[Thyroid ultrasound and its role in the investigation of thyroid disease]

In Europe thyroid ultrasound has been used at outpatient endocrine clinics since many years, and in southern Sweden only during the last years. Ultrasound has a role in the investigation of Graves' disease, subacute thyroiditis, gestational thyrotoxicosis, postpartum thyroiditis, amiodarone thyrotoxicosis and goiter with or without adenoma, but adenomas are usually investigated by endocrine surgeons in Sweden. If widely used the risk for detection of incidentaloma increases. Indications have to be strictly used to avoid further investigations. If an adenoma is localized, the risk for malignancy and requirement of aspiration is estimated by use of the EU-TIRADS classification based on morphology and size. The aspirate is judged by the Bethesda classification, which determines if further investigation is needed. The use of ultrasound at the outpatient clinic has improved the diagnostic quality and follow-up of thyroid patients.

Two Cases of Thyrotoxicosis and Euglycemic Diabetic Ketoacidosis Under Sodium-glucose Transport Protein 2 Inhibitor Treatment

Thyrotoxicosis and sodium-glucose transport protein 2 inhibitors (SGLT2is) are associated with the induction of euglycemic diabetic ketoacidosis (euDKA). We herein report two cases of euDKA in patients with diabetes mellitus wherein both thyrotoxicosis and SGLT2i treatment were the underlying causes. One patient developed thyrotoxicosis during the course of type 2 diabetes mellitus, whereas the other patient was suspected of developing slowly progressive insulin-dependent diabetes mellitus during the course of Graves' disease. Although such cases are rare, there is some concern that similar cases may occur because of the increased frequency of SGLT2i use in recent years.

[Multimodal anesthesia in a patient with Graves' disease and thyrotoxicosis: A case report]

BACKGROUND

Hyperthyroidism is the increase in the synthesis and secretion of thyroid hormones. It is rare but serious in children and constitutes approximately 5% of all cases; 15% manifests before 10 years of age. The peak of presentation and the majority of cases (80%) are diagnosed around 10-15 years of age. Adolescence is usually the stage with the highest incidence and it is more frequent in women (5:1). Acute thyrotoxic crisis or thyroid storm is rare and only occurs in a poorly controlled hyperthyroid patient or in a hyperthyroid patient undergoing emergency surgery. It is manifested by fever, extreme tachycardia, tachyarrhythmia with atrial fibrillation, vomiting, diarrhea, agitation and mental confusion.

CLINICAL CASE

17-year-old adolescent with Graves' disease with uncontrolled clinical manifestations that did not respond to medical treatment and was scheduled for radical thyroidectomy. 35 points were obtained on the Burch and Wartofsky Scale. It was managed with general anesthesia, reducing stimuli for airway and regional control to reduce surgical stimuli. Adjuvant medications such as magnesium sulfate for intraoperative stability were used.

CONCLUSION

Multimodal anesthesia managed to avoid thyroid storm, postoperative pain, as well as other complications.

Non-diabetic ketoacidosis secondary to primary hyperthyroidism: A case report

INTRODUCTION

There are variable complications of hyperthyroidism, including atrial fibrillation, heart failure, osteoporosis, and thyroid storm. One infrequent complication of hyperthyroidism is non-diabetic ketoacidosis (NDKA). To the best of our knowledge, our case is the third report of NDKA related to thyrotoxicosis.

PATIENT CONCERN

We describe a case of a 41-year-old African lady with no past medical history presented to our hospital with severe abdominal pain and vomiting for three weeks. This was associated with decreased appetite and weight loss.

DIAGNOSIS

Laboratory findings were significant for high anion gap metabolic acidosis, positive ketones in the urine, and high serum B-hydroxybutyrate. The blood glucose readings and HbA1c were within normal limits. Also, serum lactic acid and salicylate levels were within the normal range. The diagnosis of NDKA was made. Later, the thyroid functions test (TFT) confirmed the diagnosis of primary hyperthyroidism.

INTERVENTION AND OUTCOMES

The patient was managed initially with intravenous fluid and antiemetics. Then, she was started on propranolol and carbimazole. After which, her symptoms improved dramatically, and the metabolic acidosis (with serum ketones) were corrected within a few days of starting anti-thyroid medications.

