Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 14 3 2015 10 18 298 305 EN Fereshteh Alsahebfosoul Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran Ahmad Zavaran-Hosseini Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran Rasoul Salehi Department of Molecular Biology Faculty of Medicine, Isfahan University of Medical Sciences, Tehran, Iran Masood Etemadifar Neurology Department, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Nafiseh Esmaeil Department of Immunology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Azam Jamshidian Department of Immunology, Faculty of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran. 2015 10 18 2015 10 18 Soluble forms of nonclassical human leukocyte antigen (HLA)-G have recently been suggested as immunomodulatory factors in multiple sclerosis (MS). HLA-G inhibits the effecter function of T cells and natural killer (NK) cells. Also regulatory T cells (Treg) are considered as pivotal players in MS pathogenesis. Thus, we aimed to evaluate the presence of HLA-G molecules and Treg cells in Relapsing-Remitting Multiple Sclerosis (RRMS) patients and compare it to healthy controls.Patients with RRMS (n=205, mean age=31.32±8.53) and healthy subjects (n=205, mean age=32.2±7.48) were studied. The patients subgrouped to untreated and treated with Interferon  beta.  Then  sHLA-G  levels  (sHLA-G1  and  sHLA-G5)  were measured  using ELISA method. Treg (CD4+CD25+  Foxp3+) cells in patients who had sHLA-G>10 U/ml were characterized by using flow cytometry.Our data showed that there was no significant differences between RRMS patients and healthy controls in  sHLA-G concentration (p>0.05). Treg cell frequencies were higher in the patients who had sHLA-G >10 U/ml compared to healthy subjects (p<0.05).Collectively, there was significant correlation between sHLA-G and frequency of Treg cells in treated RRMS patients and healthy individuals. It seems that high level sHLA-G has been  instrumental  in  raising  frequency  of  Treg  cells  in  treated  patients  and  could  be associated with remission of MS disease. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/571 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/571/456