Preconception Counseling and Care for Pregnant Women with Thyroid Disease

Thyroid disease is associated with adverse maternal and fetal outcomes. Appropriate reference ranges should be used for the interpretation of test results, although universal screening for thyroid dysfunction is not warranted. Overt thyroid dysfunction requires careful consideration of medication adjustments and close monitoring. Mild thyroid hypofunction has been linked to adverse pregnancy outcomes including preterm delivery, and poor neurocognition in the offspring. This review summarizes the most recent evidence on the counseling and management of women with thyroid disease before and during pregnancy and highlights the areas of controversy in need of further research.

The prognostic values of thyroid disorders in predicting COVID-19 composite poor outcomes: A systematic review and meta-analysis

BACKGROUND AND AIMS

In this meta-analysis, we aimed to evaluate the prognostic properties of thyroid disorder during admission on poor prognosis and factors that may influence the relationship in patients with COVID-19.

METHODS

A systematic literature search of PubMed, EBSCO, and CENTRAL was conducted from inception to August 27, 2021. The main exposure was unspecified and specified thyroid disorders-hypothyroidism or hypothyroidism. The outcome of interest was the COVID-19 composite poor outcome that comprises of severity, mortality, ICU admission, and hospitalization.

RESULTS

There were 24,734 patients from 20 studies. Meta-analysis showed that thyroid disorder was associated with composite poor outcome (OR 2.87 (95% CI 2.04-4.04), p < 0.001; I² = 62.4%, p < 0.001). Meta regression showed that age (p = 0.047) and hypertension (p = 0.01), but not gender (p = 0.15), DM (p = 0.10), CAD/CVD (p = 0.38), obesity (p = 0.84), and COPD (p = 0.07) affected the association. Subgroup analysis showed that thyroid disorder increased risk of severe COVID-19 (OR 5.13 (95% CI 3.22-8.17), p < 0.05; I² = 0%, p = 0.70) and mortality (OR 2.78 (95%CI 1.31-5.90), p < 0.05; I² = 80%, p < 0.01). Pooled diagnostic analysis of thyroid disorder yielded a sensitivity of 0.22 (0.13-0.35), specificity of 0.92 (0.87-0.95), and AUC of 0.72. The probability of poor outcome was 38% in patients with thyroid disorder and 15% in patients without thyroid abnormality.

CONCLUSION

On-admission thyroid disorder was associated with poor prognosis in COVID-19 patients.

Mass spectrometry in the diagnosis of thyroid disease and in the study of thyroid hormone metabolism

The importance of thyroid hormones in the regulation of development, growth, and energy metabolism is well known. Over the last decades, mass spectrometry has been extensively used to investigate thyroid hormone metabolism and to discover and characterize new molecules involved in thyroid hormones production, such as thyrotropin-releasing hormone. In the earlier period, the quantification methods, usually based on gas chromatography-mass spectrometry, were complicated and time consuming. They were mainly focused on basic research, and were not suitable for clinical diagnostics on a routine basis. The development of the modern mass spectrometers, mainly coupled to liquid chromatography, enabled simpler sample preparation procedures, and the accurate quantification of thyroid hormones, of their precursors, and of their metabolites in biological fluids, tissues, and cells became feasible. Nowadays, molecules of physiological and pathological interest can be assayed also for diagnostic purposes on a routine basis, and mass spectrometry is slowly entering the clinical laboratory. This review takes stock of the advancements in the field of thyroid metabolism that were carried out with mass spectrometry, with special focus on the use of this technique for the quantification of molecules involved in thyroid diseases.

Frequency, determinants and costs of thyroid function testing in a laboratory serving a large population

OBJECTIVE

To assess the rationale and frequency of thyroid function testing and to analyse factors that influence serum thyrotropin (TSH) levels.

PATIENTS, DESIGN AND MAIN OUTCOME MEASURES

Serum TSH levels were evaluated in a hospital laboratory serving a population of 604 000 in 2018. Patients on medications or with conditions affecting thyroid function were excluded. Frequency of thyroid function testing by age and sex was assessed and the relationship between serum TSH with potential predictor variables was analysed using ordinary least square regression analysis allowing for potential non-linearity.

RESULTS

Twenty-eight percent of the local population had their thyroid function tested at least once in 2018 with significant differences by sex (28.2% women vs 23.4% men) and by age groups, with less than 2% of <16-year-old people and more than 50% of >80-year-old people being tested. Most of the symptoms commonly attributed to thyroid dysfunction were not higher in the thyroid dysfunction groups. Serum TSH levels were higher in older people particularly after the age of 60 years, in women (by 0.1 mIU/L), during the early hours of the morning, and in winter and spring seasons. There was remarkable uniformity in the frequency of subclinical thyroid dysfunction, as well as substantial cost savings, if TSH reference intervals were recalculated across sexes, age groups, time-periods and seasons.

CONCLUSIONS

Serum TSH is frequently tested in the population but is not a good discriminant of symptoms attributed to thyroid dysfunction. Furthermore, considering the influence of factors on TSH reference limits could significantly impact patient care and resource utilisation.

Assessment and treatment of thyroid disorders in pregnancy and the postpartum period

Thyroid disorders are prevalent in pregnant women. Furthermore, thyroid hormone has a critical role in fetal development and thyroid dysfunction can adversely affect obstetric outcomes. Thus, the appropriate management of hyperthyroidism, most commonly caused by Graves disease, and hypothyroidism, which in iodine sufficient regions is most commonly caused by Hashimoto thyroiditis, in pregnancy is important for the health of both pregnant women and their offspring. Gestational transient thyrotoxicosis can also occur during pregnancy and should be differentiated from Graves disease. Effects of thyroid autoimmunity and subclinical hypothyroidism in pregnancy remain controversial. Iodine deficiency is the leading cause of hypothyroidism worldwide. Despite global efforts to eradicate iodine deficiency disorders, pregnant women remain at risk of iodine deficiency due to increased iodine requirements during gestation. The incidence of thyroid cancer is increasing worldwide, including in young adults. As such, the diagnosis of thyroid nodules or thyroid cancer during pregnancy is becoming more frequent. The evaluation and management of thyroid nodules and thyroid cancer in pregnancy pose a particular challenge. Postpartum thyroiditis can occur up to 1 year after delivery and must be differentiated from other forms of thyroid dysfunction, as treatment differs. This Review provides current evidence and recommendations for the evaluation and management of thyroid disorders in pregnancy and in the postpartum period.

Thyroid Status and Brain Circulation: The Rotterdam Study

CONTEXT

Whether thyroid dysfunction is related to altered brain circulation in the general population remains unknown.

OBJECTIVE

We determined the association of thyroid hormones with different markers of brain circulation within community-dwelling elderly people.

METHODS

This was a population-based study of 3 subcohorts of the Rotterdam Study, starting in 1989, 2000, and 2006. A total of 5142 participants (mean age, 63.8 years; 55.4% women), underwent venipuncture to measure serum thyroid-stimulating hormone (TSH) and free thyroxine (FT4). Between 2005 and 2015, all participants underwent phase-contrast brain magnetic resonance imaging to assess global brain perfusion (mL of blood flow/100 mL of brain/minute). Arteriolar retinal calibers were assessed using digitized images of stereoscopic fundus color transparencies in 3105 participants as markers of microcirculation. We investigated associations of TSH, FT4 with brain circulation measures using (non)linear regression models.

RESULTS

FT4 (in pmol/L) levels had an inverse U-shaped association with global brain perfusion, such that high and low levels of FT4 were associated with lower global brain perfusion than middle levels of FT4. The difference in global brain perfusion between high FT4 levels (25 pmol/L) and middle FT4 levels (FT4 = 15 pmol/L; P nonlinearity = .002) was up to -2.44 mL (95% CI -4.31; -0.56). Higher and lower levels of FT4, compared with middle FT4 levels, were associated with arteriolar retinal vessels (mean difference up to -2.46 µm, 95% CI -4.98; 0.05 for lower FT4).

CONCLUSION

These results suggest that thyroid dysfunction could lead to brain diseases such as stroke or dementia through suboptimal brain circulation that is potentially modifiable.

Fetal and Neonatal Thyroid Dysfunction

Fetal and neonatal dysfunctions include rare serious disorders involving abnormal thyroid function during the second half of gestation, which may persist throughout life, as for most congenital thyroid disorders, or be transient, resolving in the first few weeks of life, as in autoimmune hyperthyroidism or hypothyroidism and some cases of congenital hypothyroidism (CH) with the thyroid gland in situ. Primary CH is diagnosed by neonatal screening, which has been implemented for 40 years in developed countries and should be introduced worldwide, as early treatment prevents irreversible neurodevelopmental delay. Central CH is a rarer entity occurring mostly in association with multiple pituitary hormone deficiencies. Other rare disorders impair the action of thyroid hormones. Neonatal Graves' disease (GD) results from the passage of thyrotropin receptor antibodies (TRAbs) across the placenta, from mother to fetus. It may affect the fetuses and neonates of mothers with a history of current or past GD, but hyperthyroidism develops only in those with high levels of stimulatory TRAb activity. The presence of antibodies predominantly blocking thyroid-stimulating hormone receptors may result in transient hypothyroidism, possibly followed by neonatal hyperthyroidism, depending on the balance between the antibodies present. Antithyroid drugs taken by the mother cross the placenta, treating potential fetal hyperthyroidism, but they may also cause transient fetal and neonatal hypothyroidism. Early diagnosis and treatment are key to optimizing the child's prognosis. This review focuses on the diagnosis and management of these patients during the fetal and neonatal periods. It includes the description of a case of fetal and neonatal autoimmune hyperthyroidism.

Anti-thyroid antibodies in the relation to TSH levels and family history of thyroid diseases in young Caucasian women

BACKGROUND

In young women, hypothyroidism is associated with impaired fertility, increased risk of pregnancy loss, premature delivery, and impaired infant neurodevelopment, justifying the need to recognize the risk of hypothyroidism in women of reproductive age. Thus, this study aimed at assessing the frequency of occurrence of antibodies against thyroid peroxidase (TPOAb) and thyroglobulin (TGAb) in young Caucasian women in connection with various confounders.

METHODS

The cross-sectional study involved 366 women aged 18-40 years without a diagnosis of thyroid disease. The personal and family medical history was collected, body mass and height were measured and an ultrasound examination of the thyroid gland was performed. Thyrotropin (TSH), free thyroxine, and free triiodothyronine levels, as well as TPOAb and TGAb titers, were determined by ECLIA.

RESULTS

Two cases of hyperthyroidism (0.5%) and 6 cases (1.6%) of subclinical hypothyroidism were detected. TPOAb was detected in 21 (5.7%) and TGAb in 31 (8.6%) and any of the antibodies in 42 (11.6%) women. Antibodies were more frequent in the subgroup with TSH levels ≥ 2.5 mIU/L than in the subgroup with lower TSH levels (15.5% vs 6.9%, respectively, p<0.05). Any anti-thyroid antibodies were also detected more frequently in the subgroup with TSH levels ≥ 2.5 mIU/L (18.3% vs 10.0%, respectively, p<0.05). Women with the presence of TGAb or seropositive for either TGAb or TPOAb or TPOAb and TGAb antibodies were more likely to have higher TSH levels (OR = 2.48 and OR = 2.02; respectively, p < 0.05 for both). A family history of any thyroid diseases increased the risk of any anti-thyroid antibodies positivity (OR = 1.94; p < 0.05).

CONCLUSIONS

The results of our study suggest that TSH ≥ 2.5 mIU/L and a family history of any thyroid diseases justify screening for anti-thyroid antibodies in women of reproductive age, although the occurrence of these antibodies in the majority of cases is not related to thyroid dysfunction.

Thyroid diseases and fertility disorders - Guidelines of the Polish Society of Endocrinology [Choroby tarczycy a zaburzenia płodności - rekomendacje Polskiego Towarzystwa Endokrynologicznego]

Thyroid hormones influence female fertility, directly stimulating oocyte maturation and regulating prolactin and sex hormone binding globulin (SHBG) concentrations. Hyperthyroidism affects 1-2%, overt hypothyroidism 0.3%, and subclinical hypothyroidism up to 15% of women of childbearing age. Approximately 10% of euthyroid women have elevated concentrations of anti-thyroid peroxidase antibodies (aTPO) and/or anti-thyroglobulin (aTg) antibodies. Hypothyroidism can cause menstrual and ovulation disorders, and impact fertility. Studies carried out to date have not conclusively demonstrated that subclinical hypothyroidism or elevated aTPO/aTg concentrations make it harder to conceive, but they do increase the risk of pregnancy loss. Subclinical hypothyroidism and elevated aTPO/aTg concentrations without thyroid disorders are more common in polycystic ovary syndrome, premature ovarian insufficiency, and idiopathic infertility. Fertility problems are therefore an indication for screening for thyroid diseases (in females as well as in some males). A thyroid disorder diagnosed in subfertile couples should be treated appropriately, especially before attempting assisted reproductive techniques. These recommendations are intended as a guide for the management of thyroid diseases associated with infertility.

The effect of COVID-19 on the presentation of thyroid disease in children

INTRODUCTION

Although studies suggest a potential link between COVID-19 and thyroid dysfunction in adults, there are insufficient data to confirm that association in children, and whether there is any effect on presentation to healthcare services.

AIMS

To identify whether presentations of thyroid dysfunction in children to a tertiary paediatric hospital changed as a result of the COVID-19 pandemic.

METHODS

A retrospective case note review was conducted of all children with abnormal thyroid function tests between 1^st January 2016 and 31^st December 2021 at a tertiary paediatric endocrine centre in the United Kingdom.

RESULTS

Overall, 244 children whose first presentation was within the timeframe of interest were included in this study, with a median age (range) of 11.5 (6.1, 16.8) years. Of these, 43 (18%) were hyperthyroid and 201 (82%) were hypothyroid. The greatest number of thyroid presentations occurred in 2021 (n=60, 25% of total over time period) and the fewest in 2020 (n=10, 4% of total over time period). Prior to this, the median (range) number of presentations per year was 34 (28, 39). There were no statistically significant differences in biochemistry, antibody status or other clinical characteristics between those who presented with hyperthyroidism prior to the pandemic or after. In those with hypothyroidism, baseline biochemistry was similar between the 2 groups, but the presence of other autoimmune conditions was greater pre-pandemic (17.2% vs 15.0%, p=0.03). In addition, patients were more likely to have transient thyroid dysfunction, which did not require treatment post-pandemic (70.0% vs 49.6%, p=0.0086).

CONCLUSIONS

Although overall rates of presentation with thyroid dysfunction have not altered since the first wave of the COVID-19 pandemic, presentations with transient thyroid dysfunction, not requiring ongoing treatment have increased. Further research regarding the relationship between COVID-19 and thyroid function in children and young people, is needed.

Characterisation of the onset and severity of adrenal and thyroid dysfunction associated with CTLA4-related hypophysitis

CONTEXT

The use of the CTLA4 inhibitor, ipilimumab, has proven efficacious in the treatment of melanoma, renal carcinoma and non-small cell lung cancer; however, it is associated with frequent immune-related adverse events (irAE). Ipilimumab-induced hypophysitis (IIH) is a well-recognised and not infrequent endocrine irAE.

OBJECTIVE

To investigate the timing of onset and severity of adrenal and thyroid hormone dysfunction around the development of IIH in patients treated for melanoma.

DESIGN

Aretrospective review of hormone levels in consecutive adult patients treated with ipilimumab (3 mg/kg) for advanced melanoma as monotherapy or in combination with a PD-1 inhibitor.

RESULTS

Of 189 patients, 24 (13%; 13 males; 60.5 ± 12.2 years) presented with IIH at a median of 16.1 (range: 6.7-160) weeks after commencing treatment, occurring in 14 (58%) after the fourth infusion. At the presentation of IIH, corticotroph deficiency was characterised by an acute and severe decrease in cortisol levels to ≤83 nmol/L (≤3 μg/dL) in all patients, often only days after a previously recorded normal cortisol level. Free thyroxine (fT4) levels were observed to decline from 12 weeks prior to the onset of cortisol insufficiency, with the recovery of thyroid hormone levels by 12 weeks after the presentation of IIH. A median fall in fT4 level of 20% was observed at a median of 3 weeks (IQR: 1.5-6 weeks) prior to the diagnosis of IIH.

CONCLUSION

IIH is characterised by an acute severe decline in cortisol levels to ≤83 nmol/L at presentation. A fall in fT4 can herald the development of ACTH deficiency and can be a valuable early indicator of IIH.

Thyroid tantrums in teenagers

Thyroid disorders can be difficult to manage, especially in childhood and adolescence. Sudden fluctuations may occur in thyroid function, due to a variety of physiological, pathological, pharmacological and psychosocial reasons. This communication describes the etiology and management of such conditions. We term these fluctuations as thyroid tantrums, and define them as sudden disruptions in thyroid function, in persons on treatment for hypothyroidism. Thyroid tantrums may be recognized clinically or on the basis of laboratory findings. A pragmatic approach to management, focusing on therapy assessment, testing technique, targeting biomedical illness and training, is suggested in this article.

A Case of Cyclic Neutropenia and Associated Amyloidosis

Cyclic neutropenia has been rarely associated with chronic inflammation and development of reactive AA amyloidosis. We report a family with cyclic neutropenia with associated renal and thyroid amyloid. A 12-year-old female presented with thyromegaly, recurrent aphthous ulcers, severe neutropenia, and renal failure. Renal and thyroid biopsies revealed abundant amyloid deposition. Presence of a heterozygous ELANE c.358 A>T gene mutation p.I120F variant with autosomal dominant inheritance confirmed the diagnosis of cyclic neutropenia. The patient's father also had neutropenia and amyloidosis with renal failure. We started filgrastim to attenuate neutropenia and thereby reduce chronic inflammation and minimize further amyloid deposition.

EVALUATION OF THYROID DISEASE DETECTION AMONG FEMALE POPULATION WITH BREAST PATHOLOGIES IN KVEMO KARTLI REGION (GEORGIA)

to investigate the prevalence of thyroid diseases in women, 35-65 of ages diagnosed with breast pathology in the Kvemo Kartli region and to assess the epidemiological situation; The objectives of the study: to promote the early detection and prevention of thyroid cancer in the Kvemo Kartli region; to reduce the morbidity and mortality rates of breast and thyroid diseases; to evaluate the access and/or barriers to healthcare services to optimize women's health and health care needs. Cross-sectional (prevalence) research was held in several medical institutions in Rustavi with a high number of patients. Consequently, only 103 (53%) of the respondents among the female population with breast pathologies (n=194) in Kvemo Kartli underwent thyroid examination. 169 (87%) of respondents were not informed that early detection of thyroid diseases at breast pathologies is of great importance. Breast cancer was reported in 49 (25%) of respondents, 40 (83%) of respondents belonged to the age category of 50-65 years. Only 18 (37%) of respondents with breast cancer underwent thyroid examination. Respondents utilizing the insurance packages are twice as likely to pass thyroid examination. Most patients were referred for thyroid screening by mammologists (54%) endocrinologists (32%) and family doctors (14%).The women with breast diseases in Kvemo Kartli should be exposed to timely diagnosis and treatment of thyroid diseases by screening; ensuring early detection and prevention of breast and thyroid cancers by eliminating barriers to accessing medical services and early detection of breast and thyroid diseases.

Neurological and gastrointestinal symptoms as an initial presentation of pediatric thyroid storm: report of three cases

OBJECTIVES

Thyroid storm (TS) is a rare but life-threatening condition caused by decompensated hyperthyroidism. There is no consensus on how to diagnose pediatric TS. We report three pediatric cases of TS presenting with central nervous system (CNS) and gastrointestinal (GI) symptoms as the initial presentation of Graves' disease.

CASE PRESENTATION

They were previously healthy adolescents without family history of thyroid disease. CNS symptoms varied from agitation to coma. GI symptoms included abdominal pain, vomiting, and diarrhea. Their laboratory studies revealed thyrotoxicosis and positive result of thyroid-stimulating antibody (TSAb). They were admitted to the intensive care unit (ICU) and received the combination of an antithyroid drug, Lugol's solution, a beta antagonist, and hydrocortisone. The most severe case was a 13 year-old Japanese girl who presented with loss of consciousness and hemodynamic shock. She died after 5 days of intensive treatment.

CONCLUSIONS

Pediatricians should consider TS in the differential diagnosis when a patient exhibits both CNS and GI symptoms.

Importance of Setting Up Reference Intervals and Multiple of Medians (MoM)

I was interested in the article of Kianpour et al. on reference intervals for thyroid hormones during the first trimester of gestation from an area with sufficient iodine level 1. The unavailability of data in this population had triggered this study where 436 pregnant and 444 non-pregnant women were recruited. I appreciate the great effort taken by the authors to recruit such a large population for the study. Following screening as per exclusion criteria 291 pregnant women were eliminated and thus the data of 145 pregnant was included for analysis. However, the article mentions the analysis of samples of 185 patients. The authors have also calculated the multiples of medians (MoM) to unitise different laboratory reports.

Reference Intervals for Thyroid Hormones During the First Trimester of Gestation: A Report from an Area with a Sufficient Iodine Level

A concern was raised 1 regarding the number of pregnant women in the analysis of reference range for the thyroid hormones in pregnancy 2, where we reported 185 cases and it was believed to be 145 cases.

Trends in thyroid function testing, neck ultrasound, thyroid fine needle aspiration, and thyroidectomies in North-eastern Italy

PURPOSE

Evidence of an increased diagnostic pressure on thyroid has emerged over the past decades. This study aimed to provide estimates of a wide spectrum of surveillance indicators for thyroid dysfunctions and diseases in Italy.

METHODS

A population-based study was conducted in North-eastern Italy, including 11.7 million residents (20% of the total Italian population). Prescriptions for TSH testing, neck ultrasound or thyroid fine needle aspiration (FNA), surgical procedures, and drugs for hypo- or hyperthyroidism were extracted from regional health databases. Proportions and rates of selected examinations were calculated from 2010 to 2017, overall and by sex, calendar years, age, and region.

RESULTS

Between 2010 and 2017 in North-eastern Italy, 24.5% of women and 9.8% of men received at least one TSH test yearly. In 2017, 7.1% of women and 1.5% of men were prescribed drugs for thyroid dysfunction, 94.6% of whom for hypothyroidism. Neck ultrasound examinations were performed yearly in 6.9% of women and 4.6% of men, with a nearly two-fold variation between areas. Thyroid FNA and thyroidectomies were three-fold more frequent in women (394 and 85 per 100,000) than in men (128 and 29 per 100,000) with a marked variation between areas. Both procedures decreased consistently after 2013.

CONCLUSIONS

The results of this population-based study describe recent variations over time and between surrounding areas of indicators of 'diagnostic pressure' on thyroid in North-eastern Italy. These results emphasize the need to harmonize practices and to reduce some procedures (e.g., neck ultrasound and total thyroidectomies) in certain areas.

Baseline serum TSH levels predict the absence of thyroid dysfunction in cancer patients treated with immunotherapy

PURPOSE

Immunotherapy against immune checkpoints has significantly improved survival both in metastatic and adjuvant setting in several types of cancers. Thyroid dysfunction is the most common endocrine adverse event reported. Patients who are at risk of developing thyroid dysfunction remain to be defined. We aimed to identify predictive factors for the development of thyroid dysfunction during immunotherapy.

METHODS

This is a retrospective study including a total of 68 patients who were treated with immune checkpoint inhibitors (ICIs) for metastatic or unresectable advanced cancers. The majority of patients were treated with anti-PD1 drugs in monotherapy or in combination with anti-CTLA4 inhibitors. Thyroid function and anti-thyroid antibodies, before starting immunotherapy and during treatment, were evaluated. Thyroid ultrasound was also performed in a subgroup of patients at the time of enrolment in the study.

RESULTS

Eleven out of 68 patients (16.1%) developed immune-related overt thyroid dysfunction. By ROC curve analysis, we found that a serum TSH cut-off of 1.72 mUI/l, at baseline, had a good diagnostic accuracy in identifying patients without overt thyroid dysfunction (NPV = 100%, p = 0.0029). At multivariate analysis, both TSH and positive anti-thyroid antibodies (ATAbs) levels, before ICIs treatment, were independently associated with the development of overt thyroid dysfunction during immunotherapy (p = 0.0001 and p = 0.009, respectively).

CONCLUSIONS

Pre-treatment serum TSH and ATAbs levels may help to identify patients at high risk for primary thyroid dysfunction. Our study suggests guidance for an appropriate timely screening and for a tailored management of thyroid dysfunctions in patients treated with ICIs.

45-Year-Old Woman With Fever and Malaise

A 45-year-old woman presented to our clinic in July 2019 for evaluation of intermittent fever, rigors, diaphoresis, malaise, and urinary symptoms of frequency and urgency of 5 days’ duration. Her history was notable for Graves disease after total thyroidectomy 8 months previously after failed medical management, with no neck swelling or pain at present; an incidentally discovered and resected papillary thyroid microcarcinoma; and hypertension. A reconciled medication list included levothyroxine (125 μg/d), sertraline (100 mg/d), amphetamine-dextroamphetamine (20 mg/d), propranolol (40 mg twice daily), selenium (200 μg/d), and biotin (10 mg/d). She reported no relevant family history or sick contacts, but she may have had tick exposure. Physical examination revealed a temperature of 39.4 °C, heart rate of 64 beats/min, blood pressure of 98/56 mm Hg, weight of 85 kg, exophthalmos and lagophthalmos, and healed Kocher incision with no neck masses or tenderness. Abdominal examination revealed mild suprapubic tenderness. The differential diagnosis included infection (urinary tract infection [UTI], viral syndrome, tick-borne illness) and hyperthyroidism in the setting of ongoing levothyroxine therapy and her history of Graves disease. Subsequent laboratory studies revealed the following (reference ranges provided parenthetically): hemoglobin, 10.7 g/dL (11.6 to 15.0 g/dL); white blood cell count, 16.7 × 10⁹/L (3.4 to 9.6 × 10⁹/L); creatinine, 0.91 mg/dL (0.59 to 1.04 mg/dL); 2 sets of blood cultures with negative results; urine culture growing Escherichia coli, greater than 100,000 colony-forming units per milliliter; and negative results on a tick-borne pathogen panel including Lyme disease serology. Chest radiography revealed no abnormalities. Thyroid function testing (TFT) revealed the following: thyrotropin, 0.01 mIU/L (0.3 to 4.2 mIU/L); free thyroxine (fT4), 1.3 ng/dL (0.9 to 1.7 ng/dL); and free triiodothyronine (fT3) 2.4 pg/mL (2.8 to 4.4 pg/mL). Antimicrobial therapy was initiated for a UTI.

Concurrent thyrolipomatosis and thymolipoma in a patient with myasthenia gravis: a case report and review of the literature

We present a case of a man with a background of myasthenia gravis who presented with a neck lump, which was diagnosed as thyrolipomatosis in continuity with a very large thymolipoma. Following removal of these lesions, the patient's myaesthenic symptoms improved. While thymolipomas are often seen in the context of myasthenia gravis, thyrolipomatosis is a rare entity and to our knowledge the concurrent finding of both lesions with myasthenia gravis has never been reported. We highlight the important imaging features of both entities and the clinical importance of recognising them.

Profiling retrospective thyroid function data in complete thyroidectomy patients to investigate the HPT axis set point (PREDICT-IT)

BACKGROUND

The homeostatic euthyroid set point of the hypothalamus-pituitary-thyroid axis of any given individual is unique and oscillates narrowly within substantially broader normal population ranges of circulating free thyroxine (FT4) and thyroid-stimulating hormone (TSH), otherwise termed 'thyroid function test (TFT)'. We developed a mathematical algorithm codenamed Thyroid-SPOT that effectively reconstructs the personalized set point in open-loop situations and evaluated its performance in a retrospective patient sample.

METHODS

We computed the set points of 101 patients who underwent total thyroidectomy for non-functioning thyroid disease using Thyroid-SPOT on each patient's own serial post-thyroidectomy TFT. Every predicted set point was compared against its respective healthy pre-operative euthyroid TFT per individual and their separation (i.e. predicted-observed TFT) quantified.

RESULTS

Bland-Altman analysis to measure the agreement between each pair of an individual's predicted and actual set points revealed a mean difference in FT4 and TSH of + 3.03 pmol/L (95% CI 2.64, 3.43) and - 0.03 mIU/L (95% CI - 0.25, 0.19), respectively. These differences are small compared to the width of the reference intervals. Thyroid-SPOT can predict the euthyroid set point remarkably well, especially for TSH with a 10-16-fold spread in magnitude between population normal limits.

CONCLUSION

Every individual's equilibrium euthyroid set point is unique. Thyroid-SPOT serves as an accurate, precise and reliable targeting system for optimal personalized restoration of euthyroidism. This algorithm can guide clinicians in L-thyroxine dose titrations to resolve persistent dysthyroid symptoms among challenging cases harbouring "normal TFT" within the laboratory ranges but differing significantly from their actual euthyroid set points.

Transient Hyperthyrotropinemia in Outpatient Children with Acute Infections of the Respiratory System

Background: Diagnostics of thyroid disorders (TD) are frequently based on the measurements of thyroid stimulating hormone (TSH) concentration only. If TSH is outside the reference range, the diagnostic procedure used in patients with TD isintroduced. Observations indicate that in a considerable number of these patients, TD is not confirmed. The aim of the study was to assess the incidence of transient hyperthyrotropinemia in healthy children during acute infections of the respiratory system. Patients and Methods: The study included consecutive children (49 boys and 45 girls), aged 2.2–17.3 years, who visited one General Practitioner (GP) due to respiratory tract infections. The tests: complete blood count (CBC), C-reactive protein (CRP), TSH and FT4 were run on the next day after the visit at the physician’s (initial visit) and ≥2 weeks after recovery. Results: Among these children, elevated TSH values were found in about 10% of patients, and they went back to normal values after recovery. A prospective analysis showed a reduction of TSH values in approx. 65% of all groups and TSH at the follow-up visit was significantly lower. Conclusions: Transient hyperthyrotropinemia was observed in about 10% of children with acute respiratory tract infection. This preliminary finding remains unexplained.

Exposure to the Chinese Great Famine in Early Life and Thyroid Function and Disorders in Adulthood: A Cross-Sectional Study

Background: Malnutrition in early life may permanently change the structure and function of the body, which lead to a number of diseases in adulthood. The effect of famine exposure during the early life on thyroid function and disorders remains unclear. This study investigated the association between exposure to the Great Chinese Famine (1959-1961) in early life and thyroid function and disorders in adulthood. Methods: Nine thousand eight hundred eighty-one subjects with appropriate birth dates derived from the Thyroid disorders, Iodine status, and Diabetes Epidemiological survey were included. Thyroid function and disorders were defined by the test results of blood sample and ultrasonography of all participants. Associations between famine exposure in early life and thyroid function and disorders in adulthood were assessed with binary logistic regression and linear regression. Results: Participants exposed to the Great Chinese Famine during the fetal stage was associated with a higher thyrotropin (TSH) level in adulthood (β = 0.024; p = 0.038), compared with the nonexposed participants. The association was significant among rural participants (β = 0.039; p = 0.02) but not in urban participants (β = 0.005; p = 0.77). Fetal-exposed group did not show a higher risk of thyroid disorders than the age-matched balanced control group, including overt hyperthyroidism, subclinical hyperthyroidism, overt hypothyroidism, subclinical hypothyroidism, autoimmune thyroiditis, and thyroid nodules (p > 0.05). Conclusions: Famine exposure during the fetal stage was associated with a higher TSH level in adulthood. The fetal stage could be the critical period for programming the pituitary-thyroid axis.

Thyroid Disease in Children and Adolescents

The thyroid plays a major role in growth and development, and the hormones it produces can affect many different systems of the body. For this reason, the thyroid should always be at the front of our minds when evaluating children and adolescents. The symptoms of thyroid abnormalities can often be subtle and evolve over time, so we must have a high index of suspicion when providing care for our patients. It is important to understand what can go wrong with the thyroid, how to diagnose thyroid disease, and how to manage thyroid abnormalities. Whether it is structural changes in the thyroid such as goiter or nodules, functional changes that lead to hyperthyroidism or hypothyroidism, or thyroid cancer, a thorough examination and appropriate treatment is essential to maintain optimal cognitive and physical growth throughout childhood and adolescence. This article will discuss the most common thyroid abnormalities, how to diagnose them, and how to treat and manage them in both the short and long term. [Pediatr Ann. 2021;50(4):e143-e147.].

Cushing's Syndrome Effects on the Thyroid

The most known effects of endogenous Cushing’s syndrome are the phenotypic changes and metabolic consequences. However, hypercortisolism can exert important effects on other endocrine axes. The hypothalamus–pituitary–thyroid axis activity can be impaired by the inappropriate cortisol secretion, which determinates the clinical and biochemical features of the “central hypothyroidism”. These findings have been confirmed by several clinical studies, which also showed that the cure of hypercortisolism can determine the recovery of normal hypothalamus–pituitary–thyroid axis activity. During active Cushing’s syndrome, the “immunological tolerance” guaranteed by the hypercortisolism can mask, in predisposed patients, the development of autoimmune thyroid diseases, which increases in prevalence after the resolution of hypercortisolism. However, the immunological mechanism is not the only factor that contributes to this phenomenon, which probably includes also deiodinase-impaired activity. Cushing’s syndrome can also have an indirect impact on thyroid function, considering that some drugs used for the medical control of hypercortisolism are associated with alterations in the thyroid function test. These considerations suggest the utility to check the thyroid function in Cushing’s syndrome patients, both during the active disease and after its remission.

Natural History of Thyroid Disease in Children with PTEN Hamartoma Tumor Syndrome

CONTEXT

Thyroid ultrasound screening is recommended in children with PTEN hamartoma tumor syndrome (PHTS) due to increased risk of thyroid neoplasia, but the natural history of thyroid disease in children with PHTS is unclear.

OBJECTIVE

Determine the prevalence and natural history of thyroid disease in children with PHTS.

METHODS

Retrospective cohort study (1998-2019) in an academic pediatric hospital of individuals with genetically confirmed PHTS diagnosed before age 19 years. Clinical, thyroid ultrasound, and laboratory characteristics are described. Primary outcomes were the prevalence of thyroid nodules ≥10 mm diameter and time course and risk factors for nodule development assessed by Cox regression analysis. Secondary outcomes included thyroid nodule requiring biopsy, other ultrasound findings, and prevalence of autoimmune thyroid disease.

RESULTS

Among 64 subjects with PHTS, 50 underwent thyroid ultrasound. A thyroid nodule ≥10 mm was diagnosed in 22/50 (44%) subjects at median (range) age 13.3 (7.0-22.9) years. Nodules were diagnosed earlier in females than in males (10.8 [7.0-17.9] vs 14.2 [9.9-22.9] years, P = .009). In multivariate analysis, risk of thyroid nodules was significantly associated with female sex (hazard ratio 2.90, 95% CI 1.16-7.27, P = .02) and inversely associated with the presence of neurologic findings of PHTS (HR 0.27, 95% CI 0.10-0.69, P = .007). Abnormal-appearing lymph nodes with echogenic foci were observed by ultrasound in 20% of subjects, but these were not associated with malignancy. Autoimmune thyroid disease was present in 10/33 (30.3%) of subjects in whom it was assessed.

CONCLUSION

Thyroid disease is common in children with PHTS. This study supports current consensus recommendations for ultrasound screening.

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.

Outcomes of the Bethesda system for reporting thyroid cytopathology: Real-life experience

OBJECTIVE

The 2017 revised Bethesda System for Reporting Thyroid Cytopathology (BSRTC) included new malignancy rates for each category as well as new management recommendations. Here, we evaluate the malignancy rate and test performance for BSRTC categories in a middle-sized institution outside the United States (US).

DESIGN

Retrospective single centre case series with chart review.

PATIENTS

All patients who underwent thyroid surgery with a preoperative BSRTC between the years 2010 and 2018 at our institution.

MEASUREMENTS

In order to assess the malignancy rate for each BSRTC, all medical records were reviewed to collect demographics, nodule's size, BSRTC and final pathology.

RESULTS

Three hundred and sixty-four patients were included, with an overall malignancy rate of 34.3%. The malignancy rate for BSRTC categories I-VI was as follows: 13.3%, 5.1%, 25.0%, 24.4%, 91.3% and 95.2%, respectively. The most sensitive test was when BSRTC III-VI were evaluated (91%). Overall best performance (sensitivity, specificity, PPV, NPV and accuracy) was obtained when BSRTC V-VI were grouped together with a substantial decrease when adding BSRTC III-IV (90%, 97%, 94%, 95%, 95% vs, respectively, 91%, 73%, 62%, 95%, 79%, respectively).

CONCLUSIONS

Despite differences from the reported 2017 BSRTC malignancy rates, we demonstrated that the revised 2017 BSRTC management recommendations for thyroid nodules are also valid in smaller non-US centre, supporting its use globally.

Prevalence and course of thyroid dysfunction in neonates at high risk of Graves' disease or with non-autoimmune hyperthyroidism

OBJECTIVE

Neonatal hyperthyroidism may be caused by a permanent non-autoimmune genetic disorder or, more frequently, by maternally transmitted high serum TRAb levels. Variable thyroid dysfunction may be observed in this second context. We aimed to evaluate the prevalence of neonatal non-autoimmune hyperthyroidism and of the different types of thyroid function in neonates with a high risk of hyperthyroidism due to maternal Graves' disease (GD).

DESIGN AND METHODS

This observational cohort study included all neonates identified in the database of a single academic pediatric care center, over a period of 13 years, as having non-autoimmune hyperthyroidism or an autoimmune disorder with high TRAb levels (above 6 IU/L) transmitted by their mothers. Patients were classified as having neonatal hyperthyroidism, hypothyroidism, or euthyroidism with a permanent or transient disorder.

RESULTS

Two of the 34 consecutive neonates selected (6%) had permanent non-autoimmune hyperthyroidism due to germline (n = 1) or somatic (n = 1) mutations of the TSH receptor gene. The patients with high serum TRAb levels at birth had transient hyperthyroidism (n = 23), hypothyroidism (primary n = 2, central n = 3) or persistent euthyroidism (n = 4).

CONCLUSION

These original findings highlight the need for careful and appropriate monitoring of thyroid function in the long term, not only for the rare patients with non-autoimmune neonatal hyperthyroidism, but also for repeat monitoring during the first month of life in neonates with maternally transmitted high TRAb levels, to ensure the early identification of thyrotoxicosis in more than two thirds of cases and to detect primary or central hypothyroidism, thereby potentially decreasing associated morbidity.

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.

The effect of thyroid autoantibody on assisted reproduction technology outcome in euthyroid women: One center experience

Thyroid dysfunction is an important factor to cause failure in assisted reproduction technology (ART) procedures. In this study, we recorded the serum level of thyroid autoantibody to fig. out its relationship with the ART outcome. The results showed that the serum concentrations of TSH had a statistically significant increase between the basal level and the levels at time of serum pregnancy test both in women with and without thyroid autoantibody (p= 0.002 and p=0.019, respectively). Additionally, the TSH level increased significantly in thyroid autoantibody-positive group than those in thyroid autoantibody-negative group during controlled ovarian hyper stimulation (COH) process(p = 0.006). The risk of preterm delivery was lower in thyroid autoantibody-negative group. In sum, the present study provided evidence of an association between thyroid autoantibody and preterm delivery in euthyroid women.

Seasonal Changes of Thyroid Function Parameters in Women of Reproductive Age Between 2012 and 2018: A Retrospective, Observational, Single-Center Study

BACKGROUND

Thyroid function can be influenced by external stimuli such as light and temperature. However, it is currently unknown whether there is seasonal variation of thyroid function in women of reproductive age. Adequate thyroid function in reproductive-aged women is necessary for optimal fetal-maternal outcomes. Therefore, this study aims to evaluate the seasonal changes in levels of thyrotropin (TSH), free triiodothyronine (FT₃), free thyroxine (FT₄), and TSH index (TSHI) in women of reproductive age.

METHODS

A large retrospective study was conducted that included women aged 20-49 years who visited our outpatient or checkup center between 2012 and 2018. Thyroid function was measured using the automated immunochemiluminescent assay kit. Subjects with overt thyroid dysfunction, pregnancy, thyroid disease, cancer, and severe infectious or psychological disease were excluded. Seasonal differences of thyroid function were analyzed using the Kruskal-Wallis test or the analysis of means with transformed ranks. Spearman's correlation was performed to evaluate the association between thyroid function parameters and age. A subset of 181 subjects was included in the longitudinal analyses. Differences in thyroid function between summer and winter were analyzed using the Wilcoxon signed-rank test.

RESULTS

A total of 48,990 women with a median age of 39 years were included. The prevalence of subclinical hypothyroidism was lower in summer but higher in winter (5.6% vs. 7.0%, p < 0.05). The TSH, FT₃, and FT₄ levels and TSHI reached a peak in winter, while they declined to trough in summer. The TSH concentrations (r = 0.044, p < 0.001) and TSHI (r = 0.025, p < 0.001) were positively correlated with age, whereas FT₃ (r = -0.073, p < 0.001) and FT₄ (r = -0.059, p < 0.001) were negatively correlated with age. The associations of thyroid parameters with age were similar between subjects with positive thyroid peroxidase antibody (TPOAb) and those with negative TPOAb. In the matched longitudinal analysis of 181 subjects, no differences were detected in the thyroid parameters between summer and winter.

