Latent rheumatic, thyroid and phospholipid autoimmunity in hospitalized patients with COVID-19

Autoantibodies in COVID-19: implications for disease severity and clinical outcomes

Few pathogens have historically been subjected to as intense scientific and clinical scrutiny as SARS-CoV-2. The genetic, immunological, and environmental factors influencing disease severity and post-infection clinical outcomes, known as correlates of immunity, remain largely undefined. Clinical outcomes of SARS-CoV-2 infection vary widely, ranging from asymptomatic cases to those with life-threatening COVID-19 symptoms. While most infected individuals return to their former health and fitness within a few weeks, some develop debilitating chronic symptoms, referred to as long-COVID. Autoimmune responses have been proposed as one of the factors influencing long-COVID and the severity of SARS-CoV-2 infection. The association between viral infections and autoimmune pathologies is not new. Viruses such as Epstein-Barr virus and cytomegalovirus, among others, have been shown to induce the production of autoantibodies and the onset of autoimmune conditions. Given the extensive literature on SARS-CoV-2, here we review current evidence on SARS-CoV-2-induced autoimmune pathologies, with a focus on autoantibodies. We closely examine mechanisms driving autoantibody production, particularly their connection with disease severity and long-COVID.

Prevalent and persistent new-onset autoantibodies in mild to severe COVID-19

Autoantibodies have been shown to be implied in COVID-19 but the emerging autoantibody repertoire remains largely unexplored. We investigated the new-onset autoantibody repertoire in 525 healthcare workers and hospitalized COVID-19 patients at five time points over a 16-month period in 2020 and 2021 using proteome-wide and targeted protein and peptide arrays. Our results show that prevalent new-onset autoantibodies against a wide range of antigens emerged following SARS-CoV-2 infection in relation to pre-infectious baseline samples and remained elevated for at least 12 months. We found an increased prevalence of new-onset autoantibodies after severe COVID-19 and demonstrated associations between distinct new-onset autoantibodies and neuropsychiatric symptoms post-COVID-19. Using epitope mapping, we determined the main epitopes of selected new-onset autoantibodies, validated them in independent cohorts of neuro-COVID and pre-pandemic healthy controls, and identified sequence similarities suggestive of molecular mimicry between main epitopes and the conserved fusion peptide of the SARS-CoV-2 Spike glycoprotein. Our work describes the complexity and dynamics of the autoantibody repertoire emerging with COVID-19 and supports the need for continued analysis of the new-onset autoantibody repertoire to elucidate the mechanisms of the post-COVID-19 condition.

Prevalence and factors associated with thyroid autoimmunity among children newly diagnosed with type 1 diabetes before and during the COVID-19 pandemic: Evidence from Kuwait

AIMS

This study reports the prevalence and characteristics related to the development of thyroid autoimmunity among children newly diagnosed with type I diabetes (T1D) during the COVID-19 pandemic in Kuwait.

MATERIALS AND METHODS

This is a prospective observational study of all children under age 14 years newly diagnosed with T1D in Kuwait. We define the duration of the COVID-19 pandemic from the official declaration of the first identified positive COVID-19 case on 24 February 2020 until 31 December 2022. For comparison, we use the time period directly before the COVID-19 pandemic, 1 January 2017 to 23 February 2020.

RESULTS

One thousand twenty-four (1024) children newly diagnosed with T1D in Kuwait during the study period were included. Among newly diagnosed children, 20.3% tested positive for thyroid antibodies during the COVID-19 pandemic, compared with 14.5% during the pre-pandemic period (p = 0.015). Children with positive COVID-19 status were more likely to present with thyroid antibodies (p = 0.035). After adjusting for other characteristics, patients diagnosed with T1D during the COVID-19 pandemic had double the odds of testing positive for thyroid antibodies (Adjusted odds ratio = 2.173, 95%CI: 1.108, 4.261, p = 0.024).

CONCLUSIONS

Incident cases of T1D during the COVID-19 pandemic may be different in aetiology or contextual factors leading to a higher risk of thyroid autoimmunity. Longitudinal studies are needed to understand the role of COVID-19 in the onset and progression of T1D and on thyroid autoimmunity and disease.

Autoimmunity in centenarians. A paradox

Autoimmune diseases (ADs) are one of the groups of chronic illnesses that impose a significant burden of disease and health costs worldwide. Age is a crucial risk factor for the onset of ADs. Theoretically, it is inferred that with organic and immune system aging, the loss of immune tolerance and specificity of immune activity becomes more intense, the probability of autoimmunity is increasing. However, there is a group of individuals whose prevalence of ADs is very low or non-existent, despite the biological aging. This paradox in autoimmunity raises questions. Centenarians, individuals who are over 100 years old, are possibly the most successful model of biological aging in humans. Most of these individuals exhibit a favorable health phenotype. To date, primary data evidence and potential hypotheses explaining this phenomenon are lacking globally, even though this paradox could provide valuable, original, and relevant information regarding the understanding of risk or protective factors, biological drivers, and biomarkers related to autoimmunity. Herein we discuss some hypothesis that may explain the absence of ADs in centenarians, including inflammaging, immunosenescence and immune resilience, immune system hyperstimulation, proteodynamics, and genetics.

The development of anticyclic citrullinated peptide (anti-CCP) antibody following severe COVID-19

OBJECTIVES

The dysregulated immune response is one of the cardinal features of severe coronavirus disease 2019 (COVID-19). This study was conducted to clarify the occurrence of autoantibodies (AABs) associated with systemic autoimmune rheumatic diseases (SARDs) in hospitalized patients with a moderate, severe, and critical form of COVID-19.

METHODS

The serum samples obtained from 176 hospitalized COVID-19 patients were investigated in this study, including patients with moderate (N = 90), severe (N = 50), and critical (N = 36) forms of COVID-19. Also, the serum samples collected from healthy subjects before the COVID-19 pandemic were used as controls (N = 176). The antinuclear antibodies (ANAs), antidouble-stranded DNA (anti-dsDNA), cytoplasmic-anti neutrophil cytoplasmic antibody (c-ANCA), perinuclear ANCA (p-ANCA), antiphospholipid antibodies (aPLs), and anticyclic citrullinated peptide (anti-CCP) occurrence was evaluated using a solid-phase enzyme-linked immunosorbent assay (ELISA).

