Sepsis is a life threatening disease causing millions of deaths worldwide every year [1-7]. It is caused by the systemic immune response after a severe infection, more often from bacteria, but also from fungi, viruses and parasites [3, 8]. The definition of sepsis which includes SIRS+ proofs or suspicions of an infection, can be very wide and includes a lot of patients that does not have to develop sepsis [2, 6, 9]. During sepsis, the microorganisms invade to the bloodstream, and directly proliferate locally and release various virulent factors into the bloodstream [3, 10, 11]. In the diagnostic process of identifying an infection, one of the most important steps is the analysis of laboratory biomarkers of infection. The biomarkers, such as, white blood cell count (WBC), erythrocyte sedimentation rate (ESR), reactive C-protein (CRP) and procalcitonin (PCT) can be used to help in the diagnosis, therapeutic monitoring and the risk classification. However, these blood parameters are not sensible or specific in the differentiation of an inflammation caused by a bacterial infection, from that caused as a response to a surgical damage. WBC, CRP and interleukin-1 (IL-1) are conventional markers used for the diagnosis of sepsis [5, 6, 12-14]. In this context, serum procalcitonin (PCT) has been a sensible biomarker that provides information for the prognosis in the patients with infections and so can improve the management of sepsis [5]. Compared to CRP, PCT has better