MPO and atherosclerosis: Neutrophils mediate inflammatory reactions through a variety of biochemical mechanisms, such as promoting platelet aggregation and adhesion, secreting inflammatory mediators, and releasing arachidonic acid derivatives, cytotoxic oxygen free radicals and proteolytic enzymes (including myeloperoxidase, elastase and acid phosphatase) to make plaque more vulnerable, which is positively related to atherosclerosis burden and ischemic status (40).