2534: Frequency of Ocular and Gastrointestinal Lesions Is Increased in Japanese Behçet’s Disease Patients with HLA-B61

Background/Purpose: The associations of HLA-B51 and HLA-A26 with the onset of Behçet’s disease (BD) are well established. Although BD manifests with a variety of clinical lesions, the relationships between specific HLA types and individual disease manifestations—especially HLA types beyond B51 and A26—remain unclear.
This study aimed to investigate the associations between HLA-A and HLA-B alleles and clinical lesions in Japanese patients with BD.

Methods: This retrospective study included patients with BD who visited Kagawa University Hospital in 2024 and whose HLA-A and HLA-B types had been analyzed. All patients were ≥18 years and met the International Criteria for Behçet’s Disease. The frequency of HLA-A and HLA-B alleles in BD patients was compared with that in healthy Japanese individuals. Additionally, the prevalence of specific BD manifestations was analyzed according to HLA alleles. Statistical analyses were performed using the Mann–Whitney U test and Fisher’s exact test.

Results: A total of 36 patients were included (mean age 44.3 years; 75.0% female; mean disease duration 8.6 years). As previously reported, HLA-B51 and HLA-A26 were significantly more prevalent in BD patients than in healthy controls (36.1% vs. 17.6%, p = 0.0074; 44.4% vs. 20.7%, p = 0.0014, respectively). No significant differences were found for other HLA alleles.
Among BD patients, those with HLA-B61 had significantly higher frequencies of ocular and gastrointestinal involvement compared to those without HLA-B61 (61.5% vs. 21.7%, p = 0.0298; 30.8% vs. 4.4%, p = 0.0470, respectively). No significant differences in age, sex, or disease duration were observed between HLA-B61–positive and –negative groups. Additionally, patients with HLA-A2 were significantly less likely to present with arthritis (p = 0.0144).

Conclusion: While HLA-B61 has been previously linked to ankylosing spondylitis and Crohn’s disease, this study suggests a novel association between HLA-B61 and ocular and gastrointestinal manifestations in Japanese patients with Behçet’s disease. Further studies with larger cohorts are warranted to confirm these findings.