Sepsis is a life-threating organ dysfunction resulting from the dysregulated response of the host to an infection. It is estimated that 1.5 million people present with sepsis annually in Northern America and another 1.5 million people in Europe; 30 to 50% of them die making sepsis the leading cause of death. The key-point in the management of sepsis is the early resuscitation with broad-spectrum antimicrobials and intravenous fluids, if possible within the first hour. The great mortality of sepsis indicates that this goal is not easy to be achieved for two main reasons: the first is the delay in recognition of the septic patients and the second is the resistance of the implicated pathogen to broad-spectrum antimicrobials.

In an attempt to improve the failure of physicians for early sepsis recognition, several markers have been developed. Some of them rely on clinical signs of the host and others on the measurements of circulating biomarkers. Recently, qSOFA (quick SOFA score) has been introduced to help the early recognition of sepsis in patients who present with infection outside the Intensive care Unit (ICU) i.e. either in the community or during hospitalization in the general ward1. However, there are concerns of the sensitivity of qSOFA and many introduce the need to measure biomarkers in serum. These biomarkers are usually protein molecules that are over-produced in the host as a result of the interaction with an infective insult. However, these protein molecules are produced by white blood cells. What is currently known is that although most of patients present with a similar phenotype, their pathophysiology is diverse. More precisely, although the majority of patients with sepsis present with high concentrations of protein molecules like interleukin (IL)-6, C-reactive protein (CRP) and procalcitonin (PCT) in their blood, in some patients circulating white blood cells remain over-active and in other patients they are significantly anergic, a situation often known as sepsis-induced immunoparalysis. Another molecule, called soluble urokinase plasminogen activator receptor (suPAR), is the shed uPAR receptor on neutrophils and is released in the circulation as a result of neutrophil activation; concentrations greater than 12 ng/ml can trace with negative predictive value almost 95% the patient at great chance of unfavorable outcome. As such, the robust diagnosis of sepsis may rely on a combination of clinical assessment, measurement of protein biomarkers and validation of the activity of circulating white blood cells.

One FrameWork 7-funded initiative from seven European countries aims to develop a rapid score that can integrate all clinical and laboratory information and provide early diagnosis whether a patient has sepsis or not. The vision of this initiative is to build a device that is called HemoSpec. With this approach, whole blood coming from patients will be in parallel analyzed into three aspects: a) absolute white blood cell counting; b) information on the fluidity and activity of the white blood cells using Raman spectroscopy; and c) measurement of serum levels of IL-6, CRP, PCT and suPAR. The end result is building a diagnostic algorithm where clinical information is also taken into consideration.

The project was started in November 2013 and the HemoSpec device is anticipated to be ready by February 2017. The diagnostic performance of HemoSpec is currently based on preliminary data coming from 60 patients (20 controls, 20 with systemic inflammatory response syndrome and 20 with sepsis) hospitalized in Jena University Hospital. The current study is aiming to validate and improve performance of HemoSpec for the rapid assessment of the critically ill patient in a larger phase II diagnostic study.