Adrenal autoantibodies and Addison disease in insulin-dependent diabetes mellitus.

Stored sera from 466 patients with insulin-dependent diabetes mellitus and from 144 controls were examined for organ-specific antibodies to human adrenal cortex. Adrenal antibodies were found in seven of the patients with IDDM (1.5%) and in one control (0.7%). None of 91 black patients with IDDM had adrenal antibodies. All of the seven patients with adrenal antibodies had other organ-specific antibodies. Three had clinical hypothyroidism and one was thyrotoxic. All of these seven patients had a HLA-B8-bearing haplotype, suggesting that the B8-bearing haplotype confers an extremely high "relative risk" for adrenal autoimmunity in IDDM. Organ-specific autoimmune disease and/or organ-specific antibodies were found in 30% of the first-degree relatives of these eight probands with the adrenal antibodies (seven with IDDM and one control). We conclude that screening patients with IDDM for adrenal antibodies of low yield (1.9% among white patients). Further, adrenal antibodies may be present for at least two years without the development of Addison disease. Antibodies reactive only to the zona glomerulosa of the adrenal cortex may be benign. Patients with IDDM and thyroid microsomal antibodies are more likely to have adrenal antibodies (6.5%), as are patients with IDDM and a B8-bearing haplotype and those with IDDM and family histories of organ-specific autoimmunity.