Abstract: Sepsis is complicated with dysregulation of immune system to infection, which may lead to life-threatening dysfunction of organs. In the presence of infections, pathogen-associated molecular patterns (PAMPs) initiate inflammatory responses to clear the pathogens, but hyper-activated responses of the immune system may injure the host cells and organs. Damage-associated molecules released by the injured cells amplify the inflammatory responses and may progress to develop a cytokine storm through the damage-associated molecular patterns (DAMPs) pathway. In sepsis, neutrophils shift from potent antimicrobial protectors to destructive mediators to tissues and organs. Blood purification removes the inflammatory mediators as well as the immune cells with adverse functions, and becomes an important approach for the treatment of sepsis. Here we summarize the roles of lipopolysaccharides, cytokines, DAMPs and neutrophils in the pathogenesis of sepsis. We also introduce a series of blood purification methods and their clinical trials targeting the clearance of endotoxins, cytokines, and immune cells at the upstream of inflammatory cascade in sepsis.

Key words: Sepsis, Blood purification, Adsorption, Inflammation, Neutrophils, Immune-modulating blood purification system