CONCLUSION

Despite its rarity, NDKA can be associated with severe thyrotoxicosis. Vigorous intravenous hydration and anti-thyroid medication are the mainstay treatment. TFT should be requested in a patient with unexplained NDKA.

Thyrotoxicosis following SARS-COV-2 vaccination: a case series and discussion

AIM

To describe a case series of thyrotoxicosis likely triggered by SARS-CoV-2 vaccination and to warn physicians about this potential correlation. To report clinical, laboratory and imaging findings and provide further information that goes in line with the underlying mechanisms.

METHODS

Single-center case series based on all the information collected in the hospital medical records, as well as the temporal sequence between the onset of symptoms and COVID-19 vaccination.

RESULTS

We report 8 cases with thyrotoxicosis after SARS-CoV-2 vaccination. 4 cases of Graves' disease (GD), 2 cases of subacute painful thyroiditis (SAT), 1 case of concurrent GD and SAT and 1 case of atypical subacute thyroiditis. Five patients received BNT162b2 mRNA vaccine, 3 patients 1273 mRNA vaccine. The onset of symptoms following vaccination ranged from 10 to 14 days in six of eight patients and from 7 to 8 weeks in two patients.

CONCLUSIONS

Several hypotheses have been proposed to explain the potential correlation between SARS-CoV-2 vaccination and thyrotoxicosis, including immune system hyper-stimulation, molecular mimicry and Autoimmune/Autoinflammatory Syndrome Induced by Adjuvants (ASIA). We should pay greater attention to thyroid disorders in patients receiving vaccine against SARS-CoV-2.

Silent thyroiditis following vaccination against COVID-19: report of two cases

PURPOSE

It is well established that thyroiditis and other thyroid disorders can be induced by COVID-19 infection, but there is limited information about the autoimmune/inflammatory syndrome induced by adjuvants (ASIA) after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. We report two cases of thyrotoxicosis following SARS-CoV-2 vaccine.

METHODS AND RESULTS

Two young health care peoples (wife and husband) received a first dose of SARS-CoV-2 vaccine, and few weeks later developed clinical manifestations of thyroid hyperactivity, with increased thyroid hormone levels on thyroid function tests, suppressed thyroid-stimulating hormone and negative antithyroid antibodies, despite being healthy before vaccination. They were diagnosed at the 4th week after first dose of SARS-Cov-2 vaccine as silent thyroiditis and followed without treatment, since their symptoms were not severe. At the 6th week, the patients became wholly asymptomatic and their thyroid function returned to normal.

CONCLUSIONS

Thyrotoxicosis can occur after SARS-CoV-2 vaccination probably related to silent thyroiditis.

Neonatal thyrotoxicosis with maternal hypothyroidism

Neonatal Graves' is uncommon, but a potentially fatal condition caused by transplacental transfer of thyroid stimulating immunoglobulin (TSI). It is seen in 1%-5% of infants born to a mother with Graves' disease. Here, we report a unique case of transient neonatal thyrotoxicosis with positive TSI in a premature neonate born to the mother with primary hypothyroidism. A short course of antithyroid drug treatment leads to significant clinical and biochemical improvement followed by complete recovery.

Thyrotoxic periodic paralysis (TPP): assessment in the emergency department

A male patient aged in his early twenties presented to the emergency department (ED) with quadriparesis. He was ordinarily fit and well and had exercised and eaten a carbohydrate rich meal the evening before. His point-of-care venous blood sample on arrival to the ED showed hypokalaemia of 1.6 mmol/L. (normal range=3.5-5.0 mmol/L). He was put on a cardiac monitor and started on an intravenous infusion of potassium chloride. With the benefit of hindsight, his male sex, particular features in his history and his initial ECG all pointed to a differential diagnosis of thyrotoxic periodic paralysis (TPP), although a differential diagnosis of a first attack of familial hypokalaemic paralysis was considered. As urgent thyroid function tests were sent promptly, there was minimal delay in reaching a diagnosis of TPP and promptly starting propranolol as a safe and more effective means of reversing TPP, followed by definitive treatment with carbimazole.

