Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease of the joints in children, characterized by autoimmune damage to connective tissue and systemic manifestations. Among extra-articular lesions, particular importance is attached to the involvement of the urinary system, which significantly affects the course, prognosis, and treatment strategy of the disease.

Objective: To study the clinical and immunological changes in the urinary system in children with juvenile idiopathic arthritis.

Materials and Methods:  A total of 80 patients aged 4–17 years were examined. All patients underwent clinical, laboratory, and immunological studies.

Results: Urinary system involvement was detected in 66 (82.5%) children, manifested by leukocyturia (79%), proteinuria (52%), hematuria (35%), and the presence of salts in the urine (32%). Serum IL-6 levels were elevated 5.8-fold, particularly in polyarticular and systemic forms of the disease.

Juvenile idiopathic arthritis, urinary system, kidneys

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