Serial and panel analyses of biomarkers do not improve the prediction of bacteremia compared to one procalcitonin measurement

Objectives: We evaluated the value of a single biomarker, biomarker panels, bio-markers combined with clinical signs of sepsis, and serial determinations of biomarkers in the prediction of bacteremia in patients with sepsis. Methods: Adult patients visiting the emergency department because of a suspected infection with at least two of the following symptoms: temperature >38.3 degrees C or <36 degrees C, heart rate >90/min, respiratory rate >20/min, chills, altered mental status, systolic blood pressure <90 mmHg, MAP <65 mmHg, and hyperglycemia in the absence of diabetes mellitus were included. Procalcitonin (PCT), interleukin-6 (IL-6), lipopolysaccharide-binding protein (LBP), C-reactive protein (CRP) were measured, and two blood cultures were taken. The analyses included: (1) determination of the biomarker with the highest predictive value for bacteremia and to examine the predictive value of this biomarker in combination with other biomarkers; (2) analysis of the best biomarker data in combination with clinical signs of sepsis; and (3) analysis of serial determinations of the best biomarker. Results: Of 342 included patients, PCT had the best predictive value for bacteremia with an area under the curve of 0.80, sensitivity 89%, specificity 58%. The predictive value of a combination of PCT plus a panel of other biomarkers, clinical signs, or analysis of serial PCT levels did not lead to a significant improvement of the predictive value of PCT alone. Conclusions: The ability of PCT to predict bacteremia in patients with sepsis does not further improve when combined with IL-6, LBP, CRP, clinical signs, or serial measurements. Naturally, this does not exclude that a panel of other biomarkers may lead to different results. (C) 2012 The British Infection Association. Published by Elsevier Ltd. All rights reserved.