TSH Receptor Antibodies Research Articles

US-based, Prospective, Blinded Study of Thyrotropin Receptor Antibody in Autoimmune Thyroid Disease.

Bioassays provide information on the functionality of thyrotropin receptor antibodies (TSH-R-Ab) and thus may offer more clinical utility than binding assays. In this prospective, blinded, US-based study, the clinical performance of several TSH-R-Ab assays was compared. US endocrinology clinic. One hundred sixty-two unselected, consecutive, well-documented patients with various thyroid diseases and healthy controls. Blinded TSH-R-Ab measurements. Sensitivity and specificity of 4 TSH-R-Ab assays. The 4 TSH-R-Ab assays were negative in all 42 patients without autoimmune thyroid disease (AITD). In 104 patients with Graves' disease (GD), irrespective of the disease duration, TSH-R-Ab positivity was present in 65 (63%), 67 (65%), and 87 (84%) for the Cobas and Immulite binding assays and stimulatory TSH-R-Ab [thyroid-stimulating immunoglobin (TSI)] bioassay, respectively (TSI vs Immulite P < .0025, TSI vs Cobas P < .0009). Fifteen newly diagnosed GD patients were all positive in the TSI bioassay, but only 11 (73%) were positive in the Cobas and Immulite binding assays. Nine GD patients with biochemical subclinical hyperthyroidism were TSI-positive but Immulite- and Cobas-negative. Two GD patients were blocking TSH-R-Ab [thyroid-blocking immunoglobin (TBI)]-positive and TSI-negative, and the Immulite and Cobas were positive in both. Additional serum samples from AITD patients that consisted of 30 TBI-positive and 10 TSI-positive samples were blindly tested in the binding assays. Only 6 of the 10 TSI-positive samples were positive in both binding assays, and 30 and 28 of the TBI-positive samples were positive in the Cobas and Immulite assays, respectively. Binding TSH-R-Ab assays are less sensitive than TSI bioassays and are not specific for stimulating antibodies. Measuring the function of TSH-R-Ab in a bioassay can provide useful information to clinicians.

Approach to the Patient Considering Long-term Antithyroid Drug Therapy for Graves' Disease.

Antithyroid drugs (ATD) are the treatment of choice for the majority of patients with Graves' hyperthyroidism worldwide. However, relapse of hyperthyroidism after withdrawal of arbitrarily chosen conventional 12 to 18 months of therapy is very common. In the last 2 decades, many studies have shown that treatment with long-term ATD (LT-ATD) is effective and safe in the maintenance of euthyroidism. In addition, it has been reported that serum TSH receptor antibody may not decrease permanently before 5 to 6 years of ATD treatment, and clinical trials have shown that ≥5 years of ATD treatment is accompanied by remission in the majority of patients with Graves' hyperthyroidism. The objective of this article is to discuss the optimal time to withdraw of conventional ATD therapy, to illustrate the decision-making of the management of recurrent hyperthyroidism, to review the proper management of LT-ATD, and to generate suggestions for lifelong ATD treatment by discussing 4 scenarios of decision-making in patients with Graves' disease.

Subcutaneous Injections of Triamcinolone Acetonide for Upper Eyelid Retraction and Swelling Associated with Thyroid Eye Disease: A Retrospective Case Series Study.

