Paradoxical Roles of the Neutrophil in Sepsis: Protective and Deleterious

Fabiane Sônego, Fernanda Vargas e Silva Castanheira, Raphael Gomes Ferreira, Alexandre Kanashiro, Caio Abner Vitorino Gonçalves Leite, Daniele Carvalho Nascimento, David Fernando Colón, Vanessa de Fátima Borges, José Carlos Alves-Filho, Fernando Queiróz Cunha

Sepsis, an overwhelming inflammatory response syndrome secondary to infection, is one of the costliest and deadliest medical conditions worldwide. Neutrophils are classically considered to be essential players in the host defense against invading pathogens. However, several investigations have shown that impairment of neutrophil migration to the site of infection, also referred to as neutrophil paralysis, occurs during severe sepsis, resulting in an inability of the host to contain and eliminate the infection. On the other hand, the neutrophil antibacterial arsenal contributes to tissue damage and the development of organ dysfunction during sepsis. In this review, we provide an overview of the main events in which neutrophils play a beneficial or deleterious role in the outcome of sepsis.