Elevated Free T4 Research Articles

PARALISIA PERIÓDICA HIPOCALÊMICA TIREOTÓXICA: RELATO DE CASO E REVISÃO BIBLIOGRÁFICA INTEGRATIVA

Thyrotoxic Hypokalemic Periodic Paralysis (THPP) is characterized by episodes of muscle weakness associated with hyperthyroidism and hypokalemia. The following study aims to report a case of Thyrotoxic Hypokalemic Periodic Paralysis, in addition to reviewing this uncommon topic in daily medical practice. The patient was a 38-year-old male patient, previously healthy, who was admitted to the emergency room due to pain syndrome in the lower limbs, concomitant with gradual, ascending and progressive loss of strength in the upper limbs, associated with generalized paresis. Hypokalemic flaccid paralysis was confirmed after gasometric and laboratory evidence of severe hypokalemia concomitant with the condition. Investigation was continued with a thyroid profile, which showed suppressed TSH and elevated free T4. The Burch and Wartofsky index was evaluated, compatible with imminent thyrotoxic crisis, and correction of hypokalemia and specific management with propylthiouracil (PTU), corticosteroid therapy and beta-blocker were instituted, with excellent clinical and laboratory response. Subsequently, the presence of antibodies above the reference values ​​was evidenced, confirming the presence of thyroid autoimmunity. Therefore, the insidious onset and rapid deterioration resulting from PPHT are emphasized, with the need for its early recognition as a differential diagnosis in the face of flaccid paralysis, considering the request for thyroid function tests in acute situations for adequate diagnosis and treatment.

6770 Graves’ disease induced by COVID-19 infection in a 49 year old male

Abstract Disclosure: N. Al-hosainat: None. A. Al Najada: None. T. Salar: None. S. Iqbal: None. K. Abdel Gadir: None. Introduction: Graves’ disease is an autoimmune disease causing hyperthyroidism, characterized by elevated thyrotropin-receptor antibodies. COVID-19 infection has been increasingly reported as a trigger of thyroid illness including Graves’ disease. We present a unique case of 49-year-old patient who was diagnosed with Graves’ disease after COVID-19 infection. Case description: A 49-year-old male patient with history of prediabetes presented with complaints of tremor, fatigue, generalized itching, and unintentional weight loss (30 Ibs in 6 months). He had COVID-19 infection 3 months prior. The remainder of review of systems was negative. No family history of thyroid disease. On exam, the patient had sinus tachycardia with otherwise normal vital signs. Diffuse thyromegaly was noted along with an intermittent fine tremor of the extremities. Blood work was notable for low TSH <0.01 uIU/mL, elevated free T4 (3.4 ng/dL), free T3 (17.6ng/dL), and TSH receptor antibody (12 IU/L). Thyroid ultrasound showed mild goiter with 2 nodules, one of which was TIRADS 4 and 1.5cm. This nodule was biopsied and found to be benign. Radioactive iodine uptake scan revealed homogeneous diffuse increased thyroid uptake. The diagnosis of Graves’ disease was made, and the patient was started on propranolol and methimazole with significant improvement of his symptoms and his laboratory tests normalizing. Discussion: Graves' disease is an autoimmune disease, characterized by hyperthyroidism, goiter, occasional orbitopathy and dermopathy. Caused by antibodies against thyroid-stimulating hormone receptors which stimulate thyroid hormone secretion and thyroid growth. Treatment is aimed to decrease thyroid hormone synthesis by either a Thionamide, radioiodine ablation, or surgery. Remission rates with antithyroid drugs average under 40 percent after one to two years of treatment and could exceed 80 percent after 5 to 10 years of treatment. COVID-19 is a multi-system disease, caused by SARS-CoV-2 virus, transmitted by large droplets and small particle aerosols, was declared a pandemic in 2020 and affected millions of people worldwide. There is emerging data showing the association of COVID-19 with various thyroid diseases including thyroiditis and relapse of known Graves' disease after the infection. We present a case of newly diagnosed Graves’ disease after COVID-19 infection in a patient with no personal or family history of such disease which raises the concern of autoimmune pathway activation induced by the infection. The onset of Graves’ disease after COVID-19 infection does not depend on the presence of pre-existing thyroid pathology and in this case responded well to antithyroid medication. Conclusion: COVID-19 can lead to the development of a range of medical illnesses. In patients who develop symptoms of thyrotoxicosis, Graves’ disease should be suspected, investigated, and treated appropriately Presentation: 6/3/2024

9398 Early Identification of Impending Thyroid Storm Leading to Improved Thyrotoxic Induce Cardiomyopathy

Abstract Disclosure: D.H. Sacoto: None. D. Patel: None. A. De Rosairo: None. K. Madani: None. B. Singh: None. A. Bonilla Campos: None. R. Belokovskaya: None. F. Alberto A.: None. Introduction: Heart failure can be the leading presentation in 6% of thyroid storm cases and is the leading cause of death, particularly in elderly patients. However, its importance lies in symptom control and heart function reversibility once the euthyroid state is achieved. We present a caseof thyroid storm-induced atrial fibrillation (Afib) leading to severe systolic dysfunction. Case: A 61-year-old female with a history of Graves’ disease (GD) presented to the ED with two months of palpitations and one week of shortness of breath. There were bibasilar lung crackles, irregular heart rhythm, pedal edema, and thyromegaly at the examination. EKG was consistent with Afib with rapid ventricular response (123-135 beats per minute); She was tachypneic (respiratory rate: 40 per minute) and hypoxemic (87% O2 saturation), which required bilevel positive airway pressure. Otherwise, hemodynamically stable (BP: 127/106 mmHg). Laboratories showed negative troponin T (<0.010 ng/mL, n <0.01 ng/mL). However, elevation of Pro-B-type natriuretic peptide (6000 pg/mL, n <125 pg/mL), an x-ray displaying bibasilar pleural effusions and an echocardiogram demonstrating a severely reduced ejection fraction (EF) (21%, n 50-70%), myocardial perfusion scan was normal. Thyroid evaluation showed a suppressed TSH (<0.01 uIU/mL, n 0.27-4.20 uIU/mL) with elevated free T4 (5.8 ng/dL, n 0.9-1.8 ng/dL), free T3 (202 ng/dL, n 2.0-4.4 ng/dL), and TSI (8.25 IU/L, n 0-0.55 IU/L). A thyroid ultrasound revealed increased vascular flow on the left thyroid lobe. A Burh-Schakowsky score of 45 points was consistent with impending thyroid storm. She was started on methimazole, cholestyramine, and propranolol. Three months follow-up, she was asymptomatic, TSH normalized (4.12 uIU/mL), and mild improvement of cardiac EF 25%. Discussion: A thyroid storm in the setting of GD often presents after precipitating factors such as surgery, infection, or, as in our case, anti-thyroid medication non-compliance. Increased thyroid hormone levels upregulate cardiac β receptors, enhancing sensitivity to sympathetic innervation. These can shorten the refractory period of cardiomyocytes, leading to tachyarrhythmias, with Afib occurring in 20% of patients. Chronic tachycardia finally impairs left ventricle function, with heart failure as an outcome. A high index of suspicion and the ability of early diagnosis of impending thyroid storm is critical since the first laboratory confirmation is often delayed, and second, either anti-thyroid medication, radioactive iodine ablation or thyroidectomy, in addition to non-selective beta-blockers, can reverse cardiac dysfunction and lead to clinical improvement as early as 12 -Twenty-four hours of medical treatment. In our case, the early diagnosis and treatment of thyroid storm, in addition to the rate control prevented a deadly outcome and contributed to the improvement of heart failure. Presentation: 6/1/2024

8747 A Rare Receptor Resistance with Paradoxical Outcomes!

Abstract Disclosure: I. Patoli: None. S. Batool: None. A.S. Gill: None. A. Makdissi: None. Introduction: Resistance to thyroid hormone receptor is an uncommon cause of abnormal TFTs. (1) We present an interesting case of THRB resistance with cardiac arrhythmia (CA). Clinical Case: 46-year-old man with history of atrial fibrillation (Afib) was referred to endocrinology for evaluation of abnormal TFTs and thyroid nodule. He had a recent hospital admission for Afib with rapid ventricular response; 3 years ago, he was treated with amiodarone for 2 months. TFTs revealed normal TSH of 1.375, elevated FT4 of 2.76 (normal ranges 0.55-4.78 and 0.89-1.76, respectively). Neck CT scan showed large peripherally enhancing centrally necrotic mass with calcification encompassing nearly the entirety of left thyroid lobe measuring 2.2 x 3.6 x 4.6 cm. A 0.8 cm hypodensity within right thyroid lobe also visualized. Thyroid ultrasound showed nodules bilaterally with the largest one in the lower pole of left lobe. FNA biopsy showed Bethesda category- II benign, benign appearing follicular cells and abundant colloid. Repeat labs showed similar results with persistently elevated free T4 (2.56) with equilibrium dialysis, normal alpha subunit, normal TSH (2.14) with human anti-mouse antibody (HAMA) antibody was negative. Alpha subunit:TSH ratio was <1. He remained clinically euthyroid over the course of 1.5 year but repeat labs at that time indicated that TSH had increased to 17 with elevated free T4 (2.6) . MRI brain ruled out TSH secreting adenoma. He reported thyroid abnormalities in son and brother but was unable to provide details. He was referred for genetic screening which showed THRB with pathogenic variant: c.9628> G (p.Y321C). Conclusion: THRB resistance is an uncommonly diagnosed modality in endocrinology. The genes encoding thyroid hormone receptors are THRα gene and THRβ gene (2). Patients with inherited THRB pathogenic variants present with resistance to thyroid hormone and often enlarged thyroid gland. Interestingly, despite having receptor resistance, patients may manifest with CA. This is hypothesized to be due to elevated T4 and T3 concentration in the heart which primarily has higher expression of THRA (3). The diagnosis of thyroid hormone resistance is important to avoid treating asymptomatic patients where treatment is not warranted.

