Background: 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 compared to the characteristics described in US studies.
Methods: We performed a retrospective, cross-sectional, multicenter cohort study of JSpA patients among 3 large Israeli pediatric rheumatology centers (Schneider, Tel-Hashomer, Rambam) and compared demographic and clinical features to an American cohort (University of California San Francisco) including subjects diagnosed with JSpA.
Results: Overall 87 patients (39 Israeli and 48 American patients) met the inclusion criteria. Axial symptoms and physical examination findings of sacroiliac joint tenderness upon presentation were found to be more prevalent among Israeli patients (p<0.05), whereas peripheral signs and symptoms, including arthritis and enthesitis were found to be more prevalent among American patients. 96.7% of Israeli patients vs. 29.7% of American patients demonstrated positive findings of sacroiliitis on MRI upon presentation (p<0.001). The prevalence of HLA-B27 positivity was 32% and 66.7% in the Israeli and the American cohorts, respectively (p=0.007).
Conclusion: The majority of Israeli children diagnosed with JSpA demonstrate different clinical features compared to other patient populations, emphasizing the axial involvement upon presentation and low HLA-B27 positivity prevalence. Further studies are needed to explore the genetic and environmental factors that are associated with these findings.
