title: Factors associated with a strictly undetectable viral load in HIV-1-infected patients.
abstract: OBJECTIVE
  The aim of the study was to identify factors associated with a strictly undetectable viral load (VL) using a routine sensitive real-time polymerase chain reaction (RT-PCR) technology.
  
  
  METHODS
  From a large prospective cohort, 1392 patients with a VL<50 HIV-1 RNA copies/mL while receiving a three-drug suppressive regimen for at least 1 year were included in a cross-sectional analysis. Patients were classified into three groups and compared by univariate and multivariate analysis: 479 patients with a strictly undetectable VL (group 1; 34%), 617 patients with detectable VL below the threshold of 20 copies/mL (group 2; 44%), and 296 patients with a VL of 20-50 copies/mL (group 3; 12%).
  
  
  RESULTS
  Comparing groups 1 and 2, VL zenith<5 log(10) copies/mL [odds ratio (OR) 1.51; 95% confidence interval (CI) 1.15-1.99; P=0.003], current CD4 T-cell count<500 cells/μL (OR 1.44; 95% CI 1.08-1.92; P=0.01), and duration of viral suppression<50 copies/mL longer than 2 years (OR 2.32; 95% CI 1.20-4.54; P=0.01) were associated with undetectable VL. Comparing groups 1 and 3, VL zenith<5 log(10) copies/mL (OR 2.48; 95% CI 1.75-3.50; P<0.001), duration of viral suppression<50 copies/mL longer than 1 year (OR 3.33; 95% CI 1.66-6.66; P=0.0006), and nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens (OR 1.45; 95% CI 1.03-2.04; P=0.03) were associated with undetectable VL. No individual drug effect was found within NNRTI molecules.
  
  
  CONCLUSIONS
  Longer duration of viral suppression<50 copies/mL, lower viral load zenith and NNRTI-based regimen were independently associated with a strictly undetectable viral load. This routinely used RT-PCR assay may prove to be a valuable tool in further large-scale studies.
authors.affiliation: Infectious and Tropical Diseases Department, Toulouse University Hospital, University Toulouse III, Toulouse, France. martin-blondel.g@chu-toulouse.fr
authors.forename: G
authors.initials: G
authors.lastname: Martin-Blondel
authors.forename: K
authors.initials: K
authors.lastname: Sauné
authors.forename: V
authors.initials: V
authors.lastname: Vu Hai
authors.forename: B
authors.initials: B
authors.lastname: Marchou
authors.forename: P
authors.initials: P
authors.lastname: Delobel
authors.forename: J
authors.initials: J
authors.lastname: Izopet
authors.forename: L
authors.initials: L
authors.lastname: Cuzin
authors.forename: P
authors.initials: P
authors.lastname: Massip
mesh_terms: D019380:Anti-HIV Agents / Q000008:administration & dosage*; D018791:CD4 Lymphocyte Count; D003430:Cross-Sectional Studies; D004359:Drug Therapy, Combination; D005260:Female; D006679:HIV Seropositivity / Q000097:blood* / Q000188:drug therapy / Q000235:genetics; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D060888:Real-Time Polymerase Chain Reaction; D012307:Risk Factors; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents