Peripheral polymorphonuclear leukocyte activation as a systemic inflammatory response in ischemic stroke

Stroke is one of the leading causes of mortality and morbidity in the world. The activation of polymorphonuclear leukocytes (PMNL) plays an important role in the inflammatory response after ischemic stroke. However, in the current literature, there are few studies discussing the process and role of peripheral PMNL activation. Here, we give a comprehensive description of peripheral PMNL activation after ischemic stroke and discuss their potential roles in the process of ischemic injury. Based on our analysis, peripheral PMNL activation is supposed to be attributed to systemic inflammatory response to cerebral ischemic insult, not reflecting the activity of PMNL in local ischemic brain. Inhibiting peripheral PMNL activation in stroke animals has been effective in reducing infarction and improving behavioral outcome; thus, the same approach of inhibiting peripheral PMNL activation is a promising therapeutic strategy for stroke patients.