This is a comparative study performed in 3 groups of patients/subjects: 30 severe sepsis patients, 30 non-septic patients with organ failure, 30 healthy subjects.

The only intervention is a venous blood sampling at the onset of the disease.

The purpose of the study is to compare the PC pathway and expression and inflammatory genes between the 3 groups. The main hypothesis is that systemic inflammatory response and exacerbated coagulation activation are non specific of an infection as a triggering event.

analysis of the PC pathway

• PC activity
• PS activity
• soluble thrombomodulin
• soluble EPCR
• activated protein C
• quantitative flow cytometry on monocytes (thrombomodulin and EPCR)
• whole blood mRNA (Tissue factor, thrombomodulin and EPCR)
• inflammatory gene expression analysis by MLPA

Inclusion Criteria:

• severe sepsis patients or:
• non-septic acute organ failure patients or:
• healthy subjects matched for age and sex with severe sepsis patients

Exclusion Criteria:

• criteria for organ failure lasting for more than 24 hours