RESULTS

The results showed that the occurrence of ANAs, anti-dsDNA, anti-CCP, c-ANCA, and p-ANCA was significantly higher in the COVID-19 patients compared to serum obtained from healthy subjects (p < .0001, p < .0001, p < .0001, p < .05, and p < .001, respectively). The positive number of anti-CCP tests increased significantly in severe COVID-19 compared to the moderate group (p < .01).

CONCLUSION

Our study further supports the development of autoantibodies related to systemic autoimmune rheumatologic diseases. To the best of our knowledge, this is the first study with a large sample size that reported the occurrence of anti-CCP in a severe form of COVID-19.

Antiphospholipid antibody-related hepatic vasculitis in a juvenile after non-severe COVID-19: a case report and literature review

Antiphospholipid antibodies (aPL) are both laboratory evidence and causative factors for a broad spectrum of clinical manifestations of antiphospholipid syndrome (APS), with thrombotic and obstetric events being the most prevalent. Despite the aPL-triggered vasculopathy nature of APS, vasculitic-like manifestations rarely exist in APS and mainly appear associated with other concurrent connective tissue diseases like systemic lupus erythematous. Several studies have characterized pulmonary capillaritis related to pathogenic aPL, suggesting vasculitis as a potential associated non-thrombotic manifestation. Here, we describe a 15-year-old girl who develops hepatic infarction in the presence of highly positive aPL, temporally related to prior non-severe COVID-19 infection. aPL-related hepatic vasculitis, which has not been reported before, contributes to liver ischemic necrosis. Immunosuppression therapy brings about favorable outcomes. Our case together with retrieved literature provides supportive evidence for aPL-related vasculitis, extending the spectrum of vascular changes raised by pathogenic aPL. Differentiation between thrombotic and vasculitic forms of vascular lesions is essential for appropriate therapeutic decision to include additional immunosuppression therapy. We also perform a systematic review to characterize the prevalence and clinical features of new-onset APS and APS relapses after COVID-19 for the first time, indicating the pathogenicity of aPL in a subset of COVID-19 patients.

Longitudinal rheumatoid factor autoantibody responses after SARS-CoV-2 vaccination or infection

Background

Rheumatoid factors (RFs) are autoantibodies that target the Fc region of IgG, and are found in patients with rheumatic diseases as well as in the healthy population. Many studies suggest that an immune trigger may (transiently) elicit RF responses. However, discrepancies between different studies make it difficult to determine if and to which degree RF reactivity can be triggered by vaccination or infection.

Objective

We quantitatively explored longitudinal RF responses after SARS-CoV-2 vaccination and infection in a well-defined, large cohort using a dual ELISA method that differentiates between true RF reactivity and background IgM reactivity. In addition, we reviewed existing literature on RF responses after vaccination and infection.

Methods

151 healthy participants and 30 RA patients were included to measure IgM-RF reactivity before and after SARS-CoV-2 vaccinations by ELISA. Additionally, IgM-RF responses after a SARS-CoV-2 breakthrough infection were studied in 51 healthy participants.

Results

Published prevalence studies in subjects after infection report up to 85% IgM-RF seropositivity. However, seroconversion studies (both infection and vaccination) report much lower incidences of 2-33%, with a trend of lower percentages observed in larger studies. In the current study, SARS-CoV-2 vaccination triggered low-level IgM-RF responses in 5.5% (8/151) of cases, of which 1.5% (2/151) with a level above 10 AU/mL. Breakthrough infection was accompanied by development of an IgM-RF response in 2% (1/51) of cases.

Conclusion

Our study indicates that de novo RF induction following vaccination or infection is an uncommon event, which does not lead to RF epitope spreading.

Predictors of mortality in hospitalised patients with COVID-19: a 1-year case-control study

BACKGROUND

A paucity of predictive models assessing risk factors for COVID-19 mortality that extend beyond age and gender in Latino population is evident in the current academic literature.

OBJECTIVES

To determine the associated factors with mortality, in addition to age and sex during the first year of the pandemic.

DESIGN

A case-control study with retrospective revision of clinical and paraclinical variables by systematic revision of clinical records was conducted. Multiple imputations by chained equation were implemented to account for missing variables. Classification and regression trees (CART) were estimated to evaluate the interaction of associated factors on admission and their role in predicting mortality during hospitalisation. No intervention was performed.

SETTING

High-complexity centre above 2640 m above sea level (masl) in Colombia.

PARTICIPANTS

A population sample of 564 patients admitted to the hospital with confirmed COVID-19 by PCR. Deceased patients (n=282) and a control group (n=282), matched by age, sex and month of admission, were included.

MAIN OUTCOME MEASURE

Mortality during hospitalisation.

MAIN RESULTS

After the imputation of datasets, CART analysis estimated 11 clinical profiles based on respiratory distress, haemoglobin, lactate dehydrogenase, partial pressure of oxygen to inspired partial pressure of oxygen ratio, chronic kidney disease, ferritin, creatinine and leucocytes on admission. The accuracy model for prediction was 80.4% (95% CI 71.8% to 87.3%), with an area under the curve of 78.8% (95% CI 69.63% to 87.93%).

CONCLUSIONS

This study discloses new interactions between clinical and paraclinical features beyond age and sex influencing mortality in COVID-19 patients. Furthermore, the predictive model could offer new clues for the personalised management of this condition in clinical settings.

Study Protocol of a Randomized Controlled Clinical Trial to Evaluate the Efficacy and Safety of Ropeginterferon Alfa-2b in COVID-19 Patients with Comorbidities

INTRODUCTION

Ropeginterferon alfa-2b represents a new-generation PEGylated interferon. It is approved for the treatment of polycythemia vera and shows promising anti-SARS-CoV-2 activities.

OBJECTIVE

This clinical study aims to evaluate the efficacy and safety of ropeginterferon alfa-2b in patients with coronavirus disease 2019 (COVID-19) and comorbidities.

METHODS

The randomized controlled study is designed to enroll adult patients with COVID-19 infection and comorbidities. Patients are non-responders to anti-SARS-CoV-2 drugs or not suitable to receive them. Comorbidities include hematologic cancer, solid tumor, and well-controlled autoimmune disease. Non-responders to anti-SARS-CoV-2 drugs are defined as having received treatment but have a Ct value < 30 at 14 days after symptom onset. Patients are randomized in a 1:1 ratio to receive ropeginterferon alfa-2b at 250 μg plus standard of care (SOC) or SOC alone. SARS-CoV-2 antigen test will be conducted at day 15 and day 29 visits to determine whether to administer additional ropeginterferon alfa-2b doses. Patients who are positive on the antigen test on days 15 and 29 will receive the second and third doses of ropeginterferon alfa-2b at 350 μg and 500 μg, respectively. Patients with a negative antigen test but a Ct value < 30 by reverse transcription polymerase chain reaction (RT-PCR) at days 15 and 29 are also administered the second (350 μg) and third (500 μg) doses. Patients at high risk of COVID-19 rebound/relapse, e.g., immunocompromised patients, will be given additional ropeginterferon alfa-2b doses even if the Ct is ≥ 30. Approximately 60 patients will be enrolled.

PLANNED OUTCOMES

The primary outcome is to compare the time from randomization to the achievement of Ct value ≥ 30 by RT-PCR between ropeginterferon alfa-2b and control groups. Our previous studies have shown safety and promising anti-SARS-CoV-2 activities in patients with moderate or severe COVID-19. This study will provide valuable data in patients with COVID-19 and comorbidities, for whom safe and effective treatment is urgently needed.

TRIAL REGISTRATION NUMBER

This trial is registered at ClinicalTrials.gov (Identifier NCT05808322).

Unveiling the intricacies of COVID-19: Autoimmunity, multi-organ manifestations and the role of autoantibodies

COVID-19 is a severe infectious disease caused by a SARS-CoV-2 infection. It has caused a global pandemic and can lead to acute respiratory distress syndrome (ARDS). Beyond the respiratory system, the disease manifests in multiple organs, producing a spectrum of clinical symptoms. A pivotal factor in the disease's progression is autoimmunity, which intensifies its severity and contributes to multi-organ injuries. The intricate interaction between the virus' spike protein and human proteins may engender the generation of autoreactive antibodies through molecular mimicry. This can further convolute the immune response, with the potential to escalate into overt autoimmunity. There is also emerging evidence to suggest that COVID-19 vaccinations might elicit analogous autoimmune responses. Advanced technologies have pinpointed self-reactive antibodies that target diverse organs or immune-modulatory proteins. The interplay between autoantibody levels and multi-organ manifestations underscores the importance of regular monitoring of serum antibodies and proinflammatory markers. A combination of immunosuppressive treatments and antiviral therapy is crucial for managing COVID-19-associated autoimmune diseases. The review will focus on the generation of autoantibodies in the context of COVID-19 and their impact on organ health.

Novel and unique rheumatoid factors cross-react with viral epitopes in COVID-19

Rheumatoid factors (RFs), polyreactive antibodies canonically known to bind two conformational epitopes of IgG Fc, are a hallmark of rheumatoid arthritis but also can arise in other inflammatory conditions and infections. Also, infections may contribute to the development of rheumatoid arthritis and other autoimmune diseases. Recently, RFs only in rheumatoid arthritis were found to bind novel linear IgG epitopes as well as thousands of other rheumatoid arthritis autoantigens. Specific epitopes recognized by infection-induced polyreactive RFs remain undefined but could provide insights into loss of immune tolerance. Here, we identified novel linear IgG epitopes bound by RFs in COVID-19 but not rheumatoid arthritis or other conditions. The main COVID-19 RF was polyreactive, binding two IgG and multiple viral peptides with a tripeptide motif, as well as IgG Fc and SARS-CoV-2 spike proteins. In contrast, a rheumatoid arthritis-specific RF recognized IgG Fc, but not tripeptide motif-containing peptides or spike. Thus, RFs have disease-specific IgG reactivity and distinct polyreactivities that reflect the broader immune response. Moreover, the polyreactivity of a virus-induced RF appears to be attributable to a very short peptide motif. These findings refine our understanding of RFs and provide new insights into how viral infections may contribute to autoimmunity.

COVID-19 infection and a repeated false positivity effect in HIV testing: A case report

Several reports in the literature have described the association between SARS-CoV-2 infection and false positive HIV testing results. We present a case of a cisgender male who has sex with men with a false positive HIV test after fully recovering from COVID-19 14 days prior. Initial 4th generation HIV 1 and 2 antibody/antigen testing was positive twice, but confirmatory antibody testing was negative. HIV viral load was persistently undetectable. Most of the previously published case reports describe concurrent testing and positivity for HIV and COVID-19. Our report stands out due to the implication of a potentially prolonged association that could persist for several weeks.

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 rheumatoid arthritis after COVID-19

An increase in the incidence of inflammatory arthritis after COVID-19 has been reported. Since many diseases exhibit population-specific causal effect sizes, we aimed to evaluate the incidence trends of inflammatory arthritis, including rheumatoid arthritis (RA), after COVID-19 in a large admixed Colombian population. Data analysis for this retrospective, population-based cohort study was carried out using the COOSALUD EPS registry. The following codes were selected for analyses: M059, seropositive RA, M069, unspecified RA, M060 seronegative RA, and other RA-related diagnoses: M064, M139, M068, M058, M130 and M053. The study period was limited to January 01, 2018, through December 31, 2022. Incidence rates (IRs) and incidence rate ratios (IRRs) were assessed. A Cox survival model was built to evaluate the influence of age, gender, and COVID-19 vaccination status on the development of inflammatory arthritis. A bioinformatic analysis was performed to evaluate the homology between SARS-CoV-2 and autoantigen peptides related to RA. The entire population study comprised 3,335,084 individuals. During the pandemic period (2020-2022) the total IIR for seropositive and unspecified RA were 1.60 (95% CI, 1.16-2.22) and 2.93 (95% CI, 2.04-4.19), respectively, and the IIR for overall RA-related diagnosis was 2.01 (95% CI 1.59-2.53). The age groups hazard ratios (HRs) were increased until the age group of 51-60 years (HR: 9.16; 95% CI, 7.24-11.59) and then decreased slightly in the age group 61 years or older (HR: 5.364; 95% CI, 4.24-6.78) compared to those within 18-30 years. Men were less at risk than women to develop inflammatory arthritis (HR: 0.21; 95% CI, 0.18-0.24). The greater time since COVID-19 diagnosis was associated with a lower likelihood of developing inflammatory arthritis (HR: 0.99; 95% CI:0.998-0.999). Vaccination (all types of COVID-19 vaccines included) did not prevent the development of inflammatory arthritis after COVID-19. Low identity was found between the SARS-CoV-2 ORF1ab antigen and the human antigens Poly ADP-ribose polymerase 14 and Protein mono-ADP-ribosyltransferase PARP9 isoform D (39% and 29%, respectively). In conclusion, our study confirms increased incidence of inflammatory arthritis, including RA, after COVID-19, with the greatest increase occurring before the first year post-covid. Women in their fifties were more susceptible. Further research is required to examine the effectiveness of vaccination in preventing post-COVID inflammatory arthritis and the mechanisms implicated in the development of RA after COVID-19.

Impaired immune response against SARS-CoV-2 infection is the major factor indirectly altering reproductive function in COVID-19 patients: a narrative review

Coronavirus disease 2019 (COVID-19) is an infectious disease affecting multiple systems and organs, including the reproductive system. SARS-CoV-2, the virus that causes COVID-19, can damage reproductive organs through direct (angiotensin converting enzyme-2, ACE-2) and indirect mechanisms. The immune system plays an essential role in the homeostasis and function of the male and female reproductive systems. Therefore, an altered immune response related to infectious and inflammatory diseases can affect reproductive function and fertility in both males and females. This narrative review discussed the dysregulation of innate and adaptive systems induced by SARS-CoV-2 infection. We reviewed the evidence showing that this altered immune response in COVID-19 patients is the major indirect mechanism leading to adverse reproduction outcomes in these patients. We summarized studies reporting the long-term effect of SARS-CoV-2 infection on women's reproductive function and proposed the chronic inflammation and chronic autoimmunity characterizing long COVID as potential underlying mechanisms. Further studies are needed to clarify the role of autoimmunity and chronic inflammation (long COVID) in altered female reproduction function in COVID-19.

False-Positive Screening and Confirmatory HIV Diagnostic Test in a Patient with Cured SARS-CoV-2 Infection Is Not Mediated by Env/Spike Cross-Reactive Antibodies

Acute SARS-CoV-2 infection has been associated with false-positive HIV screening tests. The underlying mechanism is unclear, and for clinical cases, evidence beyond a temporal connection is missing. However, several experimental studies point toward SARS-CoV-2 spike/HIV-1 envelope (Env) cross-reactive antibodies (Abs) as a cause. Here, we present the first case of an individual with convalescent SARS-CoV-2 infection testing false positive in both an HIV screening and confirmatory test. Longitudinal sampling showed that the phenomenon was temporary but lasted for at least 3 months before waning. After excluding a multitude of common determinants for assay interference, we further show by antibody depletion studies that SARS-CoV-2-spike-specific Abs did not cross-react with HIV-1 gp120 in the patient sample. No additional case of HIV test interference was identified in a cohort of 66 individuals who presented to a post-COVID-19 outpatient clinic. We conclude the SARS-CoV-2-associated HIV test interference to be a temporary process capable of disturbing both screening and confirmatory assays. The assay interference is short-lived and/or rare but should be considered by physicians as a possible explanation for unexpected HIV diagnostic results in patients with a recent SARS-CoV-2 infection.

Post-COVID Syndrome in Adults-An Overview

This article provides an overview of various aspects related to post-COVID syndrome. Apart from its prevalence, symptoms and sequelae, risk determinants, and psychosocial implications, the pathogenesis of post-COVID condition is discussed in more detail. A focus on thrombo-inflammation in SARS-CoV-2 infection, the role of neutrophil extracellular traps, and the prevalence of venous thromboembolism is made. Moreover, COVID-19 and post-COVID syndrome in immunocompromising conditions, and the impact of vaccination on the prevention and treatment of post-COVID symptoms are reviewed. Autoimmunity is a hallmark of post-COVID syndrome, and, therefore, is another focus of this article. Thus, misdirected cellular and humoral immune responses can enhance the risk of latent autoimmunity in post-COVID syndrome. Facing the high prevalence of COVID-19 cases worldwide, it can be assumed that autoimmune disorders will increase globally over the next few years. Recent advances in identifying genetically determined variants may open the avenue for a better understanding of the susceptibility to and severity of SARS-CoV-2 infection and post-COVID syndrome.

How much (evil) intelligence can be encoded by 30 kb?

Genomes of most RNA viruses are rarely larger than the size of an average human gene (10-15 kb) and still code for a number of biologically active polypeptides that modify the immune system and metabolism of the host organism in an amazingly complex way. Prolonged coevolution developed tricks by which viruses can dodge many protective mechanisms of the host and lead to the formation of molecular mimicry patterns. Some viruses inhibit the interferon response, interfere with the membrane destroying effects of the activated complement cascade. They can replicate in cellular compartments formed by inner membranes of the cell hiding their characteristic features from diverse pattern recognition receptors. In many cases-and in this respect, the new coronavirus is a champion-they can exploit our own defensive mechanisms to cause serious harm, severe symptoms and frequently deadly disease.

Increased prevalence of autoimmune thyroid disease after COVID-19: A single-center, prospective study

INTRODUCTION

Thyroid dysfunctions associated with SARS-CoV-2 acute infection have been extensively described since the beginning of COVID-19 pandemics. Conversely, few data are available on the occurrence of thyroid autoimmunity after COVID-19 resolution. We assessed the prevalence of autoimmune thyroid disease (ATD) and thyroid dysfunctions in COVID-19 survivors three months after hospital admission.

DESIGN AND METHODS

Single-center, prospective, observational, cohort study performed at ASST Papa Giovanni XXIII Hospital, Bergamo, Italy. 599 COVID-19 survivors were prospectively evaluated for thyroid function and autoimmunity thyroperoxidase antibodies (TPOAb), thyroglobulin antibodies (TgAb). When a positive antibody concentration was detected, thyroid ultrasound was performed. Multiple logistic regression model was used to estimate the association between autoimmunity and demographic characteristics, respiratory support, and comorbidities. Autoimmunity results were compared to a cohort of 498 controls referred to our Institution for non-thyroid diseases before the pandemic onset. A sensitivity analysis comparing 330 COVID-19 patients with 330 age and sex-matched controls was performed.

RESULTS

Univariate and multivariate analysis found that female sex was positively associated (OR 2.01, SE 0.48, p = 0.003), and type 2 diabetes (T2DM) was negatively associated (OR 0.36, SE 0.16, p = 0.025) with thyroid autoimmunity; hospitalization, ICU admission, respiratory support, or COVID-19 treatment were not associated with thyroid autoimmunity (p > 0.05). TPOAb prevalence was greater in COVID-19 survivors than in controls: 15.7% vs 7.7%, p = 0.002. Ultrasonographic features of thyroiditis were present in 94.9% of the evaluated patients with positive antibodies. TSH was within the normal range in 95% of patients.

