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.

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.

[A Case of Thyroid Gland Abscess Caused by Brucella melitensis]. / Brucella melitensis'in Neden Oldugu Bir Tiroid Bezi Apsesi Olgusu.

Brucellosis is a zoonotic disease endemic in many developing countries, including Türkiye. Among the species that are pathogenic for humans; Brucella melitensis is isolated from livestock animals like sheep and goats, Brucella abortus from cattle and Brucella suis from pigs. Laboratory diagnosis of infection caused by Brucella species with gram-negative coccobacillus morphology; can be made through characteristic culture features, serological tests and molecular methods. Brucellosis, which has a wide distribution of clinical signs and symptoms; can cause various complications by affecting many organs and systems. Among all complications, the probability of thyroid abscess is less than 1%. In this case report; an example of thyroid abscess, one of the rare complications of brucellosis that is not frequently encountered in the literature, was presented. During the physical examination of a 45-year-old female patient who admitted with the complaint of pain in the neck area, fever, neck swelling, redness and pain that increased with palpation were detected. Leukocytosis, lymphopenia, high sedimentation and CRP, low TSH and high T4 values were detected in laboratory tests and subacute thyroiditis was considered as the preliminary diagnosis. Surgical abscess drainage was planned as the patient's clinical findings progressed during follow-up and spontaneous pus discharged from the midline of the neck. The abscess aspirate sample taken during surgical intervention and the blood culture samples taken before were evaluated microbiologically. Microorganisms that did not grow on EMB agar but grew on 5% sheep blood and chocolate agar at the 72-96th hour of incubation of culture plates; were detected to have gram-negative coccobacillus morphology and positive for catalase, oxidase and urease. Although the Wright test was negative with a titer of 1/20, the Rose Bengal test was positive, Coombs test was positive with a titer of 1/160 and the Brucellacapt test was positive with a titer of >1/5120. Microorganisms growing on culture plates were identified as B.melitensis at the species level with specific antisera. As a result of antibiotic susceptibility tests evaluated according to the European Committee on Antimicrobial Susceptibility Testing version 14.0 (EUCAST v14.0), the isolate was susceptible to rifampicin, doxycycline, gentamicin and trimethoprim-sulfamethoxazole at standart dosing regimen and susceptible to ciprofloxacin and levofloxacin at increased exposure. The patient, who was started on doxycycline and rifampicin combination treatment, was discharged without any complaints. In the diagnosis of infection due to Brucella species, which is one of the pathogens that early diagnosis and initiation of treatment greatly affects the prognosis; in addition to culture, which is the gold standard method, serological tests are also very important. If diagnosis is delayed, complications may develop due to involvement in almost every part of the body, depending on the affected organs and systems. In areas where brucellosis is endemic, patients with symptoms such as neck swelling, shortness of breath and difficulty in swallowing, thyroid tissue involvement due to brucellosis should definitely be considered etiologically.

Determination of the Relationship Between the Development and Recurrence of Subacute Thyroiditis and Human Leukocyte Antigen Subtypes.

Background: There are several studies investigating the role of human leukocyte antigens (HLA) in the development and recurrence of subacute thyroiditis (SAT). The HLA subtypes associated with SAT were usually determined in a population-based manner and HLA-B*35, HLA-B*18:01, HLA-C*04:01, and HLA-DRB1*01 were detected to play a role in the disease susceptibility and prognosis. The aim of this study was to determine HLA alleles associated with the tendency of recurrence and prevention of SAT within the Turkish population. Methods: This prospective study was conducted with 51 SAT patients and 720 healthy bone marrow donor volunteers. HLA-A, -B, -C, -DRB1, and -DQB1 were genotyped using next-generation sequencing. Results: The frequency of HLA-A*02:09, HLA-B*35:01/35:02/35:03, HLA-C*04:01, HLA-DRB1*12:01, and DRB1*13:03 were associated with an increased risk of SAT development (Odds Ratio: 22.4, 9.5, 10.3, 4.2, and 3.5, respectively). While HLA-A*02:09, HLA-B*35:01, HLA-B*44:02 HLA-C*07:18, and HLA-C*16:04 were associated with nonrelapsing SAT, HLA-DR*12:01was associated with relapsing SAT. HLA-B*35:02, HLA-B*35:03, and HLA-C*04:01 were more frequent both in relapsing and nonrelapsing groups according to control group. The frequency of HLA-B*18:01, reported as a risk factor previously, was similar in the SAT and control groups (p = 0.959). HLA-DRB1*11:01 was associated with a lower risk of SAT development. Conclusions: Along with -B*358 and -C*04, HLA-A*02:09 was detected as an important risk factor for SAT development in our population. HLA-DRB1*11:01 appears to be the protective HLA subtype against SAT. HLA-A*02:09, HLA-B*35:01, HLA-B*44:02, HLA-C*07:18, HLA-C*16:04, HLA-DQ*06:03, and HLA-DR*12:01 subtypes can establish a tendency to relapsing or nonrelapsing SAT.

