Can COVID‐19 immunisation cause subacute thyroiditis?

• Published in: Clinical Endocrinology Vol. 97; no. 1; pp. 140 - 141
• Main Authors: Ratnayake, Gowri M., Dworakowska, Dorota, Grossman, Ashley B.
• Format: Journal Article Web Resource
• Language: English
• Published: England John Wiley & Sons, Inc 01.07.2022; Wiley Subscription Services, Inc; John Wiley and Sons Inc
• Subjects: COVID-19; Immunization; Letter to the Editor; Letters; Thyroiditis
• ISSN: 0300-0664; 1365-2265
• DOI: 10.1111/cen.14555

Furthermore, the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-S antibody titre was elevated at 1232 U/ml as an expected result of the recent immunisation; a viral antibody screen showed the presence of influenza A and chlamydia pneumonia immunoglobulin G levels indicative of the previous infection. SARS CoV-2 spike protein enters cells via the angiotensin-converting enzyme 2 (ACE-2) receptor, and there is evidence to suggest that thyroid cells express the ACE-2 at a very higher concentration, presumably potentiating the entry of the SARS CoV-2 spike protein into thyroid cells.10, 11 This might mediate immunisation-induced damage. In a similar manner, the binding of spike protein to the ACE-2 receptor in endothelial cells induces inflammation of the endothelial cells, with downregulation of ACE-2 leading to a reduction of nitric oxide production and secondary mitochondrial damage.12 In addition, it is also known that antibodies against the SARS CoV-2 react with cellular antigens including that on the thyroid.13 Furthermore, the spike protein shows molecular mimicry towards thyroid peroxidase. [...]the induction of antibodies to COVID-19 may interact with the thyroid surface receptors to cause transient thyroiditis which spontaneously recovers.