6724 A Broken Heart Due to Excess Thyroid

Abstract Disclosure: R. Subramani: None. R. Subramani: None. V. Zeykan: None. Introduction: Tachycardia-induced cardiomyopathy related to thyrotoxicosis is an uncommon yet serious complication affecting fewer than 1% of individuals with hyperthyroidism. Restoring a euthyroid state can potentially reverse the abnormal cardiac structure and function. Here we report a case of tachycardia-induced cardiomyopathy secondary to thyrotoxicosis Case Summary: A 52-year-old woman with a history of hypertension presented with recent-onset exertional dyspnea, a nonproductive cough, and paroxysmal nocturnal dyspnea. On examination, she exhibited tachycardia (heart rate: 150/min), tachypnea, hypertension, and was afebrile. Physical findings included a mildly enlarged, firm, non-tender thyroid gland bilaterally, without exophthalmos or tremors. Auscultation revealed bilateral crackles in the left lower lung fields. Laboratory analysis revealed undetectable TSH (<0.02 uIU/mL), elevated free T4 (5.3 ng/dL), free T3 (16.30 pg/mL), thyroid stimulating immunoglobulin (TSI) at 216%, and NT proBNP at 8528 pg/mL. Neck ultrasound and CT confirmed diffuse enlargement of the thyroid gland. Transthoracic echocardiography (TTE) displayed severely depressed left ventricular systolic function, estimating an ejection fraction (EF) of 25-30%. Initial management involved intravenous beta-blockers for heart rate control, IV Lasix, and IV hydrocortisone. Subsequently, the patient received propylthiouracil, propranolol, and prednisone, resulting in symptomatic improvement. A follow-up TTE after 6 months revealed an improved EF of 50%. Discussion: The pathophysiologic mechanisms underlying thyrotoxic cardiomyopathy encompass several factors, including tachycardia-induced cardiomyopathy, direct myopathic effects induced by the T3 hormone, and concurrent autoimmune myocarditis associated with Graves' disease. Thyroid hormone exerts a comprehensive impact on nearly all tissue and organ systems, heightening basal metabolic rate and subsequently increasing preload, myocardial contractility, and cardiac output. While thyrotoxicosis-related congestive heart failure (CHF) is relatively uncommon among patients hospitalized for acute CHF, addressing hyperthyroidism and CHF through definitive treatment yields a more favorable prognosis compared to cases of acute CHF stemming from other etiologies. The intricate interplay of these mechanisms highlights the importance of a comprehensive approach in managing thyrotoxic cardiomyopathy, emphasizing the need for targeted interventions to address both the underlying thyroid dysfunction and associated cardiac manifestations. Presentation: 6/3/2024

7081 A Spotlight on Marine Lenhart Syndrome

Abstract Disclosure: R. Alshantti: None. A.M. San Hernandez: None. J. Wu: None. C.P. Barsano: None. M.F. Siddiqui: None. Introduction: Marine-Lenhart Syndrome is a rare condition with a prevalence of 0.8-4.1% of cases with Graves’ disease. It is defined by the coexistence of Graves’ disease and autonomously functioning thyroid nodule(s). It is an under-recognized cause of hyperthyroidism. A limited number of cases have been reported in the literature. We report an interesting case of Marine-Lenhart Syndrome characterized by the presence of elevated thyroid stimulating immunoglobulins (TSI) and an autonomous right thyroid nodule. Case Description: A 37-year-old man with a history of hyperthyroidism from Graves’ disease and a right thyroid nodule was referred to endocrinology clinic. He was diagnosed with hyperthyroidism in 2015 at an outside facility. He had elevated thyroid stimulating immunoglobulins (TSI) and a 2.9 cm right thyroid nodule which was biopsied and had benign cytopathology. Hyperthyroidism was treated with methimazole (MMI) but without subsequent remission of Graves’ disease. He ran out of MMI and re-presented with symptomatic hyperthyroidism with fatigue, tremors, and hyperdefecation. There was no ocular involvement or thyroid compressive symptoms. Biochemical work up was consistent with uncontrolled hyperthyroidism (suppressed TSH 0.01 uIU/mL [Ref range: 0.45-5.33], and elevated FT4 2.58 ng/dl [Ref range: 0.70-2.20], elevated free T3 8.7 pg/ml [Ref range: 2.5-3.9], and mildly elevated TSI 0.72 IU/L [Ref range: 0.54 or less]. MMI was therefore reinitiated. Thyroid Uptake scan demonstrated an increased focal 24-hour Iodine-131 uptake of 57% in the right lobe with suppression of the left lobe. Thyroid ultrasound support the finding of large right thyroid nodule (2.3 x 2.4 x 3.9 cm) with diffuse heterogeneous thyroid. The presence of TSI, lack of control of hyperthyroidism for more than 2 years of treatment, and presence of a functioning thyroid nodule raise the suspicion of Marine-Lenhart Syndrome. Indeed, the findings of an autonomously functioning right thyroid nodule with concomitant Graves’ disease establish the diagnosis of Marine-Lenhart Syndrome. The option of RAI ablation vs total thyroidectomy was discussed with the patient. The patient opted for thyroidectomy. Conclusion: Based on studies, approximately 35% of patients with Graves’ disease have thyroid nodule(s) and only 2.7% are functioning adenomas. The combination of positive TSI or TrAb and functioning thyroid nodules has been termed Marine-Lenhart syndrome. The syndrome was named after David Marine and Carl Lenhart who initially described it in 1911. Unlike Graves’ disease, patients with Marine-Lenhart Syndrome have a lower remission rate with thioamides, require definitive treatment with RAI ablation at a high dose or total thyroidectomy, and may easily be misdiagnosed by many endocrinologists. Presentation: 6/2/2024

8471 A Rare Case of Graves' Disease in a Three-Year-Old

Abstract Disclosure: A. Rajesh: None. A. Ravari: None. L.E. Kimball-Ravari: None. H. Roan: None. Graves’ Disease (GD) is an autoimmune disease that causes hyperfunctioning of the thyroid gland which may be triggered by environmental factors such as infection or stress. Though the leading cause of hyperthyroidism in both adult and pediatric populations is GD, it is extremely rare in children under the age of four years old. Some studies show the incidence to be 1 per 1,000,000 cases[1],2. Detecting GD in children early is very important as untreated GD poses a risk for failure to thrive. There have also been cases of young children suffering from psychomotor delays, craniosynostosis, and language delays because their suspected diagnosis of GD had not been detected for one to two years. In this article, we report the case of a previously healthy three-year-old Caucasian female who presented to the pediatric endocrinologist after collapsing from an episode of hypoglycemia; plasma glucose 47 mg/dL (71-180) . The patient was diagnosed with Graves’ Disease due to her significantly elevated free T3 and T4, decreased TSH, positive thyroid peroxidase (TPO) antibodies, and elevated TSIg. She was started on methimazole treatment; however, she did not respond after six months of ATD and underwent total thyroidectomy. Her hypoglycemia was attributed to abnormal proinsulin processing and glucose metabolism, which has been associated with hyperthyroidism; thyroid hormones can produce increased GLUT2 transporters3. This case report demonstrates the importance of recognizing the signs and symptoms of GD early, as well as discuss the importance of increasing the recognition of autoimmune diseases in the pediatric population.

