Increased D-dimers at admission of COVID-19 infected patients entering hospital due to a severe disease is a risk factor for death. Understanding this acquired coagulopathy is a prerequisite before specific interventional studies. The study investigators aim to apply a normalized and automated thrombin generation test (TGT), developed for testing the thrombotic risk (triggered by 5 pM Tissue Factor, with a purified thrombomodulin (TM) challenge) and to study its association with survival.

Accumulating data describe, in COVID-19 severely infected patients necessitating hospitalized medical support, the development of an acquired coagulopathy, from a sepsis-induced coagulopathy to an overt-DIC, which is a strong risk factor for death. Understanding this coagulopathy is a prerequisite before specific interventional studies. Conventional coagulation tests, like prothrombin time PT and aPTT, only reflect 5% of the total thrombin generation and are insensitive to the patients' natural anticoagulants. The investigators thus wish to analyze the coagulopathy of SARS-CoV-2 using a global analytical test reflecting the full complexity of thrombin generation then inhibition, the thrombin generation test (TGT), in its version designed to analyze the thrombotic risk (initiation by an intermediate concentration of human Tissue: 5 pM), in its fully automated and standardized technical version. This test analyzes not only the generation of thrombin and its various informative phases (initiation phase, propagation phase culminating at the peak of formation, inhibition phase with natural anticoagulants) but also the capacity for an exogenous addition of purified thrombomodulin (TM), which quantifies the anticoagulant activity of the patient's protein C activated by thrombin, to inhibit this generation of thrombin.

The aim is to assay this TGT version in a centralized way, on the patients' plasma obtained at hospital admission, just after checking the positive COVID-19 testing , together with the traditional blood tests including platelet counts, PT, D-dimers (DDi) and soluble fibrin monomers (FMs). The various quantitative biological parameters describing the results of the TGT assay, together with relevant covariates, will be tested using multivariate analysis for their capacity to be risk factors for clinically-relevant qualitative outcomes.

Inclusion Criteria:

• Patient with SARS-CoV-2 infection entering hospitalization with or without resuscitation
• The patient (or their carer) must have given their free and informed consent and signed the consent form
• The patient must be a member or beneficiary of a health insurance plan

Exclusion Criteria:

• Pregnant or breastfeeding patient
• It is impossible to give the subject informed information
• The patient is under safeguard of justice or state guardianship
• Thrombotic events during treatment: flare-up of venous thromboembolism, flare-up of atherothrombosis.
• Long-term anticoagulant treatment (anti-vitamin K, direct oral anticoagulant).
• Chronic anti-aggregation treatment.
• Pre-existing constitutive or acquired known coagulation pathology: hemorrhagic diseases (thrombocytopenia, thrombocytopathy, hemophilia, von Willebrand's disease, hemorrhagiparous factor deficiency), and for thrombophilia (deficits in antithrombin, protein C or S , Factor V Leiden or Prothrombin 20201A mutation).

Consecutive patients hospitalized for SARS-CoV-2 infection with symptomatology / severity requiring hospital treatment.