To evaluate the efficacy of subcutaneous injection of triamcinolone acetonide (SCTA) in treating upper eyelid retraction and swelling in patients with thyroid eye disease (TED). This case series included consecutive patients (aged 16-69 years, monitored from June 2012 to December 2015) with TED-related eyelid symptom and without an enlarged extraocular muscle on magnetic resonance imaging (MRI). SCTA (0.5 mL, 40 mg/mL) was administered to target the orbital fat around the levator palpebrae superioris (LPS) muscle. Patients who did not exhibit improvement after the first trial received an additional injection. Follow-up was conducted for 12 months with 3-month intervals. Eyelid retraction, eyelid swelling, and eyelid lag were evaluated at each follow-up visit. In total, 116 eyelids of 102 patients were analyzed. SCTA led to significant improvement in 93% of eyes (108/116), disappearance of eyelid symptoms (74%, 87%, and 73% in retraction, swelling, and lag, respectively), and improvement of scores (from 1.64 to 0.12, 1.32 to 0.26, and 1.72 to 0.30, respectively). Improvement in eyelid symptoms was observed in eight eyes; however, additional steroid therapy was required in these cases due to the emergence of other extraocular muscle inflammation. Additional injection was required in 39.8% of patients. The clinical activity score was lower in the single SCTA group than in the multiple SCTA group (1.5 vs 0.9; p < 0.01). However, the levels of thyroid-stimulating hormone receptor antibody and MRI findings were not significantly different between the two groups. No elevation in intraocular pressure was observed. Eight female patients experienced menstrual disorder. SCTA effectively reduced LPS muscle enlargement and fat tissue swelling in patients with TED. A single SCTA was sufficient in almost 60% of the patients; nevertheless, follow-up is necessary to detect early signs of orbital inflammation even in eyelid-symptom-improved patients.

Stability analysis of a mathematical model for methimazole dosing in graves' hyperthyroidism: A dynamic approach

This study explores a novel mathematical model for analyzing methimazole (MMI) therapy in patients with Graves' disease, a common autoimmune cause of hyperthyroidism. The model leverages a system of ordinary differential equations to capture the interplay between key factors: methimazole concentration, thyroid-stimulating hormone (TSH), free thyroxine (FT4) concentration, thyroid-stimulating hormone receptor antibody (TRAb) concentration, and functional thyroid gland size (V). Thirteen parameters account for the underlying physiological processes. Stability analysis were employedby Lyapunov stability theory and LaSalle's principle, to demonstrate the model's asymptotic stability. This implies the system converges towards a steady state under defined conditions. Additionally, a clinically relevant chart is constructed based on FT4 levels and treatment duration.For model validation, patient data is utilized within SimBiology simulations implemented in MATLAB. These simulations offer valuable insights into the dynamic response of hyperthyroidism to MMI treatment. This approach holds promise for future applications in optimizing treatment strategies and facilitating personalized medicine approaches.

The Causes of Thyrotoxicosis, Clinical Features, and Treatment Strategies in a Former Iodine Deficient Area

Thyrotoxicosis is a hypermetabolic condition caused by excess thyroid hormones in the circulation with/without increased production from the thyroid gland. In this prospective study, we aimed to investigate the causes of thyrotoxicosis, clinical features, and treatment strategies in a former iodine-deficient area. Thyroid function tests, antithyroid and antithyroid receptor antibodies, and routine thyroid ultrasonography was obtained, and a thyroid scintigraphy/radioactive iodine uptake test was performed on need. A statistically significant difference was found between toxic multinodular goiter (TMNG) and Graves’ disease (GD) groups when mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) values were analyzed. TSH levels were significantly lower in GD patients compared to those in TMNG and TNG patients, but free triiodothyronine (FT3) and free thyroxine (FT4) values were higher. A high level of TSH receptor antibody (TRAb) was observed in patients with normal antithyroid peroxidase (Anti-TPO). TRAb levels were found to be high. Anti-TPO and anti-thyroglobulin (Anti-Tg) levels were observed to be positively correlated with sT3 and sT4 levels. TMNG is the leading cause of thyrotoxicosis; despite sufficient iodide intake in our former iodine-deficient region, TMNG is characteristically seen in older patients with much lower thyroid hormone levels than GD. According to the study results, the diagnosis of patients with thyrotoxicosis, their clinical presentation, the treatment they will receive, early detection of postoperative complications were predicted

Could effective iodine-131 half-life be extended by lithium carbonate in Graves' disease patients: Results from a retrospective analysis.

