A National Laboratory Perspective: The Impact of the Covid-19 Pandemic on the Management of Patients With Non-Communicable Disease in South Africa: Impact of COVID-19 on patients with noncommunicable diseases

OBJECTIVE

The aim of this study was to determine the impact of the COVID-19 pandemic on test requests for the diagnosis and routine care of patients with various non-communicable diseases (NCD) across South Africa (SA).

METHODS

A retrospective audit of laboratory test requests received from hospital outpatient departments and primary healthcare facilities across SA was performed. The following analytes were studied: glycated hemoglobin (HbA1c), lipids profiles, thyroid-stimulating hormone (TSH), and thyroxine (fT4), as well as triiodothyronine (fT3), serum protein electrophoresis (SPE), serum free light chains (SFLC), and prostate specific antigen (PSA); these tests were used as a proxy of NCD detection and follow-up. Requests received during the 3 waves of the pandemic were compared to requests received within the same period during 2017 - 2019.

RESULTS

During the first wave, requests for all analytes were reduced, with the biggest reduction observed for SPE (- 37%); TSH (- 29%); fT4 (- 28%); and HbA1c (- 25%). Requests received from urban facilities showed a larger decrease compared to those from rural facilities. During the third wave there was an increase in requests for all analytes; the biggest increase observed was for fT3 (21%) and HbA1c (18%).

CONCLUSIONS

The COVID-19 pandemic had a significant impact on the South African population receiving care in the public healthcare sector.

Hyperthyroidism: A Review

Importance

Overt hyperthyroidism, defined as suppressed thyrotropin (previously thyroid-stimulating hormone) and high concentration of triiodothyronine (T3) and/or free thyroxine (FT4), affects approximately 0.2% to 1.4% of people worldwide. Subclinical hyperthyroidism, defined as low concentrations of thyrotropin and normal concentrations of T3 and FT4, affects approximately 0.7% to 1.4% of people worldwide. Untreated hyperthyroidism can cause cardiac arrhythmias, heart failure, osteoporosis, and adverse pregnancy outcomes. It may lead to unintentional weight loss and is associated with increased mortality.

Observations

The most common cause of hyperthyroidism is Graves disease, with a global prevalence of 2% in women and 0.5% in men. Other causes of hyperthyroidism and thyrotoxicosis include toxic nodules and the thyrotoxic phase of thyroiditis. Common symptoms of thyrotoxicosis include anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance. Patients with Graves disease may have a diffusely enlarged thyroid gland, stare, or exophthalmos on examination. Patients with toxic nodules (ie, in which thyroid nodules develop autonomous function) may have symptoms from local compression of structures in the neck by the thyroid gland, such as dysphagia, orthopnea, or voice changes. Etiology can typically be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status. Thyroid scintigraphy is recommended if thyroid nodules are present or the etiology is unclear. Thyrotoxicosis from thyroiditis may be observed if symptomatic or treated with supportive care. Treatment options for overt hyperthyroidism from autonomous thyroid nodules or Graves disease include antithyroid drugs, radioactive iodine ablation, and surgery. Treatment for subclinical hyperthyroidism is recommended for patients at highest risk of osteoporosis and cardiovascular disease, such as those older than 65 years or with persistent serum thyrotropin level less than 0.1 mIU/L.

Conclusions and Relevance

Hyperthyroidism affects 2.5% of adults worldwide and is associated with osteoporosis, heart disease, and increased mortality. First-line treatments are antithyroid drugs, thyroid surgery, and radioactive iodine treatment. Treatment choices should be individualized and patient centered.

Control of Thyroid Dysfunction in Spanish Population Registered in the Primary Care Clinical Database: An Analysis of the Proportion of Patients with Thyrotropin Values Outside the Reference Range

Inadequate control of thyroid dysfunction is common and has deleterious health consequences. Our objective was to determine the prevalence of TSH values outside the reference range, as an indicator of inadequate control of hypothyroidism and hyperthyroidism in patients undergoing treatment for thyroid dysfunction in Spain. An observational, retrospective, non-interventional study was conducted using the Primary Care Clinical Database (BDCAP). Patients treated with thyroid hormone for hypothyroidism and with antithyroid drugs for hyperthyroidism were identified. We assessed serum TSH concentration, considering values from 0.4 to 4.0 mU/l as the reference interval. We found 360 313 people with hypothyroidism on thyroid hormone replacement and 9239 with hyperthyroidism on antithyroid drugs therapy. TSH values outside the reference range in hypothyroid subject were detected in 126 866 (35.20%) people, of whom 107 205 (29.75%) had TSH>4.0 mU/l, suggesting inappropriately low doses of levothyroxine, and 19 661 (5.46%) had TSH<0.4 mU/l, suggesting inappropriate over replacement. In the hyperthyroid group, TSH values outside the reference range were observed in 4252 (46.02%) patients. There were 2833 (30.66%) patients with TSH<0.4 mU/l, suggesting undertreatment, and 1419 (15.36%) with TSH>4.0 mU/l, suggesting overtreatment with antithyroid medication. People over 65 years of age had a lower frequency of undertreatment of hypothyroidism and a lower frequency of overtreatment and undertreatment of hyperthyroidism. In conclusion, our results suggest that inadequate control of thyroid dysfunction, due to its high frequency and its consequences for health, is a public health problem that should be addressed by clinicians and health authorities.

Calcium/calmodulin-dependent kinases can regulate the TSH expression in the rat pituitary

PURPOSE

The endocrine secretion of TSH is a finely orchestrated process controlled by the thyrotropin-releasing hormone (TRH). Its homeostasis and signaling rely on many calcium-binding proteins belonging to the "EF-hand" protein family. The Ca²⁺/calmodulin (CaM) complex is associated with Ca²⁺/CaM-dependent kinases (Ca²⁺/CaMK). We have investigated Ca²⁺/CaMK expression and regulation in the rat pituitary.

METHODS

The expression of CaMKII and CaMKIV in rat anterior pituitary cells was shown by immunohistochemistry. Cultured anterior pituitary cells were stimulated by TRH in the presence and absence of KN93, the pharmacological inhibitor of CaMKII and CaMKIV. Western blotting was then used to measure the expression of these kinases and of the cAMP response element-binding protein (CREB). TSH production was measured by RIA after time-dependent stimulation with TRH. Cells were infected with a lentiviral construct coding for CaMKIV followed by measurement of CREB phosphorylation and TSH.

RESULTS

Our study shows that two CaM kinases, CaMKII and CaMKII, are expressed in rat pituitary cells and their phosphorylation in response to TRH occurs at different time points, with CaMKIV being activated earlier than CaMKII. TRH induces CREB phosphorylation through the activity of both CaMKII and CaMKIV. The activation of CREB increases TSH gene expression. CaMKIV induces CREB phosphorylation while its dominant negative and KN93 exert the opposite effects.

CONCLUSION

Our data indicate that the expression of Ca²⁺/CaMK in rat anterior pituitary are correlated to the role of CREB in the genetic regulation of TSH, and that TRH stimulation activates CaMKIV, which in turn phosphorylates CREB. This phosphorylation is linked to the production of thyrotropin.

Biotin Interference in Assays for Thyroid Hormones, Thyrotropin and Thyroglobulin

Background: Biotin has been reported to interfere with several commonly used laboratory assays resulting in misleading values and possible erroneous diagnosis and treatment. This report describes a prospective study of possible biotin interference in thyroid-related laboratory assays, with a comparison of different commonly used assay platforms. Materials and Methods: Thirteen adult subjects (mean age 45 ± 13 years old) were administered biotin 10 mg/day for eight days. Blood specimens were collected at three time points on day 1 and on day 8 (baseline, two, and five hours after biotin ingestion). Thyrotropin (TSH), free triiodothyronine (fT3), free thyroxine (fT4), total triiodothyronine (TT3), total thyroxine (TT4), thyroxine binding globulin (TBG), and thyroglobulin (Tg) levels were analyzed with four different platforms: Abbott Architect, Roche Cobas 6000, Siemens IMMULITE 2000, and liquid chromatography with tandem mass spectrometry (LC-MS/MS). TSH, fT3, fT4, TT3, and TT4 were measured with Abbott Architect and Roche Cobas 6000. fT3, fT4, TT3, and TT4 were also measured by LC-MS/MS. Tg was measured by Siemens IMMULITE 2000. TBG was assessed with Siemens IMMULITE 2000. Results: Significant changes in TSH, fT4, and TT3 measurements were observed after biotin exposure when the Roche Cobas 6000 platform was used. Biotin intake resulted in a falsely lower Tg level when measurements were performed with Siemens IMMULITE 2000. At the time points examined, maximal biotin interference was observed two hours after biotin exposure both on day 1 and day 8. Conclusions: A daily dose of 10 mg was shown to interfere with specific assays for TSH, fT4, TT3, and Tg. Physicians must be aware of the potential risk of erroneous test results in subjects taking biotin supplements. Altered test results for TSH and Tg can be particularly problematic in patients requiring careful titration of levothyroxine therapy such as those with thyroid cancer.

First Estimation of Reference Intervals for Thyroid-Stimulating Hormone and Thyroid Hormones in Slovenian Population

For thyroid function estimation and clinical decision making, use of appropriate reference intervals for thyroid-stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) is crucial. For each laboratory, establishment of own reference intervals is advised. For the first Slovenian estimation of reference intervals for thyroid hormones a large group of 1722 healthy individuals without thyroid disease was established retrospectively. Hormone analyses were performed on automated analyser Advia Centaur XP Immunoassay System (Siemens Healthineers), which reference intervals for TSH, fT4 and fT3 were 0.55-4.78 mIU/L, 11.5-22.7 pmol/L, and 3.5-6.5 pmol/L, respectively. Statistical analysis followed non-parametric percentile method. Our laboratory reference intervals for TSH, fT4 and fT3 are mostly narrower than intervals given by manufacturer. Median value, lower and upper limit for TSH, fT4 and fT3 were 1.98 (0.59-4.23) mIU/L, 14.5 (11.3-18.8) pmol/L and 4.82 (3.79-6.05) pmol/L, respectively. Most likely, an inclusion of a high number of healthy individuals without thyroid disease was a reason for such results.

Transcription factor immunohistochemistry in the diagnosis of pituitary tumours

OBJECTIVE

The clinical utility and prognostic value of WHO 2017 lineage-based classification of pituitary tumours have not been assessed. This study aimed to (1) determine the clinical utility of transcription factor analysis for classification of pituitary tumours and (2) determine the prognostic value of improved lineage-based classification of pituitary tumours.

METHODS

This was a retrospective evaluation of patients who underwent surgical resection of pituitary tumours at St Vincent's Public and Private Hospitals, Sydney, Australia between 1990 and 2016. Included patients were at least 18 years of age and had complete histopathological data, forming the 'histological cohort'. Patients with at least 12 months of post-surgical follow-up were included in the subgroup 'clinical cohort'. The diagnostic efficacy of transcription factor immunohistochemistry in conjunction with hormone immunohistochemistry was compared with hormone immunohistochemistry alone. The prognostic value of identifying 'higher-risk' histological subtypes was assessed.

RESULTS

There were 171 patient tumour samples analyzed in the histological cohort. Of these, there were 95 patients forming the clinical cohort. Subtype diagnosis was changed in 20/171 (12%) of tumours. Within the clinical cohort, there were 21/95 (22%) patients identified with higher-risk histological subtype tumours. These were associated with tumour invasiveness (P = 0.050), early recurrence (12-24 months, P = 0.013), shorter median time to recurrence (49 (IQR: 22.5-73.0) vs 15 (IQR: 12.0-25.0) months, P = 0.005) and reduced recurrence-free survival (P = 0.031).

CONCLUSIONS

Application of transcription factor analysis, in addition to hormone immunohistochemistry, allows for refined pituitary tumour classification and may facilitate an improved approach to prognostication.

A retrospective study of pituitary-thyroid interaction in patients with first-episode of bipolar disorder type I in Mania State

ABSTRACT

Bipolar disorder (BD)-mania is related to the dysfunction of anterior pituitary gland, but the pituitary-thyroid interaction on the acute stage of BD has been controversial. In order to rule out the effects of drugs, we aimed to determine the upstream interaction of first-episode of BD type I in mania state, and tried to find the relationship between thyroid-stimulating-hormone (TSH) and Prolactin (PRL)This study included 70 real-world patients diagnosed with first-episode BD-mania recuited and 70 healthy controls (HC) matched for age and sex from 2016 to 2017 in the same district of Shanghai. We compared the levels of thyroid hormones and prolactin between the two groups, and linear regression and curve estimation were used for the correlation analysis of TSH and PRLThere were differences in triiodothyronine (TT3), total thyroxin (TT4), and free thyroxine (FT4) concentrations between the groups (P's < .05). After being grouped by sex, higher PRL in the male and female BD-mania subgroup were observed compared to each isosexual HC [(P's < .01, Cohen's d = 0.82/1.08, 95%CI (0.33, 1.31)/(0.58, 1.58)]. Higher FT4 in the male BD-mania group was observed compared to the HC males [(P's  < .01, Cohen's d = 0.90, 95%CI (0.41, 1.39)] while the female BD-mania group showed lower TT3 and TT4 compared to the HC females [(P's  < .01, Cohen's d = 0.93/0.88, 95%CI (0.43, 1.42)/(0.39, 1.37)]. In the female BD-mania group, correlation analysis established an inverse relationship between PRL and TSH (r2 = 0.25, F = 11.11, P < .01).The findings demonstrate that sex impacts the concentration of hormones secreted by the anterior pituitary of patients with first-episode BD-mania. The increased PRL may be a putative mechanism that underlies the onset in female patients with a moderate inverse relationship between TSH and PRL. Thyroid hormones and prolactin levels may be developed as potential markers for identifying BD-manic.

Interference of anti-streptavidin antibodies: More common than we thought? In relation to six confirmed cases

Automated immunoassays are extensively used in routine laboratory diagnostics of endocrine disorders because of their advantages, such as high sensitivity, precision, and specificity. However, these methods are limited by the susceptibility of the immunochemical reaction to various interferences. They may present interferences related to the assay's design, for example, the endogenous presence of anti-streptavidin antibodies (ASA) in platforms that use the biotin-streptavidin interaction. To date, there have been few reports in the literature of interference from endogenous ASA. However, such antibodies would potentially lead to falsely decreased or increased results of hormones that can lead to incorrect diagnoses. We report six patients with unusual thyroid function tests, incongruent to their clinical findings. They present elevated concentrations of total T3 and T4 and TSH values within the reference range when measured at Cobas 8000® e801 module (Roche Diagnostics®). Neither patient had been taking biotin; however, all demonstrated the presence of ASA causing falsely high results on competitive assays and also falsely low results on sandwich assays. The hormone panel was also analyzed in the same samples using a different platform available in our laboratory: Cobas 6000® e601 module (Roche Diagnostics®). Nine samples were sent to an external laboratory to be measured with the chemiluminescent method: ADVIA Centaur® (Siemens® Healthcare Diagnostics). The interference seems to affect e801 module and competitive assays the most without affecting results obtained by this chemiluminescent method. This interference could potentially affect other assays performed on the same platform, such as ATPO and estradiol. Finally, laboratories should suspect the presence of interference when there is no correlation between the hormone profile and the patient's clinic. The biotin neutralization protocol demonstrated its effectiveness to eliminate ASA interference.

Heterophilic antibody interference with TSH measurement on different immunoassay platforms

INTRODUCTION

Interference due to the presence of heterophilic antibodies may lead to falsely low or high analyte concentrations, but falsely elevated values are more common in most immunoassay platforms. We report a case of a 53-y old female patient underwent radical thyroidectomy for thyroid papillary carcinoma and the results of TSH in the Siemens Advia Centaur XP after surgery were not suppressed, ranging from 5.73 and 6.61 μIU/ml.

