Abstract：Objective To explore the changes in ribosomal DNA copy number in peripheral blood among patients with pneumoconiosis and its influencing factors, so as to provide insights into prevention and treatment of pneumoconiosis. Methods Eighty-eight patients with pneumoconiosis who visited a designated hospital and 71 community residents with no history of pneumoconiosis or dust exposure were selected as the pneumoconiosis group and control group, and age, smoking history, drinking history and cumulative years of exposure to dust were collected through questionnaire surveys. The copy number of 45S rDNA and 5S rDNA was detected using real-time fluorescence quantitative PCR, and the differences between the two groups were compared. Factors affecting the copy number of 45S rDNA and 5S rDNA were identified by a multiple linear regression model. Results The pneumoconiosis group had a median age of 56.00 (interquartile range, 15.25) and a mean cumulative dust exposure duration of (12.40±8.08) years, with 56.82% smoking and 62.50% drinking. The control group had a median age of 64.00 (interquartile range, 37.00) years, with 32.39% smoking and 26.76% drinking. The median copy number of 45S rDNA in the pneumoconiosis group was 1.29 (interquartile range, 0.59), which was lower than 2.10 (interquartile range, 1.88) in the control group; the median copy number of 5S rDNA in the pneumoconiosis group was 5.33 (interquartile range, 0.85), which was higher than 4.66 (1.34) in the control group (both P<0.05). Multiple linear regression analysis identified age (β=-0.034) and pneumoconiosis (β=-1.595) as factors affecting 45S rDNA copy number, age (β=-0.013) as a factor affecting 5S rDNA copy number, and age (β=0.018) as a factor affecting 5S rDNA copy number in the pneumoconiosis group (all P<0.05). Conclusions Compared with community residents with no history of pneumoconiosis or dust exposure, the copy number of 45S rDNA in peripheral blood among patients with pneumoconiosis is reduced and the copy number of 5S rDNA is increased.
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