CONCLUSIONS

Autoimmune thyroid disease prevalence in COVID-19 survivors was doubled as compared to age and sex-matched controls, suggesting a role of SARS-CoV-2 in eliciting thyroid autoimmunity.

COVID-19 and the antiphospholipid syndrome

Coronavirus disease 2019 (COVID-19) has resulted in a global pandemic. Most COVID-19 patients are asymptomatic or have flu-like symptoms. However, around 15% of the patients may have severe disease, including unilateral or bilateral pneumonia with acute respiratory distress syndrome and progressive hypoxemia that may require mechanical ventilation assistance. A systemic inflammatory response syndrome occurs in the most severe forms of COVID-19, with multiorgan involvement which can be life threatening caused by a cytokine storm. Although what best characterizes COVID-19 are the manifestations of the respiratory system, it has been shown that it also acts at the cardiovascular level, producing coagulation abnormalities, which causes thrombotic events mainly in the arteries/arterioles, microcirculation and venous system, and potentially increased mortality risk. This multiorgan vascular disease overlaps with other known microangiopathies, such as thrombotic microangiopathy or paroxysmal nocturnal hemoglobinuria, where complement overactivation plays an important role in the pathophysiology of thrombosis. Furthermore, coagulopathy secondary to COVID-19 occurs in the context of an uncontrolled inflammatory response, reminiscent of APS, especially in its catastrophic form. This review summarizes the current knowledge regarding the relationship between COVID-19 and the APS.

COVID-19 and antiphospholipid antibodies

Antiphospholipid syndrome and the coagulopathy of COVID-19 share many pathophysiologic features, including endotheliopathy, hypercoagulability, and activation of platelets, complement pathways, and neutrophil extracellular traps, all acting in concert via a model of immunothrombosis. Antiphospholipid antibody production in COVID-19 is common, with 50% of COVID-19 patients being positive for lupus anticoagulant in some studies, and with non-Sapporo criteria antiphospholipid antibodies being prevalent as well. The biological significance of antiphospholipid antibodies in COVID-19 is uncertain, as such antibodies are usually transient, and studies examining clinical outcomes in COVID-19 patients with and without antiphospholipid antibodies have yielded conflicting results. In this review, we explore the biology of antiphospholipid antibodies in COVID-19 and other infections and discuss mechanisms of thrombogenesis in antiphospholipid syndrome and parallels with COVID-19 coagulopathy. In addition, we review the existing literature on safety of COVID-19 vaccination in patients with antiphospholipid antibodies and antiphospholipid syndrome.

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

Since the beginning of the pandemic, numerous risk factors have been associated with SARS-CoV-2 infection and COVID-19 outcomes, such as older age, male sex, and the presence of comorbidities, such as hypertension, obesity, and diabetes. Preliminary data also suggest epidemiological association between SARS-CoV-2 infection and systemic autoimmune disease. For this reason, we investigated if patients affected by autoimmune thyroid disorders (AITD) are at risk of developing SARS-CoV-2 infection or COVID-19 disease.

From April to September 2020, we have conducted a telephone survey that included 515 consecutive unselected patients with known thyroid disorders, of which 350 were affected by AITD. All 11 definitive diagnosis of COVID-19 (def-sympt-COVID-19) belonged to the AITD group, while the rest 14 cases highly suspected for COVID-19 (suspect-sympt-COVID-19) were equally detected in both group (7 in AITD and 7 in not-AITD). The overall prevalence of symptomatic COVID-19 (def-sympt-COVID-19 + suspect-sympt-COVID-19), recorded in the 350 AITD population was statistically significant higher compared to that reported in the Italian and Tuscan general population at the same time period of the present survey (18/350 = 5.14% vs 516/100000 = 0.51% [p < 0.001; OR = 10.45, 95% CI 6.45–16.92] and vs 394/100000 = 0.39% [p < 0.001; OR = 13.70, 95% CI 8.44–22.25], respectively).

Therefore, our results suggest a higher prevalence of SARS-CoV-2 infection and COVID-19 disease in patients with AITD.

[The value of COVID-19 vaccination in the context of Long-COVID]

There are currently no strategies available on how to deal with Long-COVID (COVID "coronavirus disease"). COVID-19 vaccination could be both a preemptive and a therapeutic option for the future. The evaluation of the available studies is complicated by varying definitions. There are, however, indications that (complete) COVID-19 vaccination is able not only to prevent symptomatic infection but also to reduce the risk of Long-COVID. In some patients with Long-COVID, symptoms are modified after (first and/or second) COVID-19 vaccination; however, there is no clear evidence for a real therapeutic effect on Long-COVID.

Safety and efficacy of convalescent plasma for severe COVID-19: a randomized, single blinded, parallel, controlled clinical study

Background

Convalescent plasma (CP) has been widely used to treat COVID-19 and is under study. However, the variability in the current clinical trials has averted its wide use in the current pandemic. We aimed to evaluate the safety and efficacy of CP in severe coronavirus disease 2019 (COVID-19) in the early stages of the disease.

Methods

A randomized controlled clinical study was conducted on 101 patients admitted to the hospital with confirmed severe COVID-19. Most participants had less than 14 days from symptoms onset and less than seven days from hospitalization. Fifty patients were assigned to receive CP plus standard therapy (ST), and 51 were assigned to receive ST alone. Participants in the CP arm received two doses of 250 mL each, transfused 24 h apart. All transfused plasma was obtained from "super donors" that fulfilled the following criteria: titers of anti-SARS-CoV-2 S1 IgG ≥ 1:3200 and IgA ≥ 1:800 antibodies. The effect of transfused anti-IFN antibodies and the SARS-CoV-2 variants at the entry of the study on the overall CP efficacy was evaluated. The primary outcomes were the reduction in viral load and the increase in IgG and IgA antibodies at 28 days of follow-up. The per-protocol analysis included 91 patients.

