This is an observational prospective multicentre study on patients attending the emergency department and suspected to have sepsis. Blood markers characteristic of a Cellular Reprogramming (CR) signature and predicting severe sepsis and organ failure will be measured and validated.

Sepsis is a life-threatening medical condition caused by an infection and the complex and dysfunctional way by which the human body attempts to deal with it. It can affect people of all ages, causing 18-30 million cases and 5-8 million deaths annually worldwide. However, early diagnosis of sepsis is challenging due to the diversity and overlap of symptoms with other disorders and the lack of an early and accurate diagnostic method. Hancock and colleagues defined a gene expression signature characteristic of biological changes occurring during sepsis, known as cellular reprogramming (CR) and reflecting a type of immune amnesia (inability to respond to bacterial signals). This signature was shown to predict the development of sepsis and organ failure at first clinical presentation in the emergency room, by examining patient blood samples taken during an initial pilot single-center study.

This project will validate and refine the CR signature and demonstrate reproducibility, specificity, and sensitivity in a larger multi-center study to enable a new strategy to predict Sepsis.

Inclusion Criteria:

• Male or female
• Presenting to the Emergency Department
• Attending physician suspects possible sepsis based on at least 2 sign of Systemic inflammatory response syndrome (SIRS) criteria and suspicion of infection

Exclusion Criteria:

• Patient is terminal (death anticipated in 12 hours)
• Informed consent unobtainable if the subject survives to hospital discharge.
• Subjects who are unable to provide blood as a standard of care.
• Blood sample could not be taken within 24 hours of a physician's first contact with the patient.

Patients suspected of sepsis will be recruited at the emergency department of participating institutions.

The RNA-Seq data will be uploaded to Geo database when the study is complete or upon publication and will be freely available to researchers.