Silent Thyroiditis Associated with Ropeginterferon α-2b in a Patient with Polycythemia Vera.

Interferon is an emerging treatment option for myeloproliferative neoplasms (MPNs), especially for polycythemia vera (PV). Previous studies of interferon used therapeutically for hepatitis C have demonstrated that one of the most important adverse events associated with interferon treatment is thyroid dysfunction, and a management strategy for thyroid dysfunction has been established. However, whether or not the recommendation is also suitable for MPN settings is unclear. In this study, one PV patient developed silent thyroiditis during a phase 2 study of ropeginterferon α-2b. This case suggests that thyroid dysfunction is an important clinical issue to consider in interferon treatment for PV.

Thyroid Inflammation and Immunity During the COVID-19 Pandemic: A Comprehensive Review and Case Study.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the development of various vaccines. Reports have emerged suggesting a possible association between SARS-CoV-2 vaccination and the onset of thyroid diseases. This review explores the clinical aspects of thyroid disorders following SARS-CoV-2 vaccination, including a case report of a patient with concomitant subacute thyroiditis (SAT) and Graves' disease (GD) with blocking thyrotropin receptor autoantibodies (TSH-R-Ab) following SARS-CoV-2 vaccination. SAT, characterized by transient inflammation of the thyroid gland, has been reported after SARS-CoV-2 vaccination. GD, an autoimmune hyperthyroidism, has also been observed post-vaccination, often with stimulating TSH-R-Ab. Graves' orbitopathy (GO) has been associated with SARS-CoV-2 vaccination in patients with a history of immune thyroid disease. The unique case underscores a very rare thyroid condition of functional hypothyroidism in possible relation to SARS-CoV-2 vaccination and the usefulness of functional analysis of TSH-R-Ab that can provide valuable insights into disease pathogenesis and help to guide treatment. This review highlights the need for continued monitoring and awareness of potential thyroid-related complications following SARS-CoV-2 vaccination.

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.

Comparison of the therapeutic effects of 15 mg and 30 mg initial daily prednisolone doses in patients with subacute thyroiditis: a multicenter, randomized, open-label, parallel-controlled trial.

INTRODUCTION: Current guidelines recommendations for the initial dose of prednisolone (PSL) in the treatment of subacute thyroiditis (SAT) are based on low-quality studies. We designed a randomized controlled trial (RCT) to compare the efficacy and safety of using a low initial dose of PSL with a standard initial dose of PSL in SAT patients. PATIENTS AND METHODS: This open-label RCT was conducted at five hospitals in China from June 2019 to January 2022. SAT patients with moderate-to-severe pain or a poor response to non-steroidal anti-inflammatory drugs (NSAIDs) were randomly assigned in a 1:1 ratio to the experimental and control groups. The initial dose of PSL was 15 mg/d in the experimental group and 30 mg/d in the control group. The primary outcome was the total duration of PSL treatment, with non-inferiority prespecified with a margin of 7 days. Clinical trial registration number: ChiCTR1900023884. RESULTS: The full analysis set included 60 patients (30 in each group). The mean duration of PSL treatment in the experimental and control group was 34.62 ± 14.12 and 41.18 ± 16.89 days, respectively, meeting the non-inferiority criterion (pnon-inferiority = 0.0006). The total dose of PSL used in the experimental group was lower than in the control groups (330 vs 595 mg, p < 0.0001). There were no differences in the mean time to pain relief and complete resolution, the occurrence of recurrence, hypothyroidism, or adverse events between the groups. CONCLUSIONS: The initial dose of 15 mg/d of PSL was not inferior to the dose of 30 mg/d in terms of efficacy and showed a similar safety profile. A low initial dose of PSL could be recommended for Chinese adult SAT patients who have a suboptimal response using NSAIDs or experience moderate-to-severe pain.KEY MESSAGESLow initial dose (15 mg/d) of prednisolone was non-inferior to the standard initial dose of prednisolone (30 mg/d) in treatment duration, time to pain relief, or the prevalence of hypothyroidism, recurrence, and adverse reactions in the treatment of subacute thyroiditis.Patients with subacute thyroiditis administered a low initial dose of prednisolone had a lower total dose of prednisolone compared to those receiving the standard dose of prednisolone.

Characteristics of patients with subacute thyroiditis.

