title: Evaluation of viral load thresholds for predicting new World Health Organization stage 3 and 4 events in HIV-infected children receiving highly active antiretroviral therapy.
abstract: BACKGROUND
  This study evaluated a wide range of viral load (VL) thresholds to identify a cut-point that best predicts new clinical events in children on stable highly active antiretroviral therapy (HAART).
  
  
  METHODS
  Cox proportional hazards modeling was used to assess the adjusted risk for World Health Organization stage 3 or 4 clinical events (WHO events) as a function of time-varying CD4, VL, and hemoglobin values in a cohort study of Latin American children on HAART ≥6 months. Models were fit using different VL cut-points between 400 and 50,000 copies per milliliter, with model fit evaluated on the basis of the minimum Akaike information criterion value, a standard model fit statistic.
  
  
  RESULTS
  Models were based on 67 subjects with WHO events out of 550 subjects on study. The VL cut-points of >2600 and >32,000 copies per milliliter corresponded to the lowest Akaike information criterion values and were associated with the highest hazard ratios (2.0, P = 0.015; and 2.1, P = 0.0058, respectively) for WHO events.
  
  
  CONCLUSIONS
  In HIV-infected Latin American children on stable HAART, 2 distinct VL thresholds (>2600 and >32,000 copies/mL) were identified for predicting children at significantly increased risk for HIV-related clinical illness, after accounting for CD4 level, hemoglobin level, and other significant factors.
authors.affiliation: Pediatric, Adolescent, and Maternal AIDS Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-7510, USA. siberryg@mail.nih.gov
authors.forename: George K
authors.initials: GK
authors.lastname: Siberry
authors.forename: D Robert
authors.initials: DR
authors.lastname: Harris
authors.forename: Ricardo Hugo
authors.initials: RH
authors.lastname: Oliveira
authors.forename: Margot R
authors.initials: MR
authors.lastname: Krauss
authors.forename: Cristina B
authors.initials: CB
authors.lastname: Hofer
authors.forename: Adriana Aparecida
authors.initials: AA
authors.lastname: Tiraboschi
authors.forename: Heloisa
authors.initials: H
authors.lastname: Marques
authors.forename: Regina C
authors.initials: RC
authors.lastname: Succi
authors.forename: Thalita
authors.initials: T
authors.lastname: Abreu
authors.forename: Marinella
authors.initials: M
authors.lastname: Della Negra
authors.forename: Lynne M
authors.initials: LM
authors.lastname: Mofenson
authors.forename: Rohan
authors.initials: R
authors.lastname: Hazra
mesh_terms: D019380:Anti-HIV Agents / Q000008:administration & dosage*; D023241:Antiretroviral Therapy, Highly Active; D002648:Child; D002675:Child, Preschool; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D007223:Infant; D011379:Prognosis; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents