Effect of SARS-CoV-2 BNT162b2 mRNA vaccine on thyroid autoimmunity: A twelve-month follow-up study

Concurrent pretibial myxedema and thyroid eye disease following mRNA COVID-19 vaccine in a patient with history of Graves' disease

A 70-year-old female had a history of thyroid surgery for benign nodules and Graves' disease. Following mRNA COVID-19 vaccination, she presented Graves' orbitopathy and pretibial myxedema. Symptoms of thyroid eye disease and thyroid dermopathy improved after 500-mg methylprednisolone infusions.

Graves' Disease Following COVID-19 Vaccination: A Population-based, Matched Case-control Study

OBJECTIVE

Multiple cases and case series reported Graves' disease (GD) following coronavirus disease 2019 (COVID-19) vaccination. We aimed to determine whether COVID-19 vaccination was associated with the incidence of GD.

METHODS

We analyzed data from Clalit Health Services, the largest healthcare organization in Israel, which insures 4.7 million patients. A population-based, matched, case-control study was performed. Cases were defined as adult patients diagnosed with GD between December 2020 and November 2022. Each case was matched with controls in a 1:2 ratio. Each control was assigned an index date, which was identical to that of their matched case, defined as the date of GD diagnosis. Time between vaccination date and the diagnosis of GD or index date was assessed.

RESULTS

A total of 726 patients with GD were matched with 1452 controls. The study patients and controls have received similar proportions of the COVID-19 vaccine [at least 1 dose: 80% (581/726) vs 77.8% (1129/1452), P = .22, respectively]. In a univariate analysis, at least 1 dose of the COVID-19 vaccine was not associated with the incidence of GD [odds ratio 95% confidence interval: 1.15 (.92-1.43)]. The mean time between first COVID-19 vaccination and the diagnosis of GD for cases or index date for controls was not significantly different [275.69 days (SD 144.37) for cases compared to 275.45 days (SD 145.76) for controls].

CONCLUSION

Our study found no association between COVID-19 vaccination and the incidence of GD.

Increased Risk of Thyroid Eye Disease Following Covid-19 Vaccination

CONTEXT

SARS-CoV-2 infection and Covid-19 vaccines have been associated with thyroid disorders.

OBJECTIVE

We analyzed the risk of thyroid eye disease (TED) following Covid-19 vaccination. This was a self-controlled case series study at a tertiary referral center for TED. A total of 98 consecutive patients with newly developed (n = 92) or reactivated (n = 6) TED occurring between January 1, 2021, and August 31, 2022, were included. TED was assessed in patients undergoing Covid-19 vaccination. Person-days were defined as exposed if TED occurred 1 to 28 days after vaccination, and unexposed if occurring outside this time window. Conditional Poisson regression models were fitted to calculate incidence rate ratio (IRR) and 95% CI of exposed vs unexposed. Sensitivity analyses were conducted considering different exposed periods, and effect modification by potential TED risk factors.

RESULTS

Covid-19 vaccines were administered in 81 people, 25 (31%) of whom developed TED in exposed and 56 (69%) in unexposed periods. The IRR for TED was 3.24 (95% CI 2.01-5.20) and 4.70 (95% CI 2.39-9.23) in patients below 50 years of age. Sex, smoking, and radioiodine treatment did not modify the association between TED and vaccination. TED risk was unrelated to the number of vaccine doses, and progressively decreased over time following vaccination (P trend = .03).

CONCLUSION

The risk of TED was significantly increased after Covid-19 vaccination, especially in people below 50 years of age. Possible mechanisms include spike protein interaction with the angiotensin-converting enzyme II receptor, cross-reactivity with thyroid self-proteins, and immune reactions induced by adjuvants. We suggest monitoring of individuals undergoing Covid-19 vaccination, especially if young and at risk for autoimmunity.

SARS-CoV-2 Affects Thyroid and Adrenal Glands: An 18F-FDG PET/CT Study

BACKGROUND

Since most endocrine glands express ACE-2 receptors and can be infected by SARS-CoV-2 virus, this retrospective multicentre observational study aims to assess the metabolic activity of thyroid and adrenal glands of COVID-19 patients by 18F-FDG PET/CT.

METHODS

We retrospectively evaluated the 18F-FDG PET/CT scans of COVID-19 patients admitted by three different centres, either in a low-intensity department or in the intensive care unit (ICU). A visual assessment and a semi-quantitative evaluation of areas of interest in thyroid and adrenal glands were performed by recording SUVmax and SUVmean. The 18F-FDG PET/CT uptake in COVID-19 patients was compared with those observed in normal age-matched controls.

