Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and thyroid disease. An update

Thyroid Autoimmunity and SARS-CoV-2 Infection

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological culprit of COronaVIrus Disease 19 (COVID-19), can enter the cells via the angiotensin-converting enzyme 2 (ACE2) receptor, which has been found in several tissues including in endocrine organs, such as the ovaries, testes, pancreas, and thyroid. Several thyroid disorders have been associated with SARS-CoV-2 infection [subacute thyroiditis (SAT), thyrotoxicosis, and non-thyroidal illness syndrome (NTIS)] and, in part, they are believed to be secondary to the local virus replication within the gland cells. However, as documented for other viruses, SARS-CoV-2 seems to interfere with several aspects of the immune system, inducing the synthesis of autoantibodies and triggering latent or new onset autoimmune disease (AID), including autoimmune thyroid disease (AITD), such as Hashimoto Thyroiditis (HT) and Graves' disease (GD). Several mechanisms have been hypothesized to explain this induction of autoimmunity by SARS-CoV-2 infection: the immune system hyper-stimulation, the molecular mimicry between the self-antigens of the host and the virus, neutrophils extracellular traps, and finally, the virus induced transcriptional changes in the immune genes; nonetheless, more evidence is needed especially from large, long-term cohort studies involving COVID-19 patients, to establish or reject this pathogenetic relationship.

Increased incidence of Graves' disease during the SARS-CoV2 pandemic

INTRODUCTION

COVID-19 has a wide spectrum of clinical severity and there is evidence that SARS-Cov2 affects several organs and systems. Among the organs affected since the beginning of the pandemic, the relationship between SARS-CoV-2 infection and thyroid involvement has been demonstrated. Novel and highly effective messenger RNA and DNA-based vaccines have been rapidly developed to decrease SARS-CoV-2 morbidity and mortality. Early after mass vaccinations, cases of thyroid dysfunction mainly including episodes of subacute thyroiditis, began to be reported like adverse effects. The objective of this study is to determine the impact of the pandemic, both due to SARS-CoV2 infections and vaccinations, on the incidence of Graves' disease (GD).

METHODS

Cross-sectional, observational study comparing incidence of GD in adult population (over 18 years) before (2017-2019) and after (2020-2021) Covid-19 pandemic. Only patients with new cases of GD, no relapsed diseases, were included. SARS-CoV-2 diagnosis was based on nucleic acid amplification tests on nasopharyngeal swabs or measurement of class M and class G antibodies to SARS-CoV-2 by highly specific assays. Data on incidence and vaccination related to SARS-CoV-2 infection were obtained from the public records from Castilla y León autonomous regional government.

RESULTS

A total of 180 subjects were diagnosed and treated for GD during the study period. We observed a notable increase in expected GD cases in 2021 compared to 2017-19. The number of GD cases was higher in the second (Q2) quarter. Among 2021 GD cases, 42/66 patients (63.6%) had been vaccinated in the 90 days before symptom onset, but none of them in the first quarter of the year. A total of 97.7% were women with a mean age of 48.9 (SD 15.6) years. On average they were diagnosed 19.9 (SD 17.6) days after receiving the vaccine. A total of 7/42 (16.67%) had another previously diagnosed autoimmune disease and 11/42 (26.19%) were smokers.

DISCUSSION

Our results show a notable increase in the incidence of GD during the year 2021, specially in women with a history of smoking. Hyper activation of the immune system induced by SARS-CoV2 and by the recently released SARS-COV-2 vaccines has been highlighted in recent months. To assess whether this observed increase in the incidence of GD is sustained in the coming years or has simply been a precipitous trigger for individuals who were already predisposed to develop the disease, future studies will be needed.

Thyroid function and risk of bloodstream infections: Results from the Norwegian prospective population-based HUNT Study

OBJECTIVE

Previous studies on thyroid function and risk of infection is conflicting and often stem from intensive care cohorts were nonthyroidal illness syndrome (NTIS) may be present. The objective of this study was to identify the risk of bloodstream infections (BSI) and BSI-related mortality with thyroid-stimulating hormone (TSH) levels within the reference range in a general population.

DESIGN

Prospective follow-up.

PARTICIPANTS

The HUNT2 (1995-97) included 34,619 participants with information on TSH levels.

MEASUREMENTS

Hazard ratios (HRs) with 95% confidence interval (CI) confirmed BSIs and BSI-related mortality until 2011.

RESULTS

During a median follow-up of 14.5 years, 1179 experienced at least one episode of BSI and 208 died within 30 days after a BSI. TSH levels within the reference range of 0.5-4.5 mU/L were not associated with the risk of first-time BSI, with an HR of 0.97 (95% CI: 0.90-1.04) per mU/L. Stratified by baseline age < or ≥65 years, TSH was inversely associated with the risk of BSI (HR: 0.88; 95% CI: 0.78-1.00 per mU/L) in the youngest age group only. Persons with any baseline thyroid disease had a 30% risk and the hyperthyroid subgroup a 57%, and hypothyroidism a 20% increased risk of BSI. TSH levels were not clearly associated with BSI mortality, but the HRs were imprecise due to few BSI-related deaths.

