key: cord-0690012-nfl2js5j
authors: Mungmunpuntipantip, Rujittika; Wiwanitkit, Viroj
title: Thyrotoxicosis after COVID-19 vaccination
date: 2021-10-29
journal: Endocrine
DOI: 10.1007/s12020-021-02922-8
sha: 295526bc0ad0f1fa49fc84415c6ce9bf641b5abc
doc_id: 690012
cord_uid: nfl2js5j

nan

We would like to share ideas on the publication "Thyrotoxicosis after COVID-19 vaccination: seven case reports and a literature review" [1] . Lee et al. concluded that "COVID-19 vaccines can cause not only destructive thyroiditis but also AIT… relationship between COVID-19, vaccines, and thyroid diseases" [1] . We agree that the post-COVID-19 vaccination thyroid problem might occur and there might be an association with pathological/abnormal immune response to vaccine. In the present study, a change of thyroxine level is well demonstrated and there is a trend of decreasing when time passes. After vaccination, there is also another important process that might contribute to thyrotoxicosis occurrence. The vaccine can induce increased blood viscosity [2] . The association between hyperviscosity and thyrotoxicosis is proposed [3] . An increasing of blood viscosity is due to rapid increased level of antibody after vaccination and the viscosity will decrease when there is a decline of antibody level. This pattern is the same as observed alteration of thyroid hormone level in the present report by Lee et al. [1] . Finally, if thyroid hormone test is based on immunoassay, an interference, a false aberration of hormone level might be induced by a high blood viscosity [4] .

Conflict of interest The authors declare no competing interests.

Publisher's note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Thyrotoxicosis after COVID-19 vaccination: seven case reports and a literature review

Viscosity after COVID-19 vaccination, hyperviscosity and previous COVID-19

Neonatal thyrotoxicosis associated with the hyperviscosity syndrome

Interference in immunoassay