Methods: We analyzed age of onset, timing of diagnosis verification and initiation of B, gender, the number of active joints at the start of B, the presence ACCP+, RF, ACCP, ESR and CRP values ​​at start of B, the presence of secondary Sjögren's syndrome (SS) in all pts with RF+ JIA who received B. Since 2021, the complex of examinations included the calculation of the Juvenile Arthritis Damage Index (JADI). This evidence concerns the gene CRP and juvenile idiopathic arthritis.