AB0161 Clinical and serologic characterisation of 72 juvenile idiopathic arthritis portuguese patients

Abstract

Background Juvenile Idiopathic Arthritis (JIA) is a heterogeneous group of systemic inflammatory disorders affecting children below the age of 16 years. Objectives Methods We have used the ILAR revised classification criteria for JIA in order to evaluate the clinical patterns of disease of 72 patients regularly followed in our Unit. Results 72 children with the diagnosis of JIA are being regularly followed: 41 (57%) females and 31 (43%) males. The mean age of diagnosis was 6.6 ± 4.9 years (females) and 8.0 ± 4.5 years (males). The mean follow-up period was 5,44 ± 4.0 years, with a mean disease duration of 6,31 ± 4.6 years. Patients were classified in JIA subtypes: systemic – 16 (22,2%); polyarthritis – 6 (8,3%); oligoarthritis – 35 (48,6%): extended – 9 (12,5%) and persistent ? 26 (36,1%); enthesitis ? 13 (18,0%); psoriatic arthritis ? 2 (2,7%). The knee was the most commonly involved joint in all subtypes: 77.7% of the extended oligoarthritis patients, 92% of the persistent oligoarthritis, 75% of the systemic arthritis, 83.3% of the polyarthritis, 100% of the psoriatic arthritis and 61.5% of the enthesitis related arthritis patients. The second most affected joint was the elbow in extended oligoarthritis (66.6%), the hand in persistent oligoarthritis (30.7%), the wrist in systemic arthritis (50%); the hand and wrist in polyarthritis (83.3%) and psoriatic arthritis (100%), the ankle and hip in enthesitis related arthritis (53.8% and 46.1%). Antinuclear antibodies (ANA) were presented in 19 (26.3%) children: 4 (44.4%) extended oligoarthritis patients; 11 (42.3%) persistent oligoarthritis patients; 2 (12.5%) systemic arthritis patients and 2 (15.3%) enthesitis related arthritis. Rheumatoid factor (FR) was only present in 3 (50%) children with polyarthritis and HLA-B27 was only found in 8 (66.6%) children with enthesitis related arthritis. Uveitis affected 10 (13.8%) children: 6 (23.1%) with persistent oligoarthritis, 2 (22.2%) with extended oligoarthritis, 1 (6.2%) with systemic arthritis and 1 (7.6%) with enthesitis related arthritis. Uveitis and ANA were only observed in 4 (11.4%) children with oligoarthritis: 3 with persistent oligoarthritis (11.5%, 27,3% of the ANA positive patients) and 1 with extended oligoarthritis (11,1%, 25% of the ANA positive patients). No case of severe uveitis was detected. Erosions were present in 4 (5.5%) children: 2 (33.3%) with polyarthritis, 1 (38.4%) with persistent oligoarthritis and 1 (11.1%) with extended oligoarthritis. 17 (23.6%) patients were treated with methotrexate (MTX): 5 (55.5%) with extended oligoarthritis; 3 (11.5%) with persistent oligoarthritis; 6 (37.5%) with systemic arthritis; 2 (33.3%) with polyarthritis and 1 (50%) with psoriatic arthritis. 106 intraarticular (i.a.) injections of steroids were administered in 36 (50%) children: knee in 25 (69.6%) cases, ankle in 9 (25%) cases, elbow in 4 (11.1%) cases and hand small joints in 4 (11.1%) cases. The i.a. injections were administered in 16 patients with persistent oligoarthritis, 8 with extended oligoarthritis, 5 with systemic JIA and 7 in the other subtypes. Conclusion The pattern of joint involvement is similar to previous published results. Although, uveitis was less clearly associated with the presence of antinuclear antibodies and also appeared to be milder in comparison to other series. I.a. injections were the mainstay of therapy in the persistent oligoarthritis subtype, but MTX had to be used in 55,5% of the extended oligoarthritis group, stressing the importance of differentiating this 2 patterns of involvement.