CONCLUSIONS

This retrospective single-center study showed that thyroid hormone levels and central sensitivity to thyroid hormones are influenced by age and seasonal fluctuations among women of reproductive age, while their impact on reproductive health remains to be elucidated in future studies.

Immune Checkpoint Inhibitors-Related Thyroid Dysfunction: Epidemiology, Clinical Presentation, Possible Pathogenesis, and Management

Immune checkpoint inhibitors (ICIs) are a group of drugs employed in the treatment of various types of malignant tumors and improve the therapeutic effect. ICIs blocks negative co-stimulatory molecules, such as programmed cell death gene-1 (PD-1) and its ligand (PD-L1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), reactivating the recognition and killing effect of the immune system on tumors. However, the reactivation of the immune system can also lead to the death of normal organs, tissues, and cells, eventually leading to immune-related adverse events (IRAEs). IRAEs involve various organs and tissues and also cause thyroid dysfunction. This article reviews the epidemiology, clinical manifestations, possible pathogenesis, and management of ICIs-related thyroid dysfunction.

Thyroid Function in Preterm/Low Birth Weight Infants: Impact on Diagnosis and Management of Thyroid Dysfunction

Maternal thyroid hormone crosses the placenta to the fetus beginning in the first trimester, likely playing an important role in fetal development. The fetal thyroid gland begins to produce thyroid hormone in the second trimester, with fetal serum T4 levels gradually rising to term. Full maturation of the hypothalamic-pituitary-thyroid (HPT) axis does not occur until term gestation or the early neonatal period. Postnatal thyroid function in preterm babies is qualitatively similar to term infants, but the TSH surge is reduced, with a corresponding decrease in the rise in T4 and T3 levels. Serum T4 levels are reduced in proportion to the degree of prematurity, representing both loss of the maternal contribution and immaturity of the HPT axis. Other factors, such as neonatal drugs, e.g., dopamine, and non-thyroidal illness syndrome (NTIS) related to co-morbidities contribute to the "hypothyroxinemia of prematurity". Iodine, both deficiency and excess, may impact thyroid function in infants born preterm. Overall, the incidence of permanent congenital hypothyroidism in preterm infants appears to be similar to term infants. However, in newborn screening (NBS) that employ a total T4-reflex TSH test approach, a higher proportion of preterm babies will have a T4 below the cutoff, associated with a non-elevated TSH level. In NBS programs with a primary TSH test combined with serial testing, there is a relatively high incidence of "delayed TSH elevation" in preterm neonates. On follow-up, the majority of these cases have transient hypothyroidism. Preterm/LBW infants have many clinical manifestations that might be ascribed to hypothyroidism. The question then arises whether the hypothyroxinemia of prematurity, with thyroid function tests compatible with either non-thyroidal illness syndrome or central hypothyroidism, is a physiologic or pathologic process. In particular, does hypothyroxinemia contribute to the neurodevelopmental impairment common to preterm infants? Results from multiple studies are mixed, with some randomized controlled trials in the most preterm infants born <28 weeks gestation appearing to show benefit. This review will summarize fetal and neonatal thyroid physiology, thyroid disorders specific to preterm/LBW infants and their impact on NBS for congenital hypothyroidism, examine treatment studies, and finish with comments on unresolved questions and areas of controversy.

Evaluation and Treatment of Amiodarone-Induced Thyroid Disorders

Amiodarone is a class III antiarrhythmic drug containing 37% iodine by weight, with a structure similar to that of thyroid hormones. Deiodination of amiodarone releases large amounts of iodine that can impair thyroid function, causing either hypothyroidism or thyrotoxicosis in susceptible individuals reflecting ~20% of patients administered the drug. Not only the excess iodine, but also the amiodarone (or its metabolite, desethylamiodarone) itself may cause thyroid dysfunction by direct cytotoxicity on thyroid cells. We present an overview of the epidemiology and pathophysiology of amiodarone-induced thyroid disorders, with a focus on the various forms of clinical presentation and recommendations for personalized management of each form.

Iodine contrast prior to or during pregnancy and neonatal thyroid function: a systematic review

OBJECTIVE

Thyroid dysfunction is a known side effect of iodinated contrast media. There is some evidence to suggest that iodinated contrast media administered to pregnant women may cause thyroid dysfunction not only in themselves but also in their offspring. Here, we systematically evaluated literature on the use of iodinated contrast media prior to or during pregnancy on the offspring's thyroid function.

DESIGN

Systematic review of published literature.

MATERIALS AND METHODS

Relevant studies were identified by PubMed, EMBASE and The Cochrane Library up to June 5, 2020. All study designs, reporting on the foetal or neonatal thyroid function after exposure to iodinated contrast media prior to or during pregnancy, were included. We undertook random effects meta-analysis and pooled the estimates as proportions with 95% CIs.

RESULTS

We identified 402 articles, of which 26 were included. Six studies reported (n = 369) on exposure to iodinated contrast media prior to pregnancy by hysterosalpingography and 20 studies (n = 670) on exposure to these media during pregnancy by amniofetography, urography or CT. There was low to high risk of bias. The proportion of (transient) neonatal thyroid dysfunction was 0.0% (95% CI: 0.0-2.9% based on 3 studies) for hysterosalpingography, 2.25% (95% CI: 0.03-6.55% based on 2 studies) for amniofetography and 0.0% (95% CI: 0.0-0.02% based on 5 studies) for CT. There was a tendency towards an increased risk of thyroid dysfunction with higher amounts of contrast used.

CONCLUSIONS

Exposure to iodinated contrast media prior to or during pregnancy may increase the risk of thyroid dysfunction in offspring. We recommend keeping the amount of contrast used as low as possible.

Spontaneous Thyroid Hemorrhage Caused by Langerhans Cell Histiocytosis: A Case Report and Literature Review

PURPOSE

Langerhans cell histiocytosis (LCH) is a rare clonal disorder of Langerhans antigen-presenting cells. However, thyroid LCH involvement is relatively rare. We present the first case of spontaneous thyroid hemorrhage due to LCH progression and discuss the clinical features, diagnosis, and treatments of thyroid LCH in a literature review.

METHODS

Clinical data were collected. Previously published articles on thyroid LCH involvement were reviewed to assess the clinical features, diagnosis, and treatments for thyroid LCH.

RESULTS

A 54-year-old female presented with a multi-system LCH, affecting the uterus, liver, pituitary gland, and thyroid gland. Clinical stability was achieved after systemic chemotherapy. After 7 years of regular follow up, the patient complained of a sudden painful neck swelling and progressive dyspnea. Computed Tomography revealed bilateral goiter with hematoma, and the patient was diagnosed with spontaneous thyroid bleeding based on her clinical symptoms and radiological findings. The patient was incubated to relieve airway compromise and partial thyroidectomy was performed for definitive treatment. Pathological evaluation further confirmed the diagnosis of thyroid LCH. The patient recovered well after surgery.

CONCLUSION

Spontaneous thyroid bleeding due to thyroid LCH progression is extremely rare. Treatments for LCH vary depending on the severity of the disease. We suggest that, for patients with multi-system LCH with thyroid lesion, long-term active surveillance of thyroid hormone concentrations, and thyroid gland volume is required. Physicians should be alert of the potentially life-threatening spontaneous thyroid hemorrhage when aggravated diffuse goiter and hypothyroidism appear. Further investigation is required to establish the guidelines for thyroid LCH treatment.

