FRI0471 ADVERSE FACTORS OF COMORBID DISEASES DEVELOPMENT AT DIFFERENT VARIANTS OF JUVENILE IDIOPATHIC ARTHRITIS (JIA)
Authors: N. Shevchenko, L. Bohmat, I. Bessonova, V. Nikonova
Journal: Annals of the Rheumatic Diseases (2020)

Background: It is known that rheumatic diseases are the pathogenetic basis for the formation of many comorbid conditions, the most important of that are cardiovascular pathology, atherosclerosis, osteoporosis, chronic kidney disease and amyloidosis, chronic obstructive pulmonary disease. The start of the disease at an early age, the long-term duration of JIA, the use of basic immunosuppressive therapy lead to the possibility of the onset of the first signs of comorbid conditions in childhood. Objectives: To study risk factors for the formation of damage of internal organs and systems in children with non-systemic JIA. Methods: The case histories of 121 patients aged 7-18 years (mean age 11.0 ± 0.3 years) with polyarticular (67.7%), oligoarticular (14.88%) and uveitis-associated (17.35%) JIA were studied, mainly of females (73.5%). The age of the start of the disease was 5.9 ± 0.4 years, the duration of JIA at the time of analysis reached 67.1 ± 4.3 months. All children received basic methotrexate therapy (plus folic acid), short courses of NSAIDs. There are studied changes in the cardiovascular system (ECG, ultrasound, 6-minute walk test), lungs (spirography), kidneys (concentration function, glomerular filtration rate, daily microalbuminuria), lipid spectrum and blood coagulation. Deviations from standard age-gender normal values were taken into account. It was used statistical methods for identifying relationships (stepwise multiple regression). As the dependent value the number of detected changes in the state of internal organs and systems is taken. The independent variables included standard clinical and laboratory parameters, the age of the onset of JIA, the total duration of the disease, the characteristic of the articular syndrome, activity indicators (C-reactive protein, RF and ANA titers, JADAS27), as well as the term for the appointment of basic therapy relative to the debut of the disease, the nature of the dosage methotrexate (mg / m2 / week), the duration of its use at the time of examination. Results: Based on the analysis and the obtained regression models for the formation of extra-articular lesions in children with various JIA options, it was found that the leading factors in the formation of comorbidity are the duration of the disease (p = 0.01), VAS results (including the child, parents and the physician) (p = 0.01), the dose of methotrexate (p = 0.01). In the polyarticular variant, the body mass index (p = 0.02), erythrocyte content (p = 0.007) were significant for the formation of comorbid states and should be distinguished. The overall duration of the disease (p = 0.02), the low age of initiation of therapy (p = 0.05), VAS of child (p = 0.003), CRP (p = 0.007), dose of methotrexate (p = 0.001) had the greatest significance level among the clinical and laboratory indicators included in the regression model of the formation of comorbidity with the oligoarticular variant. A features of the prognostic model for the formation of organ lesions and metabolic disorders in uveitis-associated arthritis were GCS therapy presence (p &lt;0.001), patient age (p &lt;0.001), JADAS27 (p &lt;0.001) and methotrexate dose (p &lt;0.001). Conclusion: Thus, in children with JIA, the formation of comorbid pathology is associated with a lower age of JIA debut in oligoarthritis and uveitis-associated arthritis, low body weight in poly- and oligoarticular JIA variants, an increase in the duration of the disease in the polyarticular variant, and the level of activity of the process, respectively, JADAS 27(p &lt;0.01) and VAS. Prognostically unfavorable for the formation of pathological changes in the internal organs and homeostasis are anemia, high white blood cell count and ESR level. Disclosure of Interests: None declared