Aspects of autoimmune thyroid disease updated in this review include: immunoglobulin G4 (IgG4)-related thyroid disease (Riedel's thyroiditis, fibrosing variant of Hashimoto's thyroiditis, IgG4-related Hashimoto's thyroiditis, and Graves' disease with elevated IgG4 levels); recent epidemiological studies from China and Denmark indicating that excess iodine increases the incidence of Hashimoto's thyroiditis and hypothyroidism; immunomodulatory agents (ipilimumab, pembrolizumab, nivolumab) activate immune response by inhibiting T-cell surface receptors which down-regulate immune response, i.e., cytotoxic T-lymphocyte antigen 4 and programmed cell death protein 1 pathways; alemtuzumab is a humanised monoclonal antibody to CD52 which causes immune depletion and thyroid autoimmune disease especially Graves' hyperthyroidism; small molecule ligand (SML) agonists which activate receptors, SML neutral antagonists, which inhibit receptor activation by agonists, and SML inverse agonists which inhibit receptor activation by agonists and inhibit constitutive agonist independent signaling have been identified. SML antagonism of thyroid-stimulating hormone-receptor stimulatory antibody could treat Graves' hyperthyroidism and Graves' ophthalmopathy; and thyroxine treatment of subclinical hypothyroidism can produce iatrogenic subclinical hyperthyroidism with the risk of atrial fibrillation and osteoporosis. The increased risk of harm from subclinical hyperthyroidism may be stronger than the potential benefit from treatment of subclinical hypothyroidism.
Atrial Fibrillation ; Autoimmune Diseases ; Cell Death ; China ; CTLA-4 Antigen ; Denmark ; Epidemiologic Studies ; Graves Disease ; Hashimoto Disease ; Hyperthyroidism ; Hypothyroidism ; Immunoglobulin G ; Immunoglobulins ; Immunomodulation ; Incidence ; Iodine ; Osteoporosis ; T-Lymphocytes ; Thyroid Diseases* ; Thyroid Gland* ; Thyroiditis ; Thyroxine