Ab1424 clinical variability in patients diagnosed of juvenile idiopathic arthritis with positive and negative antinuclear antibodies (ana)

Background Juvenile Idiopathic Arthritis (JIA) involves a set of chronic arthritis of onset in childhood. JIA can be splitted into 7 categories based on the classification of the International League of Associations for Rheumatology (ILAR): systemic arthritis, oligoarthritis, rheumatoid factor (RF) negative polyarthritis, RF positive polyarthritis, enthesitis related arthritis, psoriatic arthritis, undifferentiated arthritis. In addition to this classification, some authors propose differentiating between patients who have positive (+) and negative (-) ANA in serum because there could be differences between these two subgroups, raising the possibility of homogenizing subtypes based on this 1 . Objectives To describe the variability of extra-articular manifestations, treatment and prevalence of the different JIA subtypes between patients who have positive and negative ANA in serum. Methods Cross-sectional descriptive study in 68 patients with JIA according to ILAR criteria visited in the transitional consultation of a Spanish tertiary-level hospital. Clinical features, analytical and treatment data were collected, and patients were divided according to ANA+ or ANA- in serum. A >1/80 title of ANA determined by IFI on at least 2 occasions was considered positive. Subsequently, the qualitative data was analyzed using Chi-Square test, and the means were compared using ANOVA analysis. Results 68 patients were included in the study. 33 were grouped in ANA- and 35 in ANA+. The ANA+ group was composed with 28 women (80%) and the ANA- group was made up with 18 women (54.44%) (p= n.s.). The mean age of diagnosis was 11 years old in the ANA- group and 9 years old in the ANA+ group. Variable (n ) ANA - ANA+ P-value N=33 N=35 n(%) n(%) Subtype Oligoarthritis (20) 3 (9.09%) 17 (48.57%) <0.001 RF(-) polyarthritis (14) 8 (24.24%) 6 (17.14%) 0.6719 RF(+) polyarthritis (4) 0 (0%) 4 (11.43%) 0.1372 Enthesitis related arthritis (14) 11 (33.33%) 3 (8.57%) 0.0216 Systemic arthritis (6) 6 (18.18%) 0 (0%) 0.0268 Psoriatic arthritis (4) 2 (6.06%) 2 (5.71%) 0.9999 Undifferentiated arthritis (6) 3 (9.09%) 3 (8.57%) 0.9999 Clinical features Psoriasis (8) 2 (6.06%) 6 (17.14%) 0.2979 Uveitis (10) 3 (9.09%) 7 (20%) 0.354 Enthesitis (9) 3 (9.09%) 6 (17.14%) 0.5344 Oral and genital thrush (14) 7 (21.21%) 7 (20%) 0.9999 Raynaud (6) 3 (9.09%) 3 (8.57%) 0.9999 Analytical HLAB27+ (20) 12 (42.86%) 8 (27.59%) 0.3523 RF+ (7) 1 (3.57%) 6 (18.18%) 0.1673 CCP- antibodies+ (9) 2 (6.06%) 7 (20%) 0.1811 Treatment sDMARD (31) 12 (36.36%) 19 (55.88%) 0.1748 bDMARD (30) 13 (39.39%) 17 (48.57%) 0.6049 Corticosteroids (6) 5 (15.15%) 1 (2.86%) 0.1742 Oligoarticular JIA was more frequent in the ANA+ group (48.57%) than in the ANA- (9.09%), being this difference statistically significant. Enthesitis related arthritis was more frequent in the ANA- group (33.33%) than in the ANA+ (8.57%), as it was systemic arthritis (18.18% in ANA- and 0% in ANA+), both differences being statistically significant. Uveitis, psoriasis and the use of sDMARD were more frequent in the ANA+ and corticosteroid use was more frequent in ANA- patients, but without reaching statistical significance. Conclusion In our study, as in the literature, the oligoarticular JIA type occurred more frequently in the ANA+ group, while enthesitis related arthritis and systemic arthritis were more frequent in the ANA- group. Although the treatment patterns and the prevalence of psoriasis and uveitis appear to differ between the two groups we did not find statistically significant difference. This could be due to the small number of patients included, with the possibility that it could be corrected if the sample was expanded. Reference [1] Ravelli A, Varnier GC, Oliveira S, Castell E, Arguedas O, Magnani A, et al. Arthritis Rheum. 2011;63(1):267–75. Acknowledgements: NIL. Disclosure of Interests None Declared.