Pathogenetic role of cytokines in hemorrhagic fever with renal syndrome in dynamics and disease of various severity

The aim of the work is to determine the relationship between the levels of cytokines of proinflammatory and anti-inflammatory action during the clinical course of hemorrhagic fever with renal syndrome (HFRS) and the previously described characteristics of the phenotypic composition of blood lymphocytes in disease of various severity. Materials and methods. 65 patients with a serologically verified diagnosis of HFRS were under observation. The control group included 15 conditionally healthy people. Determination of cytokines in the blood of patients with HFRS was carried out by the enzyme immunoassay method at the different stages of the disease. The phenotypic composition of blood lymphocytes was assessed by flow cytofluorimetry. Results. At the different stages of the disease, there was a quantitatively different increase in the content of cytokines in the blood associated with cytotoxic immune reactions (IL-12, IFN, TNFa, TNF), as well as IL-10 and IL-6 correlated with each other in severe cases, against the background of a drop in blood levels of IL-4 and IL-1. In the moderate course of HFRS, correlations of IL-12 and IL-4 with NKG2D+ CTL, the relationship of IL-12 with almost all other cytokines, and the correlation of CD8+ Treg with IL-6 and TNF levels were observed. In severe cases, the formation of a complex that included interconnected IL-6 and IL-10 correlating with the number of NKG2D+ CTL, CD8+ Treg, NKT was noted. Conclusion. The pathogenetically significant mechanism of HFRS is realized with the predominant participation of cytokines of the cellular immune response and IL-6, correlatively associated with NKG2D+ CTL, CD8+ Treg, NKT, which, in case of a favorable outcome, contribute to the active formation of a pool of CD8+ memory cells, disrupted presumably by excessive secretion of IL-10.