INTRODUCTION: The diagnosis and management of subacute thyroiditis (SAT) may be challenging, and more evidence on patient and disease characteristics is warranted. METHODS: This was a retrospective cohort study of all patients in the North Denmark Region with a SAT diagnosis in the Danish National Patient Registry, 2016-2018. The medical records and biochemical results prior to the diagnosis and during a two-year follow-up period were reviewed. RESULTS: A total of 71 patients with a SAT diagnosis were identified, and the diagnosis was verified in 44 (62.0%) cases with an incidence rate of 2.4/100,000/year. Patients with verified SAT were predominantly females (72.7%) with a median age of 50.7 years. Biochemical results showed thyrotoxicosis at the initial examination in 69.8% and elevated C-reactive protein in 86.5% of patients. Longitudinal biochemical assessment showed a biphasic response (median thyroid-stimulating hormone, initially: 0.02 mIU/l, at three months: 4.7 mIU/l and 2.4 mIU/l after two years). Treatment with non-steroidal anti-inflammatory drugs, beta-blockers and/or prednisolone was initiated in 23 of the 38 patients (60.5%) evaluated, and ten of 33 patients (30.3%) with follow-up data received thyroid hormone replacement therapy. CONCLUSION: In the North Denmark Region, a hospital diagnosis of SAT was verified in less than two thirds of cases. Further large studies are warranted to extend the findings concerning the treatment and outcome of SAT. FUNDING: None. TRIAL REGISTRATION: Not relevant.

Subacute thyroiditis following COVID-19 vaccination: Case presentation.

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

The association of subacute thyroiditis with viral diseases: a comprehensive review of literature

Introduction: Subacute thyroiditis (SAT), also known as de Quatrain's thyroiditis or granulomatous thyroiditis, is an inflammatory disease of the thyroid. Most of the time, it manifests in the thirties to fifties and is more common in women. SAT can have either viral or post-viral origin. Some viruses, like influenza, COVID-19, Epstein-Barr virus, cytomegalovirus, hepatitis, coxsackievirus 16, and mumps virus, have been linked to SAT development. The COVID-19 pandemic has affected people's lives all around the world and has changed our attitude toward the treatment of many diseases. It has also made us look deeper into the subject in a way that we would be able to treat this sort of disease with a newer insight. Objective: Regarding the importance of this issue, we decided to summarize our extensive searches from online databases, including PubMed, Google Scholar, Medline, Web of Science, and Scopus until February 2023, which we found effective in elucidating the association of subacute thyroiditis and viral diseases. Method: Different online databases were searched for narrative review articles, systemic review articles, and original articles, which were published until February 2023. Result: According to the included studies, we found that there is a correlation between SAT and several viruses such as Epstein-Barr virus, influenza virus, human immunodeficiency virus, cytomegalovirus, oral and cervical virus, hepatitis, dengue virus, and SARS-COV-2. The effect of each of the viral diseases mentioned in the SAT is given in the text. Conclusions: According to the results mentioned in the text, because SAT may be challenging for early diagnosis, due to the potential of classic symptoms as well as the interference of similar clinical symptoms between thyrotoxicosis and viral reactions, the correlation between SAT and viral diseases should be considered so that we can avoid misdiagnosis and lateness.

Diagnosis of thyroid disease using deep convolutional neural network models applied to thyroid scintigraphy images: a multicenter study.

Objectives: The aim of this study was to improve the diagnostic performance of nuclear medicine physicians using a deep convolutional neural network (DCNN) model and validate the results with two multicenter datasets for thyroid disease by analyzing clinical single-photon emission computed tomography (SPECT) image data. Methods: In this multicenter retrospective study, 3194 SPECT thyroid images were collected for model training (n=2067), internal validation (n=514) and external validation (n=613). First, four pretrained DCNN models (AlexNet, ShuffleNetV2, MobileNetV3 and ResNet-34) for were tested multiple medical image classification of thyroid disease types (i.e., Graves' disease, subacute thyroiditis, thyroid tumor and normal thyroid). The best performing model was then subjected to fivefold cross-validation to further assess its performance, and the diagnostic performance of this model was compared with that of junior and senior nuclear medicine physicians. Finally, class-specific attentional regions were visualized with attention heatmaps using gradient-weighted class activation mapping. Results: Each of the four pretrained neural networks attained an overall accuracy of more than 0.85 for the classification of SPECT thyroid images. The improved ResNet-34 model performed best, with an accuracy of 0.944. For the internal validation set, the ResNet-34 model showed higher accuracy (p < 0.001) when compared to that of the senior nuclear medicine physician, with an improvement of nearly 10%. Our model achieved an overall accuracy of 0.931 for the external dataset, a significantly higher accuracy than that of the senior physician (0.931 vs. 0.868, p < 0.001). Conclusion: The DCNN-based model performed well in terms of diagnosing thyroid scintillation images. The DCNN model showed higher sensitivity and greater specificity in identifying Graves' disease, subacute thyroiditis, and thyroid tumors compared to those of nuclear medicine physicians, illustrating the feasibility of deep learning models to improve the diagnostic efficiency for assisting clinicians.

