title: Ageing and long-term CD4 cell count trends in HIV-positive patients with 5 years or more combination antiretroviral therapy experience.
abstract: OBJECTIVE
  The aim of this study was to describe the long-term changes in CD4 cell counts beyond 5 years of combination antiretroviral therapy (cART). If natural ageing leads to a long-term decline in the immune system via low-grade chronic immune activation/inflammation, then one might expect to see a greater or earlier decline in CD4 counts in older HIV-positive patients with increasing duration of cART.
  
  
  METHODS
  Retrospective and prospective data were examined from long-term virologically stable HIV-positive adults from the Australian HIV Observational Database. We estimated mean CD4 cell count changes following the completion of 5 years of cART using linear mixed models.
  
  
  RESULTS
  A total of 37 916 CD4 measurements were observed for 892 patients over a combined total of 9753 patient-years. Older patients (> 50 years old) at cART initiation had estimated mean (95% confidence interval) changes in CD4 counts by year-5 CD4 count strata (< 500, 500-750 and > 750 cells/μL) of 14 (7 to 21), 3 (-5 to 11) and -6 (-17 to 4) cells/μL/year. Of the CD4 cell count rates of change estimated, none were indicative of long-term declines in CD4 cell counts.
  
  
  CONCLUSIONS
  Our results suggest that duration of cART and increasing age do not result in decreasing mean changes in CD4 cell counts for long-term virologically suppressed patients, indicating that the level of immune recovery achieved during the first 5 years of treatment is sustained through long-term cART.
authors.affiliation: The Kirby Institute, University of New South Wales, Sydney, NSW, Australia. swright@kirby.unsw.edu.au
authors.forename: S T
authors.initials: ST
authors.lastname: Wright
authors.forename: K
authors.initials: K
authors.lastname: Petoumenos
authors.forename: M
authors.initials: M
authors.lastname: Boyd
authors.forename: A
authors.initials: A
authors.lastname: Carr
authors.forename: S
authors.initials: S
authors.lastname: Downing
authors.forename: C C
authors.initials: CC
authors.lastname: O'Connor
authors.forename: M
authors.initials: M
authors.lastname: Grotowski
authors.forename: M G
authors.initials: MG
authors.lastname: Law
mesh_terms: D000328:Adult; D000375:Aging / Q000276:immunology*; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies