Abstract
The respiratory tract is the major site of infection by SARS-CoV-2, the virus causing COVID-19. The pulmonary infection can lead to acute respiratory distress syndrome (ARDS) and ultimately, death. An excessive innate immune response plays a major role in the development of ARDS in COVID-19 patients. In this scenario, activation of lung epithelia and resident macrophages by the virus results in local cytokine production and recruitment of neutrophils. Activated neutrophils extrude a web of DNA-based cytoplasmic material containing antimicrobials referred to as neutrophil extracellular traps (NETs). While NETs are a defensive strategy against invading microbes, they can also serve as a nidus for accumulation of activated platelets and coagulation factors, forming thrombi. This immunothrombosis can result in occlusion of blood vessels leading to ischemic damage. Herein we address evidence in favor of a lung-centric immunothrombosis and suggest a lung-centric therapeutic approach to the ARDS of COVID-19.
Highlights
SARS-CoV-2, the coronavirus responsible for COVID-19, initially infects the nasal, bronchial and alveolar epithelial cells (Hoffmann et al, 2020; Milewska et al, 2020; Zhu et al, 2020)
There is a notable trend for higher levels of inflammatory cytokines in BALF than plasma of acute respiratory distress syndrome (ARDS)
“cytokine storm” has been used as a descriptor of the hyperinflammatory response involved in the pathogenesis of COVID-19 (Barnes et al, 2020; Castelli et al, 2020; Fajgenbaum and June, 2020; Mehta et al, 2020; Merad and Martin, 2020; Tay et al, 2020)
Summary
The respiratory tract is the major site of infection by SARS-CoV-2, the virus causing. An excessive innate immune response plays a major role in the development of ARDS in COVID-19 patients. In this scenario, activation of lung epithelia and resident macrophages by the virus results in local cytokine production and recruitment of neutrophils. While NETs are a defensive strategy against invading microbes, they can serve as a nidus for accumulation of activated platelets and coagulation factors, forming thrombi. This immunothrombosis can result in occlusion of blood vessels leading to ischemic damage.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
