The Influence of Smoking on the State of the Thiol Disulphide System in Blood Plasma and the Frequency of TCR-Mutant Lymphocytes in Healthy Individuals and Cancer Patients

A comparative study of indicators of somatic mutagenesis and the thiol disulfide system in the peripheral blood of cancer patients before treatment and healthy individuals with different smoking status (n = 95) has been carried out. All studied parameters including the content of reduced (GSH) and oxidized (GSSG) glutathione and their ratio (GSH/GSSG), the frequency of lymphocytes with mutations at the T-cell receptor (TCR) locus were found to be significantly increased by 1.5–2.7 times in the general group of patients compared to those in the general group of healthy individuals (p < 0.01 in all cases). After cessation of smoking, a decrease in the frequency of mutant cells and the ratio of reduced and oxidized glutathione was observed in patients (p < 0.05). At the individual level, strong correlations were found between the frequency of TCR-mutant cells and the contents of GSH and GSSG only in the subgroup of smoking patients with a high level of mutagenesis. The correlation coefficient between the frequency of TCR-mutant lymphocytes and the GSH content in this subgroup was 0.82 (p < 0.001) and for GSSG r = 0.68 (p < 0.01). The results we obtained indicate the contribution of the thiol disulfide system to the formation of a high frequency of gene mutations in smokers with cancer.