6601 A Case of Recurrent Painless Thyroiditis and Discussion of Management

Abstract Disclosure: M.C. Slack: None. S. Grock: None. Introduction: Painless (silent) thyroiditis is characterized as a subacute and generally self-limited disease process in which patients develop transient thyrotoxicosis, which is often followed by a hypothyroid phase before entering the recovery euthyroid phase. Given high frequency of positive thyroid antibodies, it may be autoimmune-mediated; recurrence is rare. Here we present a case of recurrent painless thyroiditis and discuss management options. Clinical Case: A Korean woman was followed by endocrinology from age 38 to 60 and experienced at least seven episodes of painless thyroiditis over this time. The episodes occurred without an identifiable trigger and were not preceded by viral illness. During episodes she developed palpitations, hair loss, and dyspnea on exertion and biochemical evidence of thyrotoxicosis with TSH suppressed to <0.2 mIU/mL (normal 0.3-4.7) and elevated free T4 levels as high as 5.4 ng/dL (normal 0.8-1.7). TSI, TPO, and TSH receptor antibodies were checked during multiple episodes and resulted negative, though thyroglobulin antibody was significantly elevated. A radioactive iodine uptake scan was obtained during an active episode of thyroiditis and revealed diffusely low uptake. The patient’s episodes lasted approximately two to three months before normalization of her TSH and FT4. She had at least one instance of transient hypothyroidism after thyrotoxicosis with a TSH of 13.2 and FT4 of 0.6 which subsequently normalized 6 weeks later. The patient did not have known cardiovascular disease and DXA scans revealed mild osteopenia with the lowest T-score -1.3. RAI was considered for the patient based on the total number and increasing frequency of her episodes. She ultimately declined treatment with RAI and continues to follow with endocrinology. Clinical Lessons: While the deleterious effects of prolonged hyperthyroidism (e.g. osteoporosis, arrhythmia, cardiovascular disease) are well known, it is unclear what risk recurrent painless thyroiditis episodes pose. As there are no guidelines regarding treatment, clinical gestalt incorporating frequency and duration of episodes, as well as symptoms, is often used to determine if definitive management is indicated. There are case reports in the literature of treatment of recurrent thyroiditis with RAI ablation performed during a euthyroid state, which eliminated recurrence of episodes but did lead to permanent hypothyroidism necessitating hormone replacement. Surgical thyroidectomy may also be considered in select patients. This case highlights the challenges in treating rare cases of recurrent painless thyroiditis given the lack of research or established guidelines. It is reasonable to consider the frequency, severity, and total number of episodes, as well as patient risk factors, symptoms, and preferences when making recommendations regarding management. Presentation: 6/1/2024

6441 Hyperthyroidism in a patient with Lyme disease

Abstract Disclosure: J. Epstein: None. C. Berman: None. Background: Lyme disease is known to cause inflammation in many organs. There are few case reports in the literature that discuss the association between Lyme disease and thyroiditis. This case underscores the need to further research the association between Lyme disease and thyroid physiology. Clinical Case: A 15-year-old female with a history of polycystic kidney disease is referred to a pediatric endocrinologist for primary amenorrhea and hyperthyroidism. Initial thyroid function tests demonstrated suppressed TSH of 0.03 mIU/L with an elevated free T4 level of 4.0 ng/dL and total T3 of 437 ng/dL. The patient was asymptomatic with normal vital signs, and physical exam was normal without goiter, tremor, tongue fasciculations, or exophthalmos. Thyroid ultrasound demonstrated a mildly heterogenous appearance without nodules. Incidentally, Lyme disease was concurrently diagnosed based on a positive screen confirmed with immunoblot. There was no known tick exposure or rash, but the patient had recently spent time outdoors in upstate New York. Doxycycline was started for the treatment of Lyme disease and repeat thyroid tests one week later showed a decrease in free T4 and total T3 levels, although still elevated. Thyroid antibodies including thyroid peroxidase (TPO), thyroglobulin and thyroid-stimulating immunoglobulin (TSI) were negative. After finishing doxycycline treatment, she developed a hypothyroid state with a TSH of 6.39 mIU/L, free T4 of 0.6 ng/dL, and a normal total T3 of 148 ng/dL. Free T4 has since normalized however TSH remains elevated. The patient continues to be monitored closely without pharmacologic treatment. The evolution of this patient’s thyroid function is consistent with thyroiditis and appears similar to the course of Hashitoxicosis, however antibodies remain negative. There is literature that suggests molecular mimicry between Borrelia proteins and thyroid autoantigens due to amino acid sequence homology. Some Borrelial proteins are found to share antigenic properties with multiple thyroid related proteins, specifically the TSH receptor, TPO, thyroglobulin and sodium iodine symporter, potentially leading to thyroiditis. Three case reports describe adults with hyperthyroidism in the setting of Lyme disease, however in these cases thyroid antibodies (TPO +/- thyroglobulin) were positive. Two of these patients were asymptomatic, similar to our patient. This phenomenon has never been described in a pediatric patient and illustrates the need to consider Lyme disease as a potential cause of destructive, transient, thyroiditis. Presentation: 6/1/2024

