en Behavioral Neuroscience Behavioral Neuroscience Original Original <div style="text-align: justify;"><strong>Introduction:</strong> Many genetic studies are conducted on Obsessive-Compulsive Disorder (OCD). however, a high-throughput examination of proteome profile of this severe disease has not been performed yet.&nbsp;<br> <strong>Methods:</strong> Here, the proteomic study of OCD patients&rsquo; serum samples was conducted by the application of Two-Dimensional Electrophoresis (2DE) followed by Mass Spectrometry (MALDI-TOF-TOF).&nbsp;<br> <strong>Results:</strong> A total of 240 protein spots were detected and among them, five significant differentially expressed protein spots with the fold change of &ge;1.5 were considered for further evaluations. These proteins include IGKC, GC, HPX, and two isoforms of HP. While IGKC and HP show down-regulation, GC and HPX indicate up-regulation. Moreover, a validation study of overall HP levels in patients&rsquo; serum via nephelometric quantification confirmed the lower levels of this protein in the serum of OCD patients. Additionally, enrichment analysis and validation test revealed that inflammation is one of most dominant processes in OCD.&nbsp;<br> <strong>Conclusion:</strong> It is suggested that these candidate proteins and their underlying processes (especially, inflammation) may be linked to OCD pathophysiology and can promise a clinical use after extensive validation studies.</div> Obsessive Compulsive Disorder, Biomarkers, Proteomics, Protein interaction maps 337 346 http://bcn.iums.ac.ir/browse.php?a_code=A-10-941-4&slc_lang=en&sid=1 Mona Zamanian-Azodi mona.azodi@gmail.com 13700319475328460017583 13700319475328460017583 No National Elites Foundation, Tehran, Iran. Mostafa Rezaei-Tavirani tavirany@yahoo.com 13700319475328460017584 13700319475328460017584 Yes Proteomics Research Center, School of Paramedical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Mohammad Mahboubi mm59m@yahoo.com 13700319475328460017585 13700319475328460017585 No Department of Public Health, School of Medical Sciences, Abadan University of Medical Sciences, Abadan, Iran. Mohsen Hamidpour 13700319475328460017586 13700319475328460017586 No Proteomics Research Center, School of Paramedical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Majid Rezaei Tavirani 13700319475328460017587 13700319475328460017587 No Department of Surgery, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Mostafa Hamdieh 13700319475328460017588 13700319475328460017588 No Department of Psychosomatic, Taleghani Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Mohammad Rostami-Nejad 13700319475328460017589 13700319475328460017589 No Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Naser Nejadi 13700319475328460017590 13700319475328460017590 No Department of Clinical Biochemistry, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran. Mohammad Kamran Derakhshan 13700319475328460017591 13700319475328460017591 No Department of Psychosomatic, Taleghani Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.