title: Relationship between HIV/Highly active antiretroviral therapy (HAART)-associated lipodystrophy syndrome and stavudine-triphosphate intracellular levels in patients with stavudine-based antiretroviral regimens.
abstract: BACKGROUND
  The link between human immunodeficiency virus/highly active antiretroviral therapy (HAART)-associated lipodystrophy syndrome (HALS) and the use of thymidine analogues has been well established. However, to our knowledge, no relationship has been proven between intracellular levels of stavudine (d4T) and HALS.
  
  
  METHODS
  We measured peripheral blood mononuclear cell intracellular levels of d4T-triphosphate (TP) in patients who were receiving d4T as part of their antiretroviral regimens. d4T-TP levels were determined by a validated liquid chromatography-tandem mass spectrometry assay method. The diagnosis of HALS was made in accordance with the criteria of a lipodystrophy severity grading scale. The Student t test, Pearson correlations, 1-way analysis of variance with Bonferroni correction, and stepwise logistic regression were used for statistic analyses.
  
  
  RESULTS
  This was a cross-sectional study. There were 33 patients: 17 with HALS and 16 without HALS. The median concentration of d4T-TP for patients with HALS was 20.60 femtomoles (fmol)/1 x 10(6) cells (interquartile range [IQR], 14.90-26.92 fmol/1 x 10(6) cells) and for patients without HALS was 13.85 fmol/1 x 10(6) cells (IQR, 8.65-20.15 fmol/1 x 10(6) cells) (P=.013). The median d4T-TP intracellular level in patients who had developed an AIDS-defining condition was 22.50 fmol/1 x 10(6) cells (IQR, 15.80-27.37 fmol/1 x 10(6) cells) and in those who had not was 14.40 fmol/1 x 10(6) cells (IQR, 10.80-20.40 fmol/1 x 10(6) cells) (P=.037). There were no statistically significant differences in d4T-TP intracellular levels with respect to the presence of metabolic syndrome, the clinical form of HALS (pure lipoatrophic vs mixed), the degree of facial lipoatrophy, the presence of hepatitis C virus infection, and the pair of nucleosides in HAART. d4T-TP levels correlated only with cumulative d4T exposure in time and dose. d4T-TP intracellular levels were independently associated with HALS (odds ratio, 1.58; 95% confidence interval, 1.08-2.32; P=.019).
  
  
  CONCLUSIONS
  Intracellular levels of d4T-TP are strongly associated with the development of HALS.
authors.affiliation: Infectious Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain. pdomingo@santpau.cat
authors.forename: Pere
authors.initials: P
authors.lastname: Domingo
authors.forename: Maria Carmen
authors.initials: MC
authors.lastname: Cabeza
authors.forename: Alain
authors.initials: A
authors.lastname: Pruvost
authors.forename: Juliana
authors.initials: J
authors.lastname: Salazar
authors.forename: Maria Del Mar
authors.initials: Mdel M
authors.lastname: Gutierrez
authors.forename: Maria Gracia
authors.initials: MG
authors.lastname: Mateo
authors.forename: Joan C
authors.initials: JC
authors.lastname: Domingo
authors.forename: Irene
authors.initials: I
authors.lastname: Fernandez
authors.forename: Francesc
authors.initials: F
authors.lastname: Villarroya
authors.forename: Jessica
authors.initials: J
authors.lastname: Muñoz
authors.forename: Francesc
authors.initials: F
authors.lastname: Vidal
authors.forename: Montserrat
authors.initials: M
authors.lastname: Baiget
mesh_terms: D000328:Adult; D000886:Anthropometry; D023241:Antiretroviral Therapy, Highly Active / Q000009:adverse effects; D003430:Cross-Sectional Studies; D005260:Female; D039682:HIV-Associated Lipodystrophy Syndrome / Q000378:metabolism*; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011122:Polyphosphates / Q000378:metabolism*; D018119:Stavudine / Q000008:administration & dosage* / Q000493:pharmacokinetics
chemical_list: D011122:Polyphosphates; D018119:Stavudine; C005692:triphosphoric acid