Association of HLA-DR tissue types with Graves' disease in Taiwan

To determine the association of HLA-DR tissue types and Graves' disease (GD) in Chinese residing in Taiwan, we studied HLA-DR antigens on 93 unrelated patients with Graves' disease, and 106 normal persons (N). The prevalence of DR2 (GD: 40.9%, N: 21.7%, pc = 0.028 where pc is the Fisher's probability times the numbers of antigens considered), DR9 (GD: 29%, N: 13.2%, pc = 0.048), DQw1 (GD: 58.1%, N: 39.6%, pc less than 0.003) and DRw53 (GD: 58.1%, N: 41.5%, pc less than 0.002) were significantly increased in patients with Graves' disease, while the prevalence was decreased significantly for DR3 (GD: 16.1%, N: 33.0%, pc = 0.031) and DRw52 (GD: 58.1%, N: 76.4%, pc = 0.01). When the combinations of DR2, DR3 and DR9 were compared with other HLA-DR antigens, DR3 remained less prevalent in GD; DR2/9 heterozygotes were strongly associated with GD; while neither DR2 nor DR9 remained significantly associated with GD when DR2/9 heterozygotes were removed from each. When we separated the patients into subgroups according to the onset of clinical symptoms occurring by the age of 35 years, there was no significant difference in the frequencies of HLA-DR antigens in those two subgroups. Patients with or without exophthalmos, antimicrosomal antibody or antithyroglobulin antibody had similar distribution of HLA-DR types. Our data suggested that in our area DR2 and DR9 played additive roles in the susceptibility of Graves' disease.