<scp>HLA</scp> ‐ <scp>B51</scp> Positivity Correlates With Symptom Completeness From Recurrent Aphthous Stomatitis to Complete Behçet's Disease

HLA-B51 is well-established as a genetic risk factor for the development of Behçet's disease (BD), and its association with certain clinical manifestations has been documented. However, there is a lack of comprehensive research examining its role in the overall symptom completeness and full clinical expression of the disease. We performed a retrospective review of medical records from 1203 patients treated at a tertiary hospital between June 2012 and June 2017. Data regarding HLA-B51 status and clinical conditions were extracted, and patients were classified according to the "Revised Japanese Diagnostic Criteria for Behçet's disease (1987)", resulting in 878 patients diagnosed with complete (n = 250) and incomplete (n = 628) BD. Among these patients, 400 (45.6%) were tested positive for HLA-B51, with the positivity rate progressively increasing with the severity of symptoms. Male patients exhibited a higher likelihood of HLA-B51 positivity (61.9%) and a greater prevalence of skin and ocular symptoms, while female patients showed a higher incidence of erythema nodosum (42.2%) and genital ulcers (91.0%). Notably, a positive correlation was observed between skin lesions and genital ulcers, whereas ocular symptoms demonstrated a negative correlation with both skin and genital manifestations. This study underscores the significant impact of HLA-B51 positivity on the clinical presentation of BD. Insights gained from this research can enhance our understanding of genetic influences on symptom expression, ultimately leading to diagnostic and therapeutic approaches for patients with the disease.