Enhanced tumor necrosis factor- alpha expression in small sized abdominal aortic aneurysms

Area of Science:

• Cardiovascular Biology
• Immunology
• Vascular Surgery

Background:

• Elevated circulating tumor necrosis factor alpha (TNF-alpha) is observed in patients with abdominal aortic aneurysm (AAA).
• Understanding TNF-alpha expression and cellular infiltration within AAA walls is crucial for disease progression insights.

Purpose of the Study:

• To investigate the expression of TNF-alpha and cellular infiltration in AAA walls across different aneurysm sizes.
• To determine the relationship between AAA size, TNF-alpha levels, and inflammatory cell presence.

Main Methods:

• Surgical AAA specimens (n=27) were categorized into small (<50 mm), medium (50-59 mm), and large (>59 mm) diameter groups.
• Enzyme-linked immunosorbent assay (ELISA) measured TNF-alpha and interleukin-1 beta (IL-1 beta) levels in aneurysm walls.
• Immunohistochemical staining assessed TNF-alpha expression and macrophage/lymphocyte infiltration.

Main Results:

• TNF-alpha levels were significantly higher in the small AAA group compared to medium and large groups (p < 0.05).
• IL-1 beta levels did not differ significantly across size groups.
• Strong TNF-alpha expression was observed in small AAAs, particularly in areas with atheromatous changes and macrophage infiltration; expression was weak/negative in larger AAAs.

Conclusions:

• TNF-alpha expression is enhanced in the walls of small abdominal aortic aneurysms.
• This heightened TNF-alpha expression may be associated with macrophage infiltration, suggesting a role in early AAA development or progression.