Thyrotropin receptor gene expression in the association between chronic spontaneous urticaria and Hashimoto's thyroiditis

Background: Chronic spontaneous urticaria (CSU) may be associated with autoimmune thyroid diseases, and the Autologous Serum Skin Test (ASST) is an autoreactivity marker. The thyrotropin (TSH) and TSH receptor (TSHR) could play a role in the pathogenesis of CSU. The aim of this study was to evaluate ASST positivity and TSHR gene expression in healthy skin and ASST wheals in euthyroid women with CSU, with (14 patients) and without (15 patients) Hashimoto's thyroiditis (HT). Methods: ASST was performed and TSHR gene expression studied in wheals induced by ASST and in healthy skin. Results: ASST presented greater positivity (86% × 40%) and larger diameter (10.8 × 9.6 mm) in the HT group (P < 0.05). TSHR gene expression was higher in the ASST area and healthy skin of HT group (P < 0.01). Positive correlation of antibodies levels with ASST wheal measurements and TSHR gene expression was seen. Conclusions: Women with CSU and HT presented greater positivity and larger measurements for ASST and higher TSHR expression in the skin, suggesting association between CSU, thyroid autoimmunity, and TSHR.