The effective iodine-131 (I-131) half-life (EHL) plays an important role in the evaluation of radioactive iodine therapy for Graves' disease (GD) patients. It has been observed that the EHL of GD patients varies after taking lithium carbonate. The purpose of this study is to investigate whether EHL can be extended and to identify the predictive factors associated with this outcome. The clinical data of 225 GD patients were retrospectively reviewed. Patients were divided into two groups based on whether the ΔEHL was ≥ 0.5 days. EHL tested after lithium carbonate was defined as Li-EHL. In the univariate analysis, age, sex, thyrotropin receptor antibody (TRAb), thyroglobulin antibody (TgAb), thyroid peroxidase antibody (TPOAb), and baseline-EHL exhibited significant differences between the two groups (P < 0.05). Cutoff values of age and baseline-EHL to predict significant EHL extension were 40.5 years and 4.85 days, respectively, as determined by receiver operating characteristic (ROC) curve analysis. Multiple linear regression analysis further revealed that the regression equation, which included age, sex, baseline-EHL, and the FT3, free triiodothyronine (FT4)/free thyroxine(FT3) ratio, was statistically significant (P < 0.05). Li-EHL positively correlated with baseline-EHL and the FT4/FT3 ratio, but negatively correlated with age. Li-EHL was also increased in female individuals. In conclusion, age, sex, baseline-EHL and the FT4/FT3 ratio were associated with Li-EHL in GD patients.

Clinical Changes and Autoantibody Level Changes in Thyroid Eye Disease Patients after Intravenous High-dose Steroid therapy

Purpose: To evaluate the effects of intravenous steroid therapy on the clinical activity score (CAS), exophthalmos, margin-reflex distance 1 (MRD1), and autoantibody levels in patients with thyroid eye disease.Methods: In this retrospective observational study, we enrolled 83 patients diagnosed with thyroid eye disease treated with intravenous steroid therapy. We assessed exophthalmos, MRD1, CAS, thyroid-stimulating antibody (TSAb), and thyroid-stimulating hormone receptor antibody (TSHR Ab) levels at baseline, 6 and 12 weeks after initiating therapy, and 2 months after therapy termination. Additionally, baseline serum selenium levels were examined to determine their impact on treatment efficacy.Results: TSAb, TSHRAb, and CAS levels showed a continuous decline from 443.22 to 341.03 specimen-to-reference control ratio (SRR%), 22.18 to 7.91 IU/L, and 3.37 to 1.88, respectively (&lt;i&gt;p&lt;/i&gt; &lt; 0.0001), up to 2 months following therapy termination. Exophthalmos did not show significant changes at any assessed time point up to 2 months after therapy termination. MRD1 decreased until 12 weeks after therapy initiation but showed no significant change 2 months later. No correlation was found between baseline serum selenium levels and changes in exophthalmos, MRD1, TSAb, TSHR Ab, or CAS.Conclusions: Intravenous steroid therapy was effective in reducing TSAb, TSHR Ab, and CAS levels up to 2 months after therapy termination. However, it had limited positive impact on exophthalmos or eyelid retraction. Baseline selenium levels did not correlate with the changes in any of the examined parameters.

STAT3 single-nucleotide variants in autoimmune thyroid disease in the Pakhtun population of Khyber Pakhtunkhwa, Pakistan

The current study was conducted to assess the relationship between the STAT3 gene variants rs744166 and rs2293152 and autoimmune thyroid disorder in the Pakhtun population of the province, of Khyber Pakhtunkhwa, Pakistan. Blood was collected from 100 healthy individuals and 400 thyroid-disordered patients. Of these, one hundred were diagnosed with Hashimoto's thyroiditis (HT), while 32 were confirmed as Grave's disease (GD) patients. T3, T4, and TSH serum levels were checked to diagnose thyroid disorders. The blood was analyzed for anti-thyroid peroxidase antibodies (Anti-TPOAb) (AESKULISA- ATPO - elisa kit), (Germany), and thyroid stimulating hormone receptor antibodies (TSHRAb), TSHR Ab elisa kit (Diametra Italy), respectively. PCR was used to amplify the targeted STAT3 gene polymorphisms from rs744166 (301 bp) and rs2293152 (365 bp) sequences and then digested by specific restriction endonucleases (AluI) and AciI respectively. The disease displayed a female predominance. The genotype TC and CC of rs744166 showed a significant relationship with Grave's disease (p = 0.002, OR = 0.28, 95 % CI = 0.11–0.77) in patients. The C allele contributed significantly to the disease in GD patients. The SNP rs2293152 significantly differed between GD patients and control (p = 0.032, OR = 0.29, 95 % CI = 0.09–0.86). Similarly, the G and C alleles showed a significant (p = 0.02) difference between GD patients and the control. No significant association was found for both SNPs in Hashimoto's thyroiditis disease. It is concluded that the STAT3 gene (rs744166 and rs2293152) was found to have a potential role in autoimmunity in GD patients. Still, it needs further studies with larger sample sizes in the Pakhtun population to understand this relationship.

