Abstract
Objective
The maintenance of an arterial elastin's integrity is essential in the prevention
of abdominal aortic aneurysm (AAA) development. So far, the effect of intraluminal
thrombus (ILT) thickness on the elastolytic activity within the AAA wall has not been
studied. In the present study the hypothesis that thin thrombus is associated with
enhanced proteolytic activity within human AAA wall was investigated.
Methods
The specimens for analysis, from both thin (≤10 mm) thrombus-covered and thick (≥25 mm) thrombus-covered wall, had been taken from 40 patients undergoing elective repair
of AAA. We evaluated neutrophil elastase activity with the enzymatic assay. Concentrations
of active matrix metalloproteinase-9 (MMP-9), total matrix metalloproteinase-8 (MMP-8),
and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) were measured by ELISA.
Biochemical parameters were compared with the Wilcoxon signed-rank test.
Results
Statistical analysis showed that the activity of elastase (P < 0.0001) as well as concentrations of active MMP-9 (P = 0.001), total MMP-8 (P < 0.0001) and active MMP-9/total TIMP-1 ratio (P = 0.002) were significantly higher in the thin thrombus-covered wall. Furthermore the
TIMP-1 was found to have a lower concentration in the thin thrombus-covered in comparison
with the thick thrombus-covered wall (P = 0.003). There was a significant positive correlation between measurements in AAA wall
sites with thin and thick thrombus for elastase, TIMP-1, MMP-9/TIMP-1 ratio, and a
borderline correlation was observed for MMP-8. Active MMP-9 concentration did not
correlate between sites.
Conclusion
The current study demonstrates the differentiation of protease activity within the
same AAA wall and its enhancement within the thin thrombus-covered aneurysm wall.
Keywords
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Article Info
Publication History
Published online: May 31, 2010
Accepted:
April 26,
2010
Received in revised form:
April 23,
2010
Received:
November 25,
2009
Identification
Copyright
© 2010 Elsevier Ireland Ltd. Published by Elsevier Inc. All rights reserved.
