Thyroid-stimulating Antibodies Research Articles

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.

Principles and features of ultrasound hypoechogenicity in diffuse thyroid pathology.

For different thyroid diseases and hormonal metabolism, ultrasound (US) of the thyroid gland reveals hypoechogenicity. Despite the direct correlation of hypoechogenicity with the levels of thyroid-stimulating hormone and antibodies of thyroid peroxidase and thyroglobulin, ~20% of this correlation is inconsistent, thus restricting the comprehensive utilisation of this valuable diagnostic sign. Thus, it is necessary to investigate the additional circumstances affecting the extent and features of the US hypoechogenicity of the thyroid gland. The technique for assessing thyroid hypoechogenicity was based on the basic setting of the US mode and visual assessment in percentage of gray relative to a gradient gray scale. Doppler mode was used. US data were compared with the results of hormonal and immune blood tests. The study contains the morphofunctional basis of the various US hypoechogenicities detected in the diffuse pathology of the thyroid gland has been presented, and the principles and probable mechanisms of widespread and segmental hypoechogenicity formation are disclosed for the first time. Furthermore, a mandatory Doppler involving thyroid parenchyma blood flow intensity and peak systolic blood velocity of thyroid arteries, which indicates the magnitude of neurovegetative influence, has been suggested. The results of the study shows revealed that the evaluation of the importance and features of US hypoechogenicity in various diffuse thyroid pathologies is probably based on a single system involving neurohumoral regulation, segmental arrangement and compensatory reserve state of the gland parenchyma.

The evaluation of retrobulbar fat tissue in Graves' orbitopathy with shear-wave ultrasound elastography.

To evaluate retrobulbar adipose tissue of patients with active and inactive Graves' orbitopathy (GO) by shear-wave ultrasound elastography (SWE). Followed-up in our ophthalmology clinic due to GO, 72 eyes of 36 patients and 38 eyes of 19 healthy controls were included in this cross-sectional case-control study. Graves' patients were divided into two subgroups under clinical activity score (CAS): active Graves' orbitopathy (AGO) (CAS ≥ 3) and inactive Graves' orbitopathy (IGO) (CAS < 3). SWE measurement values of retrobulbar adipose tissue of all participants were recorded in meters/second, and the intergroup comparisons were performed. Thirty-four eyes of 17 patients in AGO, 38 eyes of 19 patients in IGO, and 38 eyes of 19 participants in the control group were included in the study. Mean values measured from retrobulbar adipose tissue through SWE were 1.00 ± 0.01m/sec in AGO, 1.16 ± 0.01m/sec in IGO, and 0.94 ± 0.01m/sec in the control groups. Even so, the mean SWE value was significantly higher in the IGO group than in the other groups (p < 0.001). Mean SWE values were significantly higher in the AGO group than in the controls (p = 0.008). In the correlation analysis performed, a significant positive correlation was found between SWE and Hertel exophthalmometer measurement values (p = 0.026, r = 0.212), and thyroid-stimulating hormone receptor antibody (TSHR-Ab) levels (p = 0.018, r = 0.224). We detected SWE values of retrobulbar adipose tissue high in GO, especially in the IGO group. Such a situation, which we associated with the development of fibrosis, may be an indicator of unresponsiveness to immunomodulatory treatments.

Optimizing Levothyroxine Replacement: A Precision Dosage Model for Post-Thyroidectomy Patients.

Thyroidectomy is commonly performed for benign or malignant thyroid tumors, often resulting in hypothyroidism. Levothyroxine (LT4) supplementation is crucial to maintain hormone levels within the normal range and suppress TSH for cancer control. However, determining the optimal dosage remains challenging, leading to uncertain outcomes and potential side effects. We analyzed clinical examination data from 510 total thyroidectomy patients, including demographic information, blood tests, and thyroid function. Using R, we applied data preprocessing techniques and identified 274 samples with 98 variables. Principal Component Analysis, correlation analysis, and regression analysis were conducted to identify factors associated with optimal LT4 dosage. The analysis revealed that only eight variables significantly influenced the final satisfactory dosage of LT4 in tablets: Benign0/Malignant1 (benign or malignant), BQB (electrophoretic albumin ratio), TP (total protein), FDP (fibrin degradation products), TRAB_1 (thyroid-stimulating hormone receptor antibody), PT (prothrombin time), MONO# (monocyte count), and HCV0C (hepatitis C antibody). The resulting predictive model was: . Parameters such as benign/malignant status, TRAB_1, and BQB ratio during medication can serve as observational indicators for postoperative LT4 dosage. The calculated linear model can predict the LT4 dosage for patients after thyroidectomy, leading to improved treatment effectiveness and conserving medical resources.

