title: Transient viral load increases in HIV-infected children in the U.K. and Ireland: what do they mean?
abstract: OBJECTIVE
  To investigate transient increases in viral load during sustained suppression in children in the UK and Ireland Collaborative HIV Paediatric Study (CHIPS).
  
  
  METHODS
  Cohort of HIV-infected children from 39 centres.
  
  
  METHODS
  Transient viraemia was defined as > or =1 detectable viral loads (> or =50 copies/ml) between two undetectable values (<50 copies/ml) <280 days apart, during a period of sustained viral suppression (from a confirmed level of <50 copies/ml until the last undetectectable measurement before antiretroviral therapy change or until a confirmed level of >50 copies/ml).
  
  
  RESULTS
  Of 595 children initiating HAART without previous treatment, 347 (58%) achieved sustained suppression. Of these, 78 (23%) experienced 109 episodes of transient viraemia (median 134 copies/ml); 92 (84%) had levels of <1000 copies/ml (maximum 39,839). Transient viraemia was more common during second-line therapy (25/100 child-years [CY]) and following a previous episode (19/100 CY) compared with first-line therapy without a previous episode (11/100 CY). Rates decreased with age at HAART initiation (incidence rate ratio [IRR] 0.95 per year older; P = 0.05), but were higher in those suppressed for longer (IRR 1.63 in those suppressed for 21 year versus <1 year; P = 0.03). CD4+ and CD8+ T-cell counts were similar before and after transient viraemia. Of detectable viral loads during periods of suppression 44% were transient increases rather than virological failure: experiencing transient viraemia did not increase subsequent virological failure (P = 0.20).
  
  
  CONCLUSIONS
  Transient viraemia is relatively common among children on HAART, occurring more frequently in those starting HAART at younger ages, on second-line therapy and after longer suppression. It does not appear to affect CD4+ or CD8+ T-cell counts or the risk of subsequent virological failure. Natural variation, assay effects and adherence might all have a role.
authors.affiliation: MRC Clinical Trials Unit, London, UK. kjl@ctu.mrc.ac.uk
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Lee
authors.forename: Delane
authors.initials: D
authors.lastname: Shingadia
authors.forename: Deenan
authors.initials: D
authors.lastname: Pillay
authors.forename: A Sarah
authors.initials: AS
authors.lastname: Walker
authors.forename: Andrew
authors.initials: A
authors.lastname: Riordan
authors.forename: Esse
authors.initials: E
authors.lastname: Menson
authors.forename: Trinh
authors.initials: T
authors.lastname: Duong
authors.forename: Gareth
authors.initials: G
authors.lastname: Tudor-Williams
authors.forename: Diana M
authors.initials: DM
authors.lastname: Gibb
mesh_terms: D000293:Adolescent; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D002648:Child; D002675:Child, Preschool; D005260:Female; D006678:HIV / Q000187:drug effects / Q000502:physiology*; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D007223:Infant; D007494:Ireland; D008297:Male; D006113:United Kingdom; D019562:Viral Load; D014766:Viremia
chemical_list: D019380:Anti-HIV Agents