A survey on the management practices of graves’ disease by Egyptian physicians and a comparison to similar reports from USA, Italy, China, and Brazil

BackgroundGraves’ disease is the commonest cause of hyperthyroidism in iodine replete areas. Following universal salt iodization, most Egyptians are considered iodine sufficient. The present study aims to report a survey of real-life practices in the management of graves’ disease among Egyptian physicians and compare them to other similar reports.MethodsAn online survey was sent to members and affiliates of Alexandria thyroid association. Egyptian physicians were surveyed about initial diagnostics workup, management of an index case of uncomplicated graves’ disease not desiring pregnancy. Two modified scenarios were proposed to the index case to survey the impact on treatment preferences. Anonymous responses were collected, analyzed, presented, and compared to other published similar reports.ResultsSixty-eight participated out of 120 invited physicians (56.67%). Initial workup included TSH receptor antibodies 46/68 (67. 6%), thyroid ultrasound 45/68 (66.2%), and thyroid scintigraphy 25/68 (36.8%). Treatment preferences in the index case were antithyroid drugs (ATD’s) 52/68 (76.5%), radioiodine 12/68 (17.5%), and surgery 4/68 (6%). Compared to other reports, treatment preferences were almost identical to Italian ones, ATD’s (77.1%), radioiodine (16.2%), and surgery (4.5%). If the patient is complicated with graves’ orbitopathy, treatment preferences would change into ATD’s 37/67 (55%), radioiodine 1/67 (2%), radioiodine with corticosteroids 14/67 (21%), and surgery 15/67 (22%). If the patient is desiring pregnancy, treatment preferences would be ATD’s 32/68 (47%), radioiodine 5/68 (7.4%), and surgery 31/68 (45.6%).ConclusionA high participation rate was observed. Similar to other reports, medical treatment is the preferred modality of treatment in graves’ disease and surgery is the least utilized modality. Similar treatment preferences to Italians were observed in the index case.

Correlation between the thyroid computed tomography value and thyroid function in hyperthyroidism: a retrospective study

ObjectiveRadioiodine (I-131) therapy for hyperthyroidism is a well-established and safe treatment option. This study aimed to investigate the relationship between the computed tomography (CT) value and the function and volume of the thyroid gland by identifying the factors that induce changes in the CT value of patients with hyperthyroidism.MethodsThis retrospective study evaluated 38 patients with Graves’ disease and 10 patients with Plummer disease. To obtain the mean CT value and volume of the thyroid gland, the entire thyroid gland was set as the region of interest. A test dose of 3.7 MBq I-131 was administered before initiating I-131 therapy, and the radioiodine uptake (RIU) rate was assessed after 3, 24, 96, and 168 h. An approximate curve was plotted based on the RIU values obtained, and the effective half-life (EHL) was calculated. The correlation between the mean CT value and the volume of the thyroid gland, 24-h RIU, EHL, and the free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), and TSH receptor antibody (TRAb) levels was evaluated.ResultsThe CT value exhibited a significant positive correlation with EHL in patients with Graves’ disease (r = 0.62, p < 0.0001) as well as patients with Plummer disease (r = 0.74, p < 0.05). However, it did not display any correlation with the remaining parameters.ConclusionThe CT value is significantly correlated with EHL, suggesting that it reflects thyroid function and is mainly related to the factors associated with iodine discharge.