The Presence of Anti-TPO Antibodies Increase the Likelihood of Post-I131 Hypothyroidism.

The use of radioactive iodine in the treatment of hyperthyroidism is common practice. However, a standardized treatment protocol with regard to radioactive iodine treatment (RAI) remains subject to discussion. We retrospectively analyzed 100 patient records. Patient diagnosis, age, gender, body mass index (BMI), dose of radioactive iodine, thyroid size, the 24 h radioiodine uptake (24 h RAIU) and protein bound iodine (PBI) were deducted, as well as the use of antithyroid drugs prior to RAI. Biochemical parameters were obtained, such as TSH, fT4, fT3, Anti-TPO, Anti-TG antibodies and thyroid stimulating antibodies. After 5 years of follow-up, 46% of the patients proved to be hypothyroid, whereas 8% of the patients were not cured after one dose of RAI. One year after RAI, a larger proportion of patients with a toxic nodule developed hypothyroidism compared to patients with a multinodular goiter (MNG) (44.2% vs. 21.2%). Radioactive iodine dose, PBI, RAIU, BMI, size of the thyroid gland, diagnosis, age and TPO-antibodies showed statistically significant differences in the development of hypothyroidism. Furthermore, thiamazole pretherapy was shown to be a predictor of hypothyroidism, as well as a high PBI value, exhibiting a positive predictive value of 85.2% when the PBI exceeded 0.16. We suggest a standardized measurement of TPO-Ab's to further determine their role in the development of hypothyroidism after RAI. The empirical dosing regimen was very effective, illustrating a 92% cure rate after 1 dose.

Evaluation of lamina cribrosa and peripapillary vascular density in thyroid orbitopathy and effect of intravenous methylprednisolone therapy

PurposeTo evaluate optic nerve head changes in patients with thyroid orbitopathy (TO) and investigate the effects of intravenous methylprednisolone (IV MTP) on these changes. MethodsEighty-two eyes of 41 patients with TO with and without dysthyroid optic neuropathy (DON) and 40 eyes of 40 healthy control subjects were included in the study. Lamina cribrosa thickness (LCT) and depth (LCD) measurements, peripapillary retinal nerve fibre layer thickness (RNFLT), and radial peripapillary capillary vascular density were measured using optical coherence tomography and optical coherence tomography angiography. Visual field examination and proptosis were evaluated. Patients with DON and active non-DON received IV MTP for 12 weeks, and the effect of this treatment was evaluated. ResultsPeripapillary vascular density decreased in patients with DON compared with the other groups (p < 0.001 for all); there was no difference in the total, superior hemi-sector, and inferior hemi-sector of the RNFLT between the groups. LCT was decreased in the TO group (p < 0.001). After IV MTP treatment, the LCT and best-corrected visual acuity were increased. Thyroid-stimulating hormone receptor antibody levels, intraocular pressure, the superior hemi-sector of the RNFLT, and proptosis were decreased compared with the control subjects (p = 0.012, p = 0.008, p = 0.043, and p < 0.001, respectively). ConclusionsThe RNFLT may not always increase in DON. Lamina cribrosa morphology may change in patients with TO. IV MTP therapy has a positive effect on the LCT but not on radial peripapillary capillary vascular density or LCD.

Associations of serum keratin 1 with thyroid function and immunity in Graves' disease.

