Autoimmune thyroid disease in patients with rheumatic diseases.

Thyroid function abnormalities and thyroid autoantibodies have been frequently described in patients with rheumatologic autoimmune diseases, such as Sjögren's syndrome, rheumatoid arthritis, systemic lupus erythematosus and scleroderma. Limited data are available regarding the prevalence and clinical characteristics of autoimmune thyroiditis in other rheumatologic disorders, such as rheumatic fever and juvenile systemic lupus erythematosus. The authors review the association of endocrine autoimmune and rheumatic autoimmune diseases, assessing various age groups and clinical conditions. The bibliographic survey was conducted through the search for scientific articles indexed in the general health sciences databases, such as Latin American and Caribbean Health Sciences Literature (LILACS), Medline/PubMed, and Scientific Electronic Library Online (SciELO). The following descriptors were used: "rheumatic autoimmune diseases and autoimmune thyroid diseases"; "thyroid disorders and rheumatic diseases"; "thyroiditis and rheumatic diseases"; "autoimmune diseases and thyroid"; and "pediatric rheumatic diseases and autoimmune thyroid diseases". This study showed that, despite contradictory results in the literature, there is a greater prevalence of the association between autoimmune thyroid diseases and rheumatic diseases, highlighting the possibility of common pathogenic mechanisms among them.