A biomarker panel of C-reactive protein, procalcitonin and serum amyloid A is a predictor of sepsis in severe trauma patients: a case control study

Abstract

Abstract Background Severe trauma could induce sepsis due to the loss of control of the infection, which may eventually lead to death. Accurate and timely diagnosis of sepsis with severe trauma remains challenging both for clinician and laboratory. Combinations of markers, as opposed to single ones, may improve diagnosis. We therefore compared the diagnostic characteristics of routinely used biomarkers of sepsis alone and in combination, trying to define a biomarker panel to predict sepsis in severe patients. Methods This prospective observational study included patients with severe trauma(ISS 16 or more) in the EICU at a university hospital. Blood samples were collected at 8 a.m. every day after admission to the EICU, until the day included patients were transferred out of EICU. Plasma levels of PCT, CRP, IL-6 and SAA were measured using commercial ELISA kits. Receiver operating characteristic (ROC) curves were used to evaluate the ability of the biomarkers to identify the possibility of sepsis in the enrolled patients. Logistic regression models were used to identify independent risk factors for sepsis. Results A total of 100 patients were eligible for analysis. Of these, 52 were diagnosed with sepsis. CRP yielded the highest discriminative value with an area under the ROC curve (AUC) of 0.82 (82% confidence interval [CI], 0.73–0.91; P<0.001), followed by PCT (AUC 0.77 [0.68–0.86]; P<0.001). Whereas, in multiple logistic regression, SAA, CRP, and PCT were found to be independent predictors of sepsis. Bioscore which was composed of SAA, CRP, and PCT, with AUC=0.89(95%CI, 0.82-0.95), cut-off=0.28, sensitivity=0.77, specificity=0.9, P<0.001, was shown to be far superior to that of each individual biomarker taken individually. Conclusions Compared with single markers, the biomarker panel of PCT, CRP, and SAA was more predictive of sepsis in severe polytrauma patients.