Antibodies against 1D, a recombinant 64-kDa membrane protein, are associated with ophthalmopathy in patients with thyroid autoimmunity.

We have tested for serum antibodies reactive with 1D, a recombinant 65-kDa human thyroid protein which is also expressed in eye muscle, in patients with thyroid autoimmunity and ophthalmopathy by immunofluorescence and SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. We also measured antibodies to a 64-kDa pig eye muscle membrane protein which is identified by SDS-PAGE and Western blotting, correlating the two reactivities. While antibodies to 1D, expressed in Chinese hamster ovary (CHO) cell membrane, were detected in approximately 40% of patients with ophthalmopathy, in both tests the greatest prevalence, by immunofluorescence, 73%, was demonstrated in patients with Graves' hyperthyroidism without clinically evident eye disease, although only 50% of these patients were positive in immunoblotting.