POS1320 DIFFERENCES IN CLINICAL MANIFESTATION AND DISEASE ACTIVITY OF PEDIATRIC BEHÇET DISEASE: A CROSS-SECTIONAL COHORT COMPARISON BETWEEN TURKEY AND UNITED STATES
Authors: E. Demirkaya, M. Romano, C. Swearingen, O. Kasapcopur, B. Makay, S. Özen, Y. Yazici
Journal: Annals of the Rheumatic Diseases (2021)

Background: Behçet disease (BD) is a systemic inflammatory disease which is rare in children. It is also known a higher prevalence along the ancient Silk Road and the eastern Mediterranean, especially in Turkey. Despite the presence of diagnostic criteria, the diagnosis of pediatric BD is still difficult due to atypical findings and the heterogeneity of the disease. While descriptive cohort studies in pediatric BD exist, direct comparison studies of clinical manifestations and disease activity between patients from different countries are scarce. Objectives: We aimed to compare the main clinical features and activity of pediatric BD patients from Turkey versus United States (US). Methods: The BD was diagnosed before 18 years of age and based on expert opinion. Disease activity was assessed with Physician Global Assessment (PhGA), Parents/Patient Global Assessment (PWPGA) and Behçet’s Syndrome Activity Scale (BSAS) were administered to patients from both countries. Results: A total of 161 patients were included (61 from Turkey; 100 from US). Males were more prevalent among patients from Turkey than among patients from US (63.9% vs. 32%, respectively, p &lt; 0.001). Disease duration at the diagnosis was significantly longer in US p=0.002). Oral aphthosis was the most common symptom in both groups (96.7% for Turkey and 73% for US), however a significant difference was found (p&lt;0.001). Genital ulcers were documented in 47% of US patients and in 41.4% of Turkish patients (p=0.5). There were significant difference between two groups with regards to the ocular involvement: uveitis and posterior uveitis were more frequently in Turkish patients (p=&lt;0.001 respectively) while retinal vasculitis was no seen in US patients (p&lt;0.001). Erythema nodosum occurred more frequently in Turkish group (p&lt;0.001). The pathergy test was reported as positive in 22 (37.3%) patients in Turkey and 2 (2.3%) in USA in our study (p&lt;0.001). Gastrointestinal and neurological involvement did not differ between cohorts. The rate of colchicine and oral steroids was similar. Azathioprine, cyclosporine and methotrexate usage was more frequent in Turkey (p=0.005, p=0.007, p=0.033, respectively) and infliximab was administered just in the US cohort (p = 0.002). PhGA and BSAS scores were higher in patients from Turkey (p=0.003 and p=0.017 respectively) and no significant differences were seen in PWPGA scores. Conclusion: Disease activity and clinical features seem to be different between the two countries which may be linked to the environmental factors, referral patterns and immune system responses in the expression of this disease. The diagnosis of BD in the US was based on both fulfilling the ISBD criteria and in cases when criteria were not met, based on treating physician assessment, which can explain some of the differences in disease presentation. In addition, there were differences in regard to clinical practice and treatment patterns between two countries. Increasing knowledge about heterogeneity of BD will improve the ability of diagnosis, development of new diagnostic criteria, and management of BD. References: [1] Butbul Aviel Y et al, Semin Arthritis Rheum. 2020 Disclosure of Interests: None declared