Introduction: TSI (Thyroid Stimulating Immunoglobulin) antibodies are a form of immunoglobulin G (IgG) that can bind to thyrotropin receptors on the thyroid gland causing over-production of thyroid hormones and hyperthyroidism. The presence of positive TSI is considered pathognomonic for Graves disease. Although the association between Graves disease and thyroid cancer (TC) has been reported in previous studies, the association between the levels of TSI antibodies and TC has not been investigated.
Methods: We included patients with Graves disease (with elevated TSI >1.75 iu/l) who had undergone total thyroidectomy. We measured TSH, anti-TPO, anti-TG and TSI antibodies. Patients were divided in two groups: patients with TC and patients whose pathology exam was negative.
Results: 115 patients (73 females) with mean age 51.47 years and mean TSI levels 8.83 IU/L were included. Eleven patients had TC. Among those patients, the mean TSI antibodies levels were 4.14 IU/L compared with patients who had not developed cancer, whose mean TSI antibodies levels were 9.26 IU/L (P=0.31).
Conclusions: Patients with Graves disease and TC had lower mean levels of TSI antibodies, though statistically not significant, in comparison with patients without TC.
18 - 21 May 2019
European Society of Endocrinology