title: Long-term immunologic response to antiretroviral therapy in low-income countries: a collaborative analysis of prospective studies.
abstract: BACKGROUND
  Few data are available on the long-term immunologic response to antiretroviral therapy (ART) in resource-limited settings, where ART is being rapidly scaled up using a public health approach, with a limited repertoire of drugs.
  
  
  OBJECTIVE
  To describe immunologic response to ART among ART patients in a network of cohorts from sub-Saharan Africa, Latin America, and Asia. STUDY POPULATION/METHODS: Treatment-naive patients aged 15 and older from 27 treatment programs were eligible. Multilevel, linear mixed models were used to assess associations between predictor variables and CD4 cell count trajectories following ART initiation.
  
  
  RESULTS
  Of 29 175 patients initiating ART, 8933 (31%) were excluded due to insufficient follow-up time and early lost to follow-up or death. The remaining 19 967 patients contributed 39 200 person-years on ART and 71 067 CD4 cell count measurements. The median baseline CD4 cell count was 114 cells/microl, with 35% having less than 100 cells/microl. Substantial intersite variation in baseline CD4 cell count was observed (range 61-181 cells/microl). Women had higher median baseline CD4 cell counts than men (121 vs. 104 cells/microl). The median CD4 cell count increased from 114 cells/microl at ART initiation to 230 [interquartile range (IQR) 144-338] at 6 months, 263 (IQR 175-376) at 1 year, 336 (IQR 224-472) at 2 years, 372 (IQR 242-537) at 3 years, 377 (IQR 221-561) at 4 years, and 395 (IQR 240-592) at 5 years. In multivariable models, baseline CD4 cell count was the most important determinant of subsequent CD4 cell count trajectories.
  
  
  CONCLUSIONS
  These data demonstrate robust and sustained CD4 response to ART among patients remaining on therapy. Public health and programmatic interventions leading to earlier HIV diagnosis and initiation of ART could substantially improve patient outcomes in resource-limited settings.
authors.affiliation: Columbia University, Mailman School of Public Health, International Center for AIDS Care and Treatment Programs and Department of Epidemiology, 722 W. 168th Street, Room 706, New York, NY 10032 USA. dn2145@columbia.edu
authors.forename: Denis
authors.initials: D
authors.lastname: Nash
authors.forename: Monica
authors.initials: M
authors.lastname: Katyal
authors.forename: Martin W G
authors.initials: MW
authors.lastname: Brinkhof
authors.forename: Olivia
authors.initials: O
authors.lastname: Keiser
authors.forename: Margaret
authors.initials: M
authors.lastname: May
authors.forename: Rachael
authors.initials: R
authors.lastname: Hughes
authors.forename: Francois
authors.initials: F
authors.lastname: Dabis
authors.forename: Robin
authors.initials: R
authors.lastname: Wood
authors.forename: Eduardo
authors.initials: E
authors.lastname: Sprinz
authors.forename: Mauro
authors.initials: M
authors.lastname: Schechter
authors.forename: Matthias
authors.initials: M
authors.lastname: Egger
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000188:drug therapy / Q000517:prevention & control*; D000293:Adolescent; D000328:Adult; D017954:Africa South of the Sahara; D000368:Aged; D044966:Anti-Retroviral Agents / Q000276:immunology / Q000627:therapeutic use*; D001208:Asia; D018791:CD4 Lymphocyte Count; D003906:Developing Countries; D004334:Drug Administration Schedule; D005260:Female; D015658:HIV Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology; D015497:HIV-1 / Q000276:immunology*; D006297:Health Services Accessibility / Q000592:standards; D006801:Humans; D007843:Latin America; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019562:Viral Load; D055815:Young Adult
chemical_list: D044966:Anti-Retroviral Agents