Abstract
The objective of this study was to assess the diagnostic accuracy of C-reactive protein (CRP), procalcitonin (PCT), and cellular immune markers levels in sepsis. This was a prospective observational study in adult intensive care unit (ICU) patients, between 2012 and 2014. The 8-color flow cytometric biomarker panel included CD64, CD163, and HLA-DR. Index test results were compared with sepsis, using receiver operating characteristic curve analyses. Multivariate logistic regression assessed the relationship of sets of markers with the probability of sepsis. Of 219 enrolled patients, 120 had sepsis. C-statistic was the highest for CRP (0.86) followed by neutrophil CD64 expression (0.83), procalcitonin (0.82), and Acute Physiology and Chronic Health Evaluation (APACHE) IV (0.72). After adjustment for APACHE IV, the combination of CRP, PCT, and neutrophil CD64 measure remained a significant predictor of sepsis with an excellent AUC (0.90). In a targeted ICU population at increased risk of sepsis, CRP, PCT, and neutrophil CD64 combined improve the diagnostic accuracy of sepsis.