The cytokine storm and thyroid hormone changes in COVID-19

Background COVID-19 is now a worldwide pandemic. Among the many extra-pulmonary manifestations of COVID-19, recent evidence suggested a possible occurrence of thyroid dysfunction. Purpose The Aim of the present review is to summarize available studies regarding thyroid function alterations in patients with COVID-19 and to overview the possible physio-pathological explanations. Conclusions The repercussions of the thyroid of COVID-19 seem to be related, in part, with the occurrence of a cytokine storm that would, in turn, induce a non-thyroidal illness. Some specific cytokines and chemokines appear to have a direct role on the hypothalamus-pituitary-thyroid axis. On the other hand, some authors have observed an increased incidence of a destructive thyroiditis, either subacute or painless, in patients with COVID-19. The hypothesis of a direct infection of the thyroid by SARS-Cov-2 stems from the observation that its receptor, ACE2, is strongly expressed in thyroid tissue. Lastly, it is highly probable that some pharmaceutical agents largely used for the treatment of COVID-19 can act as confounding factors in the laboratory evaluation of thyroid function parameters.

Automated summary

COVID-19 may lead to thyroid dysfunction, possibly related to cytokine storm, direct infection of the thyroid, and certain pharmaceutical treatments.