title: Factors influencing increases in CD4 cell counts of HIV-positive persons receiving long-term highly active antiretroviral therapy.
abstract: BACKGROUND
  Highly active antiretroviral therapy (HAART) results in an improvement in immunologic function. We sought to investigate the factors associated with increases in CD4 cell count among human immunodeficiency virus (HIV)-positive antiretroviral-naive patients starting HAART.
  
  
  METHODS
  Five hundred ninety-six subjects were followed for a median of 2.5 years (interquartile range, 1.0-4.0 years). Factors associated with changes in CD4 cell counts in the first 3 months of HAART and from 3 months onwards were analyzed.
  
  
  RESULTS
  After 6, 12, and 24 months of HAART, the median increases in CD4 cell counts were 114, 181, and 248 cells/mm3, respectively; 84%, 84%, and 80% of subjects had a virus load of <400 copies/mL during the same periods. White ethnicity, higher pre-HAART virus load, and lower pre-HAART CD4 and CD8 cell counts were associated with greater increases in CD4 cell counts during the first 3 months of HAART. From 3 months onward, a greater cumulative proportion of time spent with virus load <400 copies/mL was associated with a more favorable change in CD4 cell count (an average increase of 5.2 cells/mm3/year [95% confidence interval [CI], 3.8-6.7 cells/mm3/year] for each extra 10% cumulative time spent with a virus load <400 copies/mL) (P<.0001). For every 100 cells/mm3 higher in baseline CD4 cell count, the increase was 6 cells/mm3/year less (95% CI, 2-11 cells/mm3/year) (P=.02). Sex, risk group, age, and HAART regimen were not associated with increases in CD4 cell counts.
  
  
  CONCLUSIONS
  These findings emphasize the importance of maintaining virological suppression and suggest other factors that influence long-term CD4 cell response.
authors.affiliation: Royal Free Centre for HIV Medicine and Department of Primary Care and Population Sciences, Royal Free and University College Medical School, Royal Free Campus, London, United Kingdom. c.smith@pcps.ucl.ac.uk
authors.forename: Colette J
authors.initials: CJ
authors.lastname: Smith
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Sabin
authors.forename: Mike S
authors.initials: MS
authors.lastname: Youle
authors.forename: Sabine
authors.initials: S
authors.lastname: Kinloch-de Loes
authors.forename: Fiona C
authors.initials: FC
authors.lastname: Lampe
authors.forename: Sara
authors.initials: S
authors.lastname: Madge
authors.forename: Ian
authors.initials: I
authors.lastname: Cropley
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Johnson
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Phillips
mesh_terms: D000367:Age Factors; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes; D005260:Female; D006678:HIV / Q000187:drug effects / Q000502:physiology; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology* / Q000821:virology; D006801:Humans; D008131:London; D008297:Male; D012737:Sex Factors; D012725:Sexual Behavior; D013997:Time Factors; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents