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

SummaryObjectivesWe evaluated the value of a single biomarker, biomarker panels, biomarkers combined with clinical signs of sepsis, and serial determinations of biomarkers in the prediction of bacteremia in patients with sepsis.MethodsAdult patients visiting the emergency department because of a suspected infection with at least two of the following symptoms: temperature >38.3 °C or <36 °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.ResultsOf 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.ConclusionsThe 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.