CONCLUSION

There was some evidence of a weak inverse association between TSH levels and the risk of BSI in persons below 65 years of age. The increased risk seen in persons with thyroid illness is probably explained by confounding by concurrent ill health.

A survey on the psychological impact and access to health care of thyroid patients during the first SARS-COV-2 lockdown

OBJECTIVE

Information on the impact of SARS-COV-2 on the daily life of thyroid patients during lockdown is sparse. The main objective was explorative, focusing on how SARS-COV-2 affected thyroid patients.

DESIGN

Cross-sectional, questionnaire-based, using an online platform.

PATIENTS

Patients >18 years with a history of thyroid disease.

MEASUREMENTS

Demographic data, psychological impact of SARS-COV-2, medical care during the pandemic.

RESULTS

Valid responses were received from 609 responders. The median age was 50 years, 94% were female and 98.5% were UK residents. The commonest diagnosis was primary hypothyroidism (52.2%). Negative psychological effects following the lockdown were reported by 45.6%-58.7%. Cancellations of appointments with thyroid specialists were reported by 43.8%, although cancellations of thyroid investigations and treatments were relatively infrequent (12.9%-14.1%). Overall satisfaction rates for thyroid services were low (satisfaction score 40.1-42.8 out of 100), but nearly 80% were satisfied with remote consultations. Responder ratings of online information sources about SARS-COV-2 and thyroid diseases were lowest for government sites. Unmet needs during lockdown were: more remote access to thyroid specialists, more online information in 'plain English', and psychological support. In multivariate analyses, younger age, female gender, history of depression, hyperthyroidism, not having contracted SARS-COV-2 and multiple comorbidities were risk factors for a negative psychological impact of lockdown.

CONCLUSIONS

This survey identified a significant negative impact of SARS-COV-2 and lockdown on psychological wellbeing, particularly in some groups of patients defined by demographic factors, history of hyperthyroidism and comorbidities. Low satisfaction with healthcare services among thyroid patients was noted, but remote consultations were rated favourably.

Activation of Type I and Type II Interferon Signaling in SARS-CoV-2-Positive Thyroid Tissue of Patients Dying from COVID-19

Background: Thyroid dysfunctions have been reported after Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. However, the biological mechanisms behind these conditions remain unexplored. Herein, we report on changes of the immune transcriptome in autoptic thyroid tissues of people who have died from coronavirus disease 2019 (COVID-19). Methods: Twenty-five autoptic thyroid specimens of subjects dying from COVID-19 were investigated. Eleven autoptic thyroid specimens of subjects dying from causes other than infectious conditions served as controls. RNA transcripts of 770 immune-related genes together with RNA genomes of multiple coronavirus types were measured by the nCounter system. Reverse transcription-polymerase chain reaction for two SARS-CoV-2 genes was used to assess virus positivity. Results were validated by immunohistochemistry. Results: The SARS-CoV-2 genome and antigens were detected in 9 of 25 (36%) thyroid specimens from the COVID-19 cohort. Virus-negative thyroid tissues from COVID-19 subject did not show changes of gene transcription nor significant numbers of infiltrating immune cells. Conversely, SARS-CoV-2-positive thyroid specimens showed marked upregulation of immune genes, especially those proper of the type I and type II interferon (IFN) pathways. In infected tissues, infiltrates of innate immune cells (macrophages and polymorphonuclear neutrophils) were prevalent. Conclusions: The thyroid gland can be directly infected by the SARS-CoV-2. Infection strongly activates IFN pathways. The direct viral insult combined with an intense immune response may trigger or worsen thyroid conditions in predisposed individuals.

The Effects of Previous Thyroid Disease on the Susceptibility to, Morbidity of, and Mortality Due to COVID-19: A Nationwide Cohort Study in South Korea

This study aimed to investigate the associations of the susceptibility to, morbidity of, and mortality due to coronavirus disease 2019 (COVID-19) with thyroid diseases. Korea National Health Insurance Database Coronavirus disease 2019 (NHID-COVID-19) medical claim code data from 2015 to 2020 were analyzed. A total of 8070 COVID-19 patients and 32,280 matched control participants were evaluated for histories of hypothyroidism, hyperthyroidism, Graves’ disease, thyroiditis, and autoimmune thyroiditis. The relationships of susceptibility to, morbidity of, and mortality due to COVID-19 with hypothyroidism, hyperthyroidism, Graves’ disease, thyroiditis, and autoimmune thyroiditis were analyzed using a conditional logistic regression. Hypothyroidism, hyperthyroidism, Graves’ disease, thyroiditis, and autoimmune thyroiditis were not associated with susceptibility to, morbidity of, or mortality due to COVID-19. Graves’ disease was related to higher odds of mortality due to COVID-19 in the adjusted model but the confidence interval (CI) was wide, probably due to the small number of deaths among patients with Graves’ disease (aOR = 11.43, 95% CI = 1.29–101.22, p = 0.029). Previous histories of hypothyroidism, hyperthyroidism, Graves’ disease, thyroiditis, and autoimmune thyroiditis were not related to susceptibility to COVID-19. In addition, prior histories of thyroid diseases were not related to increased risks of COVID-19-related morbidity and mortality.