The New Entity of Subacute Thyroiditis amid the COVID-19 Pandemic: From Infection to Vaccine

Subacute Thyroiditis Following COVID-19: A Case of Diagnostic Challenge in the Absence of Neck Pain

This case report presents a 77-year-old woman who developed subacute thyroiditis following COVID-19. The patient exhibited atypical symptoms, including fever, fatigue, anorexia, significant weight loss, headaches, and palpitations, without the typical neck pain or tenderness associated with thyroiditis. One week later, a follow-up examination showed mild enlargement and tenderness of the thyroid. Laboratory tests indicated elevated thyroid hormone levels and suppressed thyroid-stimulating hormone. Ultrasonography revealed diffuse thyroid enlargement with poor blood flow, consistent with subacute thyroiditis. Despite the absence of typical neck pain, the diagnosis was supported by clinical, laboratory, and imaging findings. This case suggests the importance of considering subacute thyroiditis as a potential secondary condition following COVID-19, even in the absence of typical symptoms. Clinicians should consider that and perform thorough evaluations in patients with recent COVID-19 exposure and nonspecific symptoms.

The prevalence of positive thyroid autoantibodies in patients with subacute thyroiditis: a systematic review and meta-analysis

PURPOSE

Subacute thyroiditis (SAT) is a transient inflammatory disorder of the thyroid gland with a possible viral etiology. We conducted this study to estimate the pooled prevalence of thyroid autoantibodies in SAT patients. This question arose due to the varying reports on the positivity rates of thyroid autoantibodies among SAT patients.

METHODS

We searched PubMed, Embase, Scopus, and Web of Science from their inception until March 25th, 2023. Observational studies reporting the positivity rate of thyroid autoantibodies for more than ten patients were included. We used the Joanna Briggs Institute's (JBI) critical appraisal checklist to assess the quality of the included studies. Pooled prevalence estimates with 95% confidence intervals were calculated using the random effects model. Subgroup analyses were performed to find sources of heterogeneity.

RESULTS

Out of 1373 identified records, 32 studies involving 2348 SAT patients were included in our study. Thyroglobulin antibody (TgAb) and thyroid peroxidase antibody (TPOAb) were positive in 22.8% and 12.2% of patients, respectively. The Study design, mean erythrocyte sedimentation rate and mean thyroid-stimulating hormone of patients were identified as sources of heterogeneity. As our secondary objectives, we found a recurrence rate of 14.7% and permanent hypothyroidism in 11.6% of patients.

CONCLUSION

The results of our study revealed a low TPOAb positivity rate in SAT patients, consistent with its non-autoimmune etiology. The TgAb positivity rate in SAT patients was higher than that of the general population, possibly explained by the transient release of thyroglobulin into the bloodstream during the thyrotoxic phase, leading to subsequent TgAb production. Furthermore, our findings demonstrate a notable recurrence rate and permanent hypothyroidism among SAT patients, highlighting the importance of ongoing follow-up care.

Clinical Aspects in Subacute Thyroiditis: A Real-Life Study on 226 Cases in Greece Amid the COVID-19 Pandemic

PURPOSE

This study aimed to evaluate various therapeutic approaches, identify potential predictive factors for the recurrence and development of hypothyroidism, and examine specific clinical and laboratory characteristics of patients with subacute thyroiditis (SAT) due to SARS-CoV-2 infection.

METHODS

We retrospectively analyzed the medical records of 226 patients with confirmed SAT diagnosed from January 2020 to November 2022.

RESULTS

The mean age was 48.01 ± 0.75 years, and the F/M ratio was 2.3/1. At the end of the follow-up period, 69 patients (32.1%) had developed hypothyroidism. Treatment duration was significantly shorter with nonsteroidal anti-inflammatory drugs (NSAIDs) (17.40 ± 2.56 days), while time-to-symptom relief was shorter with glucocorticoids (CGs). Recurrence was observed only in those treated with corticosteroid preparations (14.1%). C-reactive protein levels at treatment discontinuation were higher in patients who experienced SAT recurrence, while the coexistence of Hashimoto's thyroiditis was a significant predictive factor for the development of hypothyroidism. The TSH value at the time of treatment withdrawal >4.12 μIU/mL showed optimal sensitivity and specificity for the prediction of permanent hypothyroidism. Regarding COVID-19, 34 patients (15%) experienced related SAT, with similar clinical manifestations of the disease but a higher BMI and shorter time-to-symptom relief.

CONCLUSION

In conclusion, GCs administration alleviated acute symptoms earlier during the onset of SAT, whereas NSAIDs had a shorter treatment duration, and both regimens could not prevent the development of delayed hypothyroidism. The clinical characteristics of SAT due to COVID-19 infections were similar to those of typical SAT disease.

Subacute thyroiditis following COVID-19 vaccination: Case presentation

Background: Subacute thyroiditis (SAT) is an organ-specific disease that various drugs, including COVID-19 vaccines, can trigger. COVID-19 infection has been associated with thyroid gland damage and disease SARS-CoV-2 direct action, euthyroid sick syndrome, and immune-mediated mechanisms are all potential mechanisms of thyroid damage. It denotes thyroid gland inflammation, most commonly of viral origin, and belongs to the transitory, self-limiting thyroid gland diseases group, causing complications in approximately 15% of patients in the form of permanent hypothyroidism. Some authors say SAT is the most common thyroid disease associated with COVID-19.Purpose: The occurrence of SAT many weeks after administering the second COVID-19 vaccine is rare and has limited documentation in academic literature. This study aims to present the occurrence of SAT after administering the COVID-19 vaccine. We present the case of a 37-year-old man who developed SAT 23 days after receiving the second dose of Pfizer BioNTech's COVID-19 mRNA vaccine.Research design and study sample: Due to neck pain and an elevated body temperature (up to 38.2°C), a 37-year-old male subject presented for examination 23 days after receiving the second Pfizer BioNTech mRNA vaccine against SARS-CoV-2 viral infection. The patient denied ever having an autoimmune disease or any other disease. Painful neck palpation and a firm, slightly enlarged thyroid gland with no surrounding lymphadenopathy were identified during the exam. The heart rate was 104 beats per minute. All of the remaining physical findings were normal.Data collection and/or Analysis: Data collected during the disease are integral to the medical record.Results: Hematology and biochemistry analyses at the initial and follow-up visits revealed minor leukocytosis, normocytic anaemia, and thrombocytosis, followed by a mild increase in lactate dehydrogenase and decreased iron levels. The patient's thyroid function and morphology had recovered entirely from post-vaccine SAT.Conclusions: Results from this study emphasise the need for healthcare professionals to promptly report any case of SAT related to COVID-19 vaccination. Further investigation is warranted to understand the immunopathogenesis of COVID-19-associated thyroiditis and the impact of COVID-19 immunization on this condition.

Endothelial dysfunction in autoimmune, pulmonary, and kidney systems, and exercise tolerance following SARS-CoV-2 infection

Long COVID is characterized by persistent symptoms beyond 3-months of severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infection that last for at least 2 months and cannot be explained by an alternative diagnosis. Autonomic, immunologic, endothelial, and hypercoagulation are implicated as possible mechanisms of long COVID symptoms. Despite recognition of the public health challenges posed by long COVID, the current understanding of the pathophysiological underpinnings is still evolving. In this narrative review, we explore the long-term effects of SARS-CoV-2 infection on T cell activation such as autoimmune disorders and endothelial cell dysfunction involving vascular impairments within pulmonary and renal architecture. We have described how endothelial dysfunction and vascular abnormalities may underscore findings of exercise intolerance by way of impaired peripheral oxygen extraction in individuals with long COVID.

SUBACUTE THYROIDITIS FOLLOWING SARS-COV-2 VACCINATION: AN AUTOIMMUNE/INFLAMMATORY SYNDROME INDUCED BY ADJUVANTS (ASIA SYNDROME)

Context

Subacute thyroiditis, a manifestation of Autoimmune/inflammatory syndrome induced by adjuvants that may develop after vaccination.

Objective

The aim of this study is to determine the importance of vaccination against COVID-19 in the etiology of subacute thyroiditis.

Design

This case reports/series is an observational, descriptive research design.

