THU0385 COMPARISON OF CLINICAL AND DEMOGRAPHIC FEATURES OF JUVENILE SPONDYLOARTHRITIS BETWEEN ISRAELI AND US CHILDREN
Authors: Merav Heshin-Bekenstein, Naseem Ghantous, Irit Tirosh, Yonatan Butbul, Liora Harel, Yaniv Lakovsky, Pamela Weiss, Nadav Rappoport, Kimberly Dequattro, Emily von Scheven, Lianne S. Gensler, Amir Hendel, John Mackenzie, Gil Amarilyo
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Clinical observations among Israeli pediatric rheumatologists reveal that some of the clinical and demographic features of Israeli children diagnosed with Juvenile Spondyloarthritis (JSpA) are different as compared to the typical characteristics described in US studies. <h3>Objectives</h3> In this study, we compared clinical, laboratory and radiographic features to determine whether differences occur between the two populations of JSpA. <h3>Methods</h3> We performed a retrospective, cross-sectional, multicenter comparison of JSpA patients from 3 large Israeli pediatric rheumatology centers and a large US pediatric rheumatology center. Patients with a diagnosis of Juvenile Ankylosing Spondylitis (JAS) and/or Enthesitis-related Arthritis (ERA) were included. The demographic, clinical and imaging features of the subjects upon presentation were compared, including MRI of the sacroiliac joints. Inter Center Comparison (ICC) between the Israeli and US musculoskeletal radiologists was conducted. <h3>Results</h3> Overall 87 patients met the inclusion criteria (39 Israeli, 48 US). As compared to the US population, the Israeli population was less likely to be male (56% vs. 75%, p=0.11), and more likely to be older at time of diagnosis (14.3 vs. 11.9 years, p&lt;0.001). Upon presentation, axial symptoms (inflammatory back pain) and physical examination findings consistent with sacroilitis (SIJ tenderness, modified Schober test), were significantly more prevalent among Israeli patients (59% vs. 35.4%, 48.7% vs. 16.7%, and 41.2% vs. 21.5%, respectively, all p&lt;0.05), whereas peripheral arthritis and enthesitis were significantly more prevalent among the US patients (43.6% vs. 91.7% and 7.7% vs. 39.6% in Israeli patients vs. US patients, p&lt;0.05). For HLA-B27, 32% of the Israeli patients vs. 66.7% of the US patients were positive (p=0.007). In addition, of those who had imaging (N= 30 and N=37 for Israeli and US cohorts) 96.7% of the Israeli patients versus 29.7% of the US patients demonstrated positive MRI findings that were consistent with sacroiliitis (p&lt;0.001, overall N=67). An excellent level of agreement was observed between the Israeli and US musculoskeletal radiologists (kappa=0.9). <h3>Conclusion</h3> We found important distinctions between two populations with JSpA. Israeli children were more likely to present with axial disease, less likely to demonstrate HLA B27 carrier positivity, and more likely to demonstrate sacroiliitis on MRI than US children, who more commonly presented with peripheral arthritis and enthesitis, HLA-B27 positivity and negative MRI findings. These unique findings of the Israeli JSpA population, also as compared to descriptions of JSpA patients in the medical literature, point to environmental and/or population specific factors that merit additional studies in order to unravel the differences in disease presentation between the two countries.&nbsp; <h3>Reference</h3> [1] Shirley M. L. Tse; Ronald M. Laxer. New advances in juvenile spondyloarthritis. Nature Reviews Rheumatology, 2012, Vol.8(5), p.269–279. <h3>Disclosure of Interests</h3> Merav Heshin-Bekenstein: None declared, Naseem Ghantous: None declared, Irit Tirosh: None declared, Yonatan Butbul: None declared, Liora Harel: None declared, Yaniv Lakovsky: None declared, Pamela Weiss Consultant for: Dr. Weiss has served as a consultant for Lilly and Novartis., Nadav Rappoport: None declared, Kimberly DeQuattro: None declared, Emily von Scheven: None declared, Lianne S. Gensler Grant/research support from: Abbvie, Amgen, UCB Pharma , Consultant for: Novartis, Lilly, Janssen, Amir Hendel: None declared, John MacKenzie: None declared, Gil Amarilyo: None declared