Septic shock is the most severe form of a bacterial infection, affecting 24 million patients per year worldwide, with a high mortality (> 30%).

Septic shock is defined by an acute circulatory failure, with low blood pressure and insufficient oxygen supply to organs. This circulatory failure is related to vascular damages, in which the endothelial vascular tissue is impaired by inflammatory mechanisms, with release of circulating endothelial cells in the blood.

Therefore, modulating inflammation on the vascular endothelial tissue could be a therapeutic strategy, and the investigators focus on the role of the type I interferons on the endothelial tissue because of the demonstrated role of type I interferons during septic shock.

Thus the investigators proceed to an observational study, in which the primary purpose will be to show a higher expression of type I interferon receptors on circulating endothelial cells in patients with septic shock compared to control subjects.

Concerning secondary purposes, the investigators will record mortality at d3, d7 and d28, perform assays about types I, II and III interferons in plasma, and test anti-interferon on endothelial cells ex vivo

• For all subjects
• Age > 18 years old
• For females: negative pregnancy test
• Subject covered by health insurance
• Written consent
• Patients with septic shock
• Patients must be in ICU
• Septic shock defined by the Sepsis-3 criteria [1]
• Inclusion within the 12 hours following the onset of norepinephrin
• Controls :
• Blood donors

Exclusion criteria:

• Moribund
• Age < 18 years old
• Absence of written consent

The study population will have two groups :

1. Patients with septic shock hospitalized in the ICU from Strasbourg University Hospital
2. Controls: blood donors recruited by the French blood establishment