Serum diiodotyrosine - a biomarker to differentiate destructive thyroiditis from Graves' disease

OBJECTIVE

Conventional diagnostic methods are limited in their ability to differentiate destructive thyroiditis from Graves' disease. We hypothesised that serum diiodotyrosine (DIT) and monoiodotyrosine (MIT) levels could be biomarkers for differentiating destructive thyroiditis from Graves' disease.

DESIGN

Patients with destructive thyroiditis (n = 13) and Graves' disease (n = 22) were enrolled in this cross-sectional study.

METHODS

We assayed the serum DIT and MIT levels using liquid chromatography-tandem mass spectrometry. A receiver operating characteristic (ROC) curve analysis was used to determine the sensitivity and specificity of the serum DIT and MIT levels as biomarkers for differentiating destructive thyroiditis from Graves' disease.

RESULTS

The serum DIT and MIT levels were significantly higher in patients with destructive thyroiditis than in those with Graves' disease. The ROC curve analysis showed that the serum DIT levels (≥359.9 pg/mL) differentiated destructive thyroiditis from Graves' disease, significantly, with 100.0% sensitivity and 95.5% specificity (P < 0.001). The diagnostic accuracy of the serum MIT levels (≥119.4 pg/mL) was not as high as that of the serum DIT levels (sensitivity, 84.6%; specificity, 77.3%; P = 0.001).

CONCLUSIONS

The serum DIT levels may serve as a novel diagnostic biomarker for differentiating destructive thyroiditis from Graves' disease.

Thyrotoxic periodic paralysis in two sexagenarian men: A case report

RATIONALE

Thyrotoxic periodic paralysis (TPP) characterized by the triad of muscle paralysis, acute hypokalemia, and the presence of hyperthyroidism is often reported in young adults but rarely reported in age >60 year-old.

PATIENT CONCERNS

Two sexagenarian males (age 61 and 62) presenting to the emergency department with progressive muscle paralysis for hours. There was symmetrical flaccid paralysis with areflexia of lower extremities. Both of them did not have the obvious precipitating factors and take any drugs.

DIAGNOSIS

Their Wayne scores, as an objective index of symptoms and signs associated with thyrotoxicosis, were <19 (7 and 14, respectively). Their blood pressure stood 162/78 and 170/82 mm Hg, respectively. Their thyroid glands were slightly enlarged. Both of them had severe hypokalemia (1.8 and 2.0 mmol/L). Their presumptive diagnosis of mineralocorticoid excess disorders with severe potassium (K+) deficit were made. However, low urine K+ excretion and relatively normal blood acid-base status were suggestive of an intracellular shift of K+ rather than K+ deficit. Hormone studies confirmed hyperthyroidism due to Graves disease.

INTERVENTIONS

A smaller dose of K+ supplementation (only a total of 50 and 70 mmol K+, respectively) were prescribed for the patient.

OUTCOMES

After treatment, their serum K+ levels became normal with a full recovery of muscle strength.

LESSONS

Our 2 cases highlight the fact that thyrotoxic periodic paralysis must be still kept in mind as the underlying cause of hypokalemia with paralysis and hypertension in elderly patients to avoid missing curable disorders.

Poorly Differentiated Thyroid Carcinoma Coexisting with Graves' Disease Involving T3 Thyrotoxicosis due to Increased D1 and D2 Activities

Background: Poorly differentiated thyroid carcinoma is rare and patients are typically euthyroid. We report a novel rare case of poorly differentiated thyroid carcinoma with triiodothyronine (T3) thyrotoxicosis. Patient's Findings: A 77-year-old man presented to Kuma Hospital due to a neck tumor. A thyroid ultrasonography revealed a 220-mL mass in the right lobe. Laboratory data showed low serum thyrotropin (TSH), low free thyroxine (fT4), and high free T3 (fT3) levels. Anti-TSH receptor antibodies and thyroid-stimulating antibodies were positive. 131I scintigraphy showed diffuse uptake only in the left thyroid lobe. The patient underwent a total thyroidectomy and histological examination identified as poorly differentiated thyroid carcinoma. He was diagnosed with poorly differentiated thyroid carcinoma coexisting with Graves' disease. The tumor showed elevated type 1 iodothyronine deiodinases (D1) and type 2 iodothyronine deiodinases (D2) activities compared with that of the left thyroid lobe. Summary and Conclusions: Increased D1 and D2 activities in poorly differentiated carcinoma resulted in T3 toxicosis with a high serum fT3/fT4 ratio.