12199 Uncontrolled Graves Disease Leading To The Development Of Pulmonary Hypertension

Abstract Disclosure: A. Agrawal: None. N. Shaykh: None. C. Marsalisi: None. L. Lam: None. C. Harrison: None. G.Y. Gandhi: None. Introduction: Graves’ disease can cause cardiorespiratory complications by increasing cardiac output, inducing endothelial dysfunction, and increasing the metabolism of intrinsic pulmonary vasodilating substances. Case: A 26-year-old female with a one-year history of Graves’ disease presented with chest pressure, shortness of breath, worsening orthopnea, a 40-pound weight loss, and subjective fevers. Her home methimazole dose was 10 mg daily, which she had missed for four days before admission. Her BP was 153/90 mmHg, heart rate 117 bpm, and temperature 100.7° F. She had mild bilateral proptosis and an enlarged but non-tender thyroid, which caused her difficulty swallowing. TSH was undetectable less than 0.005 mIU/L (0.27-4.2 mIU/L), and thyroid hormone levels were significantly elevated free T4 greater than 7.77 ng/dL (0.8-1.7 ng/dL) and free T3 29.1 pg/mL (2-4.4 pg/mL). TSI was high at 5.66 IU/L (0-0.55 IU/L) as was BNP at 1,642 pg/mL (0-125 pg/mL). Cardiac troponin was 105 ng/dL (less than 14 ng/dL) with a peak of 106 ng/dL. A Burch-Warsofsky score of 50 was highly suggestive of thyroid storm. She initially received 1 mg of IV propranolol, 1,000 mg of PTU, and 4 mg of dexamethasone followed by hydrocortisone 100 mg, methimazole 20, propanol 20 mg, and two doses of SSKI. A transthoracic echocardiogram was remarkable for severe right atrial and ventricular enlargement, and pulmonary artery pressure measured 55 mmHg (normal 20-30 mmHg). Autoimmune testing, including ANA, c-ANCA, p-ANCA, rheumatoid factor, anti-CCP, anti-SS-A, anti-SS-B antibodies, ultrasound for deep vein thrombosis, and ventilation-perfusion scan were negative. There was no history of congenital heart defects or valvulopathy. The patient reached a euthyroid state and was discharged home on methimazole 20 mg daily. Discussion: Although frequently underappreciated, pulmonary hypertension is present in 30 to 65% of Graves’ disease patients when systematically ascertained. Elevated thyroid hormones can increase heart rate, contractility, venous return, and cardiac output. An imbalance between vasoconstriction and vasodilation, along with endothelial dysfunction, can cause pulmonary vascular effects of hyperreactivity, remodeling, and thrombosis. An autoimmune mechanism is plausible due to an association between antithyroid antibodies and pulmonary hypertension. Right heart catheterization remains the gold standard for diagnosis, though in this case, it was not pursued in the acute setting. This case reinforces the importance of screening for pulmonary hypertension in patients with Graves’ disease and possibly normalizing pulmonary hypertension, thereby avoiding irreversible complications. Clinicians should consider reassessing for pulmonary hypertension even after long-term control of the thyrotoxic state, as about 30% of these patients have persistent pulmonary hypertension. Presentation: 6/3/2024

12199 Uncontrolled Graves Disease Leading To The Development Of Pulmonary Hypertension

Abstract Disclosure: A. Agrawal: None. N. Shaykh: None. C. Marsalisi: None. L. Lam: None. C. Harrison: None. G.Y. Gandhi: None. Introduction: Graves’ disease can cause cardiorespiratory complications by increasing cardiac output, inducing endothelial dysfunction, and increasing the metabolism of intrinsic pulmonary vasodilating substances. Case: A 26-year-old female with a one-year history of Graves’ disease presented with chest pressure, shortness of breath, worsening orthopnea, a 40-pound weight loss, and subjective fevers. Her home methimazole dose was 10 mg daily, which she had missed for four days before admission. Her BP was 153/90 mmHg, heart rate 117 bpm, and temperature 100.7° F. She had mild bilateral proptosis and an enlarged but non-tender thyroid, which caused her difficulty swallowing. TSH was undetectable less than 0.005 mIU/L (0.27-4.2 mIU/L), and thyroid hormone levels were significantly elevated free T4 greater than 7.77 ng/dL (0.8-1.7 ng/dL) and free T3 29.1 pg/mL (2-4.4 pg/mL). TSI was high at 5.66 IU/L (0-0.55 IU/L) as was BNP at 1,642 pg/mL (0-125 pg/mL). Cardiac troponin was 105 ng/dL (less than 14 ng/dL) with a peak of 106 ng/dL. A Burch-Warsofsky score of 50 was highly suggestive of thyroid storm. She initially received 1 mg of IV propranolol, 1,000 mg of PTU, and 4 mg of dexamethasone followed by hydrocortisone 100 mg, methimazole 20, propanol 20 mg, and two doses of SSKI. A transthoracic echocardiogram was remarkable for severe right atrial and ventricular enlargement, and pulmonary artery pressure measured 55 mmHg (normal 20-30 mmHg). Autoimmune testing, including ANA, c-ANCA, p-ANCA, rheumatoid factor, anti-CCP, anti-SS-A, anti-SS-B antibodies, ultrasound for deep vein thrombosis, and ventilation-perfusion scan were negative. There was no history of congenital heart defects or valvulopathy. The patient reached a euthyroid state and was discharged home on methimazole 20 mg daily. Discussion: Although frequently underappreciated, pulmonary hypertension is present in 30 to 65% of Graves’ disease patients when systematically ascertained. Elevated thyroid hormones can increase heart rate, contractility, venous return, and cardiac output. An imbalance between vasoconstriction and vasodilation, along with endothelial dysfunction, can cause pulmonary vascular effects of hyperreactivity, remodeling, and thrombosis. An autoimmune mechanism is plausible due to an association between antithyroid antibodies and pulmonary hypertension. Right heart catheterization remains the gold standard for diagnosis, though in this case, it was not pursued in the acute setting. This case reinforces the importance of screening for pulmonary hypertension in patients with Graves’ disease and possibly normalizing pulmonary hypertension, thereby avoiding irreversible complications. Clinicians should consider reassessing for pulmonary hypertension even after long-term control of the thyrotoxic state, as about 30% of these patients have persistent pulmonary hypertension. Presentation: 6/3/2024

