title: Improved virological outcome in White patients infected with HIV-1 non-B subtypes compared to subtype B.
abstract: BACKGROUND
  Antiretroviral compounds have been predominantly studied in human immunodeficiency virus type 1 (HIV-1) subtype B, but only ~10% of infections worldwide are caused by this subtype. The analysis of the impact of different HIV subtypes on treatment outcome is important.
  
  
  METHODS
  The effect of HIV-1 subtype B and non-B on the time to virological failure while taking combination antiretroviral therapy (cART) was analyzed. Other studies that have addressed this question were limited by the strong correlation between subtype and ethnicity. Our analysis was restricted to white patients from the Swiss HIV Cohort Study who started cART between 1996 and 2009. Cox regression models were performed; adjusted for age, sex, transmission category, first cART, baseline CD4 cell counts, and HIV RNA levels; and stratified for previous mono/dual nucleoside reverse-transcriptase inhibitor treatment.
  
  
  RESULTS
  Included in our study were 4729 patients infected with subtype B and 539 with non-B subtypes. The most prevalent non-B subtypes were CRF02_AG (23.8%), A (23.4%), C (12.8%), and CRF01_AE (12.6%). The incidence of virological failure was higher in patients with subtype B (4.3 failures/100 person-years; 95% confidence interval [CI], 4.0-4.5]) compared with non-B (1.8 failures/100 person-years; 95% CI, 1.4-2.4). Cox regression models confirmed that patients infected with non-B subtypes had a lower risk of virological failure than those infected with subtype B (univariable hazard ratio [HR], 0.39 [95% CI, .30-.52; P < .001]; multivariable HR, 0.68 [95% CI, .51-.91; P = .009]). In particular, subtypes A and CRF02_AG revealed improved outcomes (multivariable HR, 0.54 [95% CI, .29-.98] and 0.39 [95% CI, .19-.79], respectively).
  
  
  CONCLUSIONS
  Improved virological outcomes among patients infected with non-B subtypes invalidate concerns that these individuals are at a disadvantage because drugs have been designed primarily for subtype B infections.
authors: Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zürich, Switzerland. alexandra.scherrer@usz.ch
authors: Alexandra U
authors: AU
authors: Scherrer
authors: Bruno
authors: B
authors: Ledergerber
authors: Viktor
authors: V
authors: von Wyl
authors: Jürg
authors: J
authors: Böni
authors: Sabine
authors: S
authors: Yerly
authors: Thomas
authors: T
authors: Klimkait
authors: Philippe
authors: P
authors: Bürgisser
authors: Andri
authors: A
authors: Rauch
authors: Bernard
authors: B
authors: Hirschel
authors: Matthias
authors: M
authors: Cavassini
authors: Luigia
authors: L
authors: Elzi
authors: Pietro L
authors: PL
authors: Vernazza
authors: Enos
authors: E
authors: Bernasconi
authors: Leonhard
authors: L
authors: Held
authors: Huldrych F
authors: HF
authors: Günthard
mesh_terms: D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000008:administration & dosage*; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013557:Switzerland; D016896:Treatment Outcome; D019562:Viral Load; D044465:White People
chemical_list: D019380:Anti-HIV Agents