Dynamic Risk Model for the Medical Treatment of Graves' Hyperthyroidism according to Treatment Duration.

Changes in thyrotropin receptor antibody (TRAb) levels are associated with the clinical outcomes of Graves' hyperthyroidism. However, the effects of the patterns of TRAb changes on patient prognosis according to the treatment duration of antithyroid drugs (ATDs) are not well established. In this retrospective cohort study, 1,235 patients with Graves' hyperthyroidism who were treated with ATDs for more than 12 months were included. Patients were divided into two groups according to treatment duration: group 1 (12-24 months) and group 2 (>24 months). Risk prediction models comprising age, sex, and either TRAb levels at ATD withdrawal (model A) or patterns of TRAb changes (model B) were compared. The median treatment duration in groups 1 (n=667, 54%) and 2 (n=568, 46%) was 17.3 and 37.1 months, respectively. The recurrence rate was significantly higher in group 2 (47.9%) than in group 1 (41.4%, P=0.025). Group 2 had significantly more goiter, thyroid eye disease, and fluctuating and smoldering type of TRAb pattern compared with group 1 (all P<0.001). The patterns of TRAb changes were an independent risk factor for recurrence after adjusting for other confounding factors in all patients, except in group 1. Integrated discrimination improvement and net reclassification improvement analyses showed that model B performed better than model A in all patients, except in group 1. The dynamic risk model, including the patterns of TRAb changes, was more suitable for predicting prognosis in patients with Graves' hyperthyroidism who underwent longer ATD treatment duration.

Neutropenia Occurs More Often Under Carbimazole than Under Methimazole Treatment in Pediatric Graves' Disease Patients.

Background: Agranulocytosis is a rare antithyroid drug treatment (ATD) side effect seen in children suffering from Graves' disease (GD). Neutropenia is a recognized adverse event associated with ATD but has also been reported as pre-treatment neutropenia in GD. Methods: We performed a retrospective cohort study to analyze the longitudinal clinical and biochemical data of 161 pediatric patients with GD who received either methimazole (MMI) or carbimazole (CBZ) as ATD. The inclusion criteria were elevated free thyroxine (fT4 >25 pmol/L), suppressed thyrotropin (TSH <0.05 mlU/mL), and elevated thyrotropin receptor antibodies (TSHRAbs >2.5 IU/L). Absolute neutrophil count (ANC) was used to define neutropenia (ANC <1800/µL) and agranulocytosis (ANC <500/µL). Results: Nine of the 161 patients had neutropenia at diagnosis (ANC: 1348/µL ± 250) without further deterioration under ATD. In this subgroup, we found higher levels of free triiodothyronine (fT3: 31.45 pmol/L ± 3.99) at diagnosis in comparison with those who developed neutropenia (26.29 pmol/L ± 12.96; p = 0.07) and those without neutropenia before and during therapy (23.12 pmol/L ± 13.7; p = 0.003). Thirty-eight patients (23.6%) became neutropenic (ANC: 1479/µL ± 262) while receiving ATD. Neutropenia occurred after a mean of 551.8 (range: 10-1376) days, mostly without further deterioration. Two of these 38 patients developed agranulocytosis and underwent emergency thyroidectomy. The patients with neutropenia were significantly younger (p = 0.031). Neutropenia occurred significantly more often in patients receiving CBZ (50%; n = 20/40) than in those receiving MMI (16.5%; n = 18/110; p = 0.001). The minimum ANC was significantly lower in the CBZ (1971/µL ± 1008) than in the MMI group (2546 ± 959); p = 0.004. Conclusions: Neutropenia occurred significantly more often under CBZ than MMI. As this is potentially due to higher immunogenicity, we suggest that children with GD should be treated with MMI. Frequent measurements of ANC may be needed to detect severe agranulocytosis, although low pre-treatment ANC may not necessarily be a contraindication to ATD treatment. Young age may be potentially associated with an increased risk of reduced ANC. Further investigation is necessary to fully understand risk factors for neutropenia in children with GD.