Identification of Two Different Phenotypes of Patients with Amiodarone-Induced Thyrotoxicosis and Positive Thyrotropin Receptor Antibody Tests

Introduction: Serum thyrotropin (TSH) receptor antibodies (TRAbs) are occasionally found in patients with amiodarone-induced thyrotoxicosis (AIT), and usually point to a diagnosis of type 1 AIT (AIT1) due to Graves' disease (GD). However, the TRAb role and function in AIT have not been clarified. Methods: A retrospective cohort study of 309 AIT patients followed at a single academic center over a 30-year period. AIT TRAb-positive patients (n = 21, 7% of all cases) constituted the study group; control groups consisted of type 2 AIT (AIT2) TRAb-negative patients (n = 233), and 100 non-AIT patients with GD. Clinical and biochemical data at diagnosis and during the course of disease were compared. Histological samples of patients who had total thyroidectomy were reviewed. Stored serum samples were used for a functional assay of TRAb class G immunoglobulins (IgGs) in Chinese hamster ovary (CHO) cells stably transfected with complementary DNA encoding for the TSH receptor. Results: TRAb-positive patients were grouped according to color flow Doppler sonography, radioactive iodine thyroid uptake, and duration of amiodarone therapy before thyrotoxicosis in type 1 (n = 9, 43%; TRAb1) or type 2 (n = 12, 57%; TRAb2) AIT. TRAb1 patients had clinical and biochemical features indistinguishable from GD controls, and were responsive to methimazole. Conversely, TRAb2 patients had clinical features similar to AIT2 controls, and were responsive to glucocorticoids, but not to methimazole. The CHO cell functional assay demonstrated that TRAb1 IgGs had a stimulatory effect on cyclic AMP production, which was absent in TRAb2 IgGs. Pathology in TRAb1 showed hyperplastic thyroid follicles and mild lymphocyte infiltration, reflecting thyroid stimulation. On the contrary, TRAb2 samples revealed follicle destruction, macrophage infiltration, and sometimes fibrosis, consistent with a destructive process. Conclusions: Almost 60% of TRAb-positive AIT patients had a destructive thyroiditis. TRAb-positive tests in AIT patients do thus not necessarily imply a diagnosis of GD and AIT1, and should be evaluated in the clinical and biochemical setting of each AIT patient and confirmed by measuring thyroid-stimulating immunoglobulins.

Thyrotoxic Periodic Paralysis: A Case Report and Literature Review

Thyrotoxic periodic paralysis (TPP) is a rare presentation of thyrotoxicosis most commonly associated with Graves' disease. It is rare in Caucasians, but it affects approximately 2% of Asians (occurring in those of Chinese, Japanese, Vietnamese, Filipino, and Korean descent) with thyrotoxicosis of any cause. Typical thyrotoxic features may be absent despite biochemical thyrotoxicosis. Hypokalemia and muscle paralysis are the result of an acute intracellular shift of potassium and not due to total body potassium deficiency. TPP is a self-limiting condition that is easily corrected by treatment of the thyrotoxicosis. We present a case of a Filipino man, aged 47 years, who presented to the emergency department with acute bilateral lower extremity weakness and hypokalemia who was subsequently diagnosed with TPP due to Graves' disease.

Painless Thyroiditis Presenting with Headache

Although headache attributed to hypothyroidism is coded within The International Classification of Headache Disorders, 3rd edition, an association between headache and thyrotoxicosis (hyperthyroidism) is mentioned only in the appendix. Reports on relevant cases are too scarce to establish a causal relationship. A young man with a history of migraine with aura arrived at our headache clinic with a 10-day history of headache and weight loss. Brain MRI revealed normal findings. Blood tests revealed thyrotoxicosis. A test for thyroid-related antibodies was negative. Thus, the patient was diagnosed with painless thyroiditis. The patient's headache resolved as his thyroid hormone levels decreased. To the best of our knowledge, this is the first reported case of headache exaggerated by painless thyrotoxicosis.