METHODS

The status of the thyroid was then assessed using 4 assay platforms from Siemens, Abbott, Roche and Beckman.

RESULTS

The results of TSH were 5.52, 0.54, 0.12, and <0.015 μIU/ml, respectively. After the samples were pretreated with the heterophilic antibody blocker, results given by Siemens, Abbott, and Roche showed significant decreases of 0.003, 0.001, and 0.005 μIU/ml, respectively. Therefore, it was confirmed that the presence of heterophilic antibodies in the patient samples interfered with the TSH measurements in multiple assay systems.

CONCLUSIONS

Clinicians must be aware of the possible assay interference, including the measurements of FT4, FT3 and TSH, results may be misleading in the presence of heterophilic antibodies, in particular when the results of thyroid function tests do not fit the patient clinical presentation.

Assessment of Prevalence and Cost of Care Cascades After Routine Testing During the Medicare Annual Wellness Visit

IMPORTANCE

For healthy adults, routine testing during annual check-ups is considered low value and may trigger cascades of medical services of unclear benefit. It is unknown how often routine tests are performed during Medicare annual wellness visits (AWVs) or whether they are associated with cascades of care.

OBJECTIVE

To estimate the prevalence of routine electrocardiograms (ECGs), urinalyses, and thyrotropin tests and of cascades (further tests, procedures, visits, hospitalizations, and new diagnoses) that might follow among healthy adults receiving AWVs.

DESIGN, SETTING, AND PARTICIPANTS

Observational cohort study using fee-for-service Medicare claims data from beneficiaries aged 66 years and older who were continuously enrolled in fee-for-service Medicare between January 1, 2013, and March 31, 2015; received an AWV in 2014; had no test-relevant prior conditions; did not receive 1 of the 3 tests in the 6 months before the AWV; and had no test-relevant symptoms or conditions in the AWV testing period. Data were analyzed from February 13, 2019, to June 8, 2020.

EXPOSURE

Receipt of a given test within 1 week before or after the AWV.

MAIN OUTCOMES AND MEASURES

Prevalence of routine tests during AWVs and cascade-attributable event rates and associated spending in the 90 days following the AWV test period. Patient, clinician, and area-level characteristics associated with receiving routine tests were also assessed.

RESULTS

Among 75 275 AWV recipients (mean [SD] age, 72.6 [6.1] years; 48 107 [63.9%] women), 18.6% (14 017) received at least 1 low-value test including an ECG (7.2% [5421]), urinalysis (10.0% [7515]), or thyrotropin test (8.7% [6534]). Patients were more likely to receive a low-value test if they were younger (adjusted odds ratio [aOR], 1.69 for ages 66-74 years vs ages ≥85 years [95% CI, 1.53-1.86]), White (aOR, 1.32 compared with Black [95% CI, 1.16-1.49]), lived in urban areas (aOR, 1.29 vs rural [95% CI, 1.15-1.46]), and lived in high-income areas (aOR, 1.26 for >400% of the federal poverty level vs <200% of the federal poverty level [95% CI, 1.16-1.37]). A total of 6.1 (95% CI, 4.8-7.5) cascade-attributable events per 100 beneficiaries occurred in the 90 days following routine ECGs and 5.4 (95% CI, 4.2-6.5) following urinalyses, with cascade-attributable cost per beneficiary of $9.62 (95% CI, $6.43-$12.80) and $7.46 (95% CI, $5.11-$9.81), respectively. No cascade-attributable events or costs were found to be associated with thyrotropin tests.

CONCLUSIONS AND RELEVANCE

In this study, 19% of healthy Medicare beneficiaries received routine low-value ECGs, urinalyses, or thyrotropin tests during their AWVs, more often those who were younger, White, and lived in urban, high-income areas. ECGs and urinalyses were associated with cascades of modest but notable cost.

Impact of iodine supplementation during preconception, pregnancy and lactation on maternal thyroid homeostasis and offspring psychomotor development: protocol of the IodineMinho prospective study

BACKGROUND

Iodine deficiency is the most common cause of preventable brain harm and cognitive impairment in children. Portuguese women of childbearing age, pregnant women and their progeny were shown to have inadequate iodine intake. Consequently, the Portuguese Health Authorities have recommended a daily supplementation with 150-200 µg iodine in preconception, pregnancy, and lactation. The IodineMinho study intends to evaluate whether (i) this recommendation impacted on the prevalence of iodine deficiency in pregnant women from the Minho region of Portugal, (ii) the time of initiation of iodine supplementation (if any) influences the serum levels of thyroid hormones at several intervals during pregnancy and (iii) there are serum thyroid-hormone parameters in the 1st trimester of pregnancy that predict psychomotor development of the child at 18 months of age.

METHODS

Most Portuguese women are followed throughout pregnancy in community Family Health Units, where family physicians may choose to follow the National recommendation or other, concerning iodine sufficiency. This study will recruit women (N = 304) who intend to become pregnant or are already pregnant from 10 representative Units. Physician's approach and prescriptions, sociodemographic, nutrition and clinical information will be obtained at baseline and throughout pregnancy. To evaluate endocrine function, blood and urine samples will be collected at recruitment, once in each trimester of pregnancy, at delivery and 3 months after delivery. Breastmilk samples will be collected for iodine and energy content analysis. Children will be evaluated for psychomotor development at 18 months. Maternal thyroid volume will be evaluated by ultrasound scan at baseline, in the 3rd trimester and at 3 months after delivery.

DISCUSSION

Iodine deficiency early during development precludes children from achieving full intellectual capabilities. This protocol describes a study that is innovative and unique in its detailed and comprehensive evaluation of maternal and child endocrine and psychomotor parameters. By evaluating the effectiveness of the iodine supplementation recommendation, it will contribute to the public health systems' efforts to provide excellence in maternal and infant care.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04288531 . Registered 28 February 2020-Retrospectively registered.

Pituitary Gangliocytoma Producing TSH and TRH: A Review of "Gangliocytomas of the Sellar Region"

PURPOSE

Pituitary gangliocytomas (GCs) are rare neuronal tumors that present with endocrinological disorders, such as acromegaly, amenorrhea-galactorrhea syndrome, and Cushing's disease. Most pituitary GCs coexist with pituitary adenomas pathologically and are diagnosed as mixed gangliocytoma-adenomas. Herein, we report a case of 45-year-old man who presented with the syndrome of inappropriate secretion of thyroid-stimulating hormone (SITSH) and discuss the pathogenesis of pituitary GCs.

METHODS

Pituitary magnetic resonance imaging showed an 8-mm homogeneous and poorly enhanced mass inside the pituitary gland. Endoscopic transsphenoidal surgery was performed under a preoperative diagnosis of thyrotroph adenoma. However, the tumor was finally diagnosed as gangliocytoma without an adenomatous component. The tumor was further analyzed via immunohistochemistry and electron microscopy. Additionally, we searched MEDLINE and PubMed for previously published cases of isolated pituitary GCs and analyzed the reported clinicopathological findings.

RESULTS

The patient showed complete clinical and endocrinological recovery after an operation. The tumor was positive for thyrotropin (TSH), TSH-releasing hormone (TRH), Pit-1, GATA-2, and most neuronal markers. Electron microscopy demonstrated the presence of intracytoplasmic secretory granules and neuronal processes. Co-secreting hypothalamic and pituitary hormone inside the tumor indicated autocrine/paracrine endocrinological stimulation.

CONCLUSION

Herein, we report a case of SITSH caused by an isolated pituitary gangliocytoma, expressing both TSH and TRH, which, to our best knowledge, is the first reported case of such a condition. The multidirectional differentiation and multihormonal endocrine characteristics of these tumors indicate that they are a member of neuroendocrine neoplasms, further supporting that they are derived from neural crest cells.

