AB1072B THE CONSEQUENCES OF THE PROVISIONAL PAEDIATRIC RHEUMATOLOGY INTERNATIONAL TRIALS ORGANISATION JUVENILE IDIOPATHIC ARTHRITIS CLASSIFICATION CRITERIA

Background Last year the International League of Associations for Rheumatology (ILAR) classification criteria for juvenile idiopathic arthritis (JIA), [1] were challenged by the provisional Paediatric Rheumatology International Trials Organisation (PRINTO) classification criteria.[2] Four disorders were proposed: (a) systemic JIA; (b) rheumatoid factor (RF)-positive JIA; (c) enthesitis/spondylitis-related JIA; and (d) early-onset antinuclear antibody (ANA)-positive JIA. Early-onset ANA-positive JIA is defined by: arthritis for ≥ 6 weeks, and early-onset (≤ 6 yrs), and presence of 2 positive ANA tests with a titer ≥ 1/160 at least 3 months apart with the exclusions of having systemic JIA, RF-positive arthritis, or enthesitis/spondylitis-related JIA. Objectives To evaluate the shifts from the original subtypes of JIA in the new disorder of early-onset ANA–positive JIA. Methods This study used data from the international PRINTO based registry regarding pharmacovigilance in JIA called Pharmachild.[3] For this analysis we used the data of 4,165 patients completely categorized following the ILAR ‘oligoarthritis’, ‘RF-negative polyarthritis’, ‘psoriatic arthritis’ and ‘undifferentiated JIA’ (UJIA) subtypes and with complete determination of ANA status. These patients were if possible reclassified in the early-onset ANA–positive JIA according to the provisional PRINTO classification criteria. Results Table 1 shows the characteristics of all 4,165 patients according to the ILAR criteria. Of this final set of 4165 patients, 1279 (30.7%) were ANA-positive and 957 (74.8%) classified into the PRINTO ‘early onset ANA-positive JIA’ category. Of these 957, 2 patients were RF-positive, which is an exclusion criterion for the ‘early onset ANA-positive JIA’ category and therefore were not categorized as early onset ANA-positive JIA. The female proportion was higher than in any ILAR subtype being 83.0% (793/955). The origin (ILAR categories) of the 955 patients in the ‘early onset ANA-positive JIA’ category consisted of 33.7% patients with persistent oligoarthritis (322/955), 24.7% (236/955) with extended oligoarthritis, 28.0% with RF-negative polyarthritis (267/955), 4.2% with psoriatic arthritis (40/955) and 9.4% with UJIA (90/955). Conclusion This study shows that of all ANA-positive JIA patients belonging to the ‘oligoarthritis’, ‘RF-negative polyarthritis’, ‘psoriatic arthritis’ and ‘UJIA’ ILAR subtypes, 74.8% met the criteria for the PRINTO ‘early onset ANA-positive’ category. The female proportion was higher than in any ILAR subtype being 83.0%. This new category consists largely of 3 ILAR subtypes: persistent oligoarthritis (34%), extended oligoarthritis (25%) and RF negative polyarthritis (28%). Further studies on these provisional criteria are ongoing. References [1] Petty RE, Southwood TR, Manners P et al. International League of Associations for Rheumatology Classification of Juvenile Idiopathic Arthritis: Second Revision, Edmonton, 2001. J Rheumatol. 2014 [2] Martini A, Ravelli A, Avcin T et al. Toward New Classification Criteria for Juvenile Idiopathic Arthritis: First Steps, PRINTO International Consensus. J Rheumatol. 2018 Oct 1 [3] Swart J, Giancane G, Horneff G et al. Pharmacovigilance in juvenile idiopathic arthritis patients treated with biologic or synthetic drugs: combined data of more than 15,000 patients from Pharmachild and national registries. Arthritis Res Ther. 2018 Dec 27 Disclosure of Interests Vera Mars: None declared, Joost F. Swart: None declared, Gabriella Giancane: None declared, Sytze De Roock: None declared, Anne Estmann: None declared, Marija Jelusic: None declared, Estefania Moreno Ruzafa: None declared, Jaime de Inocencio: None declared, Jelena Vojinovic: None declared, Agustin Remesal: None declared, M Laday: None declared, Rolando Cimaz: None declared, A V Cochino: None declared, Inmaculada Calvo Grant/research support from: received research grants from Pfizer, Roche, Novartis, Clementia, Sanofi, MSD, BMS and GSK, Consultant for: Advisory boards: Novartis, AbbVie, Speakers bureau: AbbVie, Roche, Novartis, SOBI, M Harjacek: None declared, Nico Wulffraat: None declared, Nicolino Ruperto Grant/research support from: The Gaslini Hospital, where NR works as full-time public employee, has received contributions (> 10.000 USD each) from the following industries in the last 3 years: BMS, Eli-Lilly, GlaxoSmithKline, F Hoffmann-La Roche, Janssen, Novartis, Pfizer, Sobi. This funding has been reinvested for the research activities of the hospital in a fully independent manner, without any commitment with third parties., Consultant for: Received honoraria for consultancies or speaker bureaus (