title: Presence of Chlamydia pneumoniae in abdominal aortic aneurysms is not associated with increased activity of matrix metalloproteinases.
abstract: OBJECTIVE
  to test the hypothesis that the presence of Chlamydia pneumoniae (C. pneumoniae) in the wall of abdominal aortic aneurysms (AAA) is associated with increased activity of matrix metalloproteinase (MMP)-2 and/or MMP-9.
  
  
  METHODS
  case-control study.
  
  
  METHODS
  in a series of 40 patients with AAA > or =5cm in maximal cross-sectional diameter, C. pneumoniae-DNA was identified in the aneurysm wall by nested PCR in 14 (35%) patients. Another 14 C. pneumoniae-DNA-negative AAA patients from the same series, matched for gender and aneurysm diameter, were used as controls. In each group there were 7 asymptomatic (aAAA) and 7 ruptured (rAAA) aneurysms. MMP-2 and -9 activity was estimated in AAA wall biopsies by gelatin zymography.
  
  
  RESULTS
  patients with a C. pneumoniae-DNA-positive aneurysm wall specimen showed an over-all lower activity of MMP-2 and MMP-9 (pro- and active enzyme) compared to the C. pneumoniae-DNA negative patients. However, there were no statistically significant differences in MMP activity between the two groups of patients with aAAA. Among patients with rAAA both pro-MMP-9 (p=0,026) and active-MMP-9 (p=0.007) were significantly lower in C. pneumoniae-DNA-positive patients compared to C. pneumoniae-DNA-negative patients, whereas there were no significant differences in pro-MMP-2 or active-MMP-2.
  
  
  CONCLUSIONS
  this preliminary study does not support the hypothesis that the presence of C. pneumoniae in the AAA wall is associated with increased activity of MMP-2 and MMP-9.
mesh_terms: D034861:Abdominal Wall / Q000382:microbiology* / Q000503:physiopathology; D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000150:complications / Q000382:microbiology* / Q000503:physiopathology; D016022:Case-Control Studies; D023521:Chlamydophila Infections / Q000150:complications / Q000382:microbiology* / Q000503:physiopathology; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000502:physiology*; D020780:Matrix Metalloproteinase 9 / Q000502:physiology*; D008875:Middle Aged
chemical_list: D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9