comparative evaluation of ifnγ, il4 and il17 cytokines in healthy gingiva and moderate to advanced chronic periodontitis

background: considering the role of t cells in the pathogenesis of periodontitis, the purpose of this study was to compare the amount of ifnγ, il4 and il17 in advanced periodontal lesions with healthy gum areas to determine each th1, th2 and th17 cells activity in comparison with each other and finally, to compare the value and the role of humoral, cell mediate and autoimmune responses.     methods: in this descriptive analytical study, those with moderate to advanced periodontitis, having pocket with 4 to 7 mm in depth, were randomly selected. after preparing the healthy and affected sample tissues, the amount of the specific antibody in i ifnγ, il4 and il17 cytokines were measured using elisa method and were compared between the two groups. the findings were analyzed using the software and descriptive statistical methods and pearson correlation statistical analysis (α= 0.05). results: this study was performed on 37 patients with moderate to severe periodontitis and 22 healthy individuals without any periodontal disease. il4 and ifnγ levels in the patients with chronic periodontitis compared to those of healthy gingival samples showed a significant reduction (p > 0.05) whereas the amount of il17 in tissue samples of chronic periodontitis compared to healthy gums had a significant increase (p < 0.05). conclusion: it appears that in the periodontitis pathogenesis, as well as th1 and th2 responses, il17 causes the host immunological response to the periodontal pathogenesis.