Severe Acute Respiratory Syndrome-Corona Virus-2 infection results in a mild infection in most of the patients. However, 15-20% require hospitalization, and among them, 15-20% will develop acute respiratory failure, leading to their admission in Intensive Care Unit. There are no accepted predictive criteria for aggravation. Severe forms of Coronavirus induced disease-19 (COVID-19) are the consequence of endotheliopathy, and hyperinflammatory and pro-coagulant state. The Triggering Receptor Expressed on Myeloid cells-1 (TREM-1) is an immunoreceptor that acts as an amplifier of the inflammatory response. TREM-1 is expressed on myeloid and endothelial cells. Its activation leads to endothelial activation and damage, hyperinflammatory, and pro-coagulant state. TREM-1 activation is associated with poor outcome during septic shock and myocardial infarction. We here aim at investigating the relationship between TREM-1 pathway activation and clinical degradation and outcome of COVID-19 hospitalized patients.