Diagnostic accuracy of soluble urokinase plasminogen activator receptor (suPAR) for prediction of bacteremia in patients with systemic inflammatory response syndrome

ObjectivesSoluble urokinase plasminogen activator receptor (suPAR) serum concentrations have recently been described to reflect the severity status of systemic inflammation. In this study, the diagnostic accuracy of suPAR, C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) to predict bacteremia in patients with systemic inflammatory response syndrome (SIRS) was compared.MethodsA total of 132 patients with SIRS were included. In 55 patients blood cultures had resulted positive (study group 1, Gram positive bacteria: Staphylococcus aureus and Streptococcus spp., n = 15; study group 2, Gram-negative bacteria, n = 40) and 77 patients had negative blood culture results (control group, n = 77). Simultaneously with blood cultures suPAR, CRP, PCT, IL-6 and white blood count (WBC) were determined.ResultsSuPAR values were significantly higher in study group 1 (median 8.11; IQR 5.78–15.53; p = 0.006) and study group 2 (median 9.62; IQR 6.52–11.74; p < 0.001) when compared with the control group (median 5.65; IQR 4.30–7.83). ROC curve analysis revealed an AUC of 0.726 for suPAR in differentiating SIRS patients with bacteremia from those without. The biomarkers PCT and IL-6 showed comparable results. Regarding combinations of biomarkers multiplying suPAR, PCT and IL-6 was most promising and resulted in an AUC value of 0.804. Initial suPAR serum concentrations were significantly higher (p = 0.028) in patients who died within 28 days than in those who survived. No significant difference was seen for PCT, IL-6 and CRP.ConclusionIn conclusion, suPAR, IL-6 and PCT may contribute to predicting bacteremia in SIRS patients.

► We evaluate sepsis markers in ER patients presenting with SIRS.
► We evaluate potential of biomarkers for prediction of bacteremia.
► SuPAR, PCT and IL-6 showed comparable AUC values (0.7) for prediction of bacteremia.
► Multiplying suPAR, PCT and IL-6 was promising and resulted in an AUC value of 0.804.
► SuPAR > 7.9 and PCT > 0.78 were significant predictors in multivariate analysis.