title: CD4 cell response to antiretroviral therapy in children with vertically acquired HIV infection: is it associated with age at initiation?
abstract: BACKGROUND
  Considerable uncertainty remains as to whether early initiation of antiretroviral therapy (ART) in children with vertically acquired human immunodeficiency virus (HIV) infection increases the benefit in terms of immunological response.
  
  
  METHODS
  The association between immunological outcome and early initiation of and/or more-potent ART was investigated, using age-standardized z scores for CD4 cell counts (hereafter, "CD4 z scores"), in 131 HIV-infected children enrolled in the European Collaborative Study, a birth cohort study.
  
  
  RESULTS
  Median age at initiation of the most-potent ART was 4 years (range, 0.1-15.5 years). Initiation of treatment after 5 months of age resulted in nonsignificantly lower CD4 z scores 6 months after initiation. Time to a 20% increase in CD4 z score was associated with age at initiation of the most-potent ART (adjusted hazard ratios [AHRs], 0.37 [P<.01] and 0.43 [P = .05] for 5 months-5 years of age and >5 years of age, respectively, compared with <5 months of age), ethnicity (AHR, 0.48 [P = .01], for black vs. white), and highly active ART (HAART) with or without prior ART (AHRs, 3.16 [P<.01] and 3.95 [P<.001], vs. mono or dual ART, respectively). The risk of subsequent deterioration of CD4 z score was similar for children who initiated ART in different age groups ( chi2 = 0.824; P = .82).
  
  
  CONCLUSIONS
  We confirm the effectiveness of HAART with respect to the recovery of CD4 cell count and suggest a benefit of initiating ART before the age of 5 months. Age at initiation of the most-potent ART was not associated with the likelihood of sustaining the recovery of CD4 cell count.
authors.affiliation: Centre for Paediatric Epidemiology and Biostatistics, Institute of Child Health, University College London, United Kingdom. m.newell@ich.ucl.ac.uk
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Newell
authors.forename: Deven
authors.initials: D
authors.lastname: Patel
authors.forename: Tessa
authors.initials: T
authors.lastname: Goetghebuer
authors.forename: Claire
authors.initials: C
authors.lastname: Thorne
mesh_terms: D000293:Adolescent; D000367:Age Factors; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D002648:Child; D002675:Child, Preschool; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology* / Q000635:transmission; D006801:Humans; D007223:Infant; D018445:Infectious Disease Transmission, Vertical; D008297:Male
chemical_list: D019380:Anti-HIV Agents