Influenza and non-influenza ARVI in children. A relationship between cytokine profile, parameters of the 'lipid peroxidation – antioxidant defense system' as well as clinical and laboratory indicators

Influenza and acute respiratory viral infections (ARVI) impose a substantial damage to the population health in the Russian Federation due to their seasonal circulation and predominantly affect young children. A very few data on the cytokine profile, the nonspecific LPO — AOD system and their relationships with clinical characteristics in such diseases in preschool children are available. The aim of this study was to assess the cytokine profile, LPO — AOD system parameters and their relationship with the clinical and laboratory characteristics of diseases in preschool children with influenza and other ARVI. 86 preschool children (3–6 years old) were examined: with an established diagnosis of influenza (n = 31), non-influenza ARVI (n = 28), apparently healthy children (control group (n = 27). All pediatric samples were analyzed by enzyme-linked immunosorbent assay assessing blood serum concentrations of C-reactive protein and cytokines IL-1β, IL-4, IL-6, IL-8, TNFα, IFNα, IFNγ. Spectrophotometric, fluorometric and enzyme immunoassay methods to assess the state of the “LPO — AOD” system were used. In the group of children with influenza vs other ARVI, a higher incidence of intoxication syndrome was revealed. Cytokine profile in children from both clinical groups compared with control cohort was featured with higher indicators of both pro-inflammatory and anti-inflammatory origin. Children with non-influenza ARVI, had increased magnitude of LPO final products in the nonspecific LPO — AOD system along with lowered concentration of fat-soluble vitamins, general antioxidant activity, GSH level, and SOD activity. In the group with influenza, the level of primary and final lipid peroxidation products was increased, whereas that of for retinol,α-tocopherol, and total antioxidant activity was decreased paralleled with higher GSSG and SOD levels. Numerous correlations were noted in the group of children with ARVI: IL-1β/ketones, IL-6/ketones, IL-8/ketones, TNFα/ketones, IL-4/ketones, IFNg/shortness of breath, IFNα/cough, double bonds/fever, double bonds/AST, SO/intoxication, retinol/fever, GSSG/cough. The influenza group differed in the following relationships: IL-4/ketones, IL-4/fever, IFNα/ketones, CDs/AST. It can be concluded that in preschool children with ARVI and influenza, changes in the cytokine profile are accompanied by increased pro- and anti-inflammatory cytokine levels, increased intensity of lipid peroxidation reactions along with reduced magnitude of antioxidant factors. In the group with ARVI, there was a relationship between the final toxic products of lipid peroxidation — Schiff bases — and the intoxication index, as well as the presence of protective mechanisms in the form of connections between interferons and disease clinical manifestations. The group with influenza was distinguished by the presence of protective relations, which may have a beneficial effect in the context of developing pathological process. The data obtained will help expand the understanding of the pathogenetic mechanisms related to immune reactivity and nonspecific lipid peroxidation reactions in preschool patients and formulate appropriate measures for correction.