Graves' hyperthyroidism, ophthalmopathy and pretibial myxedema may be components of a multi-system autoimmune disorder

Abstract

The authors have used the indirect immunofluorescence test to investigate reactivity of sera from patients with Graves' disease with porcine extraocular muscle and other tissue substrates. Sera from 75% of patients with thyroid-associated ophthalmopathy (TAO) contained one or more antibodies reactive with extraocular muscle, compared to 32% of those with Graves' hyperthyroidism without the eye disorder, 41% of patients with Hashimoto's thyroiditis, and 16% of normals. Antibodies reactive with a non-organ specific connective tissue antigen(s), seen as fluorescence of the interstitium and endomysium, were found in sera from 10% of patients with TAO and 16% of those with Graves' hyperthyroidism, but not from any patient with Hashimoto's thyroiditis or normal subject. Antinuclear antibodies were detected in sera from 31% of patients with TAO, but from only 8% with Hashimoto's thyroiditis, in no patient with Graves' hyperthyroidism and in only 3% of normal subjects. The finding of a high prevalence of antinuclear antibodies and, less often, anti-connective tissue antibodies in patients with thyroid autoimmunity and ophthalmopathy, is consistent with Graves' disease being a ‘collagen-like disorder’. The possible reasons why inflammation and resulting tissue damage are mainly found in the thyroid, connective tissue of the skin and orbit, and skeletal muscle are discussed.

Key Words:

• Eye muscle antibodies
• anti-nuclear antibodies
• myopathy
• immunofluorescence
• 64 kDa protein