Immunohistochemical expression of Claudin-1 in Hashimoto's thyroiditis and Graves' disease patients

Autoimmune thyroid diseases, including Graves’ disease (GD) and Hashimoto’s thyroiditis (HT), are complex diseases in which a combination of genetic susceptibility and environmental encounters leads to breakdown of immune tolerance. Epidemiological and histological data indicate that thyroid cancer (TC) frequently occurs in the context of HT (Guarino et al. 2010), and that the association between HT and TC is antibody specific (Azizi et al. 2014). Several authors reported overexpression of claudin-1, protein of tight junctions, in invasive tumor cells, including TC, and it seems to be an early step in carcinogenesis for at least some cancer types.