Thyrotropin-receptor antibodies - diagnostic and prognostic significance in graves' disease - a clinical case

Thyrotropin-receptor antibodies - diagnostic and prognostic significance in graves' disease - a clinical case

Characterizing TSH-receptor antibody (TRAb) seropositive and TRAb seronegative patients with Graves hyperthyroidism - a cross-sectional study

Characterizing TSH-receptor antibody (TRAb) seropositive and TRAb seronegative patients with Graves hyperthyroidism - a cross-sectional study

Relationship between the functional activity and concentration of thyrotropin receptor antibodies and the duration and severity of graves’ orbitopathy

Relationship between the functional activity and concentration of thyrotropin receptor antibodies and the duration and severity of graves’ orbitopathy

Asymmetric proptosis in thyroid eye disease

PurposePatients with thyroid eye disease (TED) can present with asymmetric disease. The purpose of this study was to evaluate the prevalence of asymmetric TED in an Australian cohort and investigate clinical, biochemical, and radiological associations of asymmetric TED.MethodsThis was a retrospective study of patients with TED who underwent Hertel exophthalmometry and orbital computed tomography (CT) scans. Asymmetry was defined as a difference in the globe protrusion of ≥ 3 mm using Hertel exophthalmometry. Data was collected on patient demographics, clinical disease presentation, thyroid function tests and antibody levels. Muscles volumes were determined by manually segmenting the extraocular muscles on CT scans using a commercially available software.Results172 orbits from 86 patients were included in the study. 28 (33%) patients had asymmetric TED. No significant differences were observed in age, gender, thyroid hormone status, anti-thyroid peroxidase levels, thyroid stimulating hormone receptor antibodies, disease activity status, or dysthyroid optic neuropathy between the asymmetric and non-asymmetric groups. The extraocular muscle volumes were significantly higher in the asymmetric orbit compared to its contralateral orbit.ConclusionAsymmetric TED is a reasonably common occurrence in the course of TED. It is associated with higher extraocular muscle volumes, suggesting muscle enlargement as one of the underlying contributors to asymmetric proptosis. Thyroid eye disease should be considered in the differential of asymmetric orbital inflammatory disease.

Overweight as a biomarker for concomitant thyroid cancer in patients with Graves' disease.

The incidence of concomitant thyroid cancer in Graves' disease varies and Graves' disease can make the diagnosis and management of thyroid nodules more challenging. Since the majority of Graves' disease patients primarily received non-surgical treatment, identifying biomarkers for concomitant thyroid cancer in patients with Graves' disease may facilitate planning the surgery. The aim of this study is to identify the biomarkers for concurrent thyroid cancer in Graves' disease patients and evaluate the impact of being overweight on cancer risk. This retrospective cohort study analyzed 122 patients with Graves' disease who underwent thyroid surgery at Seoul St. Mary's Hospital (Seoul, Korea) from May 2010 to December 2022. Body mass index (BMI), preoperative thyroid function test, and thyroid stimulating hormone receptor antibody (TR-Ab) were measured. Overweight was defined as a BMI of 25 kg/m² or higher according to the World Health Organization (WHO). Most patients (88.5%) underwent total or near-total thyroidectomy. Multivariate analysis revealed that patients who were overweight had a higher risk of malignancy (Odds ratios, 3.108; 95% confidence intervals, 1.196-8.831; p = 0.021). Lower gland weight and lower preoperative TR-Ab were also biomarkers for malignancy in Graves' disease. Overweight patients with Graves' disease had a higher risk of thyroid cancer than non-overweight patients. A comprehensive assessment of overweight patients with Graves' disease is imperative for identifying concomitant thyroid cancer.

