Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 16 5 2017 10 28 396 403 EN Parisa Farahani Biology Department, East Tehran Branch, Islamic Azad University, Tehran, Iran Raheleh Halabian Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran Ensieh Vahedi Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran Jafar Salimian Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran 2017 01 03 2017 07 04 The long lasting inflammation and immune dysregulation is one of the main mechanisms involved in lung complication of veterans exposed to sulfur mustard (SM) gas. Th17/Treg cells have an important role in immunopathogenesis of chronic obstructive pulmonary disease (COPD) and mustard lung disease. In this study, expression of cytokines genes levels related to Th17/Treg cells was determined in peripheral blood mononuclear (PBMC) of mustard lung patients and was compared with COPD patients and healthy controls (HC). Real time-polymerase chain reaction was used to assay genes expression levels of Th17 related cytokines (IL-17, IL-6 and TGF-β) and Treg related cytokines (IL-10, TGF-β). IL-17 gene expression level considerably was higher in SM patients (9.98±0.65, p<0.001), and COPD (4.75±0.71, p<0.001), compare to HC group. Also, gene expression level of IL-6 in the SM group (3.31±0.93, p<0.001) and COPD group (2.93±0.21, p<0.001) were significantly higher than the HC group. The IL-10 gene expression level showed a high increase in SM patients (4.12±0.91, p<0.01), and COPD (2.1±0.45, p<0.01). Finally, the TGF-β gene expression level was increased in SM patients (4.91±0.69, p<0.001) as well as in COPD group (5.41±0.78, p<0.001). In SM patients, IL-17 (R=-0.721, p<0.05), IL-6 (R=-0.621, p<0.05) and TGF-β (R=-0.658, p<0.05) had significant negative association with FEV1 (%). Inversely, Il-10 showed positive correlation (R=0.673) with FEV1 (%). Th17/Treg cells related cytokines genes were highly expressed and imbalanced in peripheral blood mononuclear cells of SM and COPD patients which correlated with pulmonary dysfunction. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/1236 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/1236/765