Background/Purpose: Behçet’s disease (BD) is a rare pediatric vasculitis with limited epidemiological data in Latin America centers, especially in children where initial symptoms can be non-specific and disease progression may be protracted. The frequency of HLA-B51, which is associated with increased disease risk, is also lower compared with countries along the Silk-Road. It is possible that in Brazil, a country characterized by mixed population, other HLA alleles might contribute to BD susceptibility. The objective of the study was to identify the HLA alleles in childhood-onset BD patients and characterize clinical manifestations and therapies associated with them.

Methods: The study included 32 childhood-onset BD patients followed at a tertiary and university Pediatric Rheumatology Center in Brazil, diagnosed ≤ 18 years-old, based on expert pediatric rheumatologists’ opinion and/or according to the international criteria for BD (ICBD) or the pediatric BD classification criteria (PEDBD). Medical records were reviewed to assess HLA alleles, clinical and therapeutic characteristics of these patients. For further analyses patients were classified according to the presence or absence of HLA-B51 and the groups were compared regarding demographic data, clinical characteristics and treatment.

Results: Demographic data of 32 childhood-onset BD patients were: median age of 4.5(0.5-12) years at diagnosis, female sex in 16(50%) and white ethnicity in 25(78%) of cases. HLA-B51 allele was identified in 16 of 32 patients (50%). Other HLA alleles were found as following: HLA-B15 (n=8), HLA-B35 (n=6), HLA-B42 (n=3), HLA-B53 (n=3), HLA-B39 (n=2), HLA-B58 (n=1), HLA-B57 (n=1), HLA-B52 (n=1) and HLA-B14 (n=1). The presence of other HLA alleles was significantly higher in patients with negative HLA-B51 compared to patients with positive HLA-B51 (75% vs. 38%, p=0.04). HLA-B51 negative patients were significantly older than HLA-B51 positive patients [7.5 (0.5–12) vs. 3 (0.5–11) years; p=0.02] at diagnosis, in contrast to female sex that was less frequent in the former group (31% vs. 69%, p=0.04). The frequency of patients that fulfilled at least one confirmation criteria (PEDBD and/or ICBD) was similar between groups (57% vs. 44%, p=0.72). Likewise, no differences were observed between the groups regarding clinical manifestations, including fever, oral/genital ulcers, articular, cutaneous, ocular, neurological and gastrointestinal involvement. Further analysis of treatment showed that colchicine use was also similar in both groups (94% vs. 98%, p=0.5). However, HLA-B51 negative patients significantly required the use of additional immunosuppressants agents (60% vs. 23%, p=0.05), especially corticosteroids (56% vs. 19%, p=0.03) and azathioprine (69% vs. 19%, p=0.006).

Conclusion: Patients who were negative for HLA-B51 but positive for other HLA alleles were diagnosed at a later stage and required multiple immunosuppressive therapy. These results indicate that in patients outside the Silk Road, other HLA alleles may be associated with BD and could lead to a delayed diagnosis.

« Back to ACR Convergence 2025

ACR Meeting Abstracts - https://acrabstracts.org/abstract/childhood-onset-behcets-disease-hla-alleles-role-on-diagnosis-and-treatment-in-a-latin-american-tertiary-center/