Autoimmune thyroid disease (AITD) can cause enormous health burdens; however, trustworthy biomarkers in identifying the onset and progression of AITD are limited. In this study, we attempted to discover new potential serum biomarkers to discriminate AITD using mass spectrometry (MS). In the biomarker study cohort, 20 patients with Graves' disease (GD), 20 patients with Hashimoto's thyroiditis (HT), and 20 healthy controls were enrolled for a liquid chromatographic-tandem MS assessment. A novel biomarker, keratin 1 (KRT1), was selected for further evaluation in the validation cohort, including 125 patients with GD, 34 patients with HT, and 77 controls. Relationships of serum KRT1 with AITD-related immunomodulatory cytokines were also analyzed using enzyme-linked immunosorbent assays (ELISAs). In the MS analysis, KRT1 was the single marker overexpressed in GD, while it was underexpressed in HT. In the ELISA analysis of the validation cohort, KRT1 was consistently upregulated in GD, while it was not downregulated in HT. There were significant associations of KRT1 levels with thyroid function in GD, AITD, and overall subjects. Additionally, a significant association of KRT1 levels with thyroid-stimulating hormone receptor antibody (TSHRAb) levels was observed. Moreover, there were significant associations of KRT1 with osteopontin (OPN) and B-cell activating factor (BAFF) levels in GD. Serum KRT1 levels were upregulated in GD and were associated with thyroid function and TSHRAb levels. Moreover, KRT1 was correlated with the BAFF and OPN levels in GD patients. Further molecular-based research to elucidate the role of KRT1 in the pathogenesis of AITD is needed.

Hashimoto's Thyroiditis among Patients with Thyroid Diseases in Sulaimani City: A Cross-Sectional Study

This study aimed to measure the prevalence of Hashimoto's Thyroiditis among patients with thyroid diseases in Sulaimani city and to observe some features of this autoimmune disorder. Hashimoto's Thyroiditis, also known as Hashimoto's disease, is an essential cause of Hypothyroidism. Blood samples ‎were collected from 203 patients suffering from thyroid disease in Sulaimani endocrine center and Bakshin Private Hospital in Sulaimani city from December 2018 to March 2019. Serum levels of thyroid hormones, anti-thyroid peroxidase antibodies, anti-thyroglobulin antibodies, and anti-‎thyroid-stimulating hormone ‎receptor antibodies were determined using Cobas e411 Immuno‎analyzer; moreover, data about ‎gender, age, and family history of thyroid disease were recorded. The prevalence of Hashimoto's Thyroiditis among all thyroid patients was 62% (n=126/203), while Graves' disease was 15.3% (n=31/203); thus, autoimmune diseases represent 77.3% (157/203) of thyroid diseases. Hypothyroidism is diagnosed in 155/203 (76.4%) thyroid diseases, while the remaining 23.6% were patients with hyperthyroidism. The demographic data revealed that 88.9% (n=112/126) of Hashimoto's Thyroiditis are females, while 11.1 % (n=14/126) are males. The peak incidence of Hashimoto's Thyroiditis is in the age group 36-45 years; a family history of thyroid diseases was recorded in 64.3% of Hashimoto's patients. The correlation coefficient between anti-thyroid peroxidase antibodies and the ages of Hashimoto's Thyroiditis patients is 0.21938. Hashimoto's Thyroiditis is the main thyroid disorder in Sulaimani city among patients with thyroid diseases, Hypothyroidism, and autoimmune thyroid disorders; both seropositive and seronegative anti-thyroid peroxidase antibodies are recorded among Hashimoto's Thyroiditis patients. Family history of thyroid disorders and females of childbearing age are possible risk factors for developing Hashimoto's Thyroiditis. There is no significant correlation between anti-thyroid peroxidase antibodies concentrations and ages of Hashimoto's Thyroiditis patients, but these antibodies are much higher in Hashimoto's females than in Hashimoto's Thyroiditis males

Radioactive iodine treatment for Graves' hyperthyroidism: incidence of Graves orbitopathy.

