Christoph Neumayer
Medical Uiniversity Vienna, Austria
Biography
Abstract
Neutrophil extracellular cells have emerged to be more important in their role of inflammatory responses than phagocytic actions. Recent publications showed neutrophils to be involved in the activation of the IL-1 family and subsequent distribution of neutrophil proteases to the inflammatory site. The abdominal aortic aneurysm (AAA) is considered a chronic inflammatory disease with neutrophils recruited to the aneurysm site and intraluminal thombus, releasing neutrophil proteases and reactive oxygen species, which contribute to media destruction. D-Dimer and myeloperoxidase, distinctive neutrophil proteases have evolved as potential sensitive AAA markers, supporting the hypothesis of neutrophils to be key players in AAA pathogenesis. During the recruitment of neutrophils to the aneurysm site and intraluminal thrombus, activated neutrophils may undergo the process of NETosis, which involves histone modification by citrullination, allowing the DNA to be condensated and subsequent DNA and sticky traps release into the extracellular space. These NETs are recently discussed to be a potential biomarker in AAA pathogenesis. NETs were found in AAA mouse model and its inhibition prevented AAA development. Furthermore, anti-inflammatory treatment such as metformin in diabetic patients was associated with reduced AAA growth. The potential therapeutic approach of metformin in systemic lupus erythematodous could already be elucidated by reduced inflammatory skin flares through reduced NET formation. In summary, neutrophils, neutrophil proteases and NETs are intensively discussed as potential biomarkers in AAA, this lecture will give an overview of all recent findings on neutrophils and their products in AAA.