MMP-9, homocysteine and CRP circulating levels are associated with
intraluminal thrombus thickness of abdominal aortic aneurysms – new
implication of the old biomarkers
Affiliations: Department of Vascular Surgery and Angiology,
Pomeranian Medical University, Szczecin, Poland | Department of Clinical Biochemistry and Laboratory
Diagnostics, Pomeranian Medical University, Szczecin, Poland | Department of Biochemistry and Medical Chemistry,
Pomeranian Medical University, Szczecin, Poland | Department of Radiology, Pomeranian Medical
University, Szczecin, Poland
Note: [] Address for correspondence: Ireneusz Wiernicki, Department of
Vascular Surgery and Angiology, Powstancow Wielkopolskich 72, 70-111 Szczecin,
Poland. Tel.: +48 91 466 11 56; Fax: +48 91 466 11 57; E-mail: irekwie@wp.eu
Abstract: Background: Abdominal aortic aneurysms (AAAs) are characterized by
presence of high proteolytic activity, atherosclerotic lesions, extensive
transmural inflammation and the presence of variably sized and shaped
intraluminal thrombus (ILT). Therefore, we evaluated a possible association
between plasma matrix metalloproteinase-9 (MMP-9), homocysteine (Hcy),
high-sensitivity C-reactive protein (hsCRP) levels and ILT thickness in
patients with AAA. Methods: Plasma concentrations of MMP-9, Hcy and hsCRP
were determined and ILT thickness was measured in 71 patients with AAA. They
were divided into 2 groups according to ILT thickness: 34 patients with ILT
mean thickness ⩾ 9 mm and 37 patients with ILT < 9 mm. Results: Plasma MMP-9 and CRP concentrations in patients with thin ILT were
significantly higher than in group with thick ILT (medians 610 vs. 485 ng/mL,
p=0.00003, and 7.7 vs. 3.3 mg/L, p < 0.00001, respectively). In
contrast, plasma Hcy concentrations in patients with thin ILT were
significantly lower than in the group with thick ILT (medians 14.3 vs.
19.2 μmol/L, p < 0.00001). Multiple regression models adjusted for
age and AAA diameter showed that thin ILT is an independent predictor of high
MMP-9 and CRP concentrations, while thick ILT predicts high Hcy concentrations. Conclusions: Association of higher plasma levels of MMP-9 and CRP with
thin ILT may be related to two phenomena: thin thrombi convey more
elastolysis-stimulating factors from blood to the AAA wall and thin thrombi
convey more factors involved in proteolysis and inflammation from AAA wall to
blood. The association of thin ILT with lower plasma Hcy concentrations may be
related to the role of Hcy as a prothrombotic marker and needs further research.