Subjects and Methods

Five of the thirty patients who applied to our clinic with subacute thyroiditis in the last 6 months had a history of inactivated and mRNA vaccines in the last four weeks, after exclusion of infection and comorbidities. We present three cases of mRNA-based vaccination and two cases of inactive SARS-CoV-2 vaccination that met ASIA criteria.

Results

Our findings suggest that subacute thyroiditis may be a complication of vaccination against COVID-19.

Conclusion

Vaccine administration may led to autoimmune manifestation induction as well as autoantibody production. Adjuvant-induced autoimmune/inflammatory syndrome, an abnormal autoimmune response as a result of exposure to an adjuvant such as vaccine, appears likely in our cases.

Insights into SARS-CoV-2-associated subacute thyroiditis: from infection to vaccine

Since the COVID-19 emergence as a global pandemic in March 2020, more than 5 million SARS-CoV-2-related deaths have been globally documented. As the pandemic progressed, it became clear that, although the infection is mainly characterized as a respiratory disease, it also affects other organs and systems, including the thyroid gland. Indeed, emerging evidence suggests that SARS-CoV-2 can act as a trigger for various thyroid disorders, for example, subacute thyroiditis (SAT), Grave's disease, and non-thyroidal illness syndrome. The entry of SARS-CoV-2 into the host cells is mainly mediated by the ACE2-receptor, making organs and systems with high expression of this receptor, such as the thyroid gland, highly vulnerable to COVID-19. Accumulating data propose that SAT may be an underestimated manifestation of COVID-19 infection. Importantly, if SAT remains unrecognized, it may trigger or aggravate potential other complications of the disease, for example, respiratory insufficiency and cardiovascular complications, and thus negatively influence prognosis. Moreover, recent case reports, case series, and systematic reviews highlight SAT as a potential side effect of the vaccination against SARS-CoV-2. The present review aims to raise awareness of SARS-CoV-2-associated- and post-vaccination subacute thyroiditis, to discuss recent evidence regarding its pathophysiology, and to present useful information for this special form of SAT related to daily clinical practice.

Subacute thyroiditis following COVID-19: A systematic review

Background

Subacute thyroiditis (SAT) is a self-limiting thyroid inflammatory disease occurring specifically after upper respiratory tract infections. Since COVID-19 is a respiratory disease leading to multi-organ involvements, we aimed to systematically review the literature regarding SAT secondary to COVID-19.

Methods

We searched Scopus, PubMed/MEDLINE, Cochrane, Web of Science, ProQuest, and LitCovid databases using the terms "subacute thyroiditis" and "COVID-19" and their synonyms from inception to November 3, 2022. We included the original articles of the patients with SAT secondary to COVID-19. Studies reporting SAT secondary to COVID-19 vaccination or SAT symptoms' manifestation before the COVID-19 infection were not included.

Results

Totally, 820 articles were retained. Having removed the duplicates, 250 articles remained, out of which 43 articles (40 case reports and three case series) with a total of 100 patients, were eventually selected. The patients aged 18-85 years (Mean: 42.70, SD: 11.85) and 68 (68%) were women. The time from the onset of COVID-19 to the onset of SAT symptoms varied from zero to 168 days (Mean: 28.31, SD: 36.92). The most common symptoms of SAT were neck pain in 69 patients (69%), fever in 54 (54%), fatigue and weakness in 34 (34%), and persistent palpitations in 31 (31%). The most common ultrasonographic findings were hypoechoic regions in 73 (79%), enlarged thyroid in 46 (50%), and changes in thyroid vascularity in 14 (15%). Thirty-one patients (31%) were hospitalized, and 68 (68%) were treated as outpatients. Corticosteroids were the preferred treatment in both the inpatient and outpatient settings (25 inpatients (81%) and 44 outpatients (65%)). Other preferred treatments were nonsteroidal anti-inflammatory drugs (nine inpatients (29%) and 17 outpatients (25%)) and beta-blockers (four inpatients (13%) and seven outpatients (10%)). After a mean duration of 61.59 days (SD: 67.07), 21 patients (23%) developed hypothyroidism and thus, levothyroxine-based treatment was used in six of these patients and the rest of these patients did not receive levothyroxine.

