Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 19 1 2020 02 01 74 83 EN Hossein Atwan Immunology Research Center, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran AND Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Mohammad-Ali Assarehzadegan Immunology Research Center, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran AND Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Mehdi Shekarabi Immunology Research Center, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran AND Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Seyed Mohammad Jazayeri Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran AND Research Center for Clinical Virology, Tehran University of Medical Sciences, Tehran, Iran Shahram Barfi Department of Virology, School of Public Health, International Campus, Tehran University of Medical Sciences Tehran, Iran Raheleh Shokouhi Shoormasti Immunology, Asthma, and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran Narges Chimeh Behara Rehabilitation Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Hamid Reza Pouretemad Department of Psychological Medicine, Clinical Neurophysiology Section, Institute of Psychiatry, Shahid Beheshti University, Tehran, Iran Behnoosh Tayebi Department of Regenerative Medicine, Royan Institute for Stem Cell Biology and Technology, Tehran, Iran 2019 06 25 2019 08 20 Autism is a neurodevelopmental disorder that is recognized by stereotypic and repetitive behaviors after 2 years of old. Dysregulation of the immune system, especially inflammation which is mostly regulated by IL-6, imposes a deficit in CNS development. Along with this crucial biomarker, researchers have proposed BCL-2, micro RNA-23a-3p (miR-23a-3p), miR-181b-5p as other probable biomarkers involved in inflammation and apoptosis. The aim of the study was to evaluate the alteration in the expression of these biomarkers in a group of autism spectrum disorder (ASD) children. Peripheral blood mononuclear cells (PBMCs) were obtained from 37 autistic patients. After RNA extraction with precipitation method, the Syber green qReal-time Polymerase Chain Reaction (PCR) was performed in order to evaluate the possible alteration in the expression of IL-6, BCL-2, miR-181b-5p, and miR-23a-3p. The results were compared with healthy controls. IL-6 was significantly upregulated in ASD patients (p=0.003). On the other hand, miR-23a was upregulated and BCL-2 downregulated in ASD patients but the changes were not significant. In initial evaluations, expression changes of miR-181b-5p were not statistically significant. However, when Patients were divided into two groups of upregulated and downregulated, re-evaluation showed that both up- (p=0.005) and down-regulation (p=0.004) (i.e. changes regardless of the direction) of miR-181b were significant in autistic children. IL-6 and miR-181b-5p can have proper diagnostic values and are reliable biomarkers with high sensitivity and specificity. On the other hand, PBMC can be utilized for such studies and also evaluation of patients' condition instead of brain tissue as it is less accessible. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/2431