Thyroglobulin mRNA expression in peripheral blood lymphocytes of healthy subjects and patients with thyroid disease

BackgroundThyroglobulin (Tg) mRNA is expressed focally in thyroid tissue. In recent years, the Tg gene has been detected in other tissues, including lymphocytes, although the significance of its presence has not been elucidated yet. We measured Tg mRNA expression in the lymphocytes of healthy subjects and those with thyroid disease.MethodsAnalysis of the quantification of Tg mRNA from 20 healthy subjects and 47 subjects with thyroid disease was carried out by real-time PCR. Furthermore, in cultured lymphocytes we compared changes in Tg mRNA expression following stimulation with TSH.ResultsTg mRNA was detected in the lymphocytes of all subjects. Tg mRNA in the lymphocyte sequence matched that derived from thyroid tissue, and mRNA levels were higher in subjects with thyroid disease than in healthy subjects. Following lymphocyte stimulation, Tg mRNA levels were observed to be increased 2.7-fold in Graves' disease and 1.6-fold in chronic thyroiditis compared to healthy subjects.ConclusionsTg mRNA in the lymphocytes was quantified by real-time PCR. The levels of Tg mRNA in the TSH-stimulated lymphocytes were noticeably increased in subjects with thyroid disease. These results suggest an interesting relationship between production of Tg antigen in peripheral blood and autoimmunity in thyroid disease.