Six Humanitas specialists have successfully published in the European Journal of Endocrinology the findings of their THYCOV study, aimed at analyzing the links between the COVID-19 infection and the inflammation of the thyroid. Professor Andrea Lania, Head of the Department of Endocrinology, Medical Andrology and Diabetology, Professor Gherardo Mazziotti, Dr. Maria Teresa Sandri, Dr. Miriam Cellini, Dr. Marco Mirani, and Dr. Elisabetta Lavezzi have analyzed throughout March 2020 the symptoms and the clinical course of 287 patients, including 193 men and 94 women, treated at Humanitas for COVID-19.

The doctors designed the study starting from the working hypothesis that the SARS-CoV 2 virus can directly attack the thyroid gland causing a destructive inflammatory process. This effect is exacerbated by the action of the cytokines produced in response to the Covid-19 infection, similarly to what is frequently observed in patients treated with immunomodulating drugs for cancerous, autoimmune or infectious diseases. While there was previously only scarce anecdotal evidence on the effect of the COVID-19 infection on the thyroid, the clinical study conducted by Humanitas researchers has become the first to provide a detailed and systematic analysis on the subject.

The study was based on the analysis of the thyroid function in a large number of patients hospitalized in non-intensive wards and followed by Humanitas’ COVID-19 Task Force, revealing the development of thyrotoxicosis in 20% of cases: an increase in thyroid hormones circulating in the system not explained by actual hyperthyroidism, but linked to virus-related inflammation. This is a significant percentage, since only 1-2% of the general population exhibits this phenomenon.

As this direct inflammatory effect during COVID-19 infection implies an increase in circulating thyroid hormones, this response can cause a worsening of the patient’s overall clinical picture. Indeed, a significant number of patients manifesting thyrotoxicosis associated with COVID-19 have experienced cardiovascular complications, such as atrial fibrillation and cerebrovascular events.

For the immediate future, the researchers intend to follow the patients involved in the study in order to evaluate the various outcomes of the inflammatory thyroid process experienced and analyze the probability of the evolution of the transient viral thyroiditis into a chronic autoimmune disease.


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