Newborn Screening TSH Values Less Than 15 mIU/L Are Not Associated With Long-term Hypothyroidism or Cognitive Impairment

BACKGROUND

It is unclear whether newborns with mild thyrotropin elevation (mTSHe) are at risk of neurocognitive impairment. We assessed whether mTSHe at birth persists during childhood and compared neurocognitive functioning to siblings.

METHODS

This study encompassed children born in the Auckland region (New Zealand) with a newborn screen TSH level of 8 to 14 mIU/L blood, age 6.9 to 12.6 years at assessment, and their siblings. Thyroid function tests (serum TSH and free thyroxine) and neurocognitive assessments were performed, including IQ via the Wechsler Intelligence Scale for Children, fourth edition.

RESULTS

Ninety-six mTSHe individuals were studied, including 67 children recruited with 75 sibling controls. Mean mTSHe newborn TSH level was 10.1 mIU/L blood and 2.4 mIU/L at assessment (range, 0.8-7.0 mIU/L, serum). Although higher newborn TSH levels in the mTSHe group correlated with lower full-scale IQ scores (r = 0.25; P = .040), they were not associated with the magnitude of the IQ difference within sibling pairs (P = .56). Cognitive scores were similar for mTSHe and controls (full-scale IQ 107 vs 109; P = .36), with a minor isolated difference in motor coordination scores.

CONCLUSIONS

Our data do not suggest long-term negative effects of neonatal mild TSH elevation. TSH elevation below the screen threshold appears largely transient, and midchildhood neurocognitive performance of these children was similar to their siblings. We propose that associations between neonatal mild TSH elevation and IQ are due to familial confounders. We caution against the practice of reducing screening CH cutoffs to levels at which the diagnosis may not offer long-term benefit for those detected.

Interpretation of thyroid function tests during pregnancy

Thyroid hormones are crucial for normal pregnancy and fetal development. Large physiological changes occur during pregnancy, posing challenges for the correct interpretation of thyroid function tests. TSH concentrations are the principal first test to rule out thyroid disease taking into account trimester-specific reference ranges. Free T4 (FT4) measurements by immuno-assays may be subject to interference by endogenous and exogenous factors. The relevance of measuring free T3 (FT3) during pregnancy is unclear. Thyroid autoimmunity is well-reflected by the presence of antibodies against TPO. TPO-antibody positivity is associated with an increased risk of adverse pregnancy outcomes.

Perinatal risk factors for congenital hypothyroidism: A retrospective cohort study performed at a tertiary hospital in China

Congenital hypothyroidism (CH) is one of the most common neonatal endocrine diseases. This retrospective cohort study aimed to identify the potential perinatal risk factors for CH and to differentiate between transient and permanent CH (TCH and PCH, respectively) as well as determine their prevalence in a southeastern Chinese population.This study was based on an 18-year surveillance of a neonatal CH screening program in a large tertiary hospital. A retrospective review of the maternal and neonatal perinatal exposures was conducted.Of the 205,834 newborns screened between 2000 and 2018, 189 were diagnosed with CH (1/1089). Among the 131 CH patients who again underwent thyroid function testing (TFT) after discontinuation of levothyroxine at the age of 3 years, 61 (46.6%) were diagnosed with PCH and 70 (53.4%) were diagnosed with TCH. In the maternal characteristics model, women aged 35 years or older and those who had thyroid disease and/or diabetes mellitus during pregnancy had increased risk of having an offspring with CH (P = .001, .000, and .001, respectively). Significant associations were found with regard to parity and the risk of CH in the offspring (P = .000). In the neonatal characteristics model, infants with female sex, preterm birth, post-term birth, low birth weight, other birth defects, and those born as part of multiple births (P = .011, .034, .001, .000, .000, and .003, respectively) had increased risk of CH. The rate of newborns with other birth defects was higher in the PCH group than that in the TCH group (P = .008), whereas the rate of maternal thyroid disease, newborns with low birth weight, and newborns with preterm birth was higher in the TCH group than that in the PCH group (P = .041, .020, and .013, respectively). The levothyroxine dose (μg/kg/day) at 1 year, 2 years, and 3 years old was significantly lower in the TCH group than that in the PCH group (P = .000, .000, and .000, respectively).Perinatal factors should be considered during the diagnosis and treatment of CH.

Reusable on-plate immunoprecipitation method with covalently immobilized antibodies on a protein G covered microtiter plate

Covalent immobilization of antibodies to protein G beads is a basic molecular biology method, although the beads present poor recovery results. Our aim was to reuse the immobilized antibody-protein G complex on a very small scale, therefore we optimized the crosslinking procedure to be used on the wells of a standard 96-well microplate. The method used involves the affinity binding of the antibody to the protein G surface, followed by the immobilization step using different crosslinking reagents, DMP and BS³, quenching the crosslinking reaction, and binding the antibody-specific antigen. By scaling down the procedure, we were able to reuse the anti-EGFR crosslinked wells more than 20 times. This method can be used to perform assays on a wide range of solid supports containing the protein G in an immobilized form, including functionalized nanosensors, for immunoprecipitation, protein and cell lysate purification, target protein enrichment.

Sustained attention in school-age children with congenital hypothyroidism: Influence of episodes of overtreatment in the first three years of life

INTRODUCTION

Children with congenital hypothyroidism (CH) are at risk of developing mild cognitive impairment despite normal overall intellectual performance. These deficits may be caused by disease-related and treatment-related factors. This study explores the impact of abnormal thyroid function during the first 3 years of life on attention performance at school age.

METHODS

We included 49 children diagnosed with CH and receiving treatment for the condition: 14 boys (mean age 9.5±2.8 years) and 35 girls (9.6±2.6 years). The number of episodes of normal, under-, and overtreatment were estimated based on TSH levels during their first 3 years of life (at 12, 18, 24, 30, and 36 months). Children were assessed using a computerised version of a Sustained attention test. General linear models were calculated with the attention index as the dependent variable and sex, aetiology, and number of episodes of normal, under-, and overtreatment as independent variables.

RESULTS

Higher numbers of episodes of overtreatment (low TSH level) were associated with poorer attention performance at school age (P=.005, r=-0.45).

CONCLUSIONS

Children with CH should be monitored closely during the first 3 years of life in order to prevent not only hypothyroidism but also any adverse effects of overtreatment that may affect attentional function at school age.

Trust your Endocrinologist - Report and Recommendations on the Ordering of Reverse T3 Testing

Laboratory testing for markers of thyroid function is essential for the diagnosis of thyroid disease, yet, the landscape of thyroid function testing is complex and inappropriate test orders are common. Reverse T3 (rT3) is frequently seen on thyroid function testing menus as a marker of nonthyroidal illness. However, the diagnostic utility of rT3 for this indication is questionable, and testing of rT3 is not recommended by any professional practice guidelines. We reviewed a set of rT3 orders at our institution, and identified that 11 of 20 orders appeared inappropriate with respect to clinical context. These orders were less likely to have been placed at the recommendation of an endocrinologist relative to appropriate orders. We recommend that all providers refer to professional guidelines for thyroid function testing, and consult with an endocrinologist for appropriate usage of esoteric or non-standard thyroid function tests.