RESULTS

Between March 2020 and March 2022, 33 patients from three different centres (twenty-eight patients in a low-intensity department and five patients in ICU), were studied by 18F-FDG PET/CT during active illness. Seven of them were also studied after clinical remission (3-6 months after disease onset). Thirty-six normal subjects were used as age-matched controls. In the thyroid gland, no statistically significant differences were observed between control subjects and COVID-19 patients at diagnosis. However, at the follow-up PET/CT study, we found a statistically higher SUVmax and SUVmean (p = 0.009 and p = 0.004, respectively) in the thyroid of COVID-19 patients. In adrenal glands, we observed lower SUVmax and SUVmean in COVID-19 patients at baseline compared to control subjects (p < 0.0001) and this finding did not normalize after clinical recovery (p = 0.0018 for SUVmax and p = 0.002 for SUV mean).

CONCLUSIONS

In our series, we observed persistent low 18F-FDG uptake in adrenal glands of patients at diagnosis of COVID-19 and after recovery, suggesting a chronic hypofunction. By contrast, thyroid uptake was comparable to normal subjects at disease onset, but after recovery, a subgroup of patients showed an increased metabolism, thus possibly suggesting the onset of an inflammatory thyroiditis. Our results should alert clinicians to investigate the pituitary-adrenal axis and thyroid functionality at the time of infection and to monitor them after recovery.

Raman Spectroscopy as a Potential Adjunct of Thyroid Nodule Evaluation: A Systematic Review

The incidence of thyroid nodules (TNs) is estimated at 36.5% and 23% in females and males, respectively. A single thyroid nodule is usually detected during ultrasound assessment in patients with symptoms of thyroid dysfunction or neck mass. TNs are classified as benign tumours (non-malignant hyperplasia), benign neoplasms (e.g., adenoma, a non-invasive follicular tumour with papillary nuclear features) or malignant carcinomas (follicular cell-derived or C-cell derived). The differential diagnosis is based on fine-needle aspiration biopsies and cytological assessment (which is burdened with the bias of subjectivity). Raman spectroscopy (RS) is a laser-based, semiquantitative technique which shows for oscillations of many chemical groups in one label-free measurement. RS, through the assessment of chemical content, gives insight into tissue state which, in turn, allows for the differentiation of disease on the basis of spectral characteristics. The purpose of this study was to report if RS could be useful in the differential diagnosis of TN. The Web of Science, PubMed, and Scopus were searched from the beginning of the databases up to the end of June 2023. Two investigators independently screened key data using the terms "Raman spectroscopy" and "thyroid". From the 4046 records found initially, we identified 19 studies addressing the differential diagnosis of TNs applying the RS technique. The lasers used included 532, 633, 785, 830, and 1064 nm lines. The thyroid RS investigations were performed at the cellular and/or tissue level, as well as in serum samples. The accuracy of papillary thyroid carcinoma detection is approx. 90%. Furthermore, medullary, and follicular thyroid carcinoma can be detected with up to 100% accuracy. These results might be biased with low numbers of cases in some research and overfitting of models as well as the reference method. The main biochemical changes one can observe in malignancies are as follows: increase of protein, amino acids (like phenylalanine, tyrosine, and tryptophan), and nucleic acid content in comparison with non-malignant TNs. Herein, we present a review of the literature on the application of RS in the differential diagnosis of TNs. This technique seems to have powerful application potential in thyroid tumour diagnosis.

Graves' Disease after mRNA COVID-19 Vaccination, with the Presence of Autoimmune Antibodies Even One Year Later

A 45-year-old man who had received his second mRNA COVID-19 vaccination one week earlier was presented to the emergency department with chest discomfort. Therefore, we suspected post-vaccination myocarditis; however, the patient showed no signs of myocarditis. After 2 weeks, he revisited the hospital complaining of palpitations, hand tremors, and weight loss. The patient exhibited high free thyroxine (FT4) (6.42 ng/dL), low thyroid-stimulating hormone (TSH) (<0.01 μIU/mL), and high TSH receptor antibody (17.5 IU/L) levels, and was diagnosed with Graves' disease. Thiamazole was administered, and the patient's FT4 levels normalized after 30 days. One year later, the patient's FT4 is stable; however, their TSH receptor antibodies have not become negative and thiamazole has continued. This is the first case report to follow the course of Graves' disease one year after mRNA COVID-19 vaccination.