Clinical Parameters Are More Likely to Be Associated with Thyroid Hormone Levels than with Thyrotropin Levels: A Systematic Review and Meta-Analysis

Background: Though the functional states of other endocrine systems are not defined on the basis of levels of controlling hormones, the assessment of thyroid function is based on levels of the controlling hormone thyrotropin (TSH). We, therefore, addressed the question as to whether levels of thyroid hormones [free thyroxine (fT4), total triiodothyronine (TT3)/free triiodothyronine (fT3)], or TSH levels, within and beyond the reference ranges, provide the better guide to the range of clinical parameters associated with thyroid status. Methods: A PubMed/MEDLINE search of studies up to October 2019, examining associations of levels of thyroid hormones and TSH, taken simultaneously in the same individuals, with clinical parameters was performed. We analyzed atrial fibrillation, other cardiac parameters, osteoporosis and fracture, cancer, dementia, frailty, mortality, features of the metabolic syndrome, and pregnancy outcomes. Studies were assessed for quality by using a modified Newcastle-Ottawa score. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. A meta-analysis of the associations was performed to determine the relative likelihood of fT4, TT3/fT3, and TSH levels that are associated with the clinical parameters. Results: We identified 58 suitable articles and a total of 1880 associations. In general, clinical parameters were associated with thyroid hormone levels significantly more often than with TSH levels-the converse was not true for any of the clinical parameters. In the 1880 considered associations, fT4 levels were significantly associated with clinical parameters in 50% of analyses. The respective frequencies for TT3/fT3 and TSH levels were 53% and 23% (p < 0.0001 for both fT4 and TT3/fT3 vs. TSH). The fT4 and TT3/fT3 levels were comparably associated with clinical parameters (p = 0.71). More sophisticated statistical analyses, however, indicated that the associations with TT3/fT3 were not as robust as the associations with fT4. Conclusions: Thyroid hormones levels, and in particular fT4 levels, seem to have stronger associations with clinical parameters than do TSH levels. Associations of clinical parameters with TSH levels can be explained by the strong negative population correlation between thyroid hormones and TSH. Clinical and research components of thyroidology currently based on the measurement of the thyroid state by reference to TSH levels warrant reconsideration.

Classification of Thyroid Dysfunction in Pregnant Women Differs by Analytical Method and Type of Thyroid Function Test

CONTEXT

Physiological alterations challenge the assessment of maternal thyroid function in pregnancy. It remains uncertain how the reference ranges vary by week of pregnancy, and how the classification of disease varies by analytical method and type of thyroid function test.

DESIGN

Serum samples from Danish pregnant women (n = 6282) were used for the measurement of thyrotropin (TSH), total and free thyroxine (T4), total and free 3,5,3'-triiodothyronine (T3), and T-uptake using "Method A" (Cobas 8000, Roche Diagnostics). TSH and free T4 were also measured using "Method B" (ADVIA Centaur XP, Siemens Healthineers).

MAIN OUTCOME MEASURES

Pregnancy week- and method-specific reference ranges were established among thyroid antibody-negative women (n = 4612). The reference ranges were used to classify maternal thyroid function, and results were compared by analytical method and type of thyroid function test.

RESULTS

The reference ranges for TSH showed a gradual decrease during pregnancy weeks 4 to 14, a gradual increase was observed for total T4, total T3, and T-uptake, whereas free T4 and free T3 showed less variation. When TSH and free T4 were used, Method A classified 935 (14.9%) with abnormal thyroid function, Method B a total of 903 (14.4%), and the methods agreed on 554 individuals. When TSH and total T4 were used, 947 (15.1%) were classified with abnormal thyroid function, and classifications by either total T4 or free T4 agreed on 584 individuals.

CONCLUSIONS

Even when pregnancy week- and method-specific reference ranges were established, the classification of maternal thyroid dysfunction varied considerably by analytical method and type of thyroid function test.

Thyroid effects of amiodarone: clinical update

PURPOSE OF REVIEW

Amiodarone-induced thyroid dysfunction is well established and commonly encountered but is associated with several diagnostic and management challenges. The present review discusses recent evidence published related to the effects of amiodarone on the thyroid gland and thyroid function.

RECENT FINDINGS

Retrospective studies to evaluate amiodarone-induced thyroid dysfunction in children show the occurrence of potential clinically significant changes within 2 weeks of amiodarone initiation that may not be detected if standard adult guidelines for thyroid hormone monitoring are followed. A small study evaluating beta-glucuronidase activity in amiodarone-induced thyrotoxicosis (AIT) demonstrated higher levels in patients with AIT type 2 compared to type 1. New data have suggested the incidence of agranulocytosis may be higher in patients on thionamides with AIT compared to hyperthyroidism because of other causes. In a small study, investigators demonstrated the use of a combination of intravenous and oral steroids to treat refractory AIT which needs to be evaluated in further controlled trials. Finally, recent data demonstrated a possible mortality benefit of surgery over medical therapy for AIT in patients with moderate to severe reduction in left ventricular ejection fraction.

SUMMARY

Recent research regarding the prevalence, diagnosis, and management of amiodarone-induced thyroid dysfunction were reviewed.

Thyroid function abnormalities and thyroid autoantibodies in Danish pregnant women

OBJECTIVE

Abnormal thyroid function in pregnant women is a matter of concern. Knowledge on the occurrence of known and unidentified thyroid function abnormalities in a large unselected cohort of pregnant women is warranted as part of the debate on benefits and risks of routine testing.

DESIGN

Cohort study.

PARTICIPANTS

A total of 14 323 pregnant women in the North Denmark Region, who had a blood sample drawn as part of the prenatal screening program in early pregnancy (2011-2015).

MEASUREMENTS

TSH, free thyroxine, thyroid peroxidase and thyroglobulin antibodies were measured in the stored blood samples using an automatic immunoassay (ADVIA Centaur XPT, Siemens Healthineers). Cohort-, method- and week-specific reference ranges were used for classification of maternal thyroid function, and a cut-off of 60 U/mL was used for thyroid autoantibodies. Information in Danish nationwide registers was used to identify diagnosed and treated maternal thyroid disease.

RESULTS

Overall, 15.2% had thyroid function abnormalities in the early pregnancy and 14.9% were thyroid peroxidase and/or thyroglobulin antibody positive. Among women with known thyroid disease (n = 365), the frequency of abnormal thyroid function was 45.7%, and 62.8% in women (n = 172) who received current treatment in the pregnancy. When maternal thyroid disease was diagnosed in the years following pregnancy (n = 313), 46.7% had abnormal thyroid function and 54.3% were thyroid peroxidase and/or thyroglobulin antibody positive in the early pregnancy.

CONCLUSION

Thyroid function abnormalities and thyroid autoantibodies were common in Danish pregnant women, particularly in women with known or later diagnosed thyroid disease, which raises concern about inadequately treated and unidentified abnormal thyroid function.