Thyroid stimulating antibodies in patients with Graves' ophthalmopathy

The possible pathogenetic role of thyroid stimulating antibodies (TSAb) was studied in 24 patients. The TSAb were measured by their ability to stimulate concentration of cAMP in human thyroid slices incubated in vitro with the immunoglobulins of these patients. The patients were divided in two groups: Group I, 16 patients with eye disease and hyperthyroidism and Group II, eight patients with eye disease but without hyperthyroidism. TSAb, were found to be high in 15 patients of the Group I (3.22 +/- 1.74 pmol cAMP/mg of wet tissue, mean +/- S.E.M.) whilst were normal in six patients of the Group II (0.98 +/- 0.53 pmol cAMP/mg of wet tissue, mean S.E.M.) (p < 0.001). These findings indicate that TSAb is not a marker of the Graves' ophthalmopathy and support the concept that hyperthyroidism and exophthalmos are two separate disorders.