The susceptibility to the development and progression of inflammatory periodontal diseases, which depends on genetic and external factors (smoking, stress, oral hygiene), varies widely. In the development of these diseases, an important role is played not only by the presence of periodontal pathogenic microorganisms, but also by the presence of congenital or acquired immunodeficiency, immunoregulatory defects. The immune system plays a key role in the physiological and pathological processes of periodontal tissues. In this regard, IL17, produced by CD4+ Th cells, which has both Pro-inflammatory and protective activity, is of particular interest in the pathogenesis of periodontitis. The aim of study was to identify the relationship between polymorphic loci of the IL-17A (rs2275913) and MMP-1 (rs1799750) genes and clinical manifestations of chronic periodontitis in petrochemical workers. Dental examination was performed in 92 ethylene oxide production workers with chronic periodontitis and 74 patients with chronic periodontitis who did not come into contact with chemical factors (control group). Genotyping of polymorphisms rs2275913 of the IL17A gene and rs1799750 of the MMP1 gene was performed by allele-specific real-time polymerase chain reaction (PCR). Hygienic assessment of the degree of air pollution of the working area with harmful substances was carried out by gas chromatography according to the guidelines for the determination of harmful substances in the air № 5098-89, № 3119-84. When comparing the results of studies of both groups, there were no statistically significant differences in the frequency distributions of allelic variants and genotypes of the IL-17A and MMP-1 genes. The AA/AG genotypes of the IL-17A gene were associated with an increased risk of severe disease compared to the GG genotype in workers in the main group (OR=6.1; 95% CI 1.33-28.5; p=0.021) and in the control group (OR=7.26; 95% CI 1.34-39.25; p=0.016). Carriers of the A allele in the control group increased the risk of severe chronic periodontitis by 2.4 times compared to carriers of the G allele (OR=2.41; 95% CI 1.19-4.87; p=0.014). During the dental examination of employees of the ethylene oxide plant, the clinical course of periodontal diseases was more severe in comparison with the control group, and the number of patients with severe periodontitis was twice as high. It was found that the AA/AG genotypes of the IL-17A gene and the carrier of the A allele are associated with increased susceptibility to the development of severe chronic periodontitis. The association between the MMP-1 gene polymorphism and the risk of severe forms of chronic periodontitis has not been established. A risk factor for the development of inflammatory periodontal diseases in employees of the petrochemical complex is a complex of harmful production factors.