There are limited recent data on the effect of radioactive iodine (RAI) for Graves' disease on Graves' orbitopathy (GO) development or reactivation. This audit investigates the GO incidence in patients with Graves' disease after RAI treatment, and explores risk factors present, and steroid prophylaxis use. A retrospective audit of Graves' disease patients treated with RAI over a 5-year period. Data collected: smoking status, thyroid-stimulating hormone receptor antibody (TRAb) status, GO history, Graves' disease duration, eye features pre- and post-treatment, prophylactic corticosteroids, RAI dose given, post-RAI thyroid status, duration until hypothyroid. One hundred one patients were included, with a median Graves' disease duration 36 months. 34/101 (33.7%) were active/ex-smokers, 86/101 (85.1%) were TRAb-positive, 11/101 (10.9%) had a GO history; 32 (31.7%) had eye features present. Median RAI dose given was 596MBq. 8/101 (7.9%) patients received prophylactic corticosteroid; 89/101 (88.1%) achieved hypothyroid state in the year after RAI. GO developed in 5/101 (5.0%), of which 4/5 (80%) were de novo in high-risk individuals who did not receive steroids. One was a GO reactivation despite steroids. Two required intravenous steroids with/without orbital radiotherapy, one completed oral steroid taper; the remainder were treated conservatively. Our cohort had a lower GO incidence in patients with Graves' disease receiving RAI, with majority arising de novo . It is essential that all patients are assessed for Graves orbitopathy risk factors and counselled adequately prior to RAI. The decision to initiate steroids should be undertaken in a multi-disciplinary setting involving endocrinologists and ophthalmologists.

A Rare Case of Painless Destructive Thyroiditis Resulting in Thyroid Storm.

Thyroid storm is a life-threatening clinical condition that is usually triggered by untreated or interrupted treatment of Graves' disease, leading to the sudden onset of severe thyrotoxicosis, which requires an immediate diagnosis and treatment based on diagnostic criteria. Cases of thyroid storm caused by painless/painless subacute thyroiditis are very rare. We herein report an 85-year-old man with features of severe thyrotoxicosis caused by painless/painless subacute thyroiditis who had no uptake of 99mTcO4 and was negative for thyroid-stimulating hormone receptor antibodies. In thyroid storm patients in whom the findings are inconsistent with Graves' disease, careful follow-up and management are necessary, assuming the possibility of painless or painless subacute thyroiditis.

Advancing Preoperative Strategies for Thyroidectomy in Graves' Disease: A Narrative Review.

Graves' disease is an autoimmune disorder characterized by thyroid-stimulating antibodies that can potentially lead to thyrotoxicosis, goiter, skin disease, and eye disease. Available treatment options for Graves' disease include management with antithyroid drugs (ATDs), thyroid ablation with radioactive iodine (RAI), and surgical thyroid gland removal. For individuals unable to reach a normal thyroid hormone level, promptly considering a thyroidectomy is essential. Preoperative strategies to achieve a euthyroid state prevent thyroid storms and minimize postoperative complications and are therefore crucial. While variations in professional guidance exist, this review focuses on standard medical interventions as well as compares respective guidelines set forth by the American Thyroid Association, the European Thyroid Association, the American Association of Clinical Endocrinology, and the American Association of Endocrine Surgeons. There is consensus among these organizations underscoring the importance of rendering patients euthyroid prior to surgery and the use of ATDs. Most guidelines recommend screening for vitamin D deficiency as well as endorse thyroidectomy as the preferred treatment option for hyperthyroidism with skilled surgeons. Nevertheless, discrepancies do become apparent in aspects such as potassium iodide (SSKI) course duration and preoperative dexamethasone administration. By understanding these differing approaches, healthcare professionals can more effectively manage Graves' disease prior to surgery, resulting in improved patient outcomes and enhanced surgical success.

Features of the natural course of subclinical hypothyroidism in young athletes

Objective: to assess the natural course of subclinical hypothyroidism in young athletes.Methods: In the prospective single-center uncontrolled study, data from 3,062 outpatient records of young athletes (members of the Russian national team) of both sexes (middle age — 15 [14; 16] years) and underwent medical examination in the period from January 2021 to September 2022 were studied. All athletes were divided into 2 groups according to the presence of subclinical hypothyroidism (an increase in the level of thyroid-stimulating hormone from 5 to 10 mUn/l with a normal level of T4 free). During a dynamic follow-up (1 year), athletes with subclinical hypothyroidism underwent a repeated study of the concentration of thyroid-stimulating hormone, free thyroxine and antibodies to thyroperoxidase.Results: Signs of subclinical hyperthyroidism were found in 58 young athletes (30 boys (51.7 %) and 28 (48.3 %) girls). During dynamic observation with continued habitual physical activity, spontaneous normalization of the level of thyroid-stimulating hormone was observed in 74 % of young athletes. At the same time, normalization of thyroid-stimulating hormone in girls was observed less often compared to boys (p = 0,272). In no case did clinically pronounced hypothyroidism develop.Conclusion: The majority of young male and female athletes with subclinical hypothyroidism have spontaneous normalization of hormonal profile against the background of persistent physical and psycho-emotional stress. The data obtained make it possible, subject to the possibility of dynamic observation, to recommend doctors working with young elite athletes not to prescribe hormonal replacement therapy and not to modify the usual lifestyle.

THU665 Unilateral Graves’ Disease In A Bilobar Thyroid Gland: Unusual Cause Of Hyperthyroidism

Abstract Disclosure: K.H. Alaybaa: None. O. Alhuzaim: None. Introduction: Graves' disease (GD) is an autoimmune condition that affects both thyroid gland lobes. GD patients with unilateral thyroid scan uptake are rare. These patients present with classic Graves' symptoms, occasionally with Graves' ophthalmopathy characteristics and increased thyroid hormones, and scintigraphic assessment reveals radiotracer uptake in only one lobe of the thyroid gland. Patient Findings: In this case, a 48-year-old female presented with symptoms and signs indicative of thyrotoxicosis. Lab results revealed that thyroid-stimulating hormone (TSH) was undetectable, while free thyroxine (T4) and free triiodothyronine (T3) were in the high-normal range. Positive results were observed for both thyroid-stimulating immunoglobulin and TSH receptor antibodies. Ultrasonography of the thyroid gland revealed an enlarged left lobe with heterogeneous echotexture and a hyperemic gland without any focal lesions, distinct nodules, or cysts. The NM TC-99M thyroid scintigraphy revealed enlarged and increased radioisotopes uptake in the left thyroid lobe and decreased uptake in the right thyroid lobe, with no hot or cold nodules. The calculated thyroid uptake is 4.5 percent (normal range: 0.5% to 3.5 percent). The most likely diagnosis was unilateral GD. The patient was administered carbimazole and within eight weeks had improved clinically and biochemically. Summary: This patient has thyrotoxicosis symptoms and positive autoantibodies. Tc99m uptake was increased in the left thyroid lobe and decreased in the right thyroid lobe. The left thyroid lobe was hypervascular and enlarged on ultrasonography, indicating the presence of unilateral GD. Unilateral GD is a rare disease with a poorly understood pathophysiology. Presentation: Thursday, June 15, 2023