[AMIODARONE-INDUCED THYROTOXICOSIS - RISK FACTORS AND PREDICTORS OF OUTCOME: A RETROSPECTIVE STUDY]

BACKGROUND

Amiodarone induced thyrotoxicosis (AIT) occurs with considerable incidence and is associated with significant morbidity and mortality. Factors that predict poor prognosis in this disease have not yet been sufficiently investigated.

OBJECTIVES

We examined the characteristics and short-term clinical outcomes of patients with AIT (up to six months from diagnosis). We evaluated the relationship between T3 and T4 levels at time of presentation and complications associated with AIT.

METHODS

A retrospective epidemiological study was conducted reviewing all cases diagnosed with thyrotoxicosis and amiodarone consumption of patients treated in the Carmel Medical Center between the years 2004-2008. We examined the characteristics of patients who tend to develop AIT. In addition, we examined whether T3 and T4 levels at the time of presentation were a predictor of a poor prognosis. Three major complications associated with AIT were defined as primary outcomes within six months of diagnosis: 1. mortality; 2. development of AIT-related complications that required hospitalization; 3. the need for thyroidectomy.

RESULTS

A total of 400 patients were diagnosed with thyrotoxicosis and consumed amiodarone. However, only 39 patients met the definition of AIT. The composite outcome of mortality, AIT-related complications and thyroidectomy were found in the vast majority of patients (94.8%, 37 out of 39 participants); 3 (7.6%) died and 35 (89.7%) were hospitalized with AIT-related complications and 8 (20.5%) required thyroidectomy. We found a statistically significant relationship between high T4 levels (above 64.3 mcg/dL or above 3 times the upper limit of the norm) and the composite of two main endpoints: mortality and the need for thyroidectomy in the first half year of diagnosis (P=0.009).

CONCLUSIONS

AIT is associated with significant morbidity and mortality. An elevated level of free T4 reflects the severity of AIT. In patients with significantly increased T4 values, an early surgical intervention should be considered.

Clinical Studies on Potassium Iodide-induced Painless Thyroiditis in 11 Graves' Disease Patients

Objective Painless thyroiditis (PT) is characterized by transient hyperthyroidism with a low ^99mTc uptake. We herein describe 11 cases of PT that occurred during treatment with potassium iodide (KI) for Graves' disease (GD). Methods From August 2016 to December 2018, 11 women with GD who developed PT during treatment with KI were enrolled. Of these patients, 10 discontinued antithyroid drug (ATD) because of side effects and began KI, and 1 patient switched from thiamazole to KI because she was planning a pregnancy. The mean patient age was 40.1 years old. Thyroid function tests, thyroid autoantibodies including anti thyroglobulin antibody (TgAb), anti-thyroperoxidase antibody (TPOAb), and M22-TRAb, and the ^99mTc uptake were evaluated at the time of PT. Results All 11 women patients presented with transient thyrotoxicosis in which ^99mTc scans revealed a low uptake of 0.34±0.15% (normal 0.70-1.02%). M22-TRAb was absent in all cases except for one (2.4 IU/L), whereas TgAb and TPOAb were present in 10 and 6 cases, respectively. Ten patients returned to a euthyroid status without passing through the post-hypothyroid phase, and one patient underwent total thyroidectomy during the euthyroid phase of PT. Only four patients require beta-blocker therapy. All patients with KI-induced PT except 1 displayed GD remission during a mean observation period of 23.3 months, and 1 patient had recurrence of GD after PT. Conclusion We encountered 11 GD patients who developed PT during treatment with KI, which was initiated after ATD had been discontinued due to side effects.

Free triiodothyronine to free thyroxine ratio in the differential diagnosis of thyrotoxicosis and hyperthyroidism: A retrospective study

BACKGROUND

Thyroid ultrasound, thyroid scintigraphy and radioactive iodine uptake (RAIU) tests are helpful in the differential diagnosis of thyrotoxicosis and hyperthyroidism. In the setting where these techniques are unavailable or unusable more accessible, and cheaper techniques would be helpful.

AIMS

We evaluated the capability of free triiodothyronine to free thyroxine ratio (FT3/FT4) to differentiate Graves' Disease (GD) and destructive thyroiditis (DT).

