Evaluation of thyroid function and anti-thyroid autoantibodies in systemic sclerosis

Parameters of thyroid metabolism, and the presence of anti-thyroid antibodies were investigated in 43 patients with systemic sclerosis. Anti-thyroid antibodies were detected in 14 cases. Elevated levels of anti-thyroglobulin antibodies were determined in 4 cases, anti-thyroid peroxidase (TPO) antibodies in 11, and anti-microsomal antibodies in 5. The detection of anti-TPO antibodies gave the most remarkable information about the presence of autoimmune thyroiditis. The patients with anti-TPO and/or reduced T3 concentration tended to have secondary Sjögren's syndrome. Our results provide further evidence that anti-thyroid antibodies might be responsible for the remarkable appearance of autoimmune thyroiditis in systemic sclerosis.