Studies of Cell-Mediated Immunity (CMI) in Relatives of Patients with Graves' Disease*

Abstract

Sixty-five relatives of patients with Graves' disease were studied with respect to their immunological status using the E-rosette counts, E-rosette inhibition test, migration inhibition factor (MIF) in response to thyroid antigens, and thyroid antibodies. Seventy-six percent of the relatives showed significant anti-thyroglobulin titers. Eighty-five percent of relatives exhibited evidence of cell-mediated immunity (CMI). The most consistently positive test was the anti-thymocyte globulin (ATG) E-rosette inhibition test, taken as a measure of T lymphocyte sensitization. Inhibition concentrations (dose of ATG necessary to inhibit rosette formation by 25%) showed a continuous gradation from the normal range to values consistent with Hashimoto's thyroiditis. MIF was present in 54% of the relatives studied and similar results were obtained for E-rosette counts. These observations suggest that the inheritance of the phenomenon of cell-mediated immunity is a dominant in these families