title: CD4 lymphocyte percentage predicts disease progression in HIV-infected patients initiating highly active antiretroviral therapy with CD4 lymphocyte counts >350 lymphocytes/mm3.
abstract: BACKGROUND
  The optimal timing of highly active antiretroviral therapy (HAART) in human immunodeficiency virus (HIV)-infected patients with > or = 200 absolute CD4 lymphocytes/mm3 is unknown. CD4 lymphocyte percentage could add prognostic information.
  
  
  METHODS
  Persons who initiated HAART between 1 January 1998 and 1 January 2003, received > or = 30 days of therapy, and had baseline CD4 lymphocyte data available were included in the study. The log-rank test for time to event and Cox proportional hazards models were used to determine predictors of a new acquired immunodeficiency syndrome-defining illness or death.
  
  
  RESULTS
  A total of 788 patients met the inclusion criteria. At baseline, subjects had a median of 225 CD4 lymphocytes/mm3 and 17% CD4 lymphocytes. Subjects with < 17% CD4 lymphocytes had earlier disease progression, compared with subjects with > or = 17%, both in the entire cohort (P<.0001) and of those subjects with > 350 absolute CD4 lymphocytes/mm3 at baseline (P=.03). CD4 lymphocyte percentage < 17% was the strongest predictor of disease progression among subjects in this latter group (hazard ratio, 3.57; P=.045).
  
  
  CONCLUSIONS
  In this cohort, CD4 lymphocyte percentage predicted disease progression in HIV-infected subjects who initiated therapy with > 350 CD4 lymphocytes/mm3. This information may help identify persons who will derive the greatest benefit from initiation of HAART.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee 37203, USA. todd.hulgan@vanderbilt.edu
authors.forename: Todd
authors.initials: T
authors.lastname: Hulgan
authors.forename: Stephen
authors.initials: S
authors.lastname: Raffanti
authors.forename: Asghar
authors.initials: A
authors.lastname: Kheshti
authors.forename: Robert B
authors.initials: RB
authors.lastname: Blackwell
authors.forename: Peter F
authors.initials: PF
authors.lastname: Rebeiro
authors.forename: Gema
authors.initials: G
authors.lastname: Barkanic
authors.forename: Brandon
authors.initials: B
authors.lastname: Ritz
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Sterling
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D015658:HIV Infections / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology* / Q000503:physiopathology*; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D016019:Survival Analysis