Subacute thyroiditis following COVID-19: A systematic review

Risk of Incident Thyroid Dysfunction in the Post-Acute Phase of COVID-19: A Population-Based Cohort Study in Hong Kong

OBJECTIVE

The evidence of thyroid dysfunction in the post-acute phase of SARS-CoV-2 infection is limited. This study aimed to evaluate the risk of incident thyroid dysfunction in the post-acute phase of COVID-19.

METHODS

This retrospective, propensity-score matched, population-based study included COVID-19 patients and non-COVID-19 individuals between January 2020 and March 2022, identified from the electronic medical records of the Hong Kong Hospital Authority. The cohort was followed up until the occurrence of outcomes, death, or 31 January 2023, whichever came first. Patients with COVID-19 were 1:1 matched to controls based on various variables. The primary outcome was a composite of thyroid dysfunction (hyperthyroidism, hypothyroidism, initiation of antithyroid drug or levothyroxine, and thyroiditis). Cox regression was employed to evaluate the risk of incident thyroid dysfunction during the post-acute phase.

RESULTS

A total of 84 034 COVID-19 survivors and 84 034 matched controls were identified. Upon a median follow-up of 303 days, there was no significant increase in the risk of diagnosed thyroid dysfunction in the post-acute phase of COVID-19 (hazard ratio [HR] 1.058, 95% confidence interval 0.979-1.144, P = .154). Regarding the secondary outcomes, patients with COVID-19 did not have increased risk of hyperthyroidism (HR 1.061, P = .345), hypothyroidism (HR 1.062, P = .255), initiation of antithyroid drug (HR 1.302, P = .070), initiation of levothyroxine (HR 1.086, P = .426), or thyroiditis (P = .252). Subgroup and sensitivity analyses were largely consistent with the main analyses.

CONCLUSION

Our population-based cohort study provided important reassuring data that COVID-19 was unlikely to be associated with persistent effects on thyroid function.

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.

Subacute thyroiditis in the SARS-CoV-2 era: a multicentre prospective study

Objective

Many cases of subacute thyroiditis (SAT) have been described related to SARS-CoV-2 infection, but no prospective data about follow-up are known. This prospective, longitudinal, 3-year, multicentre study aims to explore the clinical peculiarities and outcome of SAT in relation to SARS-CoV-2 infection, ascertained with antibody dosage.

Methods

All patients receiving SAT diagnosis from November 2020 to May 2022 were enrolled. Data on anamnesis, physical examination, blood tests (TSH, freeT4, freeT3, thyroglobulin, anti-thyroid antibodies, C-reactive protein, erythrocyte sedimentation rate, complete blood count), and thyroid ultrasound were collected. At baseline, the presence of IgG against the SARS-CoV-2 spike protein or nucleocapsid was investigated. Patients were evaluated after 1, 3, 6, and 12 months.

Results

Sixty-six subjects were enrolled. At baseline, 54 presented with pain, 36 (67%) for at least 15 days. Serum SARS-CoV-2 IgG measurements documented that 7 out of 52 subjects (13.5%) had infection before SAT diagnosis (COVID+). No significant differences between the COVID+ and COVID- groups were found at baseline, except for respiratory symptoms and fever, which were more common in COVID+ (P = 0.039 and P = 0.021, respectively). Among the 41 subjects who completed follow-up, COVID+ and COVID- did not differ for therapeutic approach to SAT or outcome, all having an improvement in neck pain, inflammation parameters, and ultrasound features.

Conclusion

This is the first prospective study investigating any difference both at diagnosis and at follow-up between SAT presentation in patients with previous SARS-CoV-2 infection and those without. Our data demonstrate that SARS-CoV-2 does not impact on SAT onset, evolution, and outcome.

Thyroid dysfunction in COVID-19

The COVID-19 pandemic has affected over 772 million people globally. While lung damage is the major contributor to the morbidity and mortality of this disease, the involvement of multiple organs, including the endocrine glands, has been reported. This Review aims to provide an updated summary of evidence regarding COVID-19 and thyroid dysfunction, incorporating highlights of recent advances in the field, particularly in relation to long COVID and COVID-19 vaccination. Since subacute thyroiditis following COVID-19 was first reported in May 2020, thyroid dysfunction associated with COVID-19 has been increasingly recognized, secondary to direct and indirect effects on the hypothalamic-pituitary-thyroid axis. Here, we summarize the epidemiological evidence, pattern and clinical course of thyroid dysfunction following COVID-19 and examine radiological, molecular and histological evidence of thyroid involvement in SARS-CoV-2 infection. Beyond acute SARS-CoV-2 infection, it is also timely to examine the course and implication of thyroid dysfunction in the context of long COVID owing to the large population of survivors of COVID-19 worldwide. This Review also analyses the latest evidence on the relationship between the therapeutics and vaccination for COVID-19 and thyroid dysfunction. To conclude, evidence-based practice recommendations for thyroid function testing during and following COVID-19 and concerning COVID-19 vaccination are proposed.

Subacute Thyroiditis Following COVID-19 and COVID-19 Vaccination

OBJECTIVE

COVID-19 infection and immunizations have been implicated in developing a range of thyroid diseases, including subacute thyroiditis (SAT). This study aimed to evaluate the association between COVID-19 infection and/or COVID-19 vaccination with SAT.

METHODS

A population of 3 million adults insured by Clalit Health Services was evaluated from March 2020 to September 2022. Patients with a new diagnosis of SAT were identified and matched in a 1:10 ratio to a control group. Each control was assigned an index date that was identical to that of their matched case, defined as the date of SAT diagnosis. Multivariate conditional logistic regression models were used to evaluate the association between COVID-19 infection, vaccine, and thyroiditis.

RESULTS

A total of 3221 patients with SAT were matched with 32 210 controls. Rates of COVID-19 vaccination (first, second, or third dose) and COVID-19 infection were evaluated prior to the date of SAT diagnosis (disease group) or index date (control group) to detect a possible association. No difference was detected between the groups in relation to vaccinations at the 30 days, 60 days, and 90 days of time points (P = .880/0.335/0.174, respectively). No difference was found between groups in relation to COVID-19 infection at these time points (P = .735/0.362/0.956, respectively). There was higher use of medications for the treatment of thyroiditis, including nonsteroidal anti-inflammatory drugs (28.6% vs 7.9%, P < .01), steroids (10.3% vs 1.8%, P < .01), and beta-blockers (18.3% vs 5.4%, P < .01).

CONCLUSION

Based on this large population study, no association was found between COVID-19 infection and/or the COVID-19 vaccine and SAT.

Comparison of treatment outcome between glucocorticoids and non-steroidal anti-inflammatory drugs in subacute thyroiditis patients-a systematic review and meta-analysis

Importance

Subacute thyroiditis (SAT) is a self-limiting and inflammatory thyroid disease. Although SAT usually improves on its own within weeks, it needs treatment when patients have pain, fever, and symptoms of thyrotoxicosis. Therapeutic drugs mainly include non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids. Currently, there is no systematic review or meta-analysis of the comparison of outcomes between NSAIDs and glucocorticoids for the treatment of SAT.

Objectives

To conduct a systematic review and meta-analysis on the outcomes in subacute thyroiditis patients treated with glucocorticoids or NSAIDs.

Data sources

Using the four electronic databases, including PubMed, Embase, Cochrane Library, Wanfang database and Web of Science. All publications until 21 June 2023 were searched. The reference lists of all selected articles were independently screened to identify additional studies left out in the initial search.

Study selection

The literature comparing outcomes between glucocorticoids and non-steroidal anti-inflammatory drugs for patients with subacute thyroiditis will be included.

Data extraction and synthesis

Two independent investigators (Anqi Yuan and Jialu Wu) extracted the data following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines (PRISMA) and then evaluated the quality of the eligible studies with the Newcastle-Ottawa Scale. Fixed-effects models for the meta-analyses were applied. Heterogeneity was assessed with the chi-squared (x²) test (Cochran's Q) and inconsistency index (I²). The robustness of the results was tested with the sensitivity analyses. The bias of publication was assessed with the Harbord test.

Main outcomes and measures

The incidence of permanent hypothyroidism in SAT patients treated with corticosteroids or NSAIDs.

Results

Our study included a total of ten comparative cohort studies with 1337 participants. We found that the incidence of developing permanent hypothyroidism in the SAT patients who received glucocorticoids treatment was significantly lower than those who received NSAIDs treatment. (OR, 0.56; 95% CI, 0.36-0.88; P = 0.01). The risk of permanent hypothyroidism in patients who received prednisone at an average initial dose < 40 mg/d was significantly lower than that in patients who received NSAIDs (OR, 0.37; 95% CI, 0.14-0.94; P = 0.04). There was no significant difference in the occurrence of permanent hypothyroidism between SAT patients who received an average initial dose ≥ 40 mg/d of prednisone and those who received only NSAIDs (OR, 0.7; 95% CI, 0.14-3.53; P = 0.67). In addition, the recurrence rate was observably higher in those receiving glucocorticoids than in those receiving NSAIDs (OR, 1.98; 95% CI, 1.12-3.5; p = 0.02). The recurrence rate was significantly higher in patients with an average initial prednisone dose of < 40 mg/d than in the NSAIDs group. There was no significant difference in the recurrence rate between patients in the mean initial prednisone dose ≥ 40 mg/d group and those in the NSAIDs group.

Conclusions and relevance

In this meta-analysis, we compared the treatment outcomes of SAT patients between glucocorticoids and NSAIDs. Our results indicated that glucocorticoid treatment was associated with a lower incidence of permanent hypothyroidism than NSAID treatment. Patients treated with NSAIDs might have a lower recurrence rate. This finding might help to understand the outcome of the disease when choosing different drugs and help physicians to make appropriate decisions.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023427332.

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.

Occult endocrine disorders newly diagnosed in patients with post-COVID-19 symptoms

Determination of long COVID requires ruling out alternative diagnoses, but there has been no report on the features of alternative diagnoses. This study was a single-center retrospective study of outpatients who visited our clinic between February 2021 and June 2023 that was carried out to determine the characteristics of alternative diagnoses in patients with post-COVID-19 symptoms. In a total of 731 patients, 50 patients (6.8%) were newly diagnosed with 52 diseases requiring medical intervention, and 16 (32%) of those 50 patients (2.2% of the total) were considered to have priority for treatment of the newly diagnosed disorders over long COVID treatment. The proportion of patients with a new diagnosis increased with advance of age, with 15.7% of the patients aged 60 years or older having a new diagnosis. Endocrine and metabolic diseases and hematological and respiratory diseases were the most common, being detected in eight patients (16%) each. Although 35 of the 52 diseases (67%) were related to their symptoms, endocrine and metabolic diseases were the least associated with specific symptoms. Other disorders that require attention were found especially in elderly patients with symptomatic long COVID. Thus, appropriate assessment and differentiation from alternative diagnoses are necessary for managing long COVID.

Development of autoimmune thyroid disease after COVID-19 infection: case report

Background

SARS-CoV-2 could trigger multiple immune responses, leading to several autoimmune diseases, including thyroid diseases. Many cases of thyroid diseases caused by COVID-19 infection have been reported. Here, we describe the disease development of patients with autoimmune thyroid disease after COVID-19 infection.

Methods

The clinical characteristics, diagnosis and treatment of five different patients with autoimmune thyroid disease after COVID-19 infection were reported.

Results

Female patients with primary autoimmune thyroid disease which have been stable for many years were reported. One month after COVID-19 infection, the disease has undergone different evolution. Case 1, a patient with history of long-term stable Hashimoto's thyroiditis, suddenly suffered from Graves disease after COVID-19 infection. Case 2, a patient with history of long-term stable Hashimoto's thyroiditis with thyroid nodules, suddenly suffered from Graves disease after infection. Case 3, a patient with history of long-term stable Graves disease, suddenly suffered from worsening after infection. The above three cases showed thyroid-stimulating antibodies were enhanced. Case 4, a patient with history of previous hypothyroidism had an increase in thyroid-related antibody (TPOAb and TRAb) activity after infection, followed by a marked worsening of hypothyroidism. Case 5, a patient with no history of thyroid disease suddenly developed controllable "thyrotoxicosis" after infection, suggesting the diagnosis of painless thyroiditis.

Conclusion

The five case reports show a different development of the primary autoimmune thyroid disease after COVID-19 infection. The change in the trend of thyroid disease is closely related to the immune response induced by SARS-CoV-2 infection.

High Diagnostic Accuracy of Thyroid-Stimulating Hormone (TSH) Receptor Antibodies in Distinguishing Graves' Disease and Subacute Thyrotoxicosis in the Indian Population

BACKGROUND AND OBJECTIVE

Thyrotoxicosis is a common clinical condition encountered in endocrine practice. Graves' disease and subacute thyroiditis are the two common causes of thyrotoxicosis and often have overlapping clinical and biochemical features. 99mTc thyroid scintigraphy is the most commonly used confirmatory test to differentiate the two conditions but is not available in the majority of the second-tier cities of India. However, obtaining thyroid stimulating hormone (TSH) receptor antibodies (TSHrAb), another accurate test to differentiate the two conditions, in second-tier cities by outsourcing to labs in major cities is a feasible option nowadays. However, the data on the performance of TSHrAb to differentiate the two conditions in Indian patients is limited. Hence, we have evaluated the diagnostic accuracy of TSHrAb in the Indian population to differentiate Graves' disease and subacute thyroiditis.

MATERIALS AND METHODS

This prospective study was conducted on 115 consecutive newly diagnosed thyrotoxicosis patients presenting to the Department of Endocrinology at a tertiary health care centre in India. Clinical parameters like throat pain, duration of symptoms, and grade of goitre were noted. Measurement of total tri-iodothyronine (TT3), total thyroxine (TT4), TSH, TSHrAb, and 99mTc thyroid scintigraphy were performed in all participants. All participants were followed up at least for six months after the recruitment. Increased tracer uptake (>4%) and/or increased thyroid to parotid trace uptake ratio (>2.5) were used to diagnose Graves' disease.

RESULTS

Eighty-one and 34 patients were diagnosed with Graves' disease and subacute thyroiditis, respectively. TT3/TT4 ratio had low diagnostic accuracy (area under the curve (AUC): 0.6, best cut-off: 15.6, sensitivity: 53.1%, specificity: 79.4%). TSHrAb had the best AUC (0.9) to distinguish Graves' disease from subacute thyroiditis (cut-off: 2.0 IU/L, sensitivity: 97.5%, specificity: 100%). In contrast, the kit manufacturer's reference range (1.75 IU/L) was slightly more sensitive (98.8%), but less specific (94%).

CONCLUSION

The TT3/TT4 ratio is not a good test to differentiate Graves' disease and subacute thyroiditis. TSHrAb is accurate in distinguishing Graves' disease from subacute thyroiditis and a level of 2.0 may be a more accurate cut-off to differentiate the two conditions in the Indian population.

Multiparametric ultrasound-based assessment of overt hyperthyroid diffuse thyroid disease

Introduction

Hyperthyroidismis a prevalent condition affecting global populations, with an overall prevalence of 1.2%. Our research aimed to establish a systematic diagnostic approach using multiparametric ultrasound (MPUS) to diagnose hyperthyroid diffuse thyroid disease (DTD).

Methods

We conducted a retrospective study from June 2021 to June 2023 at a specialized endocrinology center in Timisoara, Romania, enrolling subjects presenting with clinical hyperthyroidism. Using the Mach 30 Aixplorer ultrasound equipment, evaluations were performed initially in B-mode US, followed by Color Doppler and Spectral Doppler measurements, and finally, 2D Shear wave elastography (SWE).

Results

From the 218 patients analyzed, the diagnosis of DTD with hyperthyroidism was confirmed through biochemical assessment, subgrouping various pathologies such as subacute thyroiditis, Graves' disease, painless thyroiditis, Hashimoto's thyroiditis, iatrogenic, as well as healthy controls. In the first step, B-mode hypoechogenicity had an AUC of 0.951 for DTD detection. In the second step, the peak systolic velocity differentiated Graves' disease with a median of 42.4 cm/s and an AUC of 1. Lastly, the third step consisted of SWE evaluation, revealing a mean elasticity index in the SAT subgroup significantly higher from other subgroups (p<0.001) with an AUC of 1.

Conclusion

Our study offers a step-by-step evaluation algorithm for DTD diagnosis, with a very good overall diagnostic performance (AUC of 0.946).

Management of thyroiditis in the context of Covid-19: cause-effect and beyond

Background

The COVID-19 pandemic hit the world in late 2019, and by 2020, everyone was affected. Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) belongs to the beta-coronavirus genre and uses the angiotensin-converting enzyme 2 (ACE2) receptor to penetrate cells. Thyroid cells are rich in such receptors. Therefore, this gland is frequently involved alongside other organs in the COVID-19 disease.

Aim

To describe COVID-19 inflammation and, eventually, dysregulations of normal thyroid function in a case series of patients diagnosed in a tertiary endocrinology care centre.

Patients and Methods

We described subacute thyroiditis cases related to COVID-19 infection or vaccination against SARS-CoV2 infection (clinical manifestations and evolution). We also reviewed the literature data regarding COVID-19 infection or vaccination implications in thyroid pathology.

Results

The literature describes two types of thyroid involvement in SARS-CoV2 infection or vaccination: subacute thyroiditis (SAT) and non-thyroidal illness syndrome (NTIS). In our case series, 5 patients (3 males), aged 41-54 years, developed the classical clinical manifestation of SAT related to COVID-19 infection (3 patients, concomitantly to upper respiratory infection or a few weeks apart) or anti-SARS-CoV2 ARNm vaccination (1-2 weeks after the vaccine administration). Clinical, laboratory and imaging findings and the evolution (steroid anti-inflammatory treatment used in 4/5 cases) were unremarkable compared to other SAT etiologies.

Conclusion

We found no differences between the "typical" viral and post-COVID-19 SAT regarding clinical presentation, severity, response to treatment, and thyroid function alteration. The only remarkable difference is the association of SAT with anti-SARS-CoV2 ARNm vaccination.