Diagnoses of obstetric and postpartum thyroid disease: a Danish validation study

Different diagnoses of thyroid disease are available in the 10th International Classification of Diseases (ICD-10), but the validity of diagnoses related to obstetric and postpartum thyroid disease is unknown. This was a retrospective cohort study of all patients in the North Denmark Region with a diagnosis of postpartum thyroiditis (PPT) (ICD-10: O905) from 2016 to 2019 or obstetric thyroid disease in 2019 (ICD-10: O992B (hypothyroidism) or O992C (hyperthyroidism)) registered in the Danish National Hospital Register. Information from nationwide registers and medical records were used to assess the validity. Among patients with an O905-diagnosis (n = 40), abnormal thyroid function test results were seen in all cases. A total of eight patients (20.0%) were positive for thyrotropin receptor antibodies postpartum, however, in low titers, and PPT was verified in 39 of 40 cases (97.5%). Altogether 45 of 50 patients with an O992B-diagnosis (90.0%) correctly had hypothyroidism, whereas hyperthyroidism was found in 25 of 39 patients with an O992C-diagnosis (64.1%). This is the first study to validate ICD-10 diagnoses of obstetric and postpartum thyroid disease. A high validity was seen for PPT (O905) and obstetric hypothyroidism (O992B), whereas for obstetric hyperthyroidism (O992C), the diagnosis could not be verified in one third of the cases.

Correlation between extraocular muscle enlargement and thyroid autoantibodies in thyroid eye disease

PurposeThis study aimed to investigate the factors affecting extraocular muscle enlargement in thyroid eye disease (TED).Study designRetrospective study.MethodsThe thyroid-stimulating hormone (TSH) receptor antibody (TRAb), thyroid-stimulating antibody (TSAb), antithyroid peroxidase antibody (ATPO), and antithyroglobulin antibody (ATG) levels in patients diagnosed with TED who underwent orbital magnetic resonance imaging were assessed. The control group comprised the contralateral eye of patients who underwent orbital magnetic resonance imaging (MRI) for unilateral eyelid tumors or orbital disease. The thickness of the bilateral rectus muscles and superior oblique muscles was measured on orbital MRI. Muscle enlargement was classified as unilateral/bilateral and symmetric/asymmetric. The effects of age, sex, smoking history, TSH, thyroid hormone, and thyroid autoantibodies on the muscle thickness and number of enlarged muscles were assessed by use of simple and multiple regression analyses.ResultsThe TED and control groups comprised 41 and 44 cases, respectively. The positivity rate of TSAb in patients with TED was 92.7% higher than that of the other autoantibodies. Muscle enlargement was observed in 29 of the 41 cases (70.7%). Older age and higher TSAb levels were identified as significant factors affecting the total muscle thickness and number of enlarged muscles. Bilateral muscle enlargement and asymmetrical muscle enlargement were observed in 17 (58.6%) and 23 (79.3%) of the 29 cases, respectively. The TSAb levels and age had no significant effect on the type of muscle enlargement.ConclusionsTSAb showed significant associations with extraocular muscle enlargement. Measurement of TSAb, rather than of TRAb, may be more useful for diagnosing extraocular muscle enlargement in patients with TED.

Severity Identification of Graves Orbitopathy via Random Forest Algorithm.

This study aims to establish a random forest model for detecting the severity of Graves Orbitopathy (GO) and identify significant classification factors. This is a hospital-based study of 199 patients with GO that were collected between December 2019 and February 2022. Clinical information was collected from medical records. The severity of GO can be categorized as mild, moderate-to-severe, and sight-threatening GO based on guidelines of the European Group on Graves' orbitopathy. A random forest model was constructed according to the risk factors of GO and the main ocular symptoms of patients to differentiate mild GO from severe GO and finally was compared with logistic regression analysis, Support Vector Machine (SVM), and Naive Bayes. A random forest model with 15 variables was constructed. Blurred vision, disease course, thyroid-stimulating hormone receptor antibodies, and age ranked high both in mini-decreased gini and mini decrease accuracy. The accuracy, positive predictive value, negative predictive value, and the F1 Score of the random forest model are 0.83, 0.82, 0.86, and 0.82, respectively. Compared to the three other models, our random forest model showed a more reliable performance based on AUC (0.85 vs. 0.83 vs. 0.80 vs. 0.76) and accuracy (0.83 vs. 0.78 vs. 0.77 vs. 0.70). In conclusion, this study shows the potential for applying a random forest model as a complementary tool to differentiate GO severity.