AB1431 APPLICABILITY OF STANDARDIZED ULTRASOUND EXAMINATION TO ESTIMATE DISEASE ACTIVITY IN COMBINATION WITH JADAS AND INFLAMMATION MARKERS IN JIA PATIENTS – THE DAISY STUDY DESIGN

Abstract

Background: New outcome measures are needed to optimize personalized tailored treatment and to predict response in patients with juvenile idiopathic arthritis (JIA). Objectives: Aim of this multicenter, longitudinal study is to identify biomarker (clinical examination of the joints, ultrasound and inflammatory biomarkers) for the evaluation of disease activity in children with JIA. Methods: DAISY study planned to recruit 120 patients with JIA polyarticular and at least 30 patients with JIA oligoarticular disease course according to International League of Association for Rheumatology (ILAR) classification criteria, with active disease calculated by JADAS 10 and 27 and treated according to current recommendations[1,2]. At enrollment, 3, 6 and 12 months patients were simultaneously evaluated for disease activity status (JADAS 10 and 27), examined by musculoskeletal ultrasound (MSUS) gray-scale (GS) and power-doppler (PD) in 44 joints using OMERACT synovitis scoring system by an expert in pediatric MSUS. At each visit blood samples are collected for evaluation of inflammatory biomarkers (cytokines, chemokines, S100A8, S100A9 and S100A12). In case of disease worsening, the same parameters were performed as unscheduled visit. Experienced sonographers in pediatric MSUS were blinded from clinical examination as well as pediatric rheumatologist performing clinical examination were blinded from the MSUS finding. Prior to the patient enrollment it was mandatory that all sonographers access the study educational material on DAISY web-portal and perform test for sonographers that represents calibration webbased reliability exercise on still images, presenting different grades of synovitis using OMERACT synovitis scoring in order to optimize interrater reliability. Results: Study is conducted in 9 participating centers in 8 different countries after Ethics Committee Approvals and Informed Consents/assents were obtained. A total of 52 JIA patients were enrolled: 15 (28.8%) males and 37(71.2%) females; median age at enrollment 11.25 years, interquartile range (IQR) 8.06-14.19 years and median disease duration 1.67 years, IQR 0.97-5.26 years. of the JIA patients, 18 (34.6%) had oligoarticular JIA, 21(40.4%) had rheumatoid factor negative polyarthritis, 5 (9.6%) had rheumatoid factor positive polyarthritis, 7 (13.5 %) had enthesitis related arthritis while only one (1.9%) had psoriatic arthritis. Two patients (3.8%) had uveitis, while eight (15.4%) of them had a family history of autoimmune diseases. In total, 42 (80.8%) were treated with synthetic disease modifying antirheumatic drugs (methotrexate) while 31(59.6%) of JIA patients were receiving biologics. Conclusion: Study results are expected to enable definition of the new more sensitive clinical tool to predict response in JIA and achieve optimized personalized tailored treatment of our patients.