MicroCLOTS pathophysiology in COVID 19.

Renzi, Samuele; Landoni, Giovanni; Zangrillo, Alberto; Ciceri, Fabio

Severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2) is the novel coronavirus responsible for the ongoing pandemic. It is known that SARS-CoV-2 infects the host through the cell surface receptor of angiotensin-converting enzyme 2 (ACE2), which is expressed in multiple organs, and in the arterial and venous endothelial cells. We have recently proposed the use of the term MicroCLOTS ( Microvascular COVID-19 lung vessels obstructive thromboinflammatory syndrome) to describe the unique type of ARDS seen in patients affected by SARS-COV-2. After a multidisciplinary assessment of more than 850 COVID-19 patients admitted to our Hospital with several bilateral pneumonia, we have collected evidences supporting a key role of vascular inflammation and microthrombosis in the pathophysiology of the multisystemic clinical manifestations that have been associated with COVID-19. There is now a general consensus on the recommendation of anticoagulation in patient with severe SARS-Cov2 infections, although the dose of the prophylaxis and even the choice between a prophylactic and a treatment regimen remains controversial. Randomized controlled trials are urgently needed to help clarifying the many therapeutic challenges associated with the management of SARS-Cov-2 patients.