Comparative Studies on Immunological Characteristics of IDDM among Asian Populations

Very little information is available related to possible differences in immunological characteristics of IDDM among Asian populations, though it has been reported that IDDM is associated with Bw54-DR4 and B17-DR3 in Japanese and Chinese, respectively. There is virtually no report related to comparative studies on Bf-DM association among Asian populations, while Bf-DM association is reported to be stronger than HLA-DM association in Caucasians. In the present paper, the results of our studies on anti-thyroid antibodies (ATA) of IDDM in Japanese, Chinese and Filipinos are presented. In Japanese, the incidence of ATA positive was higher in IDDM with a duration of less than one year (35.7%) than that in the patients with a duration of one year or more (12.5%). But, there was no such a duration dependent decrease in the incidences of ATA among Chinese or Filipino IDDM. The frequency of BfSS in Filipinos is lower than in Japanese or Chinese. However, no association was found between Bf phenotypes and IDDM in Asian populations. These results indicate that autoimmunity is transient in Japanese IDDM, but persistent in Chinese and Filipinos, and that it is too early to postulate in general that Bf-IDDM association in general populations is stronger than HLA-IDDM association.