Results

An early but transient increase in IgG anti-S1-SARS-CoV-2 antibody levels at day 4 post-transfusion was observed (Estimated difference [ED], − 1.36; 95% CI, − 2.33 to − 0.39; P = 0.04). However, CP was not associated with viral load reduction in any of the points evaluated. Analysis of secondary outcomes revealed that those patients in the CP arm disclosed a shorter time to discharge (ED adjusted for mortality, 3.1 days; 95% CI, 0.20 to 5.94; P = 0.0361) or a reduction of 2 points on the WHO scale when compared with the ST group (HR adjusted for mortality, 1.6; 95% CI, 1.03 to 2.5; P = 0.0376). There were no benefits from CP on the rates of intensive care unit admission (HR, 0.82; 95% CI, 0.35 to 1.9; P = 0.6399), mechanical ventilation (HR, 0.66; 95% CI, 0.25 to 1.7; P = 0.4039), or mortality (HR, 3.2; 95% CI, 0.64 to 16; P = 0.1584). Anti-IFN antibodies and SARS-CoV-2 variants did not influence these results.

Conclusion

CP was not associated with viral load reduction, despite the early increase in IgG anti-SARS-CoV-2 antibodies. However, CP is safe and could be a therapeutic option to reduce the hospital length of stay.

Trial registration NCT04332835

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07560-7.

Is post-COVID syndrome an autoimmune disease?

INTRODUCTION

: Coronavirus disease 2019 (COVID-19) causes a long-term and persistent condition with clinical features similar to previous virulent outbreaks and other epidemics. Currently, post-COVID syndrome (PCS) is recognized as a new entity in the context of SARS-CoV-2 infection. Though its pathogenesis is not completely understood, persistent inflammation from acute illness and the development of autoimmunity play a critical role in its development. As the pandemic develops, the increasing latent and overt autoimmunity cases indicate that PCS is at the intersection of autoimmunity.

AREAS COVERED

The mechanisms involved in the emergence of PCS, their similarities with post-viral and post-care syndromes, its inclusion in the spectrum of autoimmunity and possible targets for its treatment.

EXPERT OPINION

An autoimmune phenomenon plays a major role in most causative theories explaining PCS. Due to the wide scope of symptoms and pathophysiology associated with PCS, there is a need for both PCS definition and classification criteria (including severity scores). Longitudinal and controlled studies are necessary to better understand this new entity, and to confirm that PCS is the chronic phase of COVID-19 as well as to find what additional factors participate into its development. With the high prevalence of COVID-19 cases worldwide, together with the current evidence on latent autoimmunity in PCS, we may observe an increase of autoimmune diseases (ADs) in the coming years. Vaccination's effect on the development of PCS and ADs will also receive attention in the future. Health and social care services need to develop a new framework to deal with PCS.

Can SARS‐CoV‐2 infection trigger rheumatoid arthritis? A case report

Inflammatory arthritis has been reported after SARS‐COV‐2 infection. We present a case of a 38‐year‐old female patient who developed polyarthralgia 1 month after SARS‐COV‐2 infection. Musculoskeletal examination was significant for synovitis of hands and wrists. Antinuclear antibody (ANA), rheumatoid factor (RF), and anti‐cyclic citrullinated peptide (CCP) antibodies were positive. Magnetic resonance imaging of the hands showed synovitis of the metacarpophalangeal joints and proximal interphalangeal joints of the hands, wrist joints, and tendinitis with tenosynovitis. The patient was diagnosed with seropositive nonerosive rheumatoid arthritis (RA) and initiated on therapy using nonsteroidal anti‐inflammatory agents and disease‐modifying anti‐rheumatic drug methotrexate leading to an improvement in symptoms.

Cases of autoimmune and auto‐inflammatory diseases triggered after COVID‐19 have been reported. We report the case of a 38‐year‐old female patient who developed seropositive, nonerosive rheumatoid arthritis (RA) one month after SARS‐CoV‐2 infection.

Post-COVID-19 Condition: Where Are We Now?

COVID-19 is currently considered a systemic infection involving multiple systems and causing chronic complications. Compared to other post-viral fatigue syndromes, these complications are wider and more intense. The most frequent symptoms are profound fatigue, dyspnea, sleep difficulties, anxiety or depression, reduced lung capacity, memory/cognitive impairment, and hyposmia/anosmia. Risk factors for this condition are severity of illness, more than five symptoms in the first week of the disease, female sex, older age, the presence of comorbidities, and a weak anti-SARS-CoV-2 antibody response. Different lines of research have attempted to explain these protracted symptoms; chronic persistent inflammation, autonomic nervous system disruption, hypometabolism, and autoimmunity may play a role. Due to thyroid high ACE expression, the key molecular complex SARS-CoV-2 uses to infect the host cells, thyroid may be a target for the coronavirus infection. Thyroid dysfunction after SARS-CoV-2 infection may be a combination of numerous mechanisms, and its role in long-COVID manifestations is not yet established. The proposed mechanisms are a direct effect of SARS-CoV-2 on target cells, an indirect effect of systemic inflammatory immune response, and a dysfunction of the hypothalamic-pituitary-thyroid (HPT) axis leading to decreased serum TSH. Only a few studies have reported the thyroid gland status in the post-COVID-19 condition. The presence of post-COVID symptoms deserves recognition of COVID-19 as a cause of post-viral fatigue syndrome. It is important to recognize the affected individuals at an early stage so we can offer them the most adequate treatments, helping them thrive through the uncertainty of their condition.

Autoimmunity is a hallmark of post-COVID syndrome

Autoimmunity has emerged as a characteristic of the post-COVID syndrome (PCS), which may be related to sex. In order to further investigate the relationship between SARS-CoV-2 and autoimmunity in PCS, a clinical and serological assessment on 100 patients was done. Serum antibody profiles against self-antigens and infectious agents were evaluated by an antigen array chip for 116 IgG and 104 IgM antibodies. Thirty pre-pandemic healthy individuals were included as a control group. The median age of patients was 49 years (IQR: 37.8 to 55.3). There were 47 males. The median post-COVID time was 219 (IQR: 143 to 258) days. Latent autoimmunity and polyautoimmunity were found in 83% and 62% of patients, respectively. Three patients developed an overt autoimmune disease. IgG antibodies against IL-2, CD8B, and thyroglobulin were found in more than 10% of the patients. Other IgG autoantibodies, such as anti-interferons, were positive in 5–10% of patients. Anti-SARS-CoV-2 IgG antibodies were found in > 85% of patients and were positively correlated with autoantibodies, age, and body mass index (BMI). Few autoantibodies were influenced by age and BMI. There was no effect of gender on the over- or under-expression of autoantibodies. IgG anti-IFN-λ antibodies were associated with the persistence of respiratory symptoms. In summary, autoimmunity is characteristic of PCS, and latent autoimmunity correlates with humoral response to SARS-CoV-2.