METHODS

In total, 318 patients with GD and 140 patients with DT were included in the study. Patients were assigned to two groups: GD and DT (subacute thyroiditis, painless thyroiditis, postpartum thyroiditis). Serum thyroid-stimulating hormone (TSH), FT4, FT3 levels and FT3/FT4 ratio were evaluated in each group. To obtain the optimal diagnostic cut-off value of FT3, FT4 and FT3/FT4 ratio, ROC curve analysis was performed of all untreated thyrotoxicosis patients.

RESULTS

The optimal FT3/FT4 ratio cut-off value was 2.96, with a sensitivity of 71.7%, the specificity of 88.6%. The area under the ROC curve of the FT3/FT4 ratio regarding the diagnosis of GD was 0.864 (95% CI: 0.830-0.894). The cut-off level of FT3 for GD was determined as 6.6 pg/mL which had a sensitivity of 72.3% and specificity of 68.6% (AUC = 0.771 P < .001). The cut-off level of FT4 for GD was determined as 3.65 ng/dl with a sensitivity of 35.5% and specificity of 83.6% (AUC = 0.615 P < .001). When a high specificity is needed, FT3/FT4 cut-off value increases to 3.63 with 99.3% specificity and 36.5% sensitivity.

CONCLUSIONS

FT3/FT4 ratio helps distinguish GD and DT. In cases of situations where RAIU/scintigraphy and TRAb cannot be studied, the FT3/FT4 ratio is a viable diagnostic tool. Cut-off values with higher specificity can be more helpful in differential diagnosis of GD.

Testing, Monitoring, and Treatment of Thyroid Dysfunction in Pregnancy

Both hyperthyroidism and hypothyroidism can have adverse effects in pregnancy. The most common causes of thyrotoxicosis in pregnancy are gestational transient thyrotoxicosis and Graves' disease. It is important to distinguish between these entities as treatment options differ. Women of reproductive age who are diagnosed with Graves' disease should be counseled regarding the impact of treatment options on a potential pregnancy. Although the absolute risk is small, antithyroid medications can have teratogenic effects. Propylthiouracil appears to have less severe teratogenicity compared to methimazole and is therefore favored during the first trimester if a medication is needed. Women should be advised to delay pregnancy for at least 6 months following radioactive iodine to minimize potential adverse effects from radiation and ensure normal thyroid hormone levels prior to conception. As thyroid hormone is critical for normal fetal development, hypothyroidism is associated with adverse obstetric and child neurodevelopmental outcomes. Women with overt hypothyroidism should be treated with levothyroxine (LT4) to a thyrotropin (thyroid-stimulating hormone; TSH) goal of <2.5 mIU/L. There is mounting evidence for associations of maternal hypothyroxinemia and subclinical hypothyroidism with pregnancy loss, preterm labor, and lower scores on child cognitive assessment. Although there is minimal risk of LT4 treatment to keep TSH within the pregnancy-specific reference range, treatment of mild maternal thyroid hypofunction remains controversial, given the lack of clinical trials showing improved outcomes with LT4 treatment.

Serum thyroid stimulating hormone level for predicting utility of thyroid uptake and scan

BACKGROUND

Thyroid uptake and scan (TUS) is a clinical tool used for differentiation of thyrotoxicosis etiologies. Although guidelines recommend ordering a TUS for evaluation of low TSH levels, no specific value is defined. This study aimed to determine a TSH cutoff at which TUSs yield a greater likelihood of successful determination of etiology to avoid unnecessary testing.

METHODS

This was a retrospective study on 137 patients seen by an endocrinologist who underwent TUS for evaluation of low TSH (<0.4 μU/mL). A receiver operating curve analysis was performed to determine the TSH cutoff with maximal sensitivity and specificity for prediction of diagnostic utility.

RESULTS

Ninety percent of TUSs (n = 123) led to a diagnosis, while 10% (n = 14) were inconclusive or normal. Diagnoses included Graves' diseases (52%), toxic multinodular goiter (19%), thyroiditis (12%), and solitary toxic adenoma (7%). The median TSH value was 0.008 μU/mL (IQR 0.005, 0.011), and the median free T4 value was 1.7 μU/mL (IQR 1.3, 2.8). The ROC analysis produced an area under the curve of 0.86. The optimal TSH cutoff value was 0.02 μU/mL (sensitivity 80%, specificity 93%) for prediction of diagnostic yield.