FRI473 Central Hypothyroidism Following Neonatal Graves Presentation

Abstract Disclosure: E. Metzinger: None. K. Halpin: None. Background: Neonatal Graves’ disease is a rare disorder of neonatal autoimmune hyperthyroidism secondary to the transplacental passage of thyroid-stimulating hormone receptor antibodies. Although neonatal Graves’ disease is transient, it is associated with cardiac dysfunction, intrauterine growth restriction, prematurity, craniosynostosis, and developmental delay and can be life-threatening. Additionally, infants with neonatal Graves’ disease can rarely present with primary or central hypothyroidism later in infancy or childhood. This is suspected to be due to the disruption in the hypothalamic-pituitary-thyroid axis or development of the thyroid gland. Clinical Case: Here we describe a case of neonatal Graves’ disease that has been complicated by persistent central hypothyroidism requiring levothyroxine treatment. This was a preterm infant with tachycardia, biventricular heart failure, and hepatomegaly who was transferred to a higher level of care NICU for cardiac and respiratory failure. Pregnancy was complicated by history of maternal Graves’ disease status post radioiodine ablation. Maternal TRAB and thyroid levels were unavailable. Initial thyroid studies on DOL 1 were notable for suppressed TSH of &amp;lt;0.02mcIU/mL, elevated free T4 6.9ng/dL, and elevated total T4 &amp;gt;24.9mcg/dL. Total T3 was normal at 161ng/dL (50-452ng/dL) on DOL 2, and TSI was elevated at 4.8 (TSI Index, normal &amp;lt;/= 1.3) on DOL 3. For neonatal thyrotoxicosis, the infant was treated with methimazole, potassium iodide (KI), propranolol, and hydrocortisone. Hydrocortisone was discontinued as the infant clinically improved, and KI was discontinued after 1 week. TFTs were closely followed during admission and methimazole dosing was adjusted as needed. He was discharged from the NICU on DOL 19 on methimazole and propranolol with close outpatient lab monitoring and follow-up. Propranolol was discontinued by 1.5 months of life, and methimazole was discontinued by 2 months of life as TFTs normalized. TSI was negative by four months of life. TSH remained low with decreasing free T4 levels. Ultimately, he was started on levothyroxine at 8.5mcg/kg/day at 2.5 months of age for central hypothyroidism. At that time, TSH was 0.06mcICU/mL and FT4 was 0.7ng/dL. TSH remained low through the first 14 months of treatment with normal free T4 levels on levothyroxine. He has been continued on levothyroxine (average 20mcg/day). Conclusion: This case highlights the severity of neonatal Graves’ disease and the possibility of the subsequent development and persistence of central hypothyroidism following neonatal Graves’ diagnosis despite the resolution of hyperthyroidism and normalization of TSI antibody. Due to the risk of the development of hypothyroidism, it may be worthwhile to continue to trend TSH and FT4 to ensure that the infant has not developed hypothyroidism. Presentation: Friday, June 16, 2023

THU240 A Study Of 21 Cases Of Graves Disease In Childhood Presenting At Our Hospital For The First Time

Abstract Disclosure: T. Kashima: None. N. Ujita: None. H. Konno: None. A. Fujioka: None. H. Miyagi: None. M. Igarashi: None. H. Doi: None. K. Yoshii: None. Y. Naiki: None. R. Horikawa: None. M. Noordin: None. Although Graves disease is most common among women in their 20s and childhood-onset cases account for less than 5% of all cases of Graves disease, they account for the majority of hyperthyroidism in children. We report here a retrospective review of data on pediatric patients with Graves' disease who visited our hospital for the first time at the time of their initial examination. Methods We analyzed 21 pediatric patients with Graves disease who visited our hospital between November 2004 and January 2022. The electronic medical records of 21 patients were retrospectively reviewed for sex, age, height SD score, weight SD score, underlying disease, blood test results, and treatment initiation. Results There were 17 girls and 4 boys. The median age was 11 years and 5 months. Symptoms such as fever, feverishness, palpitations, weight loss, hyperactivity, and irritability were observed in 5 of the patients. Four patients had symptoms related to academic performance, such as low grades and poor concentration. Median physical findings were height SD score 0.62 (N=21), weight SD score 0.06 (N=21), and body mass index -4.4%. Two patients had bronchial asthma and atopic dermatitis, and one had myasthenia gravis and trisomy21 as underlying diseases. One patient was considered to have attention deficit hyperactivity disorder and was receiving antipsychotic medication. The median blood test values at the first visit were ALP 857 U/L (N=19), total cholesterol level 122 mg/dL (N=19), fT3 14.31 pg/mL (N=21), fT4 4.60 ng/dL (N=21), thyroid stimulating antibody 668 % (N=7), TSH receptor antibody 16.6 IU/L (N=20 TSH was less than sensitive in all cases. Nineteen patients received thiamazole. Fourteen patients received propranolol. Five patients received inorganic iodine. Five patients received inorganic iodine, starting at a median of 0.926 mg/kg/day of body weight. Discussion As with adults, females were more common. The symptoms were similar to those of attention deficit hyperactivity disorder, and thus warranted attention. Symptoms related to poor academic performance were also considered important. Anti-thyroglobulin antibodies and anti-TPO antibodies were also detected, suggesting that we should be careful about the possibility of the disease progressing to Hashimoto's disease. Presentation: Thursday, June 15, 2023

