title: Very low level viraemia and risk of virological failure in treated HIV-1-infected patients.
abstract: The aim of the study was to investigate whether very low level viraemia (VLLV) (20-50 HIV-1 RNA copies/mL) was associated with increased risk of virological failure (VF) as compared with persistent full suppression (< 20 copies/mL).
  
  
  
  From the VACH Cohort database, we selected those patients who started antiretroviral therapy (ART) after January 1997 and who achieved effective viral suppression [two consecutive viral loads (VLs) < 50 copies/mL] followed by full suppression (at least one VL <20 copies/mL). We carried out survival analyses to investigate whether the occurrence of VLLV rather than maintaining full suppression at < 20 copies/mL was associated with virological failure (two consecutive VLs > 200 copies/mL or one VL > 200 copies/mL followed by a change of ART regimen, administrative censoring or loss to follow-up), adjusted for nadir CD4 cell count, sex, age, ethnicity, transmission group, type of ART and time on effective suppression at < 50 copies/mL.
  
  
  
  Of 21 480 patients who started ART, 13 674 (63.7%) achieved effective suppression at < 50 copies/mL, of whom 4289 (31.4%) further achieved full suppression at < 20 copies/mL after May 2009. A total of 2623 patients (61.1%) remained fully suppressed thereafter, while 1666 had one or more episodes of VL detection > 20 copies/mL (excluding virological failure). A total of 824 patients had VLLV after suppression at < 20 copies/mL. VLLV was not associated with virological failure as compared with persistent full suppression [hazard ratio (HR) 0.67; 95% confidence interval (CI) 0.44-1.00], independently of the number of blips recorded (from one to 18).
  
  
  
  In our population of HIV-infected patients on ART who achieved viral suppression at < 20 copies/mL, the risk of virological failure was no different for patients who remained fully suppressed compared with those who experienced subsequent episodes of VLLV.
authors.affiliation: Sierrallana Hospital, Torrelavega, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Teira
authors.affiliation: Tarragona University Hospital Joan XXIII, Tarragona, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Vidal
authors.affiliation: Basurto Hospital, Bilbao, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Muñoz-Sánchez
authors.affiliation: Virgen de la Luz Hospital, Cuenca, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Geijo
authors.affiliation: Virgen del Rocío Hospital, Sevilla, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Viciana
authors.affiliation: Vall d'Hebrón Hospital, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Ribera
authors.affiliation: Santa Creu i Sant Pau Hospital, Barcelona, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Domingo
authors.affiliation: Carlos Haya Hospital, Málaga, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Castaño
authors.affiliation: Albacete Hospital, Albacete, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Martínez
authors.affiliation: General Hospital, Castellón, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Roca
authors.affiliation: Arnau de Vilanova Hospital, Lleida, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Puig
authors.affiliation: San Carlos Clinical Hospital, Madrid, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Estrada
authors.affiliation: General Hospital, Granollers, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Deig
authors.affiliation: Clinical Hospital, Valencia, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Galindo
authors.affiliation: Cabueñes Hospital, Gijón, Spain.
authors.forename: B
authors.initials: B
authors.lastname: de la Fuente
authors.affiliation: Valme Hospital, Sevilla, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Lozano
authors.affiliation: La Fé Hospital, Valencia, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Montero
authors.affiliation: Infanta Cristina Hospital, Badajoz, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Muñoz-Sanz
authors.affiliation: Virgen de Rosell Hospital, Cartagena, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Sanchez
authors.affiliation: SAS Hospital, Jérez de la Frontera, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Terrón
authors.affiliation: Clinical Hospital, Puerto Real, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Romero-Palacios
authors.affiliation: Seville University, Sevilla, Spain.
authors.forename: J R
authors.initials: JR
authors.lastname: Lacalle
authors.affiliation: VACH Medical Association, Cartaya, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Garrido
authors.affiliation: Infanta Elena Hospital, Huelva, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Suárez-Lozano
mesh_terms: D000293:Adolescent; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012306:Risk; D018570:Risk Assessment; D000072230:Sustained Virologic Response; D017211:Treatment Failure; D019562:Viral Load; D014766:Viremia; D055815:Young Adult
chemical_list: D044966:Anti-Retroviral Agents
keywords: 
  HIV
  ; cohort study; low-level viraemia; residual viraemia; virological failure