Introduction. Features of cytokine production in mononuclear cell cultures from Lyme borreliosis patients based on clinical data remained poorly studied. The study aim was to estimate the patterns of baseline and lipopolysaccharide-induced cytokine-secretory activity of peripheral blood mononuclear leukocytes from patients with erythema migrans form of acute Lyme borreliosis based on clinical parameters. Materials and methods. Groups of 22 and 12 patients with the diagnoses of mild or moderate severity of monoinfection and co-infection with tick-borne encephalitis of Lyme borreliosis with erythema migrans were examined twice: on week 1 after disease onset and day 14. The control group included 17 healthy donors. Basal and lipopolysaccharide-induced IL-6, IL-10, and TNFα secretion levels were assessed in mononuclear leukocyte culture supernatants applying enzyme immunoassay. Statistical analysis was performed by using the Mann–Whitney U-test, Wilcoxon test, and Spearman’s rank correlation. Results. The group of moderate severity patients was clinically distinguished by severer fever and intoxication manifestations. At the disease onset, the basal TNFα, IL-6 and IL-10 secretion levels in the moderate severity patient cultures were significantly higher than in those of the other groups. After antibiotics treatment, the baseline TNFα and IL-10 levels tended to decrease. At the onset, lipopolysaccharide-induced cultures from the moderate severity patients showed significantly suppressed TNFα production and increased IL-10 secretion as compared to the other groups. Lipopolysaccharide-induced IL-6 secretion in the moderate vs. mild severity group supernatants was significantly lower. In dynamics, the induced TNFα levels in the moderate severity patients were increased to the magnitude exceeding that in the controls. Positive correlations between the IL-6 and TNFα basal levels and maximum body temperature or the C-reactive protein serum concentrations were revealed in the patients. Induced TNFα levels showed negative correlations with fever levels or with IL-10 secretion. Conclusions. It was demonstrated that basal TNFα, IL-6 and IL-10 secretion levels in the mononuclear cell cultures of acute Lyme borreliosis patients increased with the increasing disease severity. Suppression of lipopolysaccharide-induced TNFα production in the moderate severity patient cultures was presumably associated with the regulatory cytokine IL-10 effects.