Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 22 1 2023 02 20 25 33 Fereshteh Beigmohammadi Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Saeed Aslani Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Hoda Kavosi Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Inflammation Research Center, Tehran University of Medical Sciences, Tehran, Iran ‎ Ali Javinani Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran ‏ ‏Shayan Mostafaei Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden Mehran Pournazari Clinical Research Department Center, Imam Raza Hospital, Kermanshah University of Medical Sciences, Kermanshah, Iran Baharak Tasorian Division of Rheumatology, Department of Internal Medicine, Arak University of Medical Sciences, Arak, Iran Elham Farhadi Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Inflammation Research Center, Tehran University of Medical Sciences, Tehran, Iran Asghar Hajiabbasi Department of Rheumatology, Guilan Rheumatology Research Center, School of Medicine, Razi Hospital, Guilan University of Medical Sciences, Rasht, Iran Habib Zayeni Department of Rheumatology, Guilan Rheumatology Research Center, School of Medicine, Razi Hospital, Guilan University of Medical Sciences, Rasht, Iran Alireza Khabbazi Connective Tissue Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Ahmadreza Jamshidi Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Irandokht Shenavar Masooleh Department of Rheumatology, Guilan Rheumatology Research Center, School of Medicine, Razi Hospital, Guilan University of Medical Sciences, Rasht, Iran Zahra Tamartash Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Mahdi Vojdanian Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran Mahdi Mahmoudi Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Inflammation Research Center, Tehran University of Medical Sciences, Tehran, Iran 2021 11 03 2022 10 24 Takayasu arteritis (TA) is a chronic inflammatory disorder characterized by vascular damage and fibrosis in the intima that commonly occurs in the aorta. In many damaged sites in TA patients, natural killer (NK) cells have been shown to be hyperactivated and produce inflammatory cytokines and toxic components. Killer cell immunoglobulin-like receptors (KIRs) are found on NK cells and interact with human leukocyte antigen (HLA) class I ligands to activate or suppress NK cells. The present study assessed the possible role of KIR and their HLA ligand genes in susceptibility to TA in Iranian patients. This case-control study included 50 TA patients and 50 healthy subjects. DNA was extracted from whole peripheral blood samples, and polymerase chain reaction with sequence-specific primers (PCR-SSP) was performed to recognize the presence or absence of polymorphism in 17 KIR genes and 5 HLA class I ligands in each participant. Among the KIR and HLA genes, a significant decrease was detected in the frequency of 2DS4 (full allele) in TA patients (38%) compared with healthy controls (82%) (OR=0.13, 95% CI=0.05–0.34). However, none of the KIR and HLA genotypes or the interactions between these genes were associated with susceptibility to TA. The KIR2DS4 gene might be involved in the regulation of activation as well as the production of cytotoxic mediators of NK cells in patients with TA. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3394 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/3394/1916