Autoantibodies and autoimmune diseases in young diabetics.

Another autoimmune disease was found to accompany insulin dependent diabetes mellitus (IDDM) in 14% of the young diabetics (n = 14) studied. Thyroid autoimmune disease was the most common of the accompanying autoimmune diseases, and was detected in 11% (n = 15) of the patients. Two thirds of the IDDM patients with autoimmune thyroiditis were hypothyroid, one was hyperthyroid, and 20% lacked detectable thyroid antibodies when thyroid disease was diagnosed. Coeliac disease was found in 2% of the patients, and one had Addison's disease. Autoantibodies were found in one third of the patients. Thyroid microsomal antibodies were detected in 22% of the patients, IgA anti-gliadin in 11%, gastric parietal cell antibodies in 3% and rheumatoid factor in 7%. Autoimmune disease and the relevant autoantibodies coexisted in 11% of the patients. Autoimmune disorders and autoantibodies were not associated to any particular HLA type. The distribution of the HLA-types in the patients was unusual in that the frequency of HLA-DR3 was not increased. The value of autoantibody tests in the diagnosis of functional disorders of the thyroid and of coeliac disease are discussed.