Procalcitonin and Other Biomarkers for the Assessment of Disease Severity and Guidance of Treatment in Bacterial Infections

The ambiguities of clinical signs and the limitations of current microbial techniques for the diagnosis of bacterial infections - and to grade their severity – are well known. The use of biomarkers provides a novel, complementary approach to diagnose infection, and to estimate treatment response and the outcome of patients. In most infections, a true “gold standard” for diagnosis does not exist, thus the measurement of biomarkers, specifically the “hormokine” procalcitonin (PCT) in a clearly defined setting, has been shown to significantly improve the diagnostic certainty and also to reduce the utilization of antimicrobial therapy. For prognostic assessment, other promising biomarkers (e.g. adrenomedullin) have demonstrated high predictive potential to estimate the risk for mortality in the short and long term, and other adverse outcomes. A critical
appraisal of the advantages and limitations of biomarkers in different clinical situations is mandatory. Herein, the present authors discuss the current data on the use of PCT and other biomarkers for the diagnosis, treatment guidance, and prognostic assessment of bacterial infections, and their potential role in the overall assessment of patients with sepsis.