Abstract P108: Inflammatory Factors and Metalloproteinases Levels Are Elevated in Aorta of Patients with Abdominal Aortic Aneurysm

Introduction: The pathophysiology of abdominal aortic aneurysm (AAA) remains poorly understood. The identification of the mechanisms involved in growth, progression, and the risk of aortic rupture could bring a novel treatment perspective and improve patient outcomes. Inflammatory mediators and metalloproteinases (MMPs) 2 and 9 have been shown to contribute to the pathophysiology of AAA in humans. It is widely recognized that these mediators produce both local (tissue) and systemic (circulation) responses. Therefore, in this study, we sought to characterize the inflammatory and MMP-2 and MMP-9 profiles in the aorta and plasma in patients with AAA. Methodology: Plasma and aorta tissue from AAA patients(n=31)were obtained during conventional AAA correction surgeries at Ribeirão Preto Medical School Hospital-University of São Paulo. The control samples were obtained from organ donors without AAA (n=15). The levels of inflammatory markers (IL-6,IL-8,TGFbeta) and MMPs were measured by radio immunoassay and zymography, respectively, in plasma and aorta. Results: Levels of IL-6 (p=0.001), IL-8 (p=0.01) and TGF beta (p=0.05) were significantly elevated in the aorta of AAA patients, but not in plasma, when compared to control group. Interestingly, levels of IL-6 (p=0.05) and IL-8 (p=0.02) were lower both in the aorta and plasma of controls. MMP-2 and MMP-9 levels were upregulated in plasma (p=0.02 and p=0.0007, respectively) and in aorta (p=0.017 and p=0.03, respectively) of AAA patients when compared to controls. The tissular levels of MMP-2 and MMP-9 were upregulated in the aorta in both AAA patients (p=0.001 and p=0.0001, respectively) and controls (p=0.008 and p=0.001, respectively) when compared to plasmatic levels of respective groups. Conclusion: Our data show that a profile of AAA patients is characterized by locally elevated inflammation factors and MMPs, and systemically elevated MMPs levels. This might suggest that the local response in aortais an important pathway in the pathophysiology of AAA development.