7439 Mercury toxicity presenting as Pheochromocytoma

Abstract Disclosure: A. Ansar: None. K. McNerney: None. B.A. Marshall: None. Background: Mercury intoxication is a rare cause of hypertension in children and can mimic other endocrinopathies such as pheochromocytoma. Mercury affects catecholamine metabolism and can cause elevated catecholamine levels, thereby incorrectly suggesting a catecholamine-secreting tumor. Clinical Case: An 8-year-old girl presented to the ED with progressive night sweats, intractable migratory myalgias, hypertension and tachycardia. Patient was in her usual state of health until 2 weeks before presentation when she started to have worsening intermittent pains in her chest, arms, back, and knees. She also experienced restlessness and inability to sleep. On presentation she was hypertensive, with blood pressure of 146/116 mm Hg while calm, heart rate 125 bpm, afebrile. She was anxious, irritable, and seemed uncomfortable. Her skin was dry and rough with a scaly eczematous rash on the arms and legs. She had persistently elevated blood pressure in upper and lower extremities, unremarkable echocardiogram and electrocardiogram, and a normal result on fundoscopic examination. Her initial electrolytes, creatinine, and urinalysis were all normal and remained so on serial evaluations. Urine drug screen was negative. Thyroid function panel showed normal TSH with slightly elevated Free T4 2.28 ng/dL (0.9-1.7), but a normal Free T3 3.9 pg/mL (2.0-4.4) and Free T4 by equilibrium dialysis 1.8 ng/dL (0.8 - 2.0). CT of the chest, abdomen and pelvis was negative and did not show any lesions. Plasma renin activity was 4.6 ng/mL/hour, supine, (<2.0) and plasma aldosterone level < 4.0 ng/dL (< 40 supine) were normal. 24-hour urinary norepinephrine was 90 μg/24h (13-65), epinephrine 37 μg/24h (0.2-10), urine metanephrines 195 μg/24h (18-144), urine normetanephrines 305 μg/24h (29-145), all elevated. Further history taking revealed that patient was taking Ayurvedic supplements prepared by hand by medicinal personnel in India for 3 months prior to presentation. These were stopped 2 weeks prior to her presentation, when she first became symptomatic. Her blood mercury level was 11 ng/mL (n <9), and urinary mercury excretion 67 μg/24 hours (n<10), both obtained 3 weeks after stopping supplementation. She was started on oral chelation therapy with succimer 10 mg/kg/day. Her hypertension was controlled with doxazosin. One week after initiation of therapy, her symptoms improved, and she became normotensive. Her acrodynia and irritability resolved. Urine metanephrine levels will be repeated at upcoming clinic follow up. Conclusion: Mercury toxicity should be considered in the differential of pheochromocytoma to avoid extensive diagnostic testing and morbidity associated with it. Lead, mercury, and arsenic have been detected in traditionally prepared Ayurvedic supplements. A careful history of intake of supplements can be important in cases with unusual symptomatology. Presentation: 6/3/2024

