Procalcitonin in acute infections: from the research laboratory to clinical impact—new perspectives of biomarker use

Procalcitonin (PCT) is a plasma polypeptide prohormone biomarker that helps distinguish bacterial infection from other causes of infection or inflammation. Several randomized controlled trials have investigated the role of PCT in acute infections. The aim of this review is to give an overview of the PCT biology, the background for using PCT as a biomarker and to summarize the current evidence for clinically applicable strategies for PCT-guided management in acute infections. We reviewed articles concerning PCT as a biomarker of acute infections, including this role in sepsis diagnosis, estimating the risk of bacteremia, treatment guidance in acute infections in critically ill patients and PCT for antibiotic reduction in acute respiratory infections and sepsis. PCT is effective for guidance of antibiotic discontinuation in acute infections. This is particularly well-documented (evidence level 1A) in acute respiratory infections and sepsis patients. PCT does not seem to help in diagnosing sepsis or when initiating antibiotics in critically ill patients. PCT is a thoroughly investigated biomarker that offers some so far unparalleled advantages in antibiotic reduction in acute infections, compared to other biomarkers, but this biomarker should probably not be used systematically for diagnostics.