Abstract
Ankylosing spondylitis (AS) is a chronic inflammatory disease traditionally regarded as mediated by T lymphocytes. Recent progress has identified that cells of innate immunity are also important for the processes of inflammation and new bone formation, a hallmark of AS. Moreover, interleukin-17 (IL-17) is a cytokine implicated in both processes. Neutrophils are increasingly recognized as mediators of autoinflammatory and autoimmune diseases through several mechanisms, one being the release of neutrophil extracellular traps (NETs). NETs are equipped with an array of bioactive molecules, such as IL-1β or IL-17. It appears that the molecules expressed over NETs vary across different disorders, reflecting diverse pathophysiologic mechanisms. As few studies have investigated the role of neutrophils in AS, the purpose of this research protocol is to study whether neutrophils from AS patients are more likely to form NETs, whether IL-17 and IL-1β are expressed over those NETs and if NETs affect new bone formation.