FRI504 Ectopic Hyperactive Mediastinal Thyroid Tissue: A Case Report

Abstract Disclosure: C. Dimech: None. G. Jaiswal: None. A. Bhargava: None. Ectopic thyroid tissue is usually located along the normal path of the caudal migration of thyroid tissue during embryonic life. Substernal goiters are thought to occur by either the enlargement of ectopic mediastinal thyroid tissue (primary mediastinal goiter) or abnormal extension of thyroid issue into the superior mediastinum (secondary mediastinal goiter). Typically these goiters remain asymptomatic, and rarely result in hyperthyroidism or local compression of the surrounding area. We report a case of an 89-year-old Caucasian female with history of a multinodular goiter status post right hemithyroidectomy, who initially presented for subclinical hyperthyroidism. Further evaluation revealed negative thyroid stimulating antibodies. A thyroid ultrasound demonstrated a surgically absent right lobe, with a small heterogenous left lobe. A nuclear medicine radioactive iodine uptake and scan showed hypermetabolic residual thyroid tissue with a large area of increased radiotracer uptake projecting over the right anterior chest, concerning for ectopic thyroid tissue. A subsequent chest CT without contrast revealed an approximately 5 centimeter partially calcified anterior mediastinal/retrosternal mass. Given the patient’s age and co-morbidities, a decision was made to treat the hyperthyroidism with methimazole and monitor the ectopic tissue for worsening symptoms of compression. In cases with severe compressive symptoms, or difficult to treat hyperthyroidism, a surgical option must be considered. Presentation: Friday, June 16, 2023

FRI565 Spontaneous Conversion Of Long-standing Hypothyroidism To Grave’s Disease: A Case Report

Abstract Disclosure: M. Dominic: None. M. Shakir: None. A. Kakkar: None. O.Z. Syed: None. A. Sood: None. D.A. Alvarez: None. Introduction: Autoimmune thyroid diseases associated with IgG4 include Hashimoto’s thyroiditis (HT) and Graves’ disease (GD). HT involves a combination of antibody-mediated thyroid gland destruction and inhibition of thyroid hormone production through a predominance of TSH receptor-blocking antibodies (TBAb). GD is due to increased thyroid hormone production in response to thyroid-stimulating antibodies (TSAb). Although transition to hypothyroidism in patients with GD is commonly encountered in clinical practice, conversion of primary hypothyroidism to GD is a rare event and is described here. Clinical Case: We describe the case of an 81-year-old female with primary hypothyroidism diagnosed more than 10 years ago. She was briefly treated with desiccated thyroid which was later changed to levothyroxine, and she remained euthyroid for several years on Levothyroxine 88 mcg daily. In 05/2021 her routine blood test showed suppressed TSH of less than 0.01uIU/mL for the first time, and it remained consistently low with elevated free T4 &amp; T3 levels despite gradually reducing levothyroxine dose. Patient also started to have tremors, weight loss and anxiety during this period. She was found to have a hypermetabolic thyroid nodule during a PET-CT for evaluation of newly diagnosed Gastrointestinal Stromal Tumor in 09/2022. Levothyroxine was stopped shortly thereafter, but the hyperthyroid labs persisted, following which TSAb levels were obtained and found positive. She was started on methimazole 10 mg twice daily, which resulted in symptomatic improvement and marked reduction of T3 &amp; T4 levels in one month. Clinical lessons: Over-replacement is the most common cause of hyperthyroid symptoms in patients receiving thyroid hormone replacement. Primary hypothyroidism is usually a permanent condition requiring lifelong therapy. Conversion of this condition to GD is a rare entity and can be missed in clinical practice by being mistaken for levothyroxine over-replacement. Proposed mechanisms for conversion of long-standing hypothyroidism to hyperthyroidism include fluctuating levels of TBAbs and TSAbs, spontaneous development of autoimmunity and rarely, production of TSAbs in patients with established Hashimoto’s thyroiditis. Another proposed theory is initial hypothyroidism due to extensive autoimmune gland damage in patients with GD who later develop hyperthyroidism after tissue recovery. It should be noted that this transition to GD has been reported to occur even 30 years after the diagnosis of hypothyroidism. Thus in patients with well-established hypothyroidism requiring lower thyroid replacement doses than before, and labs showing persistent hyperthyroid picture with no evident cause, a careful evaluation is required to check for conversion to GD in order to start appropriate treatment at the earliest. Presentation: Friday, June 16, 2023

Ultrasound measurement of vastus lateralis and vastus medialis muscle parameters to identify chronic thyrotoxic myopathy.

