The researchers had several significant findings. They reconfirmed a strong association of Behcet's disease with the HLA-B51 region of the MHC and identified an independent association area within the MHC. The researchers also identified associations on chromosome 1 with a known variant of the IL10 gene and with a variant located between the genes for the IL-23 receptor (IL23R) and a component of the IL-12 receptor (IL12RB2). Interestingly, the genetic variants found to be associated with Behcet's disease in the Turkish population were identical to those independently identified in the Japanese population, lending credence to a genetic link between two disparate populations separated by thousands of miles, but tied together by the ancient trading route.

The most encouraging finding resulted from an analysis of the function of the IL10 gene variant. They found that cells from blood donors who had two copies of the IL10 gene variant produced significantly lower levels (approximately one-third) of IL-10 protein compared to people with one or two normal IL10 genes. Since the function of IL-10 is to decrease inflammation, the researchers suggest that low levels of IL-10 protein, in conjunction with external triggers, might be a risk factor for Behcet's disease. Additionally, IL10 has an extensive disease history, with different variants of IL10 having been associated with other autoimmune and autoinflammatory diseases, including ulcerative colitis, type 1 diabetes, systemic lupus erythematosus, and severe juvenile rheumatoid arthritis. These findings suggest that there may be possible therapeutic targets that can be examined in future studies.

niams.nih/Health_Info/Behcets_Disease/default.asp 

Source: NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases