Correlation of Bacterial Coinfection Versus Matrix Metalloproteinase 9 and Tissue Inhibitor of Metalloproteinase 1 Expression in Aortic Aneurysm and Atherosclerosis (original) (raw)

2013, Annals of Vascular Surgery

Background: We searched for any relationship between Chlamydophila pneumoniae, Mycoplasma pneumoniae, matrix metalloproteinase 9 (MMP-9), and tissue inhibitor of metalloproteinase 1 (TIMP-1) in aneurysmatic atherosclerotic lesions, and whether this relationship differed from that in atherosclerotic nonaneurysmatic lesions. Methods: Twenty-eight tissue samples paired by age and sex were grouped as follows: group 1 included 14 nonaneurysmal atherosclerotic fragments obtained from abdominal aortas collected from necropsies; group 2 included 14 aneurysmatic atherosclerotic aortic fragments obtained from patients during corrective surgery. Immunohistochemistry reactions were evaluated for C pneumoniae, M pneumoniae, MMP-9, and TIMP-1 antigens. Both groups were compared using the ManneWhitney test, and the correlations among variables were obtained using the Spearman correlation test. P 0.05 was considered statistically significant. Results: C pneumoniae and M pneumoniae antigens were detected in 100% of cases. A higher amount of C pneumoniae (P ¼ 0.005), M pneumoniae (P ¼ 0.002), and MMP-9 (P ¼ 0.021) was found in adventitia of group 2 with aneurysm. A positive correlation was found in the aneurysm group, as follows: intima C pneumoniae versus adventitia thickness (r ¼ 0.70; P ¼ 0.01), media C pneumoniae versus adventitia C pneumoniae (r ¼ 0.75; P ¼ 0.002), intima C pneumoniae versus media C pneumoniae (r ¼ 0.8; P ¼ 0.00), and adventitia C pneumoniae versus intima M pneumoniae (r ¼ 0.54; P ¼ 0.05); negative correlations were as follows: adventitia thickness and adventitia M pneumoniae (r ¼ À0.65; P ¼ 0.01), media MMP-9 and media thickness (r ¼ À0.55; P ¼ 0.04), TIMP-1 media versus adventitia C pneumoniae (r ¼ À0.86; P ¼ 0.00), and TIMP-1 media versus M pneumoniae intima (r ¼ À0.67; P ¼ 0.03). Nonaneurysmal atherosclerotic group 1 results are as follows: adventitia C pneumoniae versus TIMP-1 media (r ¼ 0.75; P ¼ 0.01) and media C pneumoniae and adventitia C pneumoniae (r ¼ 0.59; P ¼ 0.03). Conclusions: The present work favors a role for coinfection of both M pneumoniae and C pneumoniae in the development of aortic atherosclerotic aneurysm, with increased adventitial inflammation, inhibition of TIMP-1 activity, and increased collagen degradation.