Intraluminal thrombus has a selective influence on matrix metalloproteinases and their inhibitors (tissue inhibitors of matrix metalloproteinases) in the wall of abdominal aortic aneurysms.
BACKGROUND
The influence of intraluminal thrombus (ILT) on the proteolytic environment within the wall of an abdominal aortic aneurysm (AAA) is unknown. This is the first study to examine the correlation between ILT thickness and the levels of matrix metalloproteinases (MMPs) and their natural inhibitors (tissue inhibitors of matrix metalloproteinases [TIMPs]) within the adjacent AAA wall.


METHODS
Thirty-five patients undergoing elective repair of AAAs were studied. A single full-thickness infrarenal aortic sample was obtained uniformly from the arteriotomy site from each patient. All samples were snap frozen and analyzed for total and active MMP 2, 8, and 9 and TIMP 1 and 2. Thrombus thickness at the specimen site was measured on the preoperative contrast computed tomographic angiograms.


RESULTS
There was a statistically significant correlation between ILT thickness, concentration of TIMP 1, and active concentration of MMP 9. MMP 2 (active and total) and TIMP 2 demonstrated a positive correlation with ILT thickness, although not statistically significant.


CONCLUSIONS
In this novel study, we found a significant positive correlation of ILT thickness with active MMP 9 and TIMP 1 concentration in the adjacent AAA wall, and this may have implications for AAA expansion and eventual rupture.
Academic Vascular Surgical Unit, Hull York Medical School and University of Hull, Hull, UK. junaid.khan@hey.nhs.uk
Junaid A
JA
Khan
M N A
MN
Abdul Rahman
F A K
FA
Mazari
Y
Y
Shahin
G
G
Smith
L
L
Madden
M J
MJ
Fagan
J
J
Greenman
P T
PT
McCollum
I C
IC
Chetter
D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000201:enzymology*; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000201:enzymology*; D001027:Aortography / Q000379:methods; D004739:England; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000032:analysis; D020784:Matrix Metalloproteinase 8 / Q000032:analysis; D020780:Matrix Metalloproteinase 9 / Q000032:analysis; D020782:Matrix Metalloproteinases / Q000032:analysis*; D008875:Middle Aged; D012044:Regression Analysis; D013927:Thrombosis / Q000000981:diagnostic imaging / Q000201:enzymology*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000032:analysis; D019714:Tissue Inhibitor of Metalloproteinases / Q000032:analysis*; D014057:Tomography, X-Ray Computed
C560822:TIMP1 protein, human; C560823:TIMP2 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D019714:Tissue Inhibitor of Metalloproteinases; D019716:Tissue Inhibitor of Metalloproteinase-2; D020782:Matrix Metalloproteinases; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; C488762:MMP8 protein, human; D020784:Matrix Metalloproteinase 8; D020780:Matrix Metalloproteinase 9