Management of Hypothyroidism in Patients with Acute Myocardial Infarction

Background and Objectives: Thyroid hormones (TH) affect cardiac function through effects on cardiac contractility and systemic vascular resistance. While TH replacement for patients with hypothyroidism might be necessary for restoration of cardiac output after an acute myocardial infarction (AMI), it could theoretically lead to excessively rapid restoration of the metabolic rate. The appropriate management of hypothyroidism in patients with AMI is unknown. We describe the practice patterns in the management of hypothyroidism in the setting of AMI as well as patients’ clinical outcomes. Material and Methods: Retrospective study of patients that were admitted to a tertiary care hospital with AMI and newly diagnosed or uncontrolled hypothyroidism (TSH ≥ 10 mIU/L) between 2011–2018. Eligible patients were identified using diagnosis codes for AMI and laboratory values, followed by medical record review. We categorized patients according to treatment status with TH and by degree of hypothyroidism. Clinical outcomes included: 30-day mortality/readmission, bleeding, stroke, arrhythmia, sudden cardiac death, and new or worsening heart failure. Summary statistics and group comparisons are presented. Results: Sixty-four patients were included, their median age was 64 years and 61% (n = 39) were women. Most of the patients (59%) had a documented history of hypothyroidism. Of these, all were restarted on levothyroxine (LT4) during the index admission when compared to patients without a history of hypothyroidism, of which 54% received LT4 treatment (p = 0.001). The median TSH in those treated with LT4 was higher (25 mIU/L) when compared to those who were not (12 mIU/L), (p = 0.007). Patients who received intravenous LT4 had higher TSH levels and other variables suggesting worse clinical presentation, but these differences were not statistically significant. No statistically significant differences were noted on clinical outcomes according to LT4 treatment status. Conclusion: A history of hypothyroidism and the degree of TSH elevation seem to guide the management of hypothyroidism in patients with AMI. The clinical effect of correcting hypothyroidism in this setting requires further evaluation.

Low intake of iodized salt and iodine containing supplements among pregnant women with apparently insufficient iodine status - time to change policy?

BACKGROUND

Iodine is an essential nutrient for human health throughout the life cycle, especially during early stages of intrauterine life and infancy, to ensure adequate neurocognitive development. The growing global reliance on desalinated iodine-diluted water raises the specter of increased iodine deficiency in several regions. The case of Israel may be instructive for exploring the link between iodine status and habitual iodine intake in the setting of extensive national reliance on desalinated water. The aim of this study was to explore the relationship between iodine intake, including iodized salt and iodine-containing supplements intake, and iodine status among pregnant women residing in a sub-district of Israel that is highly reliant on desalinated iodine-diluted water.

METHODS

A total of 134 consecutive pregnant women were recruited on a voluntary basis from the obstetrics department of the Barzilai University Medical Center during 2018. Blood was drawn from participants to determine levels of serum thyrotropin (TSH), thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TgAb) and thyroglobulin (Tg). An iodine food frequency questionnaire (sIFFQ) was used to assess iodine intake from food, IS and ICS. A questionnaire was used to collect data on demographic and health characteristics.

RESULTS

A total of 105 pregnant women without known or reported thyroid disease were included in the study. Elevated Tg values (≥ 13 μg/L), were found among 67% of participants, indicating insufficient iodine status. The estimated iodine intake (median, mean ± SD 189, 187 ± 106 μg/d by sIFFQ) was lower than the levels recommended by the World Health Organization and the Institute of Medicine (250 vs. 220 μg/day respectively). The prevalence of iodized salt intake and iodine containing supplement intake were 4 and 52% (respectively). Values of Tg > 13 μg/L were inversely associated with compliance with World Health Organization and Institute of Medicine recommendations.

CONCLUSIONS

While the Israeli Ministry of Health has recommended the intake of iodized salt and iodine containing supplements, this is apparently insufficient for achieving optimal iodine status among Israeli pregnant women. The evidence of highly prevalent probable iodine deficiency in a sample of pregnant women suggests an urgent need for a national policy of iodized salt regulation, as well as guidelines to promote iodine containing supplements and adherence to them by caregivers. In addition, studies similar to this one should be undertaken in additional countries reliant on desalinated iodine-diluted water to further assess the impact of desalinization on maternal iodine status.

Liganded T3 receptor β2 inhibits the positive feedback autoregulation of the gene for GATA2, a transcription factor critical for thyrotropin production

The serum concentration of thyrotropin (thyroid stimulating hormone, TSH) is drastically reduced by small increase in the levels of thyroid hormones (T3 and its prohormone, T4); however, the mechanism underlying this relationship is unknown. TSH consists of the chorionic gonadotropin α (CGA) and the β chain (TSHβ). The expression of both peptides is induced by the transcription factor GATA2, a determinant of the thyrotroph and gonadotroph differentiation in the pituitary. We previously reported that the liganded T3 receptor (TR) inhibits transactivation activity of GATA2 via a tethering mechanism and proposed that this mechanism, but not binding of TR with a negative T3-responsive element, is the basis for the T3-dependent inhibition of the TSHβ and CGA genes. Multiple GATA-responsive elements (GATA-REs) also exist within the GATA2 gene itself and mediate the positive feedback autoregulation of this gene. To elucidate the effect of T3 on this non-linear regulation, we fused the GATA-REs at -3.9 kb or +9.5 kb of the GATA2 gene with the chloramphenicol acetyltransferase reporter gene harbored in its 1S-promoter. These constructs were co-transfected with the expression plasmids for GATA2 and the pituitary specific TR, TRβ2, into kidney-derived CV1 cells. We found that liganded TRβ2 represses the GATA2-induced transactivation of these reporter genes. Multi-dimensional input function theory revealed that liganded TRβ2 functions as a classical transcriptional repressor. Then, we investigated the effect of T3 on the endogenous expression of GATA2 protein and mRNA in the gonadotroph-derived LβT2 cells. In this cell line, T3 reduced GATA2 protein independently of the ubiquitin proteasome system. GATA2 mRNA was drastically suppressed by T3, the concentration of which corresponds to moderate hypothyroidism and euthyroidism. These results suggest that liganded TRβ2 inhibits the positive feedback autoregulation of the GATA2 gene; moreover this mechanism plays an important role in the potent reduction of TSH production by T3.

An Investigation of Oxidative Stress and Thiol/Disulphide Homeostasis in Graves' Disease

Background and objectives: The aim of this study was to research oxidative stress and thiol/disulphide homeostasis in Graves’ patients. Materials and Methods: The study included 33 Graves’ patients (research group) and 35 healthy subjects (control group). Serum oxidative stress and thiol/disulphide homeostasis (a new and automated spectrophotometric method developed by Erel and Neselioglu) parameters were studied and compared between the groups. Results: The native and total thiol levels and the native thiol/total thiol ratio were lower in patients with Graves’ disease compared to the control group (p < 0.001, p < 0.001, and p = 0.006, respectively). TOS (total antioxidant status), PC (protein carbonyl), OSI (Oxidative stress index), and disulphide/native thiol and disulphide/total thiol ratios were determined to be higher in the Graves’ disease group than in the control group (p < 0.001, p = 0.001, p = 0.001, p = 0.004, and p = 0.006, respectively). In the Graves’ disease group, the free triiodothyronine (FT3) and free thyroxine (FT4) levels were significantly positively correlated with impaired thiol/disulphide homeostasis and oxidative stress parameters (p < 0.05). Conclusion: The results of the current study demonstrated that oxidative stress and thiol/disulphide homeostasis increased towards disulphide formation due to thiol oxidation in Graves’ disease. In addition, a positive correlation of FT3 and FT4 was observed with oxidative stress parameters and impaired thiol/disulphide homeostasis.

[Appropriate implementation of automated reflex testing]

The aim of automated reflex testing is to achieve more rational and cost-effective use of laboratory investigations in clinical practice. In order to make use of this cost-effectiveness, the new tests should have a short implementation phase and clear objective goals. To accomplish an equal health care, the usage of new tests should have minimal variations between different primary health care units. We started a new model in Ostergotland County regarding clinical usage of new tests by active follow-up in two levels, both primary health care unit level and individual physician level, during the implementation phase. This study shows that active follow-up and feedback resulted in both shorter implementation phase and minimal variation between different primary health care units.

Thyroid Function and Dysfunction in Relation to 16 Cardiovascular Diseases

BACKGROUND

Subclinical thyroid dysfunction, defined as thyroid-stimulating hormone levels outside the reference range with normal free thyroxine levels in asymptomatic patients, is associated with alterations in cardiac hemodynamics. We used Mendelian randomization to assess the role of thyroid dysfunction for cardiovascular disease (CVD).

