PRODUCTION OF INFLAMMATORY CYTOKINES BY PERIPHERAL BLOOD CELLS UNDER STIMULATION IN VITRO IN CHILDREN WITH CHRONIC VIRAL HEPATITIS C

Chronic viral hepatitis C (ChVHC) is still a relevant problem for healthcare worldwide, despite significant advances in the diagnosis and treatment of this disease. Cytokines (CTs) play an important role in the pathogenesis of ChVHC, as they are universal regulators of immune response mechanisms. Studying the production of CTs by blood cells under the influence of various stimulants in vitro provides in-depth information about the functioning of the producing cells. In this regard, the aim of this work was to study the production of cytokines by peripheral blood leukocytes of patients with ChVHC in vitro stimulation. The study included 22 children with ChVHC and 29 conditionally healthy children, average age: 10 years and 4 months and 10 years and 9 months, respectively. Samples of heparinized blood were diluted with RPMI-1640 medium, a series are prepared: control sample without stimulant; sample stimulated with phytohemagglutinin (Sigma); sample stimulated with agonistic antibodies to CD3 (aCD3, Biocon, Russia); sample stimulated with agonistic antibodies to CD3 (Biocon, Russia) and to CD28 (aCD28, Beckman Coulter, USA). Blood samples were incubated for 24 hours (37°C, 5% CO₂). The concentration of IL-6, IL-8, and IL-17 was determined in the cell cultures supernatants using ELISA (Vector-Best, Russia). Statistical analysis was performed by the Mann-Whitney test and the sign test. It was found that spontaneous production of IL-6 and IL-17 by blood cells did not differ between healthy children and patients with ChVHC, whereas IL-8 levels were higher in viral infection. In vitro exposure to various stimulants led to increased concentrations of all studied CTs complexes in both patient groups. The IL-8 concentration in the ChVHC group was lower than the control in all three stimulation variants. In patients with ChVHC exposed to aCD3 and aCD28 in combination, IL-6 and IL-17 levels were lower than in healthy controls. IL-6 levels were also lower than in controls exposed to aCD3 alone. Thus, patients with ChVHC had elevated spontaneous IL-8 concentrations and decreased stimulated levels of all studied proinflammatory CTs. This indicates a decrease in the reserve capacity of CTs producing cells during chronic infection.