Chronic thyrotoxic myopathy (CTM) is a common, easily neglected complication of hyperthyroidism. There are currently no standard diagnostic criteria for CTM, and the ultrasonic characteristics of CTM-affected skeletal muscle remain unclear. Herein, we aimed to evaluate hyperthyroid patients for CTM by ultrasound and identify ultrasonic muscle parameter cutoffs for CTM diagnosis. Each participant underwent ultrasonography. The original (muscle thickness (MT), pennation angle (PA), and cross-sectional area (CSA)) and corrected (MT/height (HT), MT/body mass index (BMI), CSA/HT, and CSA/BMI) parameters of the vastus lateralis and vastus medialis (VM) were evaluated. The diagnostic effectiveness of ultrasound for predicting CTM was determined using receiver operating characteristic (ROC) curve analysis. Our study included 203 participants: 67 CTM patients (18 males, 49 females), 67 non-CTM patients (28 males, 39 females) and 69 healthy controls (20 males, 49 females). The CTM group had lower muscular ultrasonic and anthropometric parameters, higher thyroid hormone and thyroid-stimulating hormone receptor antibody (TRAb) levels, and a longer duration of hyperthyroidism than the non-CTM group (P < 0.05). The VM-PA, VM-CSA, VM-CSA/HT, and VM-CSA/BMI were lower in females than in males (P < 0.05). Free thyroxine (FT4) and TRAb both showed significant negative correlations with VM-MT, VM-MT/HT, VM-CSA, and VM-CSA/HT (P < 0.05). VM-MT/BMI and VM-CSA/HT, respectively, best predicted male and female CTM (AUC = 0.84, 0.85; cutoff ≤ 0.07, < 4.01). Ultrasound measurement of muscular parameters, especially in the VM, is a valid and feasible way of diagnosing and characterizing possible CTM in hyperthyroidism.

Evaluation of the Abbott Alinity i Thyroid-Stimulating Hormone Receptor Antibody (TRAb) Chemiluminescent Microparticle Immunoassay (CMIA).

Background: We evaluated the performance of the Abbott thyroid-stimulating hormone receptor antibody chemiluminescent microparticle immunoassay (CMIA) on the Alinity i. Methods: Verification studies for precision, linearity, analytical measuring range, diagnostic cut offs for Graves' disease were performed. We compared the Abbott CMIA to an established TRAb assay (Roche electrochemiluminescence immunoassay). Method comparison analysis was performed between serum and plasma samples on the Abbott CMIA. Results: Repeatability (CV%) for TRAb were 4.07, 1.56, 0.71 and within-laboratory imprecision (CV%) were 4.07, 1.90, 0.71 at 3.0, 10.0, 30.0 IU/L of TRAb, respectively. Linearity and analytical measuring range were verified from 1.07-47.9 IU/L. The limit of the blank was 0 IU/L, limit of detection was 0.15 IU/L, and limit of quantification was 0.5 IU/L. Passing-Bablok analysis showed agreement between the two assays; Y-intercept = 0.787, slope = 1.04. Passing-Bablok analysis also showed agreement between the plasma and serum samples run on the Abbott CMIA; Y-intercept -0.17, slope = 0.97. Conclusions: The Abbott TRAb CMIA on the Alinity i performs within the manufacturer claims for assay precision, linearity, analytical measuring range, limit of blank, limit of detection, limit of quantitation and diagnostic cut offs for Graves' disease. Thus, the Abbott TRAb CMIA on the Alinity i is fit for clinical use.