title: Increased duration of viral suppression is associated with lower viral rebound rates in patients with previous treatment failures.
abstract: OBJECTIVE
  We investigated whether the rate of viral rebound decreases with increasing duration of viral suppression and, if so, whether rebound rates in patients previously failing antiretroviral regimens ultimately decline to levels as low as those seen in patients who have never experienced virological failure.
  
  
  METHODS
  All patients from the UK CHIC Study (n = 21 256) who achieved a viral load (VL) of < or = 50 copies/ml while receiving HAART were followed until viral rebound (two consecutive VL > 400 copies/ml). Patients could re-enter the analysis if they experienced a subsequent VL < or = 50 copies/ml. Rebound rates were calculated according to the number of regimens previously failed and duration of viral suppression.
  
  
  RESULTS
  Of 12 648 patients on HAART 10 237 (80.9%) achieved a VL < or = 50 copies/ml. During 26 494 person-years (PY) of follow-up, 1853 (18.1%) patients experienced at least one viral rebound 'event', with 2460 events in total [rebound rate, 9.3 (range, 8.9-9.7)/100 PY). Within the first year of viral suppression, the rate of viral rebound was 8.3 (7.5-9.1)/100 PY in patients who had not previously failed treatment, increasing to 32.7 (27.6-37.8)/100 PY in patients who had failed more than four regimens. Irrespective of previous treatment failure, rebound rates in those who remained suppressed for > 4 years were similar to those in patients who had at no time experienced treatment failure.
  
  
  CONCLUSIONS
  After around 4 years of viral suppression rebound rates in individuals with multiple prior treatment failures approach those of individuals with no prior treatment failure.
authors.affiliation: St. Mary's Hospital, London, UK. andrew.benzie@st-marys.nhs.uk
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Benzie
authors.forename: Loveleen K
authors.initials: LK
authors.lastname: Bansi
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Sabin
authors.forename: Simon
authors.initials: S
authors.lastname: Portsmouth
authors.forename: Teresa
authors.initials: T
authors.lastname: Hill
authors.forename: Margaret
authors.initials: M
authors.lastname: Johnson
authors.forename: Richard
authors.initials: R
authors.lastname: Gilson
authors.forename: Philippa
authors.initials: P
authors.lastname: Easterbrook
authors.forename: Brian
authors.initials: B
authors.lastname: Gazzard
authors.forename: Martin
authors.initials: M
authors.lastname: Fisher
authors.forename: Chloe
authors.initials: C
authors.lastname: Orkin
authors.forename: David
authors.initials: D
authors.lastname: Dunn
authors.forename: Valerie
authors.initials: V
authors.lastname: Delpech
authors.forename: Graham P
authors.initials: GP
authors.lastname: Taylor
authors.forename: John C
authors.initials: JC
authors.lastname: Walsh
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Phillips
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1; D006801:Humans; D008297:Male; D012008:Recurrence; D012306:Risk; D013997:Time Factors; D017211:Treatment Failure; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents