18F-FDG Uptake Assessed by PET/CT in Abdominal Aortic Aneurysms Is Associated with Cellular and Molecular Alterations Prefacing Wall Deterioration and Rupture.
Courtois, Audrey ; Richelle, Betty ; Hustinx, Roland et al
in Journal of Nuclear Medicine (The) (2013)
Rupture of abdominal aortic aneurysms (AAAs) leads to a significant morbidity and mortality in aging populations, and its prediction would be most beneficial to public health. Spots of positive uptake of ... [more ▼]
Rupture of abdominal aortic aneurysms (AAAs) leads to a significant morbidity and mortality in aging populations, and its prediction would be most beneficial to public health. Spots of positive uptake of 18F-FDG detected by PET are found in 12% of AAA patients (PET+), who are most often symptomatic and at high rupture risk. Comparing the 18F-FDG-positive site with a negative site from the same aneurysm and with samples collected from AAA patients with no 18F-FDG uptake should allow the discrimination of biologic alterations that would help in identifying markers predictive of rupture. METHODS: Biopsies of the AAA wall were obtained from patients with no 18F-FDG uptake (PET0, n = 10) and from PET+ patients (n = 8), both at the site of positive uptake and at a distant negative site of the aneurysmal wall. Samples were analyzed by immunohistochemistry, quantitative real-time polymerase chain reaction, and zymography. RESULTS: The sites of the aneurysmal wall with a positive 18F-FDG uptake were characterized by a strikingly increased number of adventitial inflammatory cells, highly proliferative, and by a drastic reduction of smooth muscle cells (SMCs) in the media as compared with their negative counterpart and with the PET0 wall. The expression of a series of genes involved in the maintenance and remodeling of the wall was significantly modified in the negative sites of PET+, compared with the PET0 wall, suggesting a systemic alteration of the aneurysmal wall. Furthermore, a striking increase of several matrix metalloproteinases (MMPs), notably the MMP1 and MMP13 collagenases, was observed in the positive sites, mainly in the adventitia. Moreover, PET+ patients were characterized by a higher circulating C-reactive protein. CONCLUSION: Positive 18F-FDG uptake in the aneurysmal wall is associated with an active inflammatory process characterized by a dense infiltrate of proliferating leukocytes in the adventitia and an increased circulating C-reactive protein. Moreover, a loss of SMC in the media and alterations of the expression of genes involved in the remodeling of adventitia and collagen degradation potentially participate in the weakening of the aneurysmal wall preceding rupture. [less ▲]Detailed reference viewed: 37 (16 ULg)
Dissection of Iliac Artery in a Patient With Autosomal Dominant Polycystic Kidney Disease
Courtois, Audrey ; Nusgens, Betty ; DELVENNE, Philippe et al
in AORTA (2013), 1(2), 123-125Detailed reference viewed: 14 (3 ULg)
Increased metabolic activity highlighted by positron emission tomography/computed tomography in the wall of the dissected ascending aorta in a patient with Horton disease.
; Courtois, Audrey ; et al
in Circulation: Cardiovascular Imaging (2013), 6(4), 606-8Detailed reference viewed: 14 (4 ULg)
Uptake of 18-FDG as detected by positron emission tomography is correlated to an increased inflammatory infiltrate and expression of proteolytic enzymes in abdominal aortic aneurysm wall
COURTOIS, Audrey ; Nusgens, Betty ; Defraigne, Jean-Olivier et al
Poster (2011)Detailed reference viewed: 14 (5 ULg)