COVID-induced thyroid autoimmunity.

Breakdown of self-tolerance to thyroid antigens (thyroperoxidase, thyroglobulin and the thyrotropin-receptor) is the driver of thyroid autoimmunity. It has been suggested that infectious disease might trigger autoimmune thyroid disease (AITD). Involvement of the thyroid has been reported during severe acute respiratory syndrome virus 2 (SARS-CoV-2) infection, in the form of subacute thyroiditis in subjects with mild coronavirus disease 19 disease (COVID-19) and of painless, destructive thyroiditis in hospitalized patients with severe infection. In addition, cases of AITD, both Graves' disease (GD) and Hashimoto's thyroiditis (HT), have been reported in association with (SARS-CoV-2) infection. In this review, we focus on the relationship between SARS-CoV-2 infection and occurrence of AITD. Nine cases of GD strictly related to SARS-CoV-2 infection and only three cases of HT associated to COVID-19 infection have been reported. No study has demonstrated a role of AITD as a risk factor for a poor prognosis of COVID-19 infection.