Epidemiologic and Etiological Features of Korean Patients With Behçet's Disease

Abstract

Behçet's disease (BD) is a multisystem disease in which environmental factors provoke an adverse immune response in patients with genetic susceptibility towards BD, subsequently leading to a cascade of dysregulated inflammation throughout the body. It is particularly prevalent in regions spanning the ancient Silk Road, including Korea, where the first known case of BD was reported in 1961. We summarize the history, epidemiology, and clinical presentation of BD in Korea, highlighting the clinical tendencies that are particularly seen in the Korean BD population as compared to European populations. Analysis of epidemiologic trends over the past three decades in Korea shows a decreasing prevalence of complete BD and a higher prevalence of intestinal BD. We also discuss the ever-evolving understanding of the pathogenesis of BD, noting the complex interplay among genetics, environment, and immunology. The HLA-B51 allele is the most significant known genetic risk factor in developing BD. We also discuss more recently studied associations between BD and immune factors such as IL-10, IL-23R-IL-12RB2, IL-1A-IL-1B, CCR1, ERAP1, and the GIMAP cluster, the last of which has been found to have an association with BD specifically in Korea. Environmental factors such as pollution and microbials are often the inciting event in developing BD, as they trigger an imbalanced immune response in genetically susceptible individuals, one that has been often found to exhibit an aberrant Th1/Th17 response. There would be value to further studying the pathogenesis and clinical characteristics of Korean BD.

Keywords: Behçet syndrome; Epidemiology; Genome-wide association studies; HLA-B51.

Figure 1

Clinical features of recurrent oral aphthous ulcers. (A) Minor ulcers, (B) major ulcers, (C) herpetiform ulcers. Ulcers ≤1 cm are considered minor ulcers while larger ulcers are considered major ulcers. Multiple scattered ulcers of several millimeters are considered herpetiform ulcers. Major ulcers may cause mucosal scarring and persist several weeks or longer.

Figure 2

Cutaneous manifestations of Behçet’s disease (BD). (A) Erythema nodosum-like lesion (arrow) and concurrent papulopustular lesions (white arrowheads) in lower leg. (B, C) Papulopustular lesion on trunk (B) and a scrotal ulcer in a male patient with BD.