Conclusion

SAT secondary to COVID-19 seems to manifest almost similarly to the conventional SAT. However, except for the case reports and case series, lack of studies has limited the quality of the data at hand.

HLA typing of patients who developed subacute thyroiditis and Graves' disease after SARS-CoV-2 vaccination: a case report

BACKGROUND

Cases of subacute thyroiditis (SAT) after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination have been reported. A human leukocyte antigen (HLA) allele, HLA-B*35, appears to be involved in the pathogenesis of SAT.

CASE PRESENTATION

We conducted HLA typing of one patient with SAT and another with both SAT and Graves' disease (GD), which developed after SARS-CoV-2 vaccination. Patient 1, a 58-year-old Japanese man, was inoculated with a SARS-CoV-2 vaccine (BNT162b2; Pfizer, New York, NY, USA). He developed fever (38 °C), cervical pain, palpitations, and fatigue on day 10 after vaccination. Blood chemistry tests revealed thyrotoxicosis and elevated serum C-reactive protein (CRP) and slightly increased serum antithyroid-stimulating antibody (TSAb) levels. Thyroid ultrasonography revealed the characteristic findings of SAT. Patient 2, a 36-year-old Japanese woman, was inoculated twice with a SARS-CoV-2 vaccine (mRNA-1273; Moderna, Cambridge, MA, USA). She developed fever (37.8 °C) and thyroid gland pain on day 3 after the second vaccination. Blood chemistry tests revealed thyrotoxicosis and elevated serum CRP, TSAb, and antithyroid-stimulating hormone receptor antibody levels. Fever and thyroid gland pain persisted. Thyroid ultrasonography revealed the characteristic findings of SAT (i.e., slight swelling and a focal hypoechoic area with decreased blood flow). Prednisolone treatment was effective for SAT. However, thyrotoxicosis causing palpitations relapsed thereafter, for which thyroid scintigraphy with ^99mtechnetium pertechnetate was conducted, and the patient was diagnosed with GD. Thiamazole treatment was then initiated, which led to improvement in symptoms.

CONCLUSION

HLA typing revealed that both patients had the HLA-B*35:01, -C*04:01, and -DPB1*05:01 alleles. Only patient 2 had the HLA-DRB1*11:01 and HLA-DQB1*03:01 alleles. The HLA-B*35:01 and HLA-C*04:01 alleles appeared to be involved in the pathogenesis of SAT after SARS-CoV-2 vaccination, and the HLA-DRB1*11:01 and HLA-DQB1*03:01 alleles were speculated to be involved in the postvaccination pathogenesis of GD.

Impact of the COVID-19 pandemic on the incidence, seasonal distribution, and characteristics of subacute thyroiditis

PURPOSE

An increasing number of cases of subacute thyroiditis (SAT) related to the coronavirus disease 2019 (COVID-19) and its vaccines continue to be published. The aim of this study was to investigate any change in the incidence and characteristics of SAT by comparing the pre-pandemic and pandemic periods.

METHODS

This retrospective, single-center study included 432 newly-diagnosed SAT patients between January 2018 and December 2021. The annual frequency of SAT was calculated as the number of newly-diagnosed SAT cases divided by the total number of outpatients that year.

RESULTS

The frequencies of newly-diagnosed SAT were 0.136% in 2018, 0.127% in 2019, 0.157% in 2020, and 0.114% in 2021 (p = 0.19). While SAT patients were clustered in the autumn (35.1%) in 2018 and 2019, it was found that this cluster shifted to the winter (33.0%) in 2020 and 2021, in parallel with COVID-19 case peaks (p = 0.017). The patients were separated into two groups as pre-COVID-19 pandemic SAT (n = 272) and COVID-19 pandemic SAT (n = 160). The mean ages of the groups were similar. There were more male patients in the COVID-19 pandemic SAT group than in the pre-pandemic group (30.6% vs. 18.7%, p = 0.005). Frequencies of overt hyperthyroidism and median free-thyroxine levels were significantly higher in the COVID-19 pandemic SAT group (p = 0.029, p = 0.001). Treatment modalities, recurrence rates, and permanent hypothyroidism were similar in both groups.

