T cell subsets and thyroid-stimulating antibodies in patients with Graves' disease in clinical remission.

Patients with active Graves' disease almost constantly show phenotypic alterations of T lymphocytes, such as an increase of "activated" cells recognized by various surface markers (e.g. la antigens). Such alterations are present in a certain number of apparently cured patients. The data herein reported refer to 25 patients with Graves' disease in clinical remission, in whom we have attempted to correlate T cell subset imbalances, the presence of thyroid-stimulating antibodies (TSAb) and the outcome of the subsequent relapse. The results obtained show a significant association between TSAb and the increase of la-positive T cells: no relationship was found between TSAb and other T lymphocyte subsets. One-year clinical follow-up of the patients enabled us to see relapses of hyperthyroidism in only two patients, who had shown in the first control both TSAb positivity and increased la-positive T cells. These results, in our opinion, suggest a role of la antigens expression on T lymphocytes in the clinical course of Graves' disease.