Procalcitonin and the role of biomarkers in the diagnosis and management of sepsis.
ABSTRACT Sepsis and severe sepsis cause significant morbidity and mortality among populations worldwide; the rapid diagnosis poses a considerable challenge to physicians in acute care settings. An ideal biomarker should allow, with high diagnostic accuracy, for an early and rapid recognition of sepsis. Procalcitonin (PCT) is a recently rediscovered biomarker that fulfills many of these requirements, especially in comparison to "older" and commonly used biomarkers, and that has demonstrated superior diagnostic accuracy for a variety of infections, including sepsis. While blood cultures are still considered the "gold standard" for the diagnosis of bacteremia and sepsis, and are perhaps one of the most important functions of the clinical microbiology laboratory, PCT provides important information in early stages of sepsis as well as during antimicrobial treatment. In fact, PCT can be useful for antimicrobial stewardship and its utilization may safely lead to significant reduction of unnecessary antimicrobial therapy. However, PCT is also less than a universal and perfect biomarker, as it can also be increased in noninfectious disease conditions. Laboratories and clinicians must appreciate the complexity of diagnostic algorithms for sepsis and understand the particular information that biomarkers, such as PCT, can offer. In that context, it is necessary to not only recognize the importance of critical clinical awareness and thorough physical patient examination, but also to understand traditional microbiological methods and the need for highly sensitive biomarker assays in order to facilitate an early diagnosis and goal-directed therapy in patients suspected of sepsis. This review is intended to provide additional information for clinicians and microbiologists to better understand the physiology and diagnostic utility of procalcitonin for sepsis and other infectious disease conditions.
Article: Procalcitonin predicts real-time PCR results in blood samples from patients with suspected sepsis.[show abstract] [hide abstract]
ABSTRACT: Early diagnosis and rapid bacterial identification are of primary importance for outcome of septic patients. SeptiFast® (SF) real-time PCR assay is of potential utility in the etiological diagnosis of sepsis, but it cannot replace blood culture (BC) for routine use in clinical laboratory. Procalcitonin (PCT) is a marker of sepsis and can predict bacteremia in septic patients. The aim of the present study was to investigate whether PCT serum levels could predict SF results, and could help screening febrile patients in which a SF assay can improve the etiological diagnosis of sepsis. From 1009 febrile patients with suspected sepsis, 1009 samples for BC, SF real-time PCR, and PCT determination were obtained simultaneously, and results were compared and statistically analysed. Receiver operating characteristic (ROC) curves were generated to determine the area under the curve and to identify which cut-off of PCT value produced the best sensitivity to detect SF results. Mean PCT values of sera drawn simultaneously with samples SF positive (35.42±61.03 ng/ml) or BC positive (23.14±51.56 ng/ml) for a pathogen were statistically higher than those drawn simultaneously with SF negative (0.84±1.67 ng/ml) or BC negative (2.79±16.64 ng/ml) samples (p<0.0001). For SF, ROC analysis showed an area under the curve of 0.927 (95% confidence interval: 0.899-0.955, p<0.0001). The PCT cut-off value of 0.37 ng/ml showed a negative predictive value of 99%, reducing the number of SF assays of 53.9%, still identifying the 96.4% of the pathogens. PCT can be used in febrile patients with suspected sepsis to predict SF positive or negative results. A cut-off value of 0.37 ng/ml can be considered for optimal sensitivity, so that, in the routine laboratory activity, SF assay should not be used for diagnosis of sepsis in an unselected patient population with a PCT value <0.37 ng/ml.PLoS ONE 01/2012; 7(12):e53279. · 4.09 Impact Factor