title: Immunologic benefits of enfuvirtide in patients enrolled in a drug assistance program.
abstract: BACKGROUND
  Randomized clinical trials have demonstrated that enfuvirtide plus an optimized background regimen can cause a significant increase in CD4+ cell counts and a reduction in HIV RNA levels.
  
  
  OBJECTIVE
  To describe and analyze CD4+ cell count and HIV RNA changes in HIV-infected patients receiving enfuvirtide and a prescribed background regimen (PBR) in a primarily clinical setting.
  
  
  METHODS
  A retrospective review from September 1998 through August 2005 of CD4+ cell counts and HIV RNA changes from baseline was conducted in patients receiving enfuvirtide. Data were stratified and analyzed according to baseline CD4+ cell count and HIV RNA.
  
  
  RESULTS
  A mean CD4+ cell count increase of approximately 102 cells/mm(3)was observed, regardless of baseline CD4+ cell count, in 187 patients receiving enfuvirtide during a mean of 19.4 months of follow-up. During 3 years of follow-up, patients initiating enfuvirtide at CD4+ cell counts less than 100 cells/mm(3)never achieved absolute CD4+ cell counts comparable to the counts in patients starting enfuvirtide at CD4+ cell counts of 100 cells/mm(3)or more. In 38.3% of patients achieving an undetectable HIV RNA level, a mean CD4+ cell count increase of 185 cells/mm(3)was observed. An unexpected finding was that a mean CD4+ cell count increase of 76 cells/mm(3)occurred in 61.7% of patients not achieving complete viral suppression.
  
  
  CONCLUSIONS
  Immunologic benefits were observed in subjects continuing enfuvirtide plus a PBR irrespective of baseline CD4+ cell count, complete viral suppression, or antiretroviral susceptibility data. Data suggest that initiation of enfuvirtide at CD4+ cell counts greater than 100 cells/mm(3)may be immunologically advantageous and independent of complete virologic response.
authors.affiliation: Department of Family and Community Medicine, University of California at San Francisco, San Francisco, CA 94143, USA. Parya.saberi@ucsf.edu
authors.forename: Parya
authors.initials: P
authors.lastname: Saberi
authors.forename: Nikolai H
authors.initials: NH
authors.lastname: Caswell
authors.forename: Cristina I
authors.initials: CI
authors.lastname: Gruta
authors.forename: Jason N
authors.initials: JN
authors.lastname: Tokumoto
authors.forename: Betty J
authors.initials: BJ
authors.lastname: Dong
mesh_terms: D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count / Q000379:methods; D000077560:Enfuvirtide; D005500:Follow-Up Studies; D015700:HIV Envelope Protein gp41 / Q000627:therapeutic use*; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology / Q000821:virology; D006801:Humans; D010446:Peptide Fragments / Q000627:therapeutic use*; D012189:Retrospective Studies; D013221:State Health Plans / Q000191:economics; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents; D015700:HIV Envelope Protein gp41; D010446:Peptide Fragments; D000077560:Enfuvirtide