Thyroid Autoantibodies in Egyptian Patients with Systemic Autoimmune Connective Tissue Diseases with or Without Clinical Thyroid Disorders

Abstract

heumatoid arthritis (RA) is a systemic autoimmune disease that is characterized by joint destruction and deformity, affecting millions of people worldwide. However, RA is more than a symmetrical inflammation of the joints, as increasing evidence supports a higher risk of other autoimmune disorders. Systemic lupus erythematosus (SLE) is an autoimmune disease affecting mostly joints, skin, blood vessels, heart, lungs, kidneys, liver, and nervous system, in which the immune system attacks tissues and cells leading to inflammation and damage. Systemic sclerosis (SSc) is a connective tissue disease characterized by degenerative microvascular phenomena and immune system activation, that lead to fibrosis of the skin and internal organs. Autoimmune thyroid diseases (AITDs) are considered to be organ specific and include Graves’ disease, and chronic autoimmune thyroiditis (CAT). The most common clinically apparent cause of CAT is Hashimoto's thyroiditis, an autoimmune disorder that often presents as a firm or hard goiter of variable size. Hashimoto's thyroiditis is characterized by thyroid autoantibodies and endocrine abnormalities.Although thyroid autoantibodies are specific to AITDs, they have been reported in patients with non-thyroid diseases and even in healthy individual.