The following is a summary of “Increased Risk of Thyroid Eye Disease Following Covid-19 Vaccination,” published in the February 2024 issue of Endocrinology by Muller, et al.
For a study, researchers sought to analyze the risk of thyroid eye disease (TED) following COVID-19 vaccination, considering the potential association between SARS-CoV-2 infection, COVID-19 vaccines, and thyroid disorders.
The self-controlled case series study was conducted at a tertiary referral center specializing in TED. A total of 98 consecutive patients with newly developed (n = 92) or reactivated (n = 6) TED between January 1, 2021, and August 31, 2022, were included. TED occurrence was assessed in patients who underwent COVID-19 vaccination. Person-days were categorized as exposed if TED manifested 1 to 28 days after vaccination and unexposed if occurring outside this timeframe. Conditional Poisson regression models were employed to calculate the incidence rate ratio (IRR) and corresponding 95% CI comparing exposed vs unexposed periods. Sensitivity analyses were conducted considering different exposed periods and exploring effect modification by potential TED risk factors.
Among 81 individuals who received COVID-19 vaccines, 25 (31%) developed TED during exposed periods, compared to 56 (69%) during unexposed periods. The IRR for TED was 3.24 (95% CI 2.01-5.20); among patients below 50 years of age, the IRR was 4.70 (95% CI 2.39-9.23). The association between TED and vaccination was not modified by sex, smoking status, or radioiodine treatment. TED risk was not associated with the number of vaccine doses and showed a decreasing trend following vaccination (P trend = .03).
The study found a significant increase in TED risk following COVID-19 vaccination, particularly among individuals below 50 years of age. Possible mechanisms for this association include spike protein interaction with the angiotensin-converting enzyme II receptor, cross-reactivity with thyroid self-proteins, and immune reactions induced by adjuvants. The findings suggest the importance of monitoring individuals undergoing COVID-19 vaccination, especially those young and at risk for autoimmunity.