STATUS OF THE CELLULAR IMMUNITY IN CLEAN-UP WORKERS OF THE CHORNOBYL ACCIDENT AND PATIENTS WITH CANCER OF THE MOUTH CAVITY, ORAL AND LARYNGEAL PART OF THE PHARYNX

Objective: to establish cellular immunity in clean-up workers of the Chornobyl accident compared to patients with malignant neoplasms of the oral cavity, oral and laryngeal parts of the pharynx according to the subpopulation organization of peripheral blood leukocytes. Materials and methods. We examined 112 males, age (56,92 ± 6,17) years (M ± SD), including 26 male clean-up workers exposed at the radiation dose 10–500 mSv; 20 male clean-up workers exposed at the dose range 504–990 mSv; 33 patients with malignant neoplasms of the oral cavity, oral and laryngeal parts of the pharynx and 33 nonexposed subjects of the control group. Immune cell subsets analysis was performed by the expression of differential and activation antigens of peripheral blood leukocytes using flow cytometry. Results. In assessing each group's cellular immunity, there was a decrease in the number of CD19+ B-lymphocytes, CD3+HLA-DR+ T- and CD3-HLA-DR+ B-lymphocytes, CD3-16+56+ natural killer cells, combined with an increase in the number of CD8+ T-lymphocytes. An increase in the relative number of CD4+CD8+ T-lymphocytes was determined in clean-up workers (D ≤ 500 mSv) and cancer patients. An increase in the number of CD8+ T-lymphocytes and a decrease in the number of CD4+ T-lymphocytes were observed in clean-up workers (D > 500 mSv), as well as in cancer patients. In addition, a decrease of monocytes, CD3+16+56+, and CD3+TCRαβ+ T-lymphocytes was determined in patients with oncological pathology. Conclusions. The obtained results show the unidirectionality of changes in cellular immunity in the participants of the liquidation of the consequences of the accident at the Chornobyl nuclear power plant and patients with the investigated oncological pathology, which indicates the formation of persistent violations of antitumor protection in the participants of the liquidation of the consequences of the accident as the basis of oncogenesis. Determining changes in the number of lymphocytes, monocytes, granulocytes, CD4+ T-lymphocytes, CD4+CD8+ immature T-lymphocytes, the immunoregulatory ratio CD4+ / CD8+, CD3+TCRαβ+ T-lymphocytes and CD3+16+56+ CTL can have an additional effect on the effectiveness antitumor protection and the probability of oncogenesis risk in immunocompromised individuals. Key words: ionizing radiation, Chornobyl, clean-up workers of the Chornobyl accident, neoplasms of the oral cavity, oral and laryngeal parts of the pharynx, immune system.