Reply re: "Thyroid Eye Disease Following COVID-19 Vaccine in a Patient With a History Graves' Disease: A Case Report".

To the Editor:

I appreciate the comments by Drs. Sriwijitalai and Wiwanitkit to the article “Thyroid Eye Disease Following COVID-19 Vaccine in a Patient With a History Graves’ Disease: A Case Report.”[1] They note that in the aforementioned article, I suggest a temporal relationship between the patient’s coronavirus disease 2019 (COVID-19) vaccine and thyroid eye disease (TED) due to an inflammatory syndrome. I agree that this one case does not in and of itself clinch the exact pathogenesis of this relationship, and indeed it may be coincidental, as I mention in the article.

Among other possibilities that Drs. Sriwijitalai and Wiwanitkit suggest, I believe an inflammatory pathogenesis is the best explanation. First, the patient’s thyroid hormone panel was normal, so thyroid hormone abnormality triggering TED is less likely. Second, as indicated in the article, she presented with elevated thyroid stimulating immunoglobulin (TSI), an antibody with high specificity to TED and with a relationship with more severe orbitopathy.[2] However, it is unknown what the TSI was before the vaccination, as TSI may still be elevated in chronic TED.[3] Third, the patient’s response to teprotumumab—an insulin-like growth factor 1 receptor blocking antibody—indicates an inflammatory role rather than a hyperviscosity role. The patient had no other signs and symptoms of hyperviscosity systemically, nor such findings on orbital imaging or ophthalmic examination. I do agree, though, that further studies and cases are necessary to elucidate the pathogenesis further.