Sepsis diagnosis and monitoring – procalcitonin as standard, but what next?

Sepsis is defined as a life-threatening organ dysfunction caused by an altered host response to infection and is a worldwide major health problem with high morbidity and mortality.It is highlighted that sepsis is a syndrome shaped by pathogen and host factors, characteristically changing over time, with diverse etiology, severity and prognosis [1].Early diagnosis and appropriate management are the most important factors influencing sepsis survival rate in the intensive care unit (ICU).The newest definitions of sepsis/septic shock do not indicate any gold standard biomarker for sepsis diagnosis and monitoring but the heterogeneity of the septic patient population suggests that multiple biomarkers should be used to evaluate the dynamics of sepsis, therapy effectiveness and finally improve the outcomes [2].Many biomarkers implicated in clinical practice are not sufficiently specific to differentiate sepsis from other non-infectious and inflammatory disorders.The commonly used biomarkers, such as procalcitonin (PCT), C-reactive protein (CRP) and interleukin (IL)-6, with different timing of release, present limited sensitivity and specificity [3].Procalcitonin is a prohormone of calcitonin and in healthy individuals PCT is produced in thyroid C cells, from a calcitonin gene-related peptide I (CALC-1) located on chromosome 11.The mRNA product is known as preprocalcitonin.It is further modified to 116-amino acid procalcitonin, and all the PCT formed in thyroid C cells is converted to calcitonin,