title: Prognostic value of plasma HIV RNA among highly active antiretroviral therapy users.
abstract: BACKGROUND
  The study objective was to compare the prognostic value of plasma HIV RNA and CD4 cell count at baseline and as time-updated variables in highly active antiretroviral therapy (HAART) users for two outcomes: development of AIDS and change in CD4 cell count.
  
  
  METHODS
  The study population comprised 387 men enrolled in the Multicenter AIDS Cohort Study who were AIDS-free and initiated HAART between 1996 and 2001. Follow-up until AIDS diagnosis (n=36, 9%) or the last AIDS-free visit was included. To determine the predictive value of combining HIV RNA and CD4 cell count, regression tree methods using recursive partitioning at pre-specified cut points for both variables were used.
  
  
  RESULTS
  Low CD4 cell count was a strong predictor of AIDS among HAART users. However, HIV RNA showed strong prognostic value for AIDS development among those with CD4 cell counts > 250 x 10(6) cells/l, in whom an HIV RNA level > 1000 copies/ml carried a 4.6-fold greater risk of developing AIDS. HIV RNA < 5000 copies/ml was also predictive of subsequent increase in CD4 cell count with significantly higher increases among those with initial CD4 counts > 300 x 10(6) cells/l.
  
  
  CONCLUSIONS
  Although, in HAART users, CD4 cell count was the primordial prognostic marker, an HIV RNA > 1000 copies/ml attained after HAART initiation was a strong predictor of the rate of subsequent CD4 cell count increase and of developing AIDS in patients whose CD4 cell counts were > 250 x 10(6) cells/l.
authors.affiliation: School of Public Health, University of Texas Health Science Center, 1100 N. Stanton, Suite 110, El Paso, TX 79902, USA.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Tarwater
authors.forename: Joel E
authors.initials: JE
authors.lastname: Gallant
authors.forename: John W
authors.initials: JW
authors.lastname: Mellors
authors.forename: Mary E
authors.initials: ME
authors.lastname: Gore
authors.forename: John P
authors.initials: JP
authors.lastname: Phair
authors.forename: Roger
authors.initials: R
authors.lastname: Detels
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Margolick
authors.forename: Alvaro
authors.initials: A
authors.lastname: Muñoz
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000276:immunology; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D018450:Disease Progression; D005500:Follow-Up Studies; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D015497:HIV-1; D006801:Humans; D008297:Male; D011379:Prognosis; D012367:RNA, Viral / Q000097:blood*
chemical_list: D012367:RNA, Viral