Two Cases-Report of Mild Graves’Disease Following Subacute Thyroiditis: More Evidence of the Role of Thyroglobulin in The Pathogenesis of Autoimmune Thyroid Disease?

Two middle aged Caucasian women with no previous history of thyroid or any other disease developed typical subacute thyroiditis (SAT) with minimal thyroidal radioactive iodine uptake. A few months after restoration of euthyroidism and discontinuation of corticosteroid therapy, they developed mild hyperthyroidism due to Graves’ disease (GD), as judged by the increased diffuse thyroidal radioactive iodine uptake. Both of them were genetically predisposed to the above diseases since they had the certain HLA haplotypes for SAT and GD. Also they developed antithyroglobulin antibodies during the period of GD. We hypothesize that genetic background and the increased load of Tg or other autoantigens released from the distracted damaged thyroid gland due to SAT triggered the development of GD a few months later.