title: Expansion of small-diameter abdominal aortic aneurysms is not reflected by the release of inflammatory mediators IL-6, MMP-9 and CRP in plasma.
abstract: OBJECTIVE
  The aim of this study was to evaluate a possible correlation between plasma levels of interleukin-6 (IL-6), metalloproteinase-9 (MMP-9) and C-reactive protein (CRP) and the expansion of small abdominal aortic aneurysms (AAAs).
  
  
  METHODS
  Patients were selected from a prospective randomised clinical trial and categorised in two groups, in which one group received active treatment (azithromycin) and the other received placebo. No statistical difference in the expansion rate of AAAs between the groups was found and the two groups were considered as one cohort in the present study.
  
  
  METHODS
  In this study, 213 patients with AAAs between 35 and 49 mm were followed-up with ultrasound examination every 6th month. Blood samples were taken on two occasions (6 months apart). IL-6 and MMP-9 were analysed on one occasion using Quantikine analysing kits (R&D Systems, Inc., USA). CRP was analysed using sensitive-CRP method.
  
  
  RESULTS
  Levels of IL-6, MMP-9 and CRP did not correlate with AAA expansion. Neither was there any correlation between statin medication and changes in MMP-9 levels over the 6-month period. Patients on statins had a lower expansion rate than those not taking statins: 0.16 versus 0.25 cm per year.
  
  
  CONCLUSIONS
  No correlation was found between levels of circulating IL-6, MMP-9, CRP and the expansion of small-diameter AAAs, indicating no clinical use of these markers in AAA surveillance.
authors.affiliation: Department of Surgical Sciences, Section of Vascular Surgery, Uppsala University Hospital, Uppsala, Sweden. lasse.karlsson@lg.se
authors.forename: L
authors.initials: L
authors.lastname: Karlsson
authors.forename: D
authors.initials: D
authors.lastname: Bergqvist
authors.forename: J
authors.initials: J
authors.lastname: Lindbäck
authors.forename: H
authors.initials: H
authors.lastname: Pärsson
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000097:blood / Q000000981:diagnostic imaging*; D002097:C-Reactive Protein / Q000032:analysis*; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D011446:Prospective Studies; D014463:Ultrasonography
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D015850:Interleukin-6; D002097:C-Reactive Protein; D020780:Matrix Metalloproteinase 9