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Journal of Immunology Research
Volume 2016 (2016), Article ID 3530752, 9 pages
Research Article

Delta Procalcitonin Is a Better Indicator of Infection Than Absolute Procalcitonin Values in Critically Ill Patients: A Prospective Observational Study

1Faculty of Medicine, Department of Anaesthesiology and Intensive Therapy, University of Szeged, 6 Semmelweis Street, Szeged 6725, Hungary
2Faculty of Medicine, Division of Infectious Diseases, First Department of Internal Medicine, University of Szeged, Szeged, Hungary
3Faculty of Medicine, Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary

Received 15 May 2016; Accepted 17 July 2016

Academic Editor: Roberta A. Diotti

Copyright © 2016 Domonkos Trásy et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Purpose. To investigate whether absolute value of procalcitonin (PCT) or the change (delta-PCT) is better indicator of infection in intensive care patients. Materials and Methods. Post hoc analysis of a prospective observational study. Patients with suspected new-onset infection were included in whom PCT, C-reactive protein (CRP), temperature, and leukocyte (WBC) values were measured on inclusion () and data were also available from the previous day (). Based on clinical and microbiological data, patients were grouped post hoc into infection- (I-) and noninfection- (NI-) groups. Results. Of the 114 patients, 85 (75%) had proven infection. PCT levels were similar at : I-group (median [interquartile range]): 1.04 [0.40–3.57] versus NI-group: 0.53 [0.16–1.68], . By PCT levels were significantly higher in the I-group: 4.62 [1.91–12.62] versus 1.12 [0.30–1.66], . The area under the curve to predict infection for absolute values of PCT was 0.64 [95% CI = 0.52–0.76], ; for percentage change: 0.77 [0.66–0.87], ; and for delta-PCT: 0.85 [0.78–0.92], . The optimal cut-off value for delta-PCT to indicate infection was 0.76 ng/mL (sensitivity 80 [70–88]%, specificity 86 [68-96]%). Neither absolute values nor changes in CRP, temperature, or WBC could predict infection. Conclusions. Our results suggest that delta-PCT values are superior to absolute values in indicating infection in intensive care patients. This trial is registered with identifier: NCT02311816.