Research Article Plasmatic Soluble Receptor for Advanced Glycation End Products as a New Oxidative Stress Biomarker in Patients with Prosthetic-Joint-Associated Infections? Luca Massaccesi, 1 Barbara Bonomelli, 1 Monica Gioia Marazzi, 2 Lorenzo Drago, 2,3 Massimiliano Marco Corsi Romanelli, 2,4 Daniela Erba, 5 Nadia Papini, 6 Alessandra Barassi, 7 Giancarlo Goi, 1 and Emanuela Galliera 2,3 1 Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy 2 Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy 3 IRCCS Galeazzi Orthopaedic Institute, Milan, Italy 4 U.O.C SMEL-1 Patologia Clinica IRCCS Policlinico San Donato, San Donato, Milan, Italy 5 Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milan, Italy 6 Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy 7 Department of Health Sciences, Università degli Studi di Milano, Milan, Italy Correspondence should be addressed to Emanuela Galliera; emanuela.galliera@unimi.it Received 7 July 2017; Revised 28 September 2017; Accepted 25 October 2017; Published 13 December 2017 Academic Editor: Benoit Dugue Copyright © 2017 Luca Massaccesi 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. Prosthetic joint infection (PJI) is the most common cause of failure of total joint arthroplasty, but a gold standard for PJI diagnosis is still lacking. Advanced glycation end products (AGEs) are proinflammatory molecules inducing intracellular oxidative stress (OS) after binding to their cell membrane receptors (RAGE). The aim of this study was to evaluate plasmatic soluble receptor for advanced glycation end products (sRAGE), as a new OS and infection marker correlating sRAGE to the level of OS and antioxidant defenses, in PJI, in order to explore the possible application of this new biomarker in the early diagnosis of PJI. Plasmatic sRAGE levels (by ELISA assay), plasma antioxidant total defenses (by lag time method), plasma reactive oxygen species (ROS), and thiobarbituric acid reactive substance (TBARS) levels (by colorimetric assay) were evaluated in 11 PJI patients and in 30 matched controls. ROS and TBARS were significantly higher (p <0 001) while plasma total antioxidant capacity and sRAGE were significantly lower (p <0 01) in patients with PJI compared to controls. Our results confirm the OS in PJI and show a strong negative correlation between the level of sRAGE and oxidative status, suggesting the plasmatic sRAGE as a potential marker for improving PJI early diagnosis. 1. Introduction The numbers of primary total hip and total knee arthroplas- ties have been increasing over the past decade. Prosthetic joints improve the quality of life, but they may fail, thus requiring revision surgery. Infection is the most serious com- plication, occurring in 0.8 to 1.9% of knee arthroplasties and 0.3 to 1.7% of hip arthroplasties. Nowadays, a wide number of tests are available for prosthetic-joint-associated infection (PIJ) diagnosis, ranging from haematological markers of infection and inflammation, intraoperative culture, and histology analysis. Nevertheless, there is still a lack of gold standards for the diagnosis of PIJ [1, 2] because the clinical presentation of PJI is often ambiguous and classical inflam- matory markers can be misleading [3, 4]. In order to optimize the diagnostic process, infection biomarkers with fast response and high sensitivity and specificity for infection are needed [5–8]. Among the scenario of infection diagnosis, an emerging role has been recently described for oxidative stress (OS) evaluation [9, 10]. Inflammatory response induces an over- production of ROS, exacerbating organ and tissue injuries Hindawi Disease Markers Volume 2017, Article ID 6140896, 7 pages https://doi.org/10.1155/2017/6140896