CONCLUSION

With the COVID-19 pandemic, although there was a change in seasonal variation of SAT and an increase in the number of male patients, there was no change in the incidence and clinical course of SAT.

Post-COVID Endocrine Disorders: Putative Role of Molecular Mimicry and Some Pathomorphological Correlates

In order to identify corresponding amino acid sequences (pentapeptides) between the SPs, MPs and NPs of human coronaviruses and human autoantigens targeted in autoimmune endocrinopathies, and for a comparative analysis of the various coronaviruses proteome and the proteome of human, the original computer program was used. Quantitatively, SP, MP and NP of the human coronaviruses were found to share totally 117 minimal immune pentapeptide epitopes: 79 in SP, 14 in MP and 24 in NP, - with 18 autoantigens expressed by human endocrinocytes. The shared pentapeptides belong to the proteins of human endocrine cells. Samples of the pituitary, adrenal and thyroid from patients who died from coronavirus infection (COVID-19) were studied morphologically using histochemical methods. A high incidence of SARS-CoV-2 infection of endocrine cells was showed. The high affinity of SARS-CoV-2 the cells of the adenohypophysis was revealed, but there was no expression of viral proteins by the cells of the neurohypophysis. The foci of lesions in endocrine organs contained abundant lymphocytic infiltrates which may indicate the impact of autoimmune processes. Autoimmune disorders have a multi-faceted etiology and depend on polygenic predispose and additive action of many epigenetic and environmental factors causing hyperstimulation of imperfectly functioning immune system. It means that the phenomenon of molecular mimicry cannot be blamed as their single prerequisite, but it is just a tile in mosaic of autoimmunity. The facts revealed emphasize the need of endocrinological diagnostic alertness of a physician while observing patients with post-vaccination and post-COVID-19 health disorders.

A Literature Review on SARS-CoV-2 and Other Viruses in Thyroid Disorders: Environmental Triggers or No-Guilty Bystanders?

A growing number of findings indicate a relationship between COVID-19 infection and thyroid dysfunction. This association is also strengthened by knowledge on the potential of viral infections to trigger thyroid disorders, although the exact underlying pathogenetic process remains to be elucidated. This review aimed to describe the available data regarding the possible role of infectious agents, and in particular of SARS-CoV-2, in the development of thyroid disorders, summarizing the proposed mechanisms and levels of evidence (epidemiological, serological or direct presence of the viruses in the thyroid gland) by which the infection could be responsible for thyroid abnormalities/diseases. Novel data on the association and mechanisms involved between SARS-CoV-2 vaccines and thyroid diseases are also discussed. While demonstrating a clear causal link is challenging, numerous clues at molecular and cellular levels and the large amount of epidemiological data suggest the existence of this relationship. Further studies should be taken to further investigate the true nature and strength of this association, to help in planning future preventive and therapeutic strategies for more personal and targeted care with attention to the underlying causes of thyroid dysfunction.

A Novel Finding of an HLA Allele's and a Haplotype's Relationship with SARS-CoV-2 Vaccine-Associated Subacute Thyroiditis

Subacute thyroiditis (SAT) is a thyroid disease associated with viral infections. Its relationship with major histocompatibility complex (MHC) antigens was shown before. SAT cases triggered by different types of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been reported. In this study, human leukocyte antigen (HLA) genotypes of 27 SAT patients (13 vaccine-associated (V-SAT) and 14 non-SARS-CoV-2-infection non-vaccine-associated (non-V-SAT)) were compared with those of 362 healthy donors. HLA analyses were performed with low-resolution DNA-based sequence-specific oligonucleotide or sequence-specific primer methods. Statistical analyses were performed using IBM SPSS Statistics 25 and Stata/MP 14.1 with the hapipf function. Allele and haplotype frequencies were estimated by PyPop and gene[RATE] tool programs. The allele frequencies of HLA-A*11, HLA-B*35, and HLA-C*04 were higher in the patient groups. Both the allele frequency of HLA-A*11 and the haplotype frequency of A*11-B*35-C*04 were higher in the V-SAT group. The A*11-B*35-C*04 haplotype, including all three loci of MHC class I genes, is shown to be associated with the disease for the first time, especially in the V-SAT group. This finding will contribute to a better understanding of the etiopathogenesis of vaccine-associated SAT and the role of HLA genotypes in the functioning mechanisms of the SARS-CoV-2 vaccines.

