Cytokine pattern in aneurysmal and occlusive disease of the aorta.

BACKGROUND: Prominent inflammatory infiltrates of macrophages and T-lymphocytes are found in both aortic occlusive disease (AOD) and abdominal aortic aneurysms (AAA). These cells secrete different cytokines that might affect matrix turnover through modulation of matrix metalloproteinase expression. A different cytokine pattern might account for the evolution of AOD vs AAA. MATERIALS AND METHODS: Six different cytokines were examined to determine whether AOD and AAA could be characterized by unique cytokine patterns. AOD (n = 8) and AAA (n = 8) tissues were collected and serially treated with salt, dimethyl sulfoxide, and urea buffers to extract the soluble matrix or cell-bound cytokines. Levels of IL-1 beta, TNF-alpha, IL-10, IL-12, and IFN-gamma were measured by immunoenzymatic methods. Additionally, RNA levels of IL-12 and IFN-gamma were measured. RESULTS: AAA tissue contained higher levels of IL-10 compared to AOD tissue (P < 0.05). Higher levels of the proinflammatory cytokines IL-1 beta, TNF-alpha, and IL-6 were found in AOD (P < 0.05). mRNA levels of IL-12 and IFN-gamma did not differ between the diseases. Aortic tissues contained large amounts of matrix or cell-bound cytokines. CONCLUSIONS: AAA is characterized by greater levels of IL-10 while IL-1 beta, TNF-alpha, and IL-6 are higher in AOD. Targeted deletion of these cytokines in animal models might help in identifying their role in the progression of AAA.