The Roles of Procalcitonin, C-Reactive Protein and Erythrocyte Sedimentation Rate in Predicting Bacteremia

Abstract

Background and objectives: The early differentiation between infectious and non-infectious sepsis remains a challenge due to the lack of a reliable, ready available and quick biomarker of bacterial sepsis. This study aims to determine the diagnostic accuracies of procalcitonin (PCT), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) as individual and combined predictors of bacterial sepsis, when compared to the gold standard microbiological cultures. Patients and methods: Forty-three patients were included in this study, provided they fulfilled the criteria established by ACCP/SCCM consensus conference for systemic inflammatory response syndrome (SIRS) and sepsis. The primary outcome was to determine the best predictor of bacteremia. The diagnostic accuracies of PCT, CRP and ESR, individually and in combinations were calculated. Results: Among 43 patients, 27 yielded positive blood cultures. Procalcitonin, CRP and ESR, individually, were able to predict 74.1% (95% CI; 0.553 to 0.868), 66.7% (95% CI; 0.478 to 0.814) and 70.4% (95% CI; 0.515 to 0.842), of positive blood cultures, respectively. In comparison, interpreting PCT & CRP, PCT & ESR and PCT, CRP & ESR in combinations were able to predict 51.9% (95% CI; 0.340 to 0.693), 59.3% (95% CI; 0.407 to 0.755), 37.0% (95% CI; 0.215 to 0.558). Conclusion: Procalcitonin, on its own, is the best predictor of bacteremia. Although PCT is an indispensible biomarker for the early prediction of bacteremia, careful evaluation of patients’ clinical status and other laboratory markers are also crucial.