title: Interleukin-6 promoter genotype and restenosis after femoropopliteal balloon angioplasty: initial observations.
abstract: OBJECTIVE
  To investigate whether there is an association between a functional polymorphism in the interleukin (IL)-6 gene promoter (-174)G/C and restenosis after percutaneous transluminal angioplasty (PTA) of the femoropopliteal artery.
  
  
  METHODS
  A total of 281 patients underwent PTA of the femoropopliteal artery during the study period; 23 (8%) patients had to be excluded due to missing genetic data. We studied 258 patients with intermittent claudication (n = 174) or critical limb ischemia (n = 84). The IL-6 promoter genotype was determined from venous blood samples before intervention by using a mutagenically separated polymerase chain reaction, and patients were followed up for 6 months with duplex ultrasonography for the occurrence of restenosis (> or =50%) after angioplasty. Multivariate Cox proportional hazards analysis was performed to assess the association between the IL-6 promoter genotype and restenosis, with adjustment for possible confounders such as atherosclerotic risk factors and angiographic covariates.
  
  
  RESULTS
  The 6-month restenosis rate was 26% (23 of 90) in patients with the (-174)GG genotype, 28% (33 of 117) with the (-174)GC genotype, and 43% (22 of 51) with the (-174)CC genotype (P =.044). Homozygous carriers of the (-174)C allele ([-174]CC) exhibited a 2.42-fold increased adjusted risk for restenosis (95% CI: 1.28, 4.58; P =.007) compared with homozygous (-174)G allele carriers ([-174]GG). Heterozygous carriers ([-174]GC) had no significantly increased restenosis risk (hazard ratio, 1.37; 95% CI: 0.84, 2.22; P =.21).
  
  
  CONCLUSIONS
  The IL-6 promoter polymorphism (-174)G/C seems to influence the occurrence of restenosis after PTA. Homozygous carriers of the (-174)C allele have an increased rate of intermediate-term restenosis.
authors.affiliation: Department of Medical and Chemical Laboratory Diagnostics, University of Vienna Medical School, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Exner
authors.forename: Martin
authors.initials: M
authors.lastname: Schillinger
authors.forename: Erich
authors.initials: E
authors.lastname: Minar
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Mlekusch
authors.forename: Schila
authors.initials: S
authors.lastname: Sabeti
authors.forename: Georg
authors.initials: G
authors.lastname: Endler
authors.forename: Marianne
authors.initials: M
authors.lastname: Raith
authors.forename: Christine
authors.initials: C
authors.lastname: Mannhalter
authors.forename: Oswald
authors.initials: O
authors.lastname: Wagner
mesh_terms: D000368:Aged; D000800:Angioplasty, Balloon; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000235:genetics* / Q000628:therapy; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging; D005838:Genotype; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011150:Popliteal Artery / Q000000981:diagnostic imaging; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016016:Proportional Hazards Models; D012008:Recurrence; D012307:Risk Factors; D018615:Ultrasonography, Doppler, Color
chemical_list: D015850:Interleukin-6