Association of MICA gene and HLA-B*5101 with Behcet's disease in Greece

PURPOSE. Behcet's disease (BD) is known to be associated with HLA-BSI in ma ny different ethnic groups. Recently MICA, a member of a novel family of th e human major histocompatibility complex (MHC) class I genes termed MIC (MH C class I chain-related genes), was identified near the HLA-B gene, and a t riplet repeat microsatellite polymorphism was found in the transmembrane (T M) region. Because a strong association with ED of one particular MICA-TM a llele, BG, was shown in a Japanese population, the present study was conduc ted to investigate microsatellite polymorphism in Creek patients with ED to know whether this association is generally observed in ED occurring in oth er populations. METHODS. Thirty-eight Creek patients with ED and 40 ethnically matched cont rol subjects were examined for MICA microsatellite polymorphism using polym erase chain reaction (PCR) and subsequent automated fragment detection by f luorescent-based technology. RESULTS. Similar to the Japanese patients with ED, the phenotype frequency of the MICA-TM AG allele was significantly increased in the Creek patients with ED (50.0% in control subjects versus 86.8% in ED cases), with an odds ratio (OR) of 6.60 (P = 0.0012). The MICA-A6 allele was found in a high fre quency both in males and females (weighted OR = 6.68; P = 0.0017). No assoc iation was found between the AG allele and several disease features. A stro ng association exists between the MICA-TM A6 allele and the B*5101 allele i n both the control subjects and patients with ED (weighted OR = 44.39; P = 0.0000023). CONCLUSIONS. This study revealed in Creek patients a strong association of ED with a particular MICA-TM allele, MICA-A6, providing insight into the mo lecular mechanism underlying the development of ED.