5150 When Few Options Exist: Graves’ Disease Treated with Potassium Iodide and Levothyroxine Block-and-Replace Therapy

Abstract Disclosure: O. Magvanjav: None. S.K. Majumdar: None. Background: In the US, methimazole and propylthiouracil are effective first-line agents for the treatment of Graves’ disease. However, side effects including liver dysfunction may limit their use. In such instances, alternative non-conventional agents such as potassium iodide (KI) may be considered. Here, we present a case of a patient with Graves’ disease successfully treated with KI, drawing on the example of similar treatment experiences in Japan. Clinical case: Our patient is a 29-year-old woman who presented with a 3-week history of palpitations accompanied by fatigue, heat intolerance, itchiness, insomnia, and unintentional weight loss. Exam was notable for tachycardia (135 bmp), elevated blood pressure (BP) (150/81 mmHg), normal temperature, slight thyromegaly, brisk reflexes, mild anxiousness, and tremulousness. She was found to have a TSH of 0.007 mIU/ml (normal: 0.270-4.200 mIU/ml), elevated free T4 of 5.19 ng/dl (normal: 0.80-1.70 ng/dL), total T3 of 330 ng/dl (normal: 72.0-153.0 ng/dl), total T4 of 12.1 ug/dl (normal: 4.5-11.7 ug/dl), and positive antibodies (TSI 443%; TRAB 5.42 IU/L). A thyroid ultrasound showed diffuse hyperemia and a 1.4 cm right lobe TR3 nodule. She had a normal baseline neutrophil count with mild eosinophilia; a baseline hepatic function panel was not obtained. She was started on methimazole 20 mg daily and metoprolol XL 50 mg daily for symptom control. One week into treatment, a hepatic function panel showed elevated liver enzyme levels: AST 70 U/L (normal: 10-35 U/L) and ALT 223 U/L (normal: 10-35 U/L); previous values from 2 years prior were normal. Repeat levels a few days later showed increasing liver enzyme levels (AST 83 U/L; ALT 268 U/L) despite decreasing thyroid hormone levels. Methimazole was stopped, and she was then seen by a gastroenterologist, who concurred with the possibility of an adverse drug reaction to methimazole. She declined definitive therapy with surgery or radioactive iodine therapy and wanted to pursue alternative and less invasive options. Drawing on a previous successful experience from Japan, we initiated her on KI (50 mg twice daily), which resulted in normalization of her thyroid hormones within two weeks of initiation. She subsequently developed hypothyroidism 2 months later, at which point we initiated block-and-replace therapy with the addition of 50 mcg of levothyroxine. Her liver enzymes normalized with normalization of thyroid hormones. Conclusions: We present a patient with symptomatic Graves’ disease who was successfully treated with KI in the setting of limited treatment options, specifically an adverse reaction to methimazole (transaminitis), and who declined both surgery and radioactive iodine. This case demonstrates that KI may be useful in Graves’ disease as either a bridge to more definitive therapy when thioamides are not tolerated, or perhaps as a treatment option for those most likely to go into remission. Presentation: 6/1/2024

Association of Free Thyroxine with Progression-Free Survival in Intermediate and High Risk Differentiated Thyroid Cancer.

Supraphysiologic thyroxine (T4) doses are used in intermediate and high-risk patients with differentiated thyroid cancer (IR/HR-DTC) to suppress tumor progression by thyrotropin (TSH). However, preclinical data suggest that T4 can also act as a growth stimulus for cancer, but there is no clinical evidence supporting this claim. We analyzed the association between free T4 (FT4) and progression-free survival (PFS) in patients with IR/HR-DTC. This longitudinal cohort study, approved by multi-institutional review board, included patients with IR/HR-DTC treated uniformly with total thyroidectomy, radioiodine (RAI), and TSH suppression therapy, with at least three TSH and FT4 values available. Association between FT4 and PFS at landmarks 6, 12, and 18 months was assessed by Kaplan-Meier survival curves, while competing risks were assessed through Cox proportional hazards model. From 739 screened patients 382 met the inclusion criteria and were characterized by a median age of 46 (34-59) years, 64.1% women, treated with a median RAI dosage of 159 (110-410) mCi. During follow up of 7.1 (3.4-12.7) years 34.6% experienced disease progression.Elevated FT4, observed in 29.3% of patients, was not associated with worse PFS (HR 0.9, CI 0.54-1.5, p=0.69), while age (HR 1.02, CI 1.004-1.04, p=0.01), tumor size (HR 1.15, CI 1.04-1.28, p=0.01), and metastases to the lateral neck lymph nodes (HR 2.9, CI 1.7-4.74, p<0.001), bones (HR 4.87, CI 1.79-13.3, p=0.002), and brain (HR 5.56, CI 2.54-12.2, p<0.001) were associated with shorter PFS. Contrary to preclinical evidence, elevated FT4 levels do not affect PFS in patients with IR/HR-DTC.

R243W Mutation in Thyroid Hormone Resistance Syndrome Beta

A three-year-old female with a history of recurrent tonsillitis was investigated for failure to thrive and global developmental delay. Clinically, she had a triangular face with low-set ears and intermittent tachycardia. She had growth failure with her weight under the third centile while her height was within normal limits. Other systemic examinations were unremarkable. The presence of an elevated free T4 (FT4) with an inappropriately high thyroid stimulating hormone (TSH) in this patient raised the clinical suspicion of Thyroid Hormone Resistance Syndrome. DNA sequencing confirmed the diagnosis, which showed R243W gene mutation in Thyroid Hormone Receptor-Beta1 (THRB1).

Unmasking Subacute Thyroiditis in a Young Male with PUO: A Case Report

Pyrexia of unknown origin (PUO) poses a diagnostic challenge, defined as persistent fever exceeding 38.3°C (100°F) without an identified cause after extensive investigation. Subacute thyroiditis (SAT), an uncommon inflammatory condition of the thyroid gland, typically presents with neck pain, thyrotoxic symptoms, and elevated inflammatory markers. However, it rarely manifests as PUO without typical symptoms. We report a case of a 32-year-old Indian male presenting with a 20-day history of persistent fever without localized symptoms, initially treated empirically with antibiotics without improvement. Clinical examination revealed a firm, non-tender goiter, and laboratory investigations showed elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Subsequent thyroid function tests indicated elevated free T4 levels with low TSH, suggestive of thyroiditis, after negative thyroid autoantibodies ruling out Graves' disease. Further investigations including imaging and tests for PUO were negative, prompting an empirical trial of steroid therapy which resulted in rapid clinical improvement. Subsequent thyroid function tests revealed transient hypothyroidism, resolving without intervention. Retrospectively, a diagnosis of subacute thyroiditis was established, highlighting its atypical presentation as PUO. Our case sheds light on the importance of considering uncommon thyroid pathologies in the differential diagnosis of PUO, especially when typical symptoms are absent.