Persistent Autoimmune Activation and Proinflammatory State in Post-COVID Syndrome

Background

The immunopathological pathways enabling post-COVID syndrome (PCS) development are not entirely known. We underwent a longitudinal analysis of patients with COVID-19 who developed PCS aiming to evaluate the autoimmune and immunological status associated with this condition.

Methods

Thirty-three patients were included for longitudinal clinical and autoantibody analyses of whom 12 patients were assessed for cytokines and lymphocyte populations. Patients were followed during 7-11 months after acute COVID-19. Autoimmune profile and immunological status were evaluated mainly by enzyme-linked-immunosorbent assays and flow cytometry.

Results

Latent autoimmunity and overt autoimmunity persisted over time. A proinflammatory state was observed in patients with PCS characterized by upregulated IFN-α, TNF-α, G-CSF, IL-17A, IL-6, IL-1β, and IL-13, whereas IP-10 was decreased. In addition, PCS was characterized by increased levels of Th9, CD8+ effector T cells, naive B cells, and CD4+ effector memory T cells. Total levels of IgG S1-SARS-CoV-2 antibodies remained elevated over time.

Discussion

The clinical manifestations of PCS are associated with the persistence of a proinflammatory, and effector phenotype induced by SARS-CoV-2 infection. This long-term persistent immune activation may contribute to the development of latent and overt autoimmunity. Results suggest the need to evaluate the role of immunomodulation in the treatment of PCS.

High Prevalence of Common Human Viruses in Thyroid Tissue

INTRODUCTION

Evidence points to viral infections as possible triggers of autoimmune thyroid disease (AITD), but little is known about the prevalence of common viruses in the thyroid gland. Using a novel approach based on virus enrichment in multiple cell lines followed by detection of the viral genome and visualization of viral proteins, we investigated the presence of multiple human viruses in thyroid tissue from AITD patients and controls.

METHODS

Thyroid tissue was collected by core needle biopsy or during thyroid surgery from 35 patients with AITD (20 Graves' disease and 15 Hashimoto's thyroiditis). Eighteen thyroid tissue specimens from patients undergoing neck surgery for reasons other than thyroid autoimmunity served as controls. Specimens were tested for the presence of ten different viruses. Enteroviruses and human herpesvirus 6 were enriched in cell culture before detection by PCR and immunofluorescence, while the remaining viruses were detected by PCR of biopsied tissue.

RESULTS

Forty of 53 cases (75%) carried an infectious virus. Notably, 43% of all cases had a single virus, whereas 32% were coinfected by two or more virus types. An enterovirus was found in 27/53 cases (51%), human herpesvirus 6 in 16/53 cases (30%) and parvovirus B19 in 12/53 cases (22%). Epstein-Barr virus and cytomegalovirus were found in a few cases only. Of five gastroenteric virus groups examined, only one was detected in a single specimen. Virus distribution was not statistically different between AITD cases and controls.

CONCLUSION

Common human viruses are highly prevalent in the thyroid gland. This is the first study in which multiple viral agents have been explored in thyroid. It remains to be established whether the detected viruses represent causal agents, possible cofactors or simple bystanders.

Systematic review of COVID-19 and autoimmune thyroiditis

COVID-19 is a severe acute respiratory syndrome. Recent reports showed that autoimmune thyroiditis might occur following COVID-19 infection. We aimed to review the literature to assess the prevalence, clinical features and outcome of autoimmune thyroid disorders triggered by COVID-19. We reviewed case reports, case series, and observational studies of autoimmune thyroiditis including Graves' disease, Hashimoto thyroiditis, and silent thyroiditis developed in COVID-19 patients by searching PubMed, SCOPUS and Web of Science and included in the systematic review. Our search yielded no prevalence study. We noted 20 reported cases: Fourteen cases of Graves' disease, 5 cases of hypothyroidism due to Hashimoto's thyroiditis and one case of postpartum thyroiditis. The majority (16/20, 80%) were middle-aged (mean age: 40 years) female patients. Autoimmune thyroiditis was diagnosed either concomitantly or 7-90 days after the COVID-19 infection. Eight out of 14 cases with Graves' disease had a known thyroid disorder and they were stable in remission. One out of 5 cases with Hashimoto's thyroiditis had known prior hypothyroidism. The majority of the patients achieved remission within 3 months. One patient with thyroid storm due to Graves' disease and one patient with myxedema coma have died. Current data suggest that COVID-19 may cause autoimmune thyroid disease or exacerbate the underlying thyroid disease in remission. It is reasonable to routinely assess the thyroid functions both in the acute phase and during the convalescence so as not to overlook a thyroid disorder and not to delay treatment especially in patients with preexisting autoimmune thyroid diseases.

Autoimmune complications of COVID-19

Coronavirus disease 2019 (COVID-19) is still propagating a year after the start of the pandemic. Besides the complications patients face during the COVID-19 disease period, there is an accumulating body of evidence concerning the late-onset complications of COVID-19, of which autoimmune manifestations have attracted remarkable attention from the first months of the pandemic. Autoimmune hemolytic anemia, immune thrombocytopenic purpura, autoimmune thyroid diseases, Kawasaki disease, Guillain-Barre syndrome, and the detection of autoantibodies are the cues to the discovery of the potential of COVID-19 in inducing autoimmunity. Clarification of the pathophysiology of COVID-19 injuries to the host, whether it is direct viral injury or autoimmunity, could help to develop appropriate treatment.

SARS-Cov2 acute and post-active infection in the context of autoimmune and chronic inflammatory diseases

The clinical and immunological spectrum of acute and post-active COVID-19 syndrome overlaps with criteria used to characterize autoimmune diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Indeed, following SARS-Cov2 infection, the innate immune response is altered with an initial delayed production of interferon type I (IFN-I), while the NF-kappa B and inflammasome pathways are activated. In lung and digestive tissues, an alternative and extrafollicular immune response against SARS-Cov2 takes place with, consequently, an altered humoral and memory T cell response leading to breakdown of tolerance with the emergence of autoantibodies. However, the risk of developing severe COVID-19 among SLE and RA patients did not exceed the general population except in those having pre-existing neutralizing autoantibodies against IFN-I. Treatment discontinuation rather than COVID-19 infection or vaccination increases the risk of developing flares. Last but not least, a limited number of case reports of individuals having developed SLE or RA following COVID-19 infection/vaccination have been reported. Altogether, the SARS-Cov2 pandemic represents an unique opportunity to investigate the dangerous interplay between the immune response against infectious agents and autoimmunity, and to better understand the triggering role of infection as a risk factor in autoimmune and chronic inflammatory disease development.

