The tendency to increase the number of patients with Mycobacterium tuberculosis resistant to specific antibacterial drugs persists. An unfavorable factor is the increase in multidrug resistance and polyresistance. Some authors showed the role of T cell immunity defect in pulmonary tuberculosis. All components of immune cell metabolism (energy metabolism, synthesis of substances, use of metabolic products) are linked and coordinated with each other and are regulated by programs developed during the evolution of the organism that give the biochemical processes the necessary direction. Therefore, normalization of the immune system condition includes a mandatory component - normalizing metabolic disorders of immune cells. The purpose of the research was to study the action of the BioR preparation on functional activity and the enzymatic system of lymphocytes. Methods and object of research. According to the method of randomization and doubleblind investigation, the following groups of patients were constituted: I group, 48 patients - antituberculous treatment and BioR capsule preparation (BioR); II group, 21 patients – antituberculosis treatment and placebo (placebo); III group, 48 patients - anti-tuberculosis treatment (Anti-TB). In the supernatant solution after lymphocyte culture, the lactate-dehidrogenase level was estimated. The reaction of blast transformation of lymphocytes (RBTL) with phycohemagglutinin (PHA) was used for evaluation of functional lymphocyte activity. Results and discussions. Upon admission, functional lymphocyte activity in all groups was lowered with the same intensity and did not significantly differ. After treatment, the functional activity of lymphocytes in all groups increased, with the exception of patients who received antituberculous treatment. The results of RBTL+PHA + BioR demonstrate an immunocorrection index with the same values in patients of all groups. After treatment, in a higher lymphocyte functional activity, the immunocorrection score in groups decreased (except for placebo), the reduction was conclusive for patients who received BioR. Changes in the placebo and anti-tuberculosis groups were less pronounced than those after BioR treatment. Thus, on the functional activity of lymphocytes, a more pronounced immunocorrection effect is manifested by BioR. In the process of lymphocyte proliferation, there is an increase in lactate dehydrogenase (LDH) content, which regulates the intensity of anaerobic and aerobic cell energy processes, reflecting the particularities of metabolism and the functional specificity of cells and tissues. Hence the use of this enzyme as an indicator of functional state of cells, allows a more complete evaluation of lymphocyte functional activity. The LDH content at hospitalization was lower in patients in comparison with the content of this enzyme in the healthy group. After treatment, the lymphocyte content of LDH increased in all groups, more conclusive for patients who received BioR (p<0.01). Conclusion. Thus, BioR preparation, according to the mechanism of action, manifests as an immunocorrector on the immunological reactivity of the organism and exhibits a pronounced immunocorrective activity on the functional and enzymatic lymphocyte system.