Aortic Abdominal Aneurysm (AAA) is characterized by an increase of diameter (>1.5 times to reference diameter) and loss of parallelism of the vessel wall. This disease is more often asymptomatic and its rupture is responsible for 1-4 % of mortality in males older than 65 years. Surgery treatment is possible in the case of detection by echography but no specific biological markers are available. In order to identify markers of AAA, we have established a clinical protocol, named CORONA, in which 265 patients undergoing coronary bypass grafting were recruited from 2002 to 2006 in CHRU of Lille. For 6.4 % of them (n=17), an AAA was detected by abdominal ultrasound after the bypass. From the 265 patients included, 98 % of plasma samples, 89 % of macrophages cultures and 40 % of smooth muscle cells cultures were obtained to compare proteomes between aneurismal and non-aneurismal patients. First, every AAA patient was matched to three non-AAA, according to their age, tobacco consumption, arterial hypertension, diabetes and dyslipidemia. Then, according to this classification, the biological and clinical data of the CORONA sample set, composed of 68 plasma samples from 17 AAA and 51 non-AAA bypass patients, were analyzed by exact nonparametric inference tests using StatXact.8 software. Next, proteomic analysis of plasma samples by a powerful data independent mass spectrometry method was performed in order to obtain qualitative as well as quantitative information. The results obtained in the statistical analysis showed that there are not important significant differences in the biological and clinical characteristics between both groups of patients, suggesting that the potential biomarkers found in the proteomic analysis will be more specific for AAA than in the case that control samples were from completely healthy patients. Regarding plasma proteome analysis, around 1000 plasma proteins were identified with false positive discovery rate < 1 %. From identified proteins, one third are multiple hits (at least 2 peptides per protein were identified), and from those around 75 proteins might be involved in AAA pathology (matrix proteins, proteases and inflammation proteins). The quantification of these proteins is still under work.Le texte complet de cet article est disponible en PDF.