Thyroid hormone enhances efficacy of cisplatin in lung cancer patients via down-regulating GLUT1 expression and reversing the Warburg effect

Cisplatin (CDDP) is a standard non-small cell lung cancer (NSCLC) chemotherapy, but its efficacy is hampered by resistance, partly due to the Warburg effect. This study investigates how thyroid hormones enhance the Warburg effect, increasing sensitivity to cisplatin in lung cancer. Clinical data from advanced NSCLC patients were analyzed based on thyroid hormone levels, categorizing patients into high and low groups. Cellular experiments involved Control, 10uM CDDP, 10uM CDDP + 0.1uM T3, and 10uM CDDP + 0.1uM T4 categories. Parameters were measured in A549 and PC9 lung cancer cells, including proliferation, apoptosis, mitochondrial membrane potential, ROS production, glycolysis enzyme activity, lactic acid level, and ATP content. Gene and protein expressions were assessed using qPCR and Western Blot. Analysis revealed higher FT3 levels correlated with prolonged progression-free survival before chemotherapy (median PFS: high FT3 group = 12.67 months, low FT3 group = 7.03 months, p = 0.01). Cellular experiments demonstrated that thyroid hormones increase lung cancer cell sensitivity to cisplatin, inhibiting proliferation and enhancing efficacy. The mechanism involves thyroid hormones and cisplatin jointly down-regulating MSI1/AKT/GLUT1 expression, reducing lactic acid and glycolysis. This Warburg effect reversal boosts ATP levels, elevates ROS, and decreases MMP, enhancing cisplatin effectiveness in A549 and PC9 cells. In conclusion, elevated free T3 levels in advanced NSCLC patients correlate with prolonged progression-free survival under cisplatin chemotherapy. Cellular experiments reveal that thyroid hormones enhance lung cancer cell sensitivity to cisplatin by reversing the Warburg effect, providing a mechanistic basis for improved therapeutic outcomes.

Resistance To Thyroid Hormone Receptor Alpha Due to Heterozygous Pathogenic Variant in THRA Gene: A Case Report from India

Background: Thyroid Hormone Receptor Alpha (THRA) gene mutation is a thyroid hormone resistance syndrome characterized by non-responsiveness of target tissues to the active form of TH (T3). Clinical Description: We describe a heterozygous missense variant in exon 8 of THRA gene detected in a 2-month-old female with clinical phenotype of hypothyroidism, low free thyroxine, elevated free triiodothyronine &amp; normal levels of thyroid stimulating hormone. Management &amp; Outcome: Clinical improvement in linear growth, motor development domain, hypotonia &amp; constipation were noted with levothyroxine therapy but insufficiencies in cognitive and fine motor skills may remain. Conclusion: THRA gene mutation should be considered in patients with features of clinical hypothyroidism and elevated free T3, decreased/ normal free thyroxine &amp; normal thyroid-stimulating hormone levels.

Pituitary Hyperplasia and Overt Hypothyroidism Induced by Methimazole in an Adolescent Girl with Resistance to Thyroid Hormone Accompanying Hashimoto’s Thyroiditis: A Case Report

We describe a 13-year-old girl who presented at her local hospital with a diffuse goiter and had discrepant thyroid function test (TFT) of elevated free T4 (FT4), free T3 (FT3) levels with mildly elevated thyroid-stimulating hormone (TSH) and a pituitary magnetic resonance imaging (MRI) report of a pituitary hyperplasia. She was referred to our hospital where a repeat TFT found low FT4 and high TSH levels, and high levels of antithyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) antibodies, leading to the diagnosis of Hashimoto’s thyroiditis (HT) with overt primary hypothyroidism. The girl had a good response after daily 100 µg levothyroxine treatment for 8 months with decreased goiter size along with disappearance of the pituitary mass. However, her FT4 and FT3 levels were elevated while the TSH was in the high normal range, although at this time there were no signs of hyperthyroidism. A genetic study confirmed our provisional diagnosis that the patient had a p.Pro453Thr monoallelic loss-of-function mutation of the thyroid hormone receptor beta (THRB) gene, suggesting the diagnosis of coexisting resistance to thyroid hormone-β (RTHβ) and HT in this patient.

The prevalence of thyroid disorders in COVID-19 patients: a systematic review and meta-analysis.

To conduct a systematic review and meta-analysis to evaluate the prevalence of thyroid disorders in COVID-19 patients. Scopus, PubMed, ISI Web of Science, and Google Scholar databases were used in this review. We also consider the results of grey literature. Cohort, cross-sectional, and case-control studies were included. The required data were extracted by the first author of the article and reviewed by the second author. The Pooled prevalence of outcomes of interest was applied using the meta-prop method with a pooled estimate after Freeman-Tukey Double Arcsine Transformation to stabilize the variances. The different thyroid disorders were the main outcomes of this study. The diseases include non-thyroidal illness syndrome, thyrotoxicosis, hypothyroidism, isolated elevated free T4, and isolated low free T4. Eight articles were included in our meta-analysis(Total participants: 1654). The pooled prevalence of events hypothyroidism, isolated elevated FT4, isolated low FT4, NTIS, and thyrotoxicosis were estimated (Pooled P = 3%, 95% CI:2-5%, I2: 78%), (Pooled P = 2%, 95% CI: 0-4%, I2: 66%), (Pooled P = 1%, 95% CI: 0-1%, I2: 0%), (Pooled P = 26%, 95% CI: 10-42%, I2: 98%), and (Pooled P = 10%, 95% CI: 4-16%, I2: 89%), respectively. Thyroid dysfunction is common in COVID-19 patients, with a high prevalence of non-thyroidal illness syndrome (NTIS) and thyrotoxicosis. Our meta-analysis found a 26% prevalence of NTIS and a 10% prevalence of thyrotoxicosis. PROSPERO CRD42022312601.