Thyroid autoimmunity and SARS-CoV-2 infection: Report of a large Italian series

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.

Impact of COVID-19 and vaccination campaign on 1,755 systemic sclerosis patients during first three years of pandemic. Possible risks for individuals with impaired immunoreactivity to vaccine, ongoing immunomodulating treatments, and disease-related lung involvement during the next pandemic phase

Introduction

The impact of COVID-19 pandemic represents a serious challenge for 'frail' patients' populations with inflammatory autoimmune systemic diseases such as systemic sclerosis (SSc). We investigated the prevalence and severity of COVID-19, as well the effects of COVID-19 vaccination campaign in a large series of SSc patients followed for the entire period (first 38 months) of pandemic.

Patients and method

This prospective survey study included 1755 unselected SSc patients (186 M, 1,569F; mean age 58.7 ± 13.4SD years, mean disease duration 8.8 ± 7.3SD years) recruited in part by telephone survey at 37 referral centers from February 2020 to April 2023. The following parameters were carefully evaluated: i. demographic, clinical, serological, and therapeutical features; ii. prevalence and severity of COVID-19; and iii. safety, immunogenicity, and efficacy of COVID-19 vaccines.

Results

The prevalence of COVID-19 recorded during the whole pandemic was significantly higher compared to Italian general population (47.3 % vs 43.3 %, p < 0.000), as well the COVID-19-related mortality (1.91 % vs 0.72 %, p < 0.001). As regards the putative prognostic factors of worse outcome, COVID-19 positive patients with SSc-related interstitial lung involvement showed significantly higher percentage of COVID-19-related hospitalization compared to those without (5.85 % vs 1.73 %; p < 0.0001), as well as of mortality rate (2.01 % vs 0.4 %; p = 0.002). Over half of patients (56.3 %) received the first two plus one booster dose of vaccine; while a fourth dose was administered to 35.6 %, and only few of them (1.99 %) had five or more doses of vaccine. Of note, an impaired seroconversion was recorded in 25.6 % of individuals after the first 2 doses of vaccine, and in 8.4 % of patients also after the booster dose. Furthermore, the absence of T-cell immunoreactivity was observed in 3/7 patients tested by QuantiFERON® SARSCoV-2 Starter Set (Qiagen). The efficacy of vaccines, evaluated by comparing the COVID-19-related death rate recorded during pre- and post-vaccination pandemic periods, revealed a quite stable outcome in SSc patients (death rate from 2.54 % to 1.76 %; p = ns), despite the significant drop of mortality observed in the Italian general population (from 2.95 % to 0.29 %; p < 0.0001).

Conclusions

An increased COVID-19 prevalence and mortality rate was recorded in SSc patients; moreover, the efficacy of vaccines in term of improved outcomes was less evident in SSc compared to Italian general population. This discrepancy might be explained by concomitant adverse prognostic factors: increased rate of non-responders to vaccine in SSc series, low percentage of individuals with four or more doses of vaccine, ongoing immunomodulating treatments, disease-related interstitial lung disease, and/or reduced preventive measures in the second half of pandemic. A careful monitoring of response to COVID-19 vaccines together with adequate preventive/therapeutical strategies are highly recommendable in the near course of pandemic in this frail patients' population.

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.

COVID-induced thyroid autoimmunity

Breakdown of self-tolerance to thyroid antigens (thyroperoxidase, thyroglobulin and the thyrotropin-receptor) is the driver of thyroid autoimmunity. It has been suggested that infectious disease might trigger autoimmune thyroid disease (AITD). Involvement of the thyroid has been reported during severe acute respiratory syndrome virus 2 (SARS-CoV-2) infection, in the form of subacute thyroiditis in subjects with mild coronavirus disease 19 disease (COVID-19) and of painless, destructive thyroiditis in hospitalized patients with severe infection. In addition, cases of AITD, both Graves' disease (GD) and Hashimoto's thyroiditis (HT), have been reported in association with (SARS-CoV-2) infection. In this review, we focus on the relationship between SARS-CoV-2 infection and occurrence of AITD. Nine cases of GD strictly related to SARS-CoV-2 infection and only three cases of HT associated to COVID-19 infection have been reported. No study has demonstrated a role of AITD as a risk factor for a poor prognosis of COVID-19 infection.

The Expression Levels of SARS-CoV-2 Infection-Mediating Molecules Promoted by Interferon-γ and Tumor Necrosis Factor-α Are Downregulated by Hydrogen Sulfide

Autoimmune thyroid diseases (AITDs), which include Hashimoto's thyroiditis (HT) and Graves' disease (GD), have a higher prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the literature. The effects of AITD-associated cytokines on SARS-CoV-2 infection-mediating molecule levels might be involved in the pathogenesis of susceptibility. We speculated that hydrogen sulfide (H2S) might attenuate this process since H2S has antiviral effects. Using immunohistochemistry, we found that angiotensin-converting enzyme-II (ACE2) expression was higher in the HT group and neuropilin 1 (NRP1) expression was higher in HT and GD groups than in the normal group, while transmembrane protease serine type 2 (TMPRSS2) expression was lower in HT and GD groups. When culturing primary thyrocytes with cytokines or sodium hydrosulfide (NaHS) plus cytokines, we found that ACE2 and NRP1 mRNA levels were upregulated while TMPRSS2 levels were downregulated by interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α). After pretreatment with NaHS in thyrocytes, ACE2 and NRP1 expression were downregulated compared to IFN-γ or TNF-α treatment, and NaHS had no effect on TMPRSS2 expression. Our findings suggested that IFN-γ and TNF-α, which are elevated in AITDs, promoted ACE2 and NRP1 expression and inhibited TMPRSS2 expression. H2S might protect against SARS-CoV-2 infection by downregulating ACE2 and NRP1 levels.