METHODS

Single-nucleotide polymorphisms associated with thyroid function were identified from a genome-wide association meta-analysis in up to 72 167 individuals. Data for genetic associations with CVD were obtained from meta-analyses of genome-wide association studies of atrial fibrillation (n=537 409 individuals), coronary artery disease (n=184 305 individuals), and ischemic stroke (n=438 847) as well as from the UK Biobank (n=367 703 individuals).

RESULTS

Genetically predicted thyroid-stimulating hormone levels and hyperthyroidism were statistically significantly associated with atrial fibrillation but no other CVDs at the Bonferroni-corrected level of significance ( P<7.8×10-4). The odds ratios of atrial fibrillation were 1.15 (95% CI, 1.11-1.19; P=2.4×10-14) per genetically predicted 1 SD decrease in thyroid-stimulating hormone levels and 1.05 (95% CI, 1.03-1.08; P=5.4×10-5) for genetic predisposition to hyperthyroidism. Genetically predicted free thyroxin levels were not statistically significantly associated with any CVD.

CONCLUSIONS

This Mendelian randomization study supports evidence for a causal association of decreased thyroid-stimulating hormone levels in the direction of a mild form of hyperthyroidism with an increased risk of atrial fibrillation but no other CVDs.

Serum levels of insulin-like growth factor 1 are negatively associated with log transformation of thyroid-stimulating hormone in Graves' disease patients with hyperthyroidism or subjects with euthyroidism: A prospective observational study

Insulin-like growth factor 1 (IGF-1) has a molecular structure similar to that of insulin. As an essential mediator of growth hormone, IGF-1 plays a vital role in growth of children and anabolic effects of adults. We evaluated the serum levels of IGF-1 in patients with hyperthyroidism or euthyroidism.In this study, 30 patients each of Graves' disease with hyperthyroidism (HY group) and euthyroid individuals (EU group) were recruited. The HY patients were treated with antithyroid regimens as clinically indicated. No medications were given to EU patients. The demographic characteristics and anthropometric and laboratory data of both groups at baseline and 6 months were compared. Associations between levels of IGF-1 and free thyroxine (fT4), thyroid-stimulating hormone (TSH), or log transformation of TSH (logTSH) were analyzed.At baseline, the HY patients had significantly higher serum IGF-1 levels than EU patients (median [Q1, Q3]: 305.4 [257.4, 368.1] vs. 236.7 [184.6, 318.8] ng/mL, P = .007). At 6 months, the HY patients still had higher serum levels of IGF-1 than EU patients (299.5 [249.9, 397.9] vs 222.1 [190.2, 305.4] ng/mL, P = .003). At baseline, the serum levels of IGF-1 in the HY and EU patients were positively associated with fT4 (β = 29.02, P = .002) and negatively associated with TSH (β = -31.46, P = .042) and logTSH (β = -29.04, P = .007). The associations between serum levels of IGF-1 with fT4 or TSH became insignificant at 6 months. However, the serum IGF-1 levels had persistent negative associations with logTSH at 6 months (β = -26.65, P = .021). The negative associations between IGF-1 and logTSH at baseline and 6 months remained significant even after adjustment with sex and age (β = -20.22, P = .023 and β = -20.51, P = .024, respectively).The HY patients had higher serum IGF-1 levels than EU patients. The serum IGF-1 concentrations were negatively associated with logTSH in patients with hyperthyroidism or euthyroidism.

Current Thyrotropin Immunoassays Recognize Macro-Thyrotropin Leading to Hyperthyrotropinemia in Females of Reproductive Age

BACKGROUND

Macro-thyrotropin (macro-TSH) is a high molecular weight form of TSH that leads to hyperthyrotropinemia. This study was undertaken to examine the prevalence and nature of macro-TSH in females of reproductive age.

METHODS

Blood samples were taken from 1794 female patients who visited the Hamada Obstetrics and Gynecology Hospital in Tokyo, Japan, complaining of infertility. The serum of 305 patients with TSH concentrations >2.5 mIU/L was screened for macro-TSH by the polyethylene glycol method. Samples with TSH precipitation ratios by polyethylene glycol >70% were further analyzed using gel filtration chromatography (GFC), protein G columns, and ¹²⁵I-TSH binding experiments.

RESULTS

Screening of the 305 patients revealed that 63 had serum TSH precipitation ratios >70%. GFC revealed that immunoreactive TSH, with a molecular weight of approximately 150 kDa, eluted at higher ratios (79.6 ± 24.4%) in 27 of the 63 patients compared to 0.4 ± 2.0% in the control group. Serum TSH concentrations in 24 of the 27 patients were spuriously elevated due to human anti-mouse antibodies. Macro-TSH was found in the other three patients, and one of them had detectable anti-TSH autoantibodies. Eight of the remaining 36 patients who did not have high-molecular-weight TSH assessed by GFC had immunoglobulin G-associated TSH. Three commercially available TSH immunoassays (Elecsys^®, Centaur^®, and Architect^®) all recognized macro-TSH leading to the elevated serum TSH concentrations.

CONCLUSIONS

Macro-TSH was present in 0.17% of infertile women. Commercial TSH immunoassays recognized macro-TSH, resulting in the diagnosis of hyperthyrotropinemia.

TSH-STAINING PITUITARY ADENOMAS: RARE, SILENT, AND PLURIHOROMONAL

OBJECTIVE

To characterize a single referral center experience with thyroid-stimulating hormone (TSH)-staining adenomas.

METHODS

A retrospective chart review was conducted on histopathologic-proven TSH-staining adenomas resected between 2000-2015 at a single center. Tumors were classified as functional (hormonally active) or silent (hormonally inactive). Categorical variables were summarized using counts (n) and percentages; continuous variables were summarized using medians and ranges.

RESULTS

From the 1,065 pituitary adenomas operated, 32 (3.0%) showed diffuse staining for TSH. Median (range) age of patients was 49 years (20 to 77 years), and 21 (66%) were male. Tumor diameter was 20 mm (2 to 37 mm), with 7 (22%) microadenomas and 25 (78%) macroadenomas. Functional tumors (n = 5, 16%) had median diameter of 10 mm (5 to 21 mm) (2 microadenomas). At diagnosis, median (range) TSH was 4.3 μU/mL (1.2 to 6.9 μU/mL), and free thyroxine (FT4) was 2.4 ng/dL (2.1 to 3.4 ng/dL). Three tumors stained for TSH alone, and 2 tumors costained with growth hormone (GH). No cavernous sinus invasion was seen, and 3 (60%) were considered cured after surgery. Silent tumors (n = 27, 84%) had median diameter of 20 mm (2 to 37 mm), with 5 (19%) microadenomas and 22 (81%) macroadenomas. Median (range) TSH was 1.2 μU/mL (0.48 to 4.6 μU/mL), and FT4 was 1.2 ng/dL (0.6 to 1.6). Only 2 (7.4%) tumors stained for TSH alone; the rest were plurihormonal, with GH being the most common. Cavernous sinus invasion was seen in 7 (27%) of the tumors, and 17 (63%) were considered surgically cured.

CONCLUSION

In our series, 22% of TSH-staining adenomas were microadenomas, and 84% were silent. Most TSH-staining adenomas were plurihormonal, particularly costaining with GH.

ABBREVIATIONS

αSU = alpha-subunit; ACTH = adrenocorticotropic hormone; FSH = follicle-stimulating hormone; FT3 = free triiodothyronine; FT4 = free thyroxine; GH = growth hormone; LH = luteinizing hormone; MRI = magnetic resonance imaging; PRL = prolactin; T4 = thyroxine; TSH = thyroid-stimulating hormone.

The etiologies and incidences of congenital hypothyroidism before and after neonatal TSH screening program implementation: a study in southern Thailand

BACKGROUND

Congenital hypothyroidism (CH) is one of the common causes of intellectual disability which can be prevented by early detection of an elevated thyroid stimulating hormone (TSH) level in the newborn and by treatment with thyroxine. In Thailand, neonatal TSH screening was implemented nationwide in 2005. The objective of the study was to determine the etiologies and the estimated incidences of CH in southern Thailand before and after the implementation of a neonatal TSH screening program in 2005.

METHODS

The medical records of pediatric patients who were diagnosed with primary CH at Songklanagarind Hospital during 1995-2013 were retrospectively reviewed. The study was divided into two time periods: study period 1 (SP1) (1995-2004) and study period 2 (SP2) (2005-2013), the time before and after TSH program implementation.

RESULTS

The most common form of CH during SP1 was overt permanent CH (66%), mostly caused by athyreosis or ectopic thyroid. In SP2, the most common form of CH was mild permanent CH (39%) (mostly due to dyshormonogenesis), followed by overt CH (32%) and transient CH (29%). The overall annual estimated incidence of CH per 10,000 live births in Songkhla Province was 1.69 (1:5021) in SP1, increasing to 4.77 (1:2238) in SP2; in all 14 provinces in southern Thailand, the estimated incidence was 1.24 (1:8094) in SP1 and 2.33 (1:4274) in SP2.

CONCLUSIONS

Neonatal TSH screening has a significant impact on the increased detection of the mild form of permanent and transient CH cases, which may be important for the prevention of brain damage from less severe CH although this remains to be documented.

Thyrotropin level and cognitive performance: Baseline results from the ELSA-Brasil Study

BACKGROUND AND AIMS

The role of subtle thyroid alterations, such as subclinical thyroid disease and low/high serum thyrotropin (TSH) within the normal range, on cognitive decline is controversial. The aim of this study was to evaluate the association of serum TSH and subclinical thyroid dysfunction with performance on cognitive tests in a large sample of Brazilian middle-aged adults without overt thyroid disease.

METHODS

In this cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health, we excluded individuals aged 65 years and older, with overt thyroid dysfunction, prevalent stroke, in use of medications that affect thyroid function or that indicate neurologic diseases, and from Asian or indigenous ethnicity. Thyroid status was assessed by serum TSH and free thyroxine (only when the TSH was altered). Individuals were divided according to TSH tertiles and classified according to thyroid function as euthyroidism, subclinical hypothyroidism, or subclinical hyperthyroidism. Cognition was evaluated using delayed word recall test, semantic verbal fluency test, and trail making test version B. The associations of cognitive tests performance with TSH tertiles (using the middle tertile as reference) and thyroid function were investigated using linear regression models, adjusted for an extensive set of possible confounders (sociodemographic characteristics, cardiovascular risk factors, and depression).

RESULTS

The mean age of the 10,362 participants was 49.5±7.4years, 52.3% women. After adjustment for confounders, the first TSH tertile was associate with worse performance on the trail making test (β=-0.05, 95% CI=-0.09; -0.01, p=0.017). When restricting the analysis to the 9769 individuals with TSH within the normal range, the association between TSH and performance on the trail making test remained significant (β=-0.05, 95% CI=-0.09; -0.01, p=0.020) on multiple linear regression. Subclinical thyroid disease was not associated with performance on cognitive tests.

CONCLUSION

Low TSH is associated with poorer performance on an executive function test in middle-aged adults without overt thyroid dysfunction.

Rare Manifestations of Anaplastic Thyroid Carcinoma: the Role of BRAF Mutation Analysis

Anaplastic thyroid carcinoma (ATC) is difficult to distinguish from other cancers, especially when its pathological features are atypical for ATC or when the tumor is totally undifferentiated and occurs after a considerable lapse of time, in an area remote from the original site of the tumor. Here, we present two patients (68-year-old man and 56-year-old woman) with rare manifestations of ATC, which were initially thought to be other malignancies. Immunohistochemical tests, using various markers, failed to provide information about the origin of these tumors. However, both patients had a history of papillary thyroid carcinoma (PTC) from several years ago and BRAF mutations were observed in the undifferentiated tumors, as well as in the previous PTCs. Therefore, we could make a diagnosis of ATC derived from PTC. As such, BRAF mutation analysis may serve as a useful tool for ATC diagnosis in challenging ATC cases.

Soy isoflavones inducing overt hypothyroidism in a patient with chronic lymphocytic thyroiditis: a case report

BACKGROUND

Many people have thyroid conditions that make them susceptible to hypothyroidism. If the foods they eat may interfere with the production of thyroid hormone, which can lead to development of serious hypothyroidism. The danger of health drinks should always be noted.

CASE PRESENTATION

A 72-year-old Japanese woman was previously diagnosed with chronic lymphocytic thyroiditis caused by a goiter and had an elevated thyroid-stimulating hormone level (6.56 μIU/ml), a high anti-thyroid peroxidase antibody level (>600 IU/ml), and a high antithyroglobulin level (> 4000 IU/ml) but normal levels of free triiodothyronine (3.08 pg/ml) and thyroxine (1.18 ng/ml). She presented to our hospital with sudden-onset general malaise, edema, and hoarseness with an elevated thyroid-stimulating hormone (373.3 μIU/ml) level and very low triiodothyronine (< 0.26 pg/ml) and thyroxine (0.10 ng/ml) levels. It was determined that for 6 months she had been consuming a processed, solved health drink ("barley young leaf") in amounts of 9 g/day, which included soybean and kale powder extract. Hypothyroidism might be affected by ingredients of health drinks. She discontinued consumption of the health drink immediately and began taking 12.5 μg of levothyroxine. The amount of levothyroxine was gradually increased every 3 days up to 100 μg. At day 61, her thyroid-stimulating hormone level had decreased (6.12 μIU/ml), her free triiodothyronine (2.69 pg/ml) and thyroxine (1.56 ng/ml) levels had increased, and her general condition was improved. Among risky foods lowering thyroid function, some experimental studies have revealed that isoflavones reduce thyroid function. Therefore, we measured the presence of isoflavones in the patient's frozen serum with thin-layer chromatography. After she discontinued consumption of the health drink, two components quickly disappeared, and the other three components gradually decreased. On the basis of developing solvent composition and a positive ferric chloride reaction in thin-layer chromatography experiment, the five ingredients that disappeared or decreased were highly suspected to be soy isoflavones.

CONCLUSIONS

This case emphasizes that consuming health drinks that include soy isoflavone powder extracts can lead to severe hypothyroidism.

Neuroleptic malignant syndrome with thyroid disorder: An unusual case report

RATIONALE

Neuroleptic malignant syndrome (NMS) is a life threatening neurologic emergency associated with neuroleptic or antipsychotic agent use. NMS is rarely related to thyroid disease.

PATIENT CONCERNS

We report a case of NMS in a 66-year-old male with past medical history of paranoid schizophrenia on chlorpromazine, diabetes, hypertension and asthma, who presented with a humeral fracture after a fall. Patient developed hyperpyrexia, altered consciousness, autonomic instability, elevated serum creatine kinase (CK) without rigidity.

DIAGNOSES

CT head and workup for infection were negative. Electroencephalogram (EEG) showed generalized slow wave activity. Ultrasound revealed a large goiter with nodules.

INTERVENTIONS

Chlorpromazine was stopped due to concern of NMS. Patient was treated with cooling, fluid and electrolyte maintenance.

OUTCOMES

Patient slowly improved and CK level normalized. Thyroid-stimulating hormone (TSH) level trended down from 10.2 mIU/L to 0.02 mIU/L. Patient was discharged with aripiprazole.

LESSONS

Hypothyroidism predisposes patients to NMS by altering central dopaminergic systems. The typical symptoms may be masked by hypothyroidism. Thyroid dysfunction should be excluded in all patients with NMS. Discontinuing antipsychotic agents decreases TSH levels which maybe due to the negative feedback of dopaminergic activity. This is the first case report describing dramatic changes in TSH after discontinuing chlorpromazine in NMS.

Biochemical Testing in Thyroid Disorders

This article summarizes the main principles for the appropriate use of laboratory testing in the diagnosis and management of thyroid disorders, as well as controversies that have arisen in association with some of these biochemical tests. To place a test in perspective, its sensitivity and accuracy should be taken into account. Ordering the correct laboratory tests facilitates the early diagnosis of a thyroid disorder and allows for timely and appropriate treatment. This article focuses on a comprehensive update regarding thyroid-stimulating hormone, thyroxine/triiodothyronine, thyroid autoantibodies, thyroglobulin, and calcitonin. Clinical uses of these biochemical tests are outlined.

Relevant researches on chronic viral myocarditis (CVMC) in children, complicated with arrhythmia and thyroid hormone level

OBJECTIVE

To analyze the correlation between chronic viral myocarditis (CVMC) in children, complicated with arrhythmia and thyroid hormone level.

PATIENTS AND METHODS

60 patients with CVMC complicated with arrhythmia were continuously selected (course of disease > 3 months) and they are were diagnosed with arrhythmia by the routine 18-lead electrocardiogram and 24-hour Holter; the average follow-up time is about 2 years, during which the left ventricular end-diastolic diameter (LVEDd), left ventricular ejection fraction (LVEF), the occurrence rate of malignant arrhythmia events, immune state of T cell and thyroid hormone level (FT3, FT4, TSH, TGAb and TPOAb) were compared.

RESULTS

Among the selected 60 patients, 18 patients (30.0%) who were suffering from malignant arrhythmia have been taken as the observation group. When compared with the control group, the standard deviation normal to normal intervals (SDNN), LVEF, CD4 and CD4/CD8 were reduced and LVEDd and CD8 were increased in the observation group; the difference has statistical significance (p < 0.05). When compared with the control group, FT3 and FT4 are significantly reduced and TSH, thyroglobulin antibody TGAB and thyroid peroxidase antibodies (TPOAb) are significantly increased; the difference has statistical significance (p < 0.05). According to the logistic regression analysis, we can conclude that: SDNN, FT3, FT4, TSH, TGAb and TPOAb are the independent risk factors of malignant arrhythmia (p < 0.05).

CONCLUSIONS

Thyroid hormones and antibody level are helpful to the prognosis of malignant arrhythmia resulting from children chronic VMC complicated with arrhythmia complications.

The quantitative evaluation of the immunohistochemical expression of the pituitary adenomas

BACKGROUND

The aim of this study was to evaluate morphometrically the pituitary adenomas immunoexpression.

METHODS

The cases of 72 patients were analyzed, who underwent transsphenoidal surgery for pituitary adenomas. Subsequently, the immunohistochemical pituitary hormone panel was applied including alpha- subunit of the glycoprotein hormones. Immunohistochemical sections were analyzed quantitatively with the help of morphometric grid. The percentage rate of the immunoexpression was calculated separately for every single hormone.

RESULTS

As a result, 22 monohormonal adenomas (30.56%), 21 plurihormonal adenomas (29.17%), 21 immunonegative adenomas (29.17%) and 8 unreliable cases (11.11%) were recognized. The immunopositivity for particular hormones was found as follows: PRL and GH (25% each), α-SU (22.22%), ACTH (13.89%), LH and FSH (12.5% each), and TSH (5.56%). An average percentage of immunoexpression in each positive staining groups occurred as follows: for PRL - 59.98%, for GH - 53.97%, for ACTH - 39.21%, for TSH - 25.05%, for LH - 37.3%, for FSH - 54.66%, for α-SU - 45.71.

CONCLUSION

The morphometrical method utilizing the immunoexpression index introduced in this study provided a very precise recognition of pituitary adenomas pathology. This method may limit the subjectivity of a single researcher and enable better comparison of the studies. The plurihormonality is a common phenomenon, and immunohistochemical staining for all adenohypophyseal hormones is obligatory in order to classify pituitary adenomas correctly. The awareness of an operating neurosurgeon of the importance of meticulous collecting histopathological material, especially in microadenoma cases, has essential impact on further neuropathological evaluation and possibility of immunohistochemical staining.

Thyroid function and cardiovascular disease risk factors in euthyroid adults: a cross-sectional and longitudinal study

OBJECTIVE AND DESIGN

We explored the cross-sectional and longitudinal associations of thyroid function within the normal range with cardiovascular disease (CVD) risk factors and adiposity measures.

PATIENTS AND MEASUREMENTS

A total of 3483 (50·4% women) participants for the cross-sectional CVD study and 1630 (41·2% women) participants for the cross-sectional body composition substudy were drawn from the Framingham Third Generation Exam 1; 2912 participants (50·1% women) for the longitudinal CVD study and 713 participants (35·9% women) for the longitudinal body composition substudy were drawn from the Framingham Third Generation Exams 1-2. Thyroid function was assessed by thyrotropin [thyroid-stimulating hormone (TSH)] and free thyroxine (fT4) concentrations within the reference range at Exam 1. The associations between thyroid function and CVD risk factors were modelled via multivariable-adjusted regression models. Multivariable adjustment included age, sex, current smoking, postmenopausal status and BMI.

RESULTS

Cross-sectionally, higher TSH concentration was associated with increased odds of hypertriglyceridaemia [odds ratio (OR)=1·10], and higher BMI (β = 0·19 kg/m² ), total cholesterol (β = 0·05 mmol/l), triglycerides (β = 0·0006 mmol/l) and subcutaneous adipose tissue (SAT) volume (β = 38·8 cm³ ) (all P < 0·05). Cross-sectionally, fT4 was inversely associated with metabolic and adiposity-related CVD risk factors, including obesity (OR = 1·17), hypertriglyceridaemia (OR = 1·09), BMI (β = 0·42 kg/m² ), total cholesterol (β = 0·05 mmol/l), triglycerides (β = 0·0002 mmol/l), visceral adipose tissue (VAT) volume (β = -20·7 cm³ ) and attenuation (0·17 HU) and VAT/SAT ratio (β = -0·01) (all P < 0·05). However, during 6·1 years of follow-up, baseline TSH and fT4 levels were not longitudinally associated with CVD risk factors and adiposity measures.

CONCLUSIONS

Thyroid function within the normal range is cross-sectionally, but not longitudinally, associated with CVD risk factors and adiposity measures.

Coexistence of resistance to thyroid hormone and ectopic thyroid: ten-year follow-up

Resistance to thyroid hormone (RTH) coexisting with ectopic thyroid is rare. Here we report a case of RTH with ectopic thyroid. A ten-year-old girl had been misdiagnosed as congenital hypothyroidism and treated with levothyroxine since she was born. Ten-year follow-up showed that the elevated thyrotropin was never suppressed by levothyroxine and no signs indicating hyperthyroidism or hypothyroidism despite elevated FT3 and FT4 levels. Therefore the girl developed no defects in physical and cognitive development. Pituitary adenoma was excluded by magnetic resonance imaging. Ultrasonography did not find the thyroid gland in the normal place, while the thyroid scan found a large lingual thyroid gland. The octreotide inhibition test showed a reduction in thyrotropin by 41.98%. No mutation was detected in the thyroid hormone receptor (THR) β, THRα, thyrotropin receptor (TSHR), and GNAS1 genes. To our knowledge, it is an interesting RTH case coexisting with lingual thyroid.

[Standardization of Thyroid Function Tests]

The values of free T4 (FT4) and TSH are discrepant depending on reagents. Standardization of testing is crucial because the decision limits in absolute values are described in current clinical practice guidelines. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has worked over the years towards the goal of test standardization. However, it will take several years before implementation becomes effective. Therefore, the standardization committee of the Japanese Society of Laboratory Medi- cine suggested the recalculation of formulas to standardize the value of TSH. These formulas may be used until the standardization of TSH is reached. [Review].

A low incidence of iodine-induced hyperthyroidism following administration of iodinated contrast in an iodine-deficient region

OBJECTIVE

There are limited data on the incidence of iodinated contrast-induced thyrotