Hindawi Publishing Corporation Mediators of Infammation Volume 2013, Article ID 190145, 7 pages http://dx.doi.org/10.1155/2013/190145 Clinical Study Cytokines and Chemokines as Biomarkers of Community-Acquired Bacterial Infection Michal Holub, 1 David A. Lawrence, 2 Nancy Andersen, 2 AlDbJta Davidová, 1 OndLej Beran, 1 Vilma Marešová, 3 and Pavel Chalupa 1 1 Department of Infectious and Tropical Diseases, First Faculty of Medicine, Charles University in Prague and Na Bulovce Hospital, Prague, CZ 180 81, Czech Republic 2 Laboratory of Immunology, Wadsworth Center, NYS DOH, Albany, NY 12201-0509, USA 3 Division of Infectious Diseases, Institute of Postgraduate Medical Education and Na Bulovce Hospital, Prague, CZ 180 81, Czech Republic Correspondence should be addressed to Michal Holub; michal.holub@lf1.cuni.cz Received 10 January 2013; Accepted 26 March 2013 Academic Editor: Oreste Gualillo Copyright © 2013 Michal Holub et al. Tis 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. Routinely used biomarkers of bacterial etiology of infection, such as C-reactive protein and procalcitonin, have limited usefulness for evaluation of infections since their expression is enhanced by a number of diferent conditions. Terefore, several infammatory cytokines and chemokines were analyzed with sera from patients hospitalized for moderate bacterial and viral infectious diseases. In total, 57 subjects were enrolled: 21 patients with community-acquired bacterial infections, 26 patients with viral infections, and 10 healthy subjects (control cohorts). Te laboratory analyses were performed using Luminex technology, and the following molecules were examined: IL-1Ra, IL-2, IL-4, IL-6, IL-8, TNF-, INF-, MIP-1, and MCP-1. Bacterial etiology of infection was associated with signifcantly ( < 0.001) elevated serum concentrations of IL-1Ra, IL-2, IL-6, and TNF- in comparison to levels observed in the sera of patients with viral infections. In the patients with bacterial infections, IL-1Ra and IL-8 demonstrated positive correlation with C-reactive protein, whereas, IL-1Ra, TNF-, and MCP-1 correlated with procalcitonin. Furthermore, elevated levels of IL-1Ra, IL-6, and TNF- decreased within 3 days of antibiotic therapy to levels observed in control subjects. Te results show IL-1Ra as a potential useful biomarker of community-acquired bacterial infection. 1. Introduction Rapid diferentiation between viral and bacterial etiology of infection is necessary for decision on empirical antibi- otic treatment. Furthermore, the initial antibiotic treatment cannot be switched to a pathogen-directed therapy in many patients, because the etiologic diagnosis of community- or hospital-acquired bacterial infections could not be confrmed or eventually is confrmed with a signifcant delay. Terefore, certain biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT) are routinely used in clinical settings to help with both initial decision about antibiotic treatment and followup of its efect. It must be stressed that CRP and PCT plasma levels are not 100% sensitive or specifc, and these limitations hinder their clinical use. Te major limitation of CRP is its low speci- fcity in diferentiating bacterial infection from autoimmune diseases and some hematological malignancies [1, 2]; CRP levels also are elevated by stress and cardiovascular disorders, which can be associated with metabolic syndrome [3]. Sim- ilarly, PCT is not a reliable biomarker of bacterial infection in patients with systemic infammatory syndrome elicited by noninfectious causes, such as cardiopulmonary surgery and heat injury [4, 5]. Furthermore, an ideal biomarker of bacterial infection should be helpful in determining the efcacy of the antibiotic treatment. It is well known that the decline of CRP plasma level is a good predictor of the efectiveness of antibiotics, and the same opinion seems to hold true for PCT [6, 7]. On the other hand, both biomarkers have relatively long biological half-life, which is a problem