Schilddrüse und SARS-CoV-2

Es gibt verschiedene Wechselwirkungen zwischen einer SARS-CoV-2-Infektion und der Schilddrüse, bidirektional in beide Richtungen: Bei einer schweren COVID-19-Infektion sind Veränderungen der Schilddrüsenhormonspiegel ein Marker für eine schlechtere Prognose. SARS-CoV‑2 scheint sowohl direkt mit Thyreozyten zu interagieren als auch das Immunsystem zu modulieren und Immunthyreopathien triggern zu können. Bereits 2020 wurde die „SARS-CoV-2-assoziierte Thyreoiditis“ bei Patienten mit COVID-19 beschrieben, die ähnlich einer subakuten Thyreoiditis verläuft, allerdings typischerweise schmerzlos. Es gibt inzwischen verschiedenste Berichte über das Auftreten einer chronischen Immunthyreoiditis und eines Morbus Basedow sowohl nach Virusinfektion als auch nach Impfung. Eine bestehende Schilddrüsenerkrankung scheint weder mit einem höheren Risiko für eine SARS-CoV-2-Infektion noch mit einem schwereren Krankheitsverlauf assoziiert zu sein. In der vorliegenden Arbeit wird der derzeitige Wissensstand bezüglich Schilddrüse und SARS-CoV‑2 zusammengefasst.

Subacute (De Quervain's) thyroiditis presenting as painful thyroid nodule suspicious of papillary thyroid carcinoma: Case report

INTRODUCTION

We report a case of subacute thyroiditis (SAT) in a 29 -year-old female who presented with painful thyroid swelling.

PRESENTATION OF CASE

Patient presented with neck pain, tender neck swelling and generalized fatigue. She had no history of neck or chest radiation or compressive symptoms. Ultrasound (US) imaging reveled bilateral nodules of the thyroid gland. Lymph nodes were unremarkable. FNAC was suspicious for papillary thyroid carcinoma. The patient was discussed at the thyroid multidisciplinary meeting, and after deliberation the decision was to offer the patient the choice of repeating FNAC of the bilateral nodules in one month or to proceed with total thyroidectomy.

DISCUSSION

Despite being aware of the possibility that the final pathology could be benign, the patient insisted on total thyroidectomy, given that her FNAC results were suspicious of papillary thyroid carcinoma, and in order to avoid recurrence of the condition and the pain. Following the patient's preference, total thyroidectomy was performed, and surgery was not straightforward as intraoperatively, there was a diffusely inflamed gland. Histopathology findings revealed benign pathology. Follow up until 1.5 years showed that the patient was satisfied, and with normal voice.

CONCLUSION

SAT is a painful but potentially self-limiting. In some cases, FNAC findings might be suspicious for papillary thyroid carcinoma. Treatment is mostly conservative, but if the pain is severe and the patient insists on surgery as in our case despite the possibility of the condition being of benign pathology, then surgery should be undertaken.

Endocrine system after 2 years of COVID-19 vaccines: A narrative review of the literature

PURPOSE

The purpose of this study was to describe the current knowledge on the potential endocrine adverse effects post-COVID-19 vaccines.

METHODS

A PubMed/MEDLINE, Web of Science, and Scopus research was performed. Case reports, case series, original studies, and reviews written in English and published online up to 31 July 2022 were selected and reviewed. The final reference list was defined based on the relevance of each paper to the scope of this review.

RESULTS

The available data showed that endocrine side effects are generally rare and with favorable outcome, being thyroid disorders the most common. Conversely, data on type 1 diabetes mellitus are rare; adrenal and pituitary events are even anecdotal. Finally, the available clinical studies suggest no impact on female reproductive system and on male and couple fertility.

CONCLUSION

Overall, these data show that, after 2 years of COVID-19 vaccines, the endocrine system is not heavily threatened.