Characteristics of pediatric Behçet's disease in Turkey and Israel: A cross-sectional cohort comparison

Background: Behçet's disease (BD) is a variable vessel vasculitis which is rare in children. Objective: We aimed to compare the main characteristics of pediatric BD patients from Turkey versus Israel. Methods: Three centers from Turkey and two centers from Israel participated in this study. The BD diagnosis was before 16 years of age and based on expert opinion. Disease activity was assessed with BD current activity form (BDCAF). Results: A total of 205 patients were included (165 from Turkey; 40 from Israel). HLA-B51 positivity (68.3% vs. 46.2%, p = 0.028), male gender (52% vs. 30%, p = 0.012), and skin involvement (55.2% vs. 22.5%, p<0.001) were more frequent among patients from Turkey compared to patients from Israel. Tests of pathergy and HLA-B51 were more frequently performed in patients from Turkey than patients from Israel (93.3% vs. 32.5%, p<0.001 and 97.6% vs. 65%, p<0.001; respectively). For BD classification in the whole group, International Criteria for BD (ICBD) had the highest sensitivity (73.2%), followed by pediatric BD (PED-BD) (47.8%), and The International Study Group (ISG) (42%) criteria sets. The most commonly prescribed drug was colchicine in the whole group (96.6%). Significantly more patients were treated with corticosteroids (50% vs. 28.5%, p = 0.006), methotrexate (17.5% vs. 3%, p = 0.002), and nonsteroidal anti-inflammatory drugs (12.5% vs. 1.8%, p = 0.007) in Israel than in Turkey. The median BDCAF values were higher at the first visit for patients from Turkey compared to those in Israel (4 vs. 2, p<0.001). Conclusion: This is the largest cohort of pediatric BD reported to date. The disease characteristics significantly differ among pediatric BD patients from Turkey and Israel, which may be due to different ethnicity and environmental factors.