Abstract
The prevalence of ICA, thyroid-microsomal antibodies and gastric parietal cell antibodies was studied in 149 Japanese IDD, and the data were compared with the prevalence of the same antibodies in 150 Caucasians.
ICA were detected in 6 of 37 Japanese IDD (16.2%) during the first year after diagnosis and in 5.2% between 1 and 2 years after the onset of the disease. The prevalence of ICA decreased to 2.8% at 2 to 5 years and to 0% at 5-10 years and 10-20 years. This prevalence of ICA in Japanese was very low compared to that of Caucasians. In the Caucasian IDD, ICA were present in 55% of the patients during the first year and in 39% between 1 and 2 years after the onset of the disease. No correlation existed between the HLA types and ICA in the Japanese IDD. The prevalence of antithyroid-microsomal antibodies in the 150 Caucasian IDD was 16%, which was not significantly different from that in the 149 Japanese IDD (15%). However, the prevalence of gastric parietal cell antibodies was significantly higher (p<0.05) in the Caucasians (20%) than in the Japanese (9.3%).
The lower frequencies of ICA and gastric parietal cell antibodies in the Japanese subjects suggest that the Japanese may have a lower tendency to develop organ-specific autoimmunity. The pathogenic significance of such antibodies remains unclear, although the present findings do suggest that racial background may play a very important role in the incidence of autoantibodies.
