title: Simplified maintenance therapy with abacavir/lamivudine/zidovudine plus tenofovir after sustained HIV load suppression: four years of follow-up.
abstract: OBJECTIVE
  To assess the virologic and immunologic outcome of a treatment simplification strategy based on the substitution of protease inhibitor (PI)-based regimen with abacavir/lamivudine/zidovudine (ABC/3TC/ZDV, also known as trizivir or TZV) plus tenofovir (TDF) in viral-suppressed patients.
  
  
  METHODS
  The study population included 17 HIV-infected patients with undetectable viral loads over 12 months of a stable PI-based therapy. Patients were switched to a combination of TZV (2 pills twice a day) plus TDF (1 pill once a day) and were followed up for 48 months. They were studied for intracellular HIV DNA, CD4 cell count, HIV RNA levels, and lipid metabolism.
  
  
  RESULTS
  All patients had undetectable HIV RNA for the entire period of the follow-up. After 24 months of treatment with TZV plus TDF, the levels of cellular HIV DNA significantly decreased (p = .021). When we stratified the patients on the basis of HIV DNA outcome, we observed a significant increase of CD4 count only in patients who had undetectable HIV DNA after 24 months of TZV/TDF treatment. On the contrary, the CD4 count did not change in patients whose HIV DNA was still detectable at 24 months. The percentage of patients taking lipid-lowering agents declined significantly after switching to TZV/TDF.
  
  
  CONCLUSIONS
  This small pilot study suggests that a single-class quadruple regimen of TZV/TDF may represent a safe and appealing approach in the setting of simplification/switching antiretroviral strategies.
authors.affiliation: Department of Infectious and Tropical Diseases, University of La Sapienza, Rome.
authors.forename: Gabriella
authors.initials: G
authors.lastname: d'Ettorre
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Zaffiri
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Ceccarelli
authors.forename: Mauro
authors.initials: M
authors.lastname: Andreotti
authors.forename: Anna Paola
authors.initials: AP
authors.lastname: Massetti
authors.forename: Stefano
authors.initials: S
authors.lastname: Vella
authors.forename: Claudio M
authors.initials: CM
authors.lastname: Mastroianni
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Vullo
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D004279:DNA, Viral / Q000097:blood; D015224:Dideoxynucleosides / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D063065:Organophosphonates / Q000627:therapeutic use*; D010865:Pilot Projects; D012367:RNA, Viral / Q000097:blood; D000068698:Tenofovir; D019562:Viral Load; D015215:Zidovudine / Q000627:therapeutic use*; D000099227:Abacavir
chemical_list: D000225:Adenine; D019380:Anti-HIV Agents; D004279:DNA, Viral; D015224:Dideoxynucleosides; D019259:Lamivudine; D063065:Organophosphonates; D012367:RNA, Viral; D000068698:Tenofovir; D015215:Zidovudine; D000099227:Abacavir