title: A comparison of the CD4 response to antiretroviral regimens in patients commencing therapy with low CD4 counts.
abstract: OBJECTIVE
  To compare the immunological response to highly active antiretroviral therapy (HAART) in treatment-naive patients with a baseline CD4 count of <200 cells/mm(3).
  
  
  METHODS
  We identified treatment-naive human immunodeficiency virus (HIV-1)-infected individuals who had commenced HAART since 1996 and who had a starting CD4 count of <200 cells/mm(3). Immunological success was defined as achieving a CD4 count of >200 cells/mm(3) and treatments were compared using univariate and multivariate Cox's proportional hazards models in order to establish whether protease inhibitor (PI)-based regimens were significantly different to regimens based on non-nucleoside reverse transcriptase inhibitors (NNRTIs). Both regimens utilize a nucleoside analogue (NA) backbone.
  
  
  RESULTS
  A total of 599 patients were identified. When the variables were entered into a multivariate analysis, no significant differences between HAART regimens were found. We showed that compared with efavirenz regimens a two NA plus one PI regimen was not significantly less likely to achieve immunological success (adjusted HR: 0.65, 95% CI 0.41-1.03, P=0.07). Two NA and boosted PI (adjusted HR: 1.33, 95% CI 0.81 to 2.16) or two NA and nevirapine (adjusted HR: 0.93, 95% CI 0.67-1.29) regimens were also not significantly different from efavirenz-based regimens, based on the endpoint of immunological success.
  
  
  CONCLUSIONS
  PI-, boosted PI- and NNRTI-based HAART regimens are not significantly different in achieving increased CD4 counts in individuals who commence therapy with a low CD4 count.
authors.affiliation: St Stephen's Centre, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK. laura.waters@Chelwest.nhs.uk
authors.forename: L
authors.initials: L
authors.lastname: Waters
authors.forename: J
authors.initials: J
authors.lastname: Stebbing
authors.forename: R
authors.initials: R
authors.lastname: Jones
authors.forename: C
authors.initials: C
authors.lastname: Michailidis
authors.forename: S
authors.initials: S
authors.lastname: Sawleshwarkar
authors.forename: S
authors.initials: S
authors.lastname: Mandalia
authors.forename: M
authors.initials: M
authors.lastname: Bower
authors.forename: M
authors.initials: M
authors.lastname: Nelson
authors.forename: B
authors.initials: B
authors.lastname: Gazzard
mesh_terms: D000328:Adult; D000480:Alkynes; D023241:Antiretroviral Therapy, Highly Active; D048588:Benzoxazines; D018791:CD4 Lymphocyte Count; D003521:Cyclopropanes; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology*; D017320:HIV Protease Inhibitors / Q000627:therapeutic use; D015497:HIV-1; D006801:Humans; D008297:Male; D019829:Nevirapine / Q000627:therapeutic use; D010078:Oxazines / Q000627:therapeutic use; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000480:Alkynes; D048588:Benzoxazines; D003521:Cyclopropanes; D017320:HIV Protease Inhibitors; D010078:Oxazines; D018894:Reverse Transcriptase Inhibitors; D019829:Nevirapine; C098320:efavirenz