The interplay between neutrophils, complement, and microthrombi in COVID-19

As of the end of 2020, coronavirus disease 2019 (COVID-19) remains a global healthcare challenge with alarming death tolls. In the absence of targeted therapies, supportive care continues to be the mainstay of treatment. The hallmark of severe COVID-19 is a thromboinflammatory storm driven by innate immune responses. This manifests clinically as acute respiratory distress syndrome, and in some patients, widespread thrombotic microangiopathy. Neutrophils and complement are key players in the innate immune system, and their role in perpetuating fatal severe COVID-19 continues to receive increasing attention. Here, we review the interplay between neutrophils, neutrophil extracellular traps, and complement in COVID-19 immunopathology, and highlight potential therapeutic strategies to combat these pathways. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

COVID-19 continues to pose a global healthcare challenge with supportive care being the mainstay of treatment due to the lack of targeted therapies. Severe cases are characterized by a thromboinflammatory storm driven by innate immune responses, with neutrophils and complement playing key roles in perpetuating fatal outcomes, warranting increased attention for potential therapeutic strategies.