TG and myasthenia gravis: Moreover, it is well known that the development of TLH is associated with several other autoimmune diseases (i.e., myasthenia gravis, systemic sclerosis, rheumatoid arthritis, systemic lupus erythematosus, pemphigus, polymyositis, and Addison’s disease) [9, 27], and this can be boosted by the coexistence of an excess of thyroid hormones in a background of thyroid autoimmunity.