Asymmetric diffuse thyroid uptake on 18F-FDG PET/CT in patient with subacute thyroiditis: Case report and literature review.

A 48-year-old man with an intermittent fever of 39.0oC for more than three weeks underwent computed tomography (CT) and blood testing, which revealed no clues. Antibiotics wereadministered, but his condition did not improve. Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) showed right-lobe-dominant diffuse thyroid uptake. On technetium-99m (99mTc) pertechnetate scintigraphy, the thyroid gland could not be visualized, and he was diagnosed with subacute thyroiditis (SAT). When asymmetric 18F-FDG diffuse thyroid uptake on PET/CT is observed in a patient with a fever of unknown origin (FUO), SAT may need to be considered.

Beyond Acute COVID-19: Investigating the Incidence of Subacute Thyroiditis in Long COVID-19 in Korea.

BACKGRUOUND: The correlation between acute coronavirus disease 2019 (COVID-19) and subacute thyroiditis (SAT) has not been clearly investigated in "long COVID" patients. We aimed to investigate the incidence of SAT during convalescence and after the acute phase of COVID-19, comparing with that of the general population. METHODS: Data from a total of 422,779 COVID-19 patients and a control group of 2,113,895 individuals were analyzed. The index date was defined as the date 3 months after confirmation of COVID-19. The incidence rate (IR) of SAT and hazard ratios (HRs) were calculated per 100,000 persons. Subgroup analysis included analysis of HRs 90-179 and 180 days post-COVID-19 diagnosis; and additional analysis was conducted according to hospitalization status, sex, and age group. RESULTS: The IR of SAT was 17.28 per 100,000 persons (95% confidence interval [CI], 12.56 to 23.20) in the COVID-19 group and 8.63 (95% CI, 6.37 to 11.45) in the control group. The HR of COVID-19 patients was 1.76 (95% CI, 1.01 to 3.06; P=0.045). The HR of SAT was 1.39 (95% CI, 0.82 to 2.34; P=0.220) up to 6 months after the index date and 2.30 (95% CI, 1.60 to 3.30; P<0.001) beyond 6 months. The HR for SAT among COVID-19 patients was 2.00 (95% CI, 1.41 to 2.83) in hospitalized patients and 1.76 (95% CI, 1.01 to 3.06) in non-hospitalized patients compared to the control group. The IR of SAT was 27.09 (95% CI, 20.04 to 35.82) for females and 6.47 (95% CI, 3.34 to 11.30) for males. In the 19 to 64 age group, the IR of SAT was 18.19 (95% CI, 13.70 to 23.67), while the IR was 9.18 (95% CI, 7.72 to 10.84) in the 65 to 69 age group. CONCLUSION: SAT could be a potential long-term complication of COVID-19. Long-term surveillance for thyroid dysfunction is needed especially in hospitalized, female and young-aged subjects.

The value of FT4/TSH ratio in the differential diagnosis of Graves' disease and subacute thyroiditis.

Objective: To explore the value of the FT4/TSH ratio in the etiological diagnosis of newly diagnosed patients with thyrotoxicosis. Methods: The retrospective study was conducted on 287 patients with thyrotoxicosis (122 patients with subacute thyroiditis and 165 patients with Graves' disease) and 415 healthy people on their first visit to our hospital. All patients underwent thyroid function tests including the measurement of T3, T4, FT3, FT4, TSH, T3/TSH, and T4/TSH. The receiver operating characteristic (ROC) curve was employed to evaluate the value of FT4/TSH in the differential diagnosis of Graves' disease and subacute thyroiditis, and compared with other related indicators. Results: The area under the curve of FT4/TSH for diagnosing Graves' disease and thyroiditis was 0.846, which was significantly larger than the area under the curve of T3/T4 ratio (P< 0.05) and FT3/FT4 ratio (P< 0.05). When the cut-off value of the FT4/TSH ratio was 5731.286 pmol/mIU, the sensitivity was 71.52%, the specificity was 90.16%, the positive predictive value was 90.77% and the negative predictive value was 70.06%. The diagnostic accuracy was 79.44%. Conclusion: FT4/TSH ratio can be used as a new reference index for the differential diagnosis of thyrotoxicosis.