).
  
  
  RESULTS
  Forty-five percent of patients were antiretroviral naive at initiation of cART. Virological suppression was achieved by 58% of 689 subtype-B-infected patients and 66% of 102 non-B-infected patients (P=0.159). After adjustment for potential confounders, there was no significant difference in odds of achieving virological suppression (non-B compared with B; odds ratio [OR]: 1.05, 95% confidence interval [CI]: 0.58-1.93, P=0.866). An immunological response was achieved by 43% of 753 B-infected patients and 48% of 114 non-B-infected patients (P=0.334). After adjustment, there was no significant difference in odds of an immunological response (OR: 1.17, 95% CI: 0.73-1.87, P=0.524).
  
  
  CONCLUSIONS
  There was no evidence of significant differences in virological or immunological response to cART between patients infected with HIV-1 B and non-B subtypes.
authors.affiliation: Department of Primary Care and Population Sciences, Royal Free and University College Medical School, London, UK. w.bannister@pcps.ucl.ac.uk
authors.forename: Wendy P
authors.initials: WP
authors.lastname: Bannister
authors.forename: Lidia
authors.initials: L
authors.lastname: Ruiz
authors.forename: Clive
authors.initials: C
authors.lastname: Loveday
authors.forename: Stefano
authors.initials: S
authors.lastname: Vella
authors.forename: Kai
authors.initials: K
authors.lastname: Zilmer
authors.forename: Jesper
authors.initials: J
authors.lastname: Kjaer
authors.forename: Brygida
authors.initials: B
authors.lastname: Knysz
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Phillips
authors.forename: Amanda
authors.initials: A
authors.lastname: Mocroft
mesh_terms: D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D004359:Drug Therapy, Combination; D005060:Europe / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000187:drug effects*; D006801:Humans; D008297:Male; 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