Аннотация:Phytomix-40 (PhM-40) is a phytomixture containing plant adaptogenes. It was formulated to be effective biological response modifier for cancer patients and for. The aim of the study was to investigate the immune mechanisms of precancer oral leukoplakia (OL) and the PhM-40 use for immune correction. PhM-40 and vitamin A (VA) were taken by 40 subjects (two groups) with OL. Immune cell subpopulations were analyzed by quantifying the expression of markers using flow cytometry. Interferon (IFN) status parameters were assessed in vitro on human fibroblasts. Treatment with VA did not improve IFN status. Assessment of immunity revealed the increase in the percentage of lymphoid cells expressing surface markers for T-helper cells (CD4) only. The treatment with PhM-40 improved their IFN status parameters: the elevation of IFN-α and IFN-7 levels increasing the sensitivity to IFN-α, IFN-7 preparations and inductors. PhM-40 resulted in improvement of the immunity: an increase in the percentage of lymphoid cells expressing markers for T-cells (CD3), T-helpers (CD4), interleukin-2 receptors (CD25), ICAM-1 adhesive molecules (CD54) and in a level decrease of T-supressors (CD8). Elevated persentages of B-cells (CD20) as well as macrophages and natural killers (CD11b and CD16) were also observed in humans after treatment. The rising level of the cells expressing adhesive molecule ICAM-3 (CD50) presented on the matured lym¬phocytes correlated with upregulated apoptosis marker Fas/APO-1 antigen expression (CD95). So there was no significant clinical improvement of the patients treated with VA. The patients treated with PhM-40 showed the improvement of their condition: erosions epithelialization, hyperkeratosis reduction. The verrucous form was reduced to common leukoplakia cancelling surgery and improving the prognosis. The immune parameters modulation with PhM-40 may be an existing clinical possibility in the control of malignant transformation.