Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 19 5 2020 10 18 534 538 EN Masoumeh Beheshti Cellular and Molecular Research Center, Shahr-e-kord University of Medical Sciences, Shahr-e-kord, Iran Zahra Salehi Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Roya Abolfazli Department of Neurology, Amir A’lam Hospital, Tehran, Iran Hedayatolah Shirzad Cellular and Molecular Research Center, Shahr-e-kord University of Medical Sciences, Shahr-e-kord, Iran Maryam Izad Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran AND MS Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran 2019 09 17 2020 09 19 Multiple sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system, in which proinflammatory cytokines play a critical role in the pathogenic formation of lesions. Caspase-1 is a cysteine protease that proteolytically cleaves precursors of interleukin (IL)-18 and IL-1β and turns them into their active forms. These inflammatory cytokines play an important role in the development of MS. The aim of the present study was the investigation of caspase-1 and its downstream products, IL-18 and IL-1β, in relapsing-remitting MS (RRMS) patients. In this study, we used an ELISA assay to measure serum and cellular caspase-1 and serum levels of IL-18 and IL-1β in RRMS patients in the relapse phase (n=23) and healthy age-and gender-matched controls (n=19). We observed that the caspase-1 level was significantly increased in the serum of MS patients compared to the healthy controls (p=0.03). Although caspase-1 concentration in the lysate of peripheral blood mononuclear cells (PBMCs) was higher than serum among patients and controls (p<0.001), no significant difference was found in cellular levels of caspase-1 between the two groups. There was no significant difference in serum levels of IL-18 and IL-1β between patients and controls. In this study, we found an elevation of extracellular caspase-1, as a reflection of its intracellular level, in the serum of RRMS patients during the relapse phase. Therefore, it suggests being a suitable peripheral biomarker of disease activity in multiple sclerosis. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/2528