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

Area of Science:

• Immunology
• Infectious Diseases
• Pathology

Background:

• Coronavirus disease 2019 (COVID-19) presents a significant global health burden.
• Severe COVID-19 is characterized by a thromboinflammatory response, involving innate immunity.
• Current treatments primarily focus on supportive care due to a lack of targeted therapies.

Purpose of the Study:

• To review the complex interplay between neutrophils, neutrophil extracellular traps (NETs), and complement in COVID-19 immunopathology.
• To highlight potential therapeutic strategies targeting these innate immune pathways in severe COVID-19.

Main Methods:

• Literature review focusing on the roles of neutrophils, NETs, and complement in COVID-19.
• Analysis of clinical manifestations such as acute respiratory distress syndrome and thrombotic microangiopathy.
• Synthesis of current understanding of COVID-19 immunopathology.

Main Results:

• Neutrophils and complement are identified as key drivers of the innate immune response in severe COVID-19.
• The formation of neutrophil extracellular traps (NETs) is implicated in the thromboinflammatory storm.
• These pathways contribute to severe clinical outcomes including ARDS and thrombotic microangiopathy.

Conclusions:

• The interplay of neutrophils, NETs, and complement is central to severe COVID-19 pathogenesis.
• Targeting these innate immune components offers promising therapeutic avenues.
• Further research into these pathways is essential for effective COVID-19 treatment strategies.