title: Association of thymidylate synthase gene polymorphisms with stavudine triphosphate intracellular levels and lipodystrophy.
abstract: The antiviral activity and toxicity of stavudine (d4T) depend on its triphosphate metabolite, stavudine triphosphate (d4T-TP). Therefore, modifications in intracellular levels of d4T-TP may change the toxicity profile of stavudine. d4T-TP intracellular levels in peripheral blood mononuclear cells were determined with a prominence liquid chromatograph connected to a triple-quadruple mass spectrometer. Polymorphisms in the thymidylate synthase (TS), methylenetetrahydrofolate reductase (MTHFR), dihydrofolate reductase (DHFR), reduced folate carrier 1 (RFC1; SLC19A1), and cyclin D1 (CCND1) genes were determined by direct sequencing using an ABI Prism 3100 genetic analyzer or Fluidigm's Biomark system. The Mann-Whitney test, rank analysis of variance (with Bonferroni's adjusted post hoc comparisons), and logistic regression were used for the inferential analyses. Thirty-three stavudine-treated patients were enrolled in this cross-sectional study. d4T-TP intracellular levels were 11.50 fmol/10(6) cells (interquartile range [IQR] = 8.12 to 13.87 fmol/10(6) cells) in patients with a high-expression TS genotype (2/3G, 3C/3G, and 3G/3G), whereas in those with a low-expression TS genotype (2/2, 2/3C, and 3C/3C), they were 21.40 fmol/10(6) cells (IQR = 18.90 to 27.0 fmol/10(6) cells) (P < 0.0001). Polymorphisms in the MTHFR, DHFR, RFC1, and CCND1 genes did not influence the intracellular concentration of d4T-TP. d4T-TP levels were independently associated with the TS genotype (low versus high expression; odds ratio [OR] = 86.22; 95% confidence interval [CI] = 8.48 to nonestimable; P = 0.0023). The low-expression TS genotype was associated with the development of HIV/highly active antiretroviral therapy-associated lypodystrophy syndrome (HALS) (OR = 14.0; 95% CI = 2.09 to 108.0; P = 0.0032). Our preliminary data show that polymorphisms in the thymidylate synthase gene are strongly associated with d4T-TP intracellular levels and with development of HALS.
authors.affiliation: Infectious Diseases Unit, Hospital de Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain. pdomingo@santpau.es
authors.forename: Pere
authors.initials: P
authors.lastname: Domingo
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Cabeza
authors.forename: Alain
authors.initials: A
authors.lastname: Pruvost
authors.forename: Ferran
authors.initials: F
authors.lastname: Torres
authors.forename: Juliana
authors.initials: J
authors.lastname: Salazar
authors.forename: M
authors.initials: M
authors.lastname: del Mar Gutierrez
authors.forename: M Gracia
authors.initials: MG
authors.lastname: Mateo
authors.forename: Angels
authors.initials: A
authors.lastname: Fontanet
authors.forename: Irene
authors.initials: I
authors.lastname: Fernandez
authors.forename: Joan C
authors.initials: JC
authors.lastname: Domingo
authors.forename: Francesc
authors.initials: F
authors.lastname: Villarroya
authors.forename: Francesc
authors.initials: F
authors.lastname: Vidal
authors.forename: Montserrat
authors.initials: M
authors.lastname: Baiget
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000009:adverse effects* / Q000378:metabolism; D003430:Cross-Sectional Studies; D019938:Cyclin D1 / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008060:Lipodystrophy / Q000139:chemically induced / Q000201:enzymology* / Q000235:genetics*; D016015:Logistic Models; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D018119:Stavudine / Q000009:adverse effects* / Q000378:metabolism; D013940:Thymidylate Synthase / Q000235:genetics*
chemical_list: D019380:Anti-HIV Agents; D026901:Membrane Transport Proteins; C120043:SLC19A2 protein, human; D019938:Cyclin D1; D018119:Stavudine; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D013940:Thymidylate Synthase