Polymorphism of antioxidant defense enzyme genes as the risk for formation of chronic dust bronchitis in long-term labour experience coal mine workers

Abstract

Introduction. The antioxidant defense system is involved in protecting the body from long-term exposure to harmful damaging factors. Polymorphisms in the genes of antioxidant defense enzymes change the response to oxidative stress in occupational respiratory diseases such as asbestosis, silicosis, occupational asthma, and others. The aim was to study the polymorphism of the MnSOD (rs4880) and GPX1 (rs1050450) genes to predict the risk of developing chronic dust bronchitis in miners of the main occupations of coal enterprises in the South of Kuzbass. Materials and methods. One hundred eighty two coal mine workers with long-term exposure to high concentrations of coal-rock dust (exceeding the maximum permissible concentrations by up to 35 times), including 116 people with a previously proven diagnosis of chronic dust bronchitis, were examined. The comparison group (66 workers) consisted of the persons without a proven diagnosis, working in the same sanitary and hygienic conditions. Genomic DNA was isolated from peripheral blood leukocytes using phenol-chloroform extraction method. Typing of the MnSOD (rs4880) and GPX1 (rs1050450) genes was performed using the Real-Time method. Results. The chance of detecting the AA genotype of the MnSOD gene and the GG genotype of the GPX1 gene in long-term labour experience miners with chronic dust bronchitis was found to be 2 times and 6 times higher than in the comparison group, respectively. The AA GPX1 genotype had been shown to be a factor in resistance to the development of this disease. The combination of AA/GG genotypes of the MnSOD/GPX1 genes was statistically significantly associated with a 1.5-fold risk of developing chronic dust bronchitis. Combinations of genotypes of the MnSOD/GPX1 GG/AA, AA/AA, and AG/AA genes were associated with the resistance to the development of chronic dust bronchitis. The data obtained can be used for personalized prediction of the risk of developing chronic dust bronchitis in long-term labour experience miners of the main occupations. Limitations. The study was limited to the number of miners who underwent periodic medical examinations and were hospitalized at the Research Institute for Complex Problems of Hygiene and Occupational Diseases. Conclusion. The results obtained indicate to the contribution of the polymorphism of the MnSOD (rs4880) and GPX1 (rs1050450) genes to the development of chronic dust bronchitis.