title: Immunologic response to antiretroviral therapy in hepatitis C virus-coinfected adults in a population-based HIV/AIDS treatment program.
abstract: BACKGROUND
  We sought to characterize the impact that hepatitis C virus (HCV) infection has on CD4 cells during the first 48 weeks of antiretroviral therapy (ART) in previously ART-naive human immunodeficiency virus (HIV)-infected patients.
  
  
  METHODS
  The HIV/AIDS Drug Treatment Programme at the British Columbia Centre for Excellence in HIV/AIDS distributes all ART in this Canadian province. Eligible individuals were those whose first-ever ART included 2 nucleoside reverse transcriptase inhibitors and either a protease inhibitor or a nonnucleoside reverse transcriptase inhibitor and who had a documented positive result for HCV antibody testing. Outcomes were binary events (time to an increase of > or = 75 CD4 cells/mm3 or an increase of > or = 10% in the percentage of CD4 cells in the total T cell population [CD4 cell fraction]) and continuous repeated measures. Statistical analyses used parametric and nonparametric methods, including multivariate mixed-effects linear regression analysis and Cox proportional hazards analysis.
  
  
  RESULTS
  Of 1186 eligible patients, 606 (51%) were positive and 580 (49%) were negative for HCV antibodies. HCV antibody-positive patients were slower to have an absolute (P<.001) and a fraction (P = .02) CD4 cell event. In adjusted Cox proportional hazards analysis (controlling for age, sex, baseline absolute CD4 cell count, baseline pVL, type of ART initiated, AIDS diagnosis at baseline, adherence to ART regimen, and number of CD4 cell measurements), HCV antibody-positive patients were less likely to have an absolute CD4 cell event (adjusted hazard ratio [AHR], 0.84 [95% confidence interval [CI], 0.72-0.98]) and somewhat less likely to have a CD4 cell fraction event (AHR, 0.89 [95% CI, 0.70-1.14]) than HCV antibody-negative patients. In multivariate mixed-effects linear regression analysis, HCV antibody-negative patients had increases of an average of 75 cells in the absolute CD4 cell count and 4.4% in the CD4 cell fraction, compared with 20 cells and 1.1% in HCV antibody-positive patients, during the first 48 weeks of ART, after adjustment for time-updated pVL, number of CD4 cell measurements, and other factors.
  
  
  CONCLUSIONS
  HCV antibody-positive HIV-infected patients may have an altered immunologic response to ART.
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, University of British Columbia, Vancouver, Canada. pbraitstein@ispm.unibe.ch
authors.forename: Paula
authors.initials: P
authors.lastname: Braitstein
authors.forename: Carlos
authors.initials: C
authors.lastname: Zala
authors.forename: Benita
authors.initials: B
authors.lastname: Yip
authors.forename: Martin W G
authors.initials: MW
authors.lastname: Brinkhof
authors.forename: David
authors.initials: D
authors.lastname: Moore
authors.forename: Robert S
authors.initials: RS
authors.lastname: Hogg
authors.forename: Julio S G
authors.initials: JS
authors.lastname: Montaner
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications / Q000188:drug therapy* / Q000276:immunology*; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D016516:CD4-CD8 Ratio; D015331:Cohort Studies; D005260:Female; D017320:HIV Protease Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use; D006526:Hepatitis C / Q000150:complications* / Q000276:immunology; D018937:Hepatitis C Antibodies / Q000097:blood; D006801:Humans; D008297:Male; D018894:Reverse Transcriptase Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D017320:HIV Protease Inhibitors; D018937:Hepatitis C Antibodies; D018894:Reverse Transcriptase Inhibitors