POS1304 JUVENILE SYSTEMIC SCLEROSIS (JSSC) PATIENTS WITH OVERLAP CHARACTERISTICS DO NOT HAVE MILD DISEASE. RESULTS FROM THE JSSC INCEPTION COHORT. WWW.JUVENILESCLERODERMA.COM
Authors: I. Foeldvari, J. Klotsche, O. Kasapcopur, A. Adrovic, K. Torok, M. T. Terreri, A. P. Sakamoto, B. Feldman, V. Stanevicha, J. Anton, F. R. Sztajnbok, R. Khubchandani, E. Alexeeva, M. Katsikas, S. Sawhney, V. Smith, S. Appenzeller, T. Avcin, M. Kostik, T. Lehman, E. Marrani, D. Schonenberg, W. A. Sifuentes-Giraldo, N. Vasquez-Canizares, M. Janarthanan, M. Moll, D. Nemcova, A. Patwardhan, M. J. Santos, C. Battagliotti, L. Berntson, B. Bica, J. Brunner, R. Cimaz, P. Costa Reis, D. Eleftheriou, L. Harel, G. Horneff, S. Johnson, D. Kaiser, T. Kallinich, D. Lazarevic, K. Minden, S. Nielsen, F. Nuruzzaman, S. Opsahl Hetlevik, Y. Uziel, N. Helmus
Journal: Annals of the Rheumatic Diseases (2021)

Background: Juvenile systemic sclerosis (jSSc) is an orphan disease with a prevalence of around 3 in 1, 000,000 children. It is known that in pediatric jSSc cohorts, there are a significant number of patients with overlap features, such as arthritis and myositis. However, the disease burden between those with and without overlap features in jSSc has not been defined. Objectives: Compare the clinical phenotype between children with and without overlap features in the juvenile systemic scleroderma inception cohort (jSScC). Methods: A cross-sectional study was performed using baseline visit data. Demographic, organ system evaluation, autoantibody profile, treatment, and patient and physician reported outcome variables were extracted from jSScC. Comparison between patients with and without overlap features was performed using chi-square test and Mann Whitney U-test. Results: At the time of data extraction, 175 jSSc patients were enrolled in the cohort, 81% were Caucasian and 81% female. Mean disease duration was 3.1 year (±2.7). Mean age at Raynaud´s onset was 10 years (±3.8) and mean age of first non-Raynaud´s was 10.2 years (±3.8). Overlap features occurred 17% (n=30) of the cohort, 12.5% in the diffuse cutaneous (dc) jSSc and in 30% in the limited cutaneous (lc) jSSc. Significant differences in clinical characteristics were found between those patients with compared to without overlap characteristics. Patients with overlap features presented more frequently with Gottron papules (p=0.007), swollen joints (p=0.019), muscle weakness (p=0.003), and lung involvement documented by decreased DLCO &lt; 80% (p=0.06) and/or abnormal high resolution computed tomography (p=0.049). Anti-PM/Scl autoantibodies were also more common in this group (p=0.001). Significantly more patients without overlap features had Raynaud´s (p=0.006). Physician Global Assessment of disease activity was significantly higher in patients with overlap features (41 vs 34; p=0.041). (Table 1.) Table 1. Demographic and clinical characteristics of jSSc patients with and without overlap features. Whole Cohort N=175 Patients without overlap N=145 Patients with overlap N=30 P value Female to Male Ratio 4.3:1 (142/33) 4:1 (116/29) 6.5:1 (26/4) 0.395 Cutaneous subtype Diffuse subtype (N) 73% (128) 112 16 Limited subtype (N) 27% (47) 33 17 Mean disease duration (years) 3.1 (± 2.7) 3.2 (± 2.8) 3.1 (± 2.2) 0.291 Mean age of onset of Raynaud´s (years) 10.0 (± 3.8) 17 non-Raynaud 10.0 (± 3.8) 10 non-Raynaud 10.0 (± 3.7) 7 non-Raynaud 0.931 Mean age of onset of non-Raynaud´s (years) 10.2 (± 3.8) 10.2 (± 3.9) 9.8 (± 3.7) Disease modifying drugs (N) 88% (154) 89% (129) 83% (25) 0.388 Raynaud´s phenomenon 90% (158) 93% (135) 77% (23) 0.006 Anti-PMScl 18% (12/68) 9% (5/53) 47% (7/15) 0.001 Gottron Papules (N) 27% (46/171) 23% (33/144) 48% (13/27) 0.007 DLCO &lt;80% (N) 44% (39/88) 39% (28/71) 65% (11/17) 0.06 Abnormal findings in HRCT (N) 44% (59/133) 40% (43/107) 62% (16/26) 0.049 Proportion of patients with swollen joints 18% (32) 14% (21) 37% (11) 0.019 Muscle Weakness (N) 21% (31/149) 16% (20/123) 42% (11/26) 0.003 Physician global disease activity (0-100) min -max 35 (0-90) n=141 34 (0-90) n=114 41 (0-80) n=27 0.041 Conclusion: Results from this large international cohort of jSSc patients demonstrate significant differences between patients with and without overlap features. Patients with overlap have significantly more interstitial lung disease and more physician rated disease activity and should not be considered to have more “mild disease”. Supported by the “Joachim Herz Stiftung” Disclosure of Interests: None declared