CONCLUSION

This study demonstrates that TSH is a useful predictor of the utility of TUS in yielding an etiology of thyrotoxicosis. Our analysis showed that TUS had a greater likelihood of determining an etiology when TSH was ≤0.02 μU/mL. This information can help clinicians avoid unnecessary cost and patient time burden when TUS is unlikely to aid in determining the etiology of thyrotoxicosis.

Thyroid Dysfunction in Relation to Immune Profile, Disease Status, and Outcome in 191 Patients with COVID-19

OBJECTIVE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related thyroiditis is increasingly recognized. The role of thyroid autoimmunity and SARS-CoV-2 viral load in SARS-CoV-2-related thyroid dysfunction is unclear. We evaluated the thyroid function of a cohort of coronavirus disease 2019 (COVID-19) patients, in relation to their clinical features, and biochemical, immunological, and inflammatory markers.

METHODS

Consecutive adult patients, without known thyroid disorders, admitted to Queen Mary Hospital for COVID-19 from July 21 to August 21, 2020, were included. Serum levels of thyroid-stimulating hormone (TSH), free thyroxine, free triiodothyronine (fT3), and antithyroid antibodies were measured on admission.

RESULTS

Among 191 patients with COVID-19 (mean age 53.5 ± 17.2 years; 51.8% male), 84.3% were mild, 12.6% were moderate, and 3.1% were severe. Abnormal thyroid function was seen in 13.1%. Ten patients had isolated low TSH, suggestive of subclinical thyrotoxicosis due to thyroiditis, although the contribution of autoimmunity was likely in 2 of them. Autoimmune thyroiditis probably also contributed to subclinical hypothyroidism in another patient. Ten patients had isolated low fT3, likely representing nonthyroidal illness syndrome. Lower SARS-Cov-2 polymerase chain reaction cycle threshold values and elevated C-reactive protein were independently associated with occurrence of low TSH (P = .030) and low fT3 (P = .007), respectively. A decreasing trend of fT3 with increasing COVID-19 severity (P = .032) was found. Patients with low fT3 had more adverse COVID-19-related outcomes.

CONCLUSION

Around 15% of patients with mild to moderate COVID-19 had thyroid dysfunction. There may be a direct effect of SARS-CoV-2 on thyroid function, potentially leading to exacerbation of pre-existing autoimmune thyroid disease. Low fT3, associated with systemic inflammation, may have a prognostic significance.

Two Cases of Thyrotoxicosis due to Redotex Ingestion, a Mexican Weight Loss Drug

BACKGROUND

Redotex™ is a Mexican weight-loss supplement that is not U.S. Food and Drug Administration-approved. It consists of the following five ingredients: tri-iodothyronine 75 μg, atropine 0.36 mg, diazepam 8 mg, aloin 16 mg, and d-norpseudoephedrine 50 mg per tablet. There are few case reports with clinically severe ingestions. We report two cases of clinical thyrotoxicosis due to use of Redotex.

CASE REPORTS

A 29-year-old woman presented to the emergency department (ED) with anxiety and palpitations. She reported taking Redotex daily for 1 week. Her temperature was 37.1°C, blood pressure (BP) was 166/104 mm Hg, and heart rate (HR) was 140 beats/min. Laboratory analysis was significant for a bicarbonate level of 20 mmol/L (reference 22-29 mmol/L), free T4 0.75 ng/dL (reference 0.93-1.70 ng/dL), and thyroid-stimulating hormone (TSH) 0.05 uIU/mL (reference 0.27-4.20 uIU/mL). She was treated with 2 mg i.v. lorazepam and 20 mg oral propranolol. A 37-year-old woman presented with chest pain, palpitations, and nausea after taking Redotex 1 to 2 tablets daily for 6 weeks. Her HR was 134 beats/min and BP was 130/66 mm Hg. Thyroid function tests on initial presentation showed a TSH of 0.013 uU/mL, free T4 of 0.24 ng/dL, and free T3 of >30 pg/mL. She was treated with propranolol 1 mg i.v. twice per day and 2 doses of lorazepam 1 mg. Both patients had resolution of their symptoms. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: When taken chronically and at recommended doses, Redotex can present with clinically significant T3 thyrotoxicosis. This has not been seen in prior reports.