The mosaic of autoimmunity - A taste for more. The 12th international congress of autoimmunity 2021 (AUTO12) virtual

Notwithstanding the fact that the 12th international congress of autoimmunity (AUTO12) was held virtual this year, the number of the abstracts submitted and those presented crossed the thousand marks. Leading investigators and researchers from all over the world presented the latest developments of their research in the domain of autoimmunity and its correlation with various diseases. In terms of mechanisms of autoimmunity, an update on the mechanisms behind the association of autoimmunity with systemic diseases focusing on hyperstimulation was presented during AUTO12. In addition, a new mechanism of ASIA syndrome caused by an intrauterine contraceptive device was revealed demonstrating a complete resolution of symptoms following device removal. In regard to the correlation between autoimmunity and neurogenerative diseases, the loss of structural protein integrity as the trigger of immunological response was shown. Schizophrenia as well, and its correlation to pro-inflammatory cytokines was also addressed. Furthermore, and as it was said AUTO12 virtual due to COVID-19 pandemic, various works were dedicated to SARS-CoV-2 infection and COVID-19 in terms of autoimmune mechanisms involved in the pathogenesis, treatment and complications of COVID-19. For instance, the correlation between autoimmunity and the severity of COVID-19 was viewed. Moreover, the presence and association of autoantibodies in COVID-19 was also demonstrated, as well as the clinical outcomes of COVID-19 in patients with rheumatic diseases. Finally, immune-mediated reactions and processes secondary to SARS-CoV-2 vaccination was displayed. Due to the immense importance of all of the topics addressed and while several hundreds of works were presented which cannot be summed up in one paper, we aimed hereby to highlight some of the outstanding abstracts and presentations during AUTO12.

Systematic Review of Antiphospholipid Antibodies in COVID-19 Patients: Culprits or Bystanders?

PURPOSE OF REVIEW

COVID-19 patients have a procoagulant state with a high prevalence of thrombotic events. The hypothesis of an involvement of antiphospholipid antibodies (aPL) has been suggested by several reports. Here, we reviewed 48 studies investigating aPL in COVID-19 patients.

RECENT FINDINGS

Prevalence of Lupus Anticoagulant (LA) ranged from 35% to 92% in ICU patients. Anti-cardiolipin (aCL) IgG and IgM were found in up to 52% and up to 40% of patients respectively. Anti-β2-glycoprotein I (aβ2-GPI) IgG and IgM were found in up to 39% and up to 34% of patients respectively. Between 1% and 12% of patients had a triple positive aPL profile. There was a high prevalence of aβ2-GPI and aCL IgA isotype. Two cohort studies found few persistent LA but more persistent solid phase assay aPL over time. aPL determination and their potential role is a real challenge for the treatment of this disease.

SARS-COV-2-related immune-inflammatory thyroid disorders: facts and perspectives

Introduction: During the COVID-19 pandemic thyroid gland alteration/dysfunction has been emerged as a possible endocrine complication. The present review is focused on inflammatory and autoimmune thyroid complications triggered by SARS-CoV-2 infection by searching through databases like MEDLINE and Scopus up to April 2021.Areas covered: Beside the occurrence of 'non-thyroidal illness' in severe clinical conditions, alterations of thyroid function and structure may occur during COVID-19 as a consequence of either direct or indirect effects of SARS-CoV-2 infection on the gland. On the one hand, SARS-CoV-2 uses ACE2 as a receptor to infect the host cells and ACE2 is highly expressed by follicular thyroid cells. On the other hand, COVID-19 is associated with a systemic inflammatory and immune response, involving Th1/Th17/Th2 lymphocytes and proinflammatory cytokines, which resembles the immune activation that occurs in immune-mediated thyroid diseases. COVID-19-related thyroid disorders include destructive thyroiditis and onset or relapse of autoimmune thyroid disorders, leading to a broad spectrum of thyroid dysfunction ranging from thyrotoxicosis to hypothyroidism, that may worsen COVID-19 clinical course and affect prognosis.Expert opinion: Physicians should be aware of the possible occurrence of thyroid dysfunction during and after SARS-CoV-2 infection. Further longitudinal studies are warranted to evaluate potential long-term sequelae.

The Association of Thyroid Hormone Changes with Inflammatory Status and Prognosis in COVID-19

BACKGROUND

COVID-19 infection may have multiorgan effects in addition to effects on the lungs and immune system. Recently, studies have found thyroid function abnormalities in COVID-19 cases which were interpreted as euthyroid sick syndrome (ESS) or destructive thyroiditis. Therefore, in this study, we aimed to evaluate the thyroid function status and thyroid autoimmunity in COVID-19 patients. Material and Method. 205 patients were included. The medical history and laboratory parameters at admission were collected from medical records. Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), thyroid peroxidase antibody, and thyroglobulin antibody were measured, and patients were classified according to thyroid function status.

RESULTS

34.1% of the patients were euthyroid. Length of hospitalization (p < 0.001), rate of oxygen demand (p < 0.001), and intensive care unit (ICU) admission (p=0.022) were lower, and none of the euthyroid patients died. 108 (52.6%) patients were classified to have ESS, 57 were classified as mild, and 51 were moderate. The inflammatory parameters were higher in patients with moderate ESS. In cluster analysis, a high-risk group with a lower median FT3 value (median = 2.34 ng/L; IQR = 0.86), a higher median FT4 value (median = 1.04 ng/dL; IQR = 0.33), and a lower median TSH value (median = 0.62 mIU/L; IQR = 0.59) included 8 of 9 died patients and 25 of the 31 patients that were admitted to ICU. Discussion. Length of hospitalization, oxygen demand, ICU admission, and mortality were lower in euthyroid patients. Moreover, none of the euthyroid patients died. In conclusion, evaluation of thyroid function tests during COVID-19 infection may give information about the prognosis of disease.