[Analysis of HLA-DQWa antigen ethnic polymorphism among a Japanese and Caucasian population and an association with Harada's disease].

A novel HLA-DQ antigen, DQWa was analysed with its serological, immunochemical, and molecular biological polymorphism. Furthermore, A disease association with DQWa was analysed by investigating HLA antigen frequencies of 24 patients with Harada's disease. DQWa was in linkage disequilibrium mainly with DR4-Dw15 in Japanese, and with DRw8 -Dw8 in Caucasians. The former haplotype was observed only in Japanese. A significant increase of DQWa was observed in the patients with Harada's disease (73.9% compared with 35.9% of the control, chi 2 = 9.77, P less than 0.005, Pc less than 0.05, Relative risk = 5.17). DQWa antigen molecules were different from each other between Japanese and in Caucasians, when they were analysed immunochemically by two dimensional electrophoresis, or molecular biologically by restriction fragment length polymorphism analysis. These results suggest that HLA-DQWa antigen may play a role in the pathogenesis of Harada's disease, which is seen only in Japanese.