The effect of interleukin-17 on the course of juvenile idiopathic arthritis

Background. Juvenile idiopathic arthritis (JIA) is a heterogeneous group of chronic joint diseases in children who have different course and prognosis, so they continue to be investigated. In the presented part of the study, the content of soluble ІL-17-retseptoru, ІL-1 and γ -interferon in blood serum was determined to assess the role of their ratios and cooperation in the course of the disease in various subvariants of JIA. This will make it possible to predict the further course of the disease and choose the right treatment tactics. Purpose – The aim is to study the influence of interleukin 17 on the course of idiopathic arthritis. Materials and Methods. A statistical analysis of the immunological examination was carried out, which included the assessment of the content of interferon-ɣ, interleukin-1β and IL-17 receptor in blood serum using multivariate correlation and linear dispersion analysis of data. An analysis of the medical documentation of 40 patients with JIA, who during 2017-2019 at the clinical base of the Department of Pediatrics, Childrenʼs Infectious Diseases, Immunology and Allergology of P.L. Shupyk Scientific and Practical Center for Pediatric Rheumatology and Transitional Support of Children and Adolescents with Rheumatic Diseases State Institution «Institute of Pediatrics, Obstetrics and Gynecology of the National Academy of Medical Sciences of Ukraine». Results. The analysis of the content of pro-inflammatory cytokines in the blood serum of patients with JIA, depending on the subvariant, showed that the content of IL-1β in the blood serum was significantly increased only in sJIA, which was significantly (p < 0.05) higher than in other JIA. An increase in its content was found in 2/3 of patients, and it was also higher (p < 0.05) in teenagers compared to children aged 4–12 years. And when analyzing depending on age, the highest values of IL-17R were in the middle age group. The obtained data indicate the compensatory value of the increase of IL-17R and the simultaneous initiation of inflammatory and anti-inflammatory processes in the exacerbation of JIA. The level of IL-17R in blood serum was the highest to a greater extent in patients with pJIA and eJIA, in these groups the highest frequency of detection of increased IL-17R was also noted. A similar regularity was not observed in sJIA. The obtained data indicate the compensatory role of its increase and the simultaneous initiation of inflammatory and anti-inflammatory processes during an active inflammatory process against the background of JIA. The assessment of the ratio of stimulating and inhibitory cytokines showed that in patients with uveitis the ratio of IFN-γ/IL-1β (4379.29 ± 476.83) was higher than in other JIA (from 60.84 ± 14.92 in oJIA to 105 .20 ± 66.01 in pJIA) and IFN-γ/IL-17R (4474.01 ± 3899.19 vs. 20.14 ± 11.48 in pJIA to 934.55 ± 931.37 in sJIA). An increase in the IL-1β/IL-17R ratio was characteristic only for sUIA (34.12 ± 26.17). Conclusions. The balance of cytokines determines the directionality of the inflammatory process in JIA. The most unfavorable is the presence of increased IL-1β/IL-17R. The ratio of IFN-γ/IL-1β and IFN-γ/IL-17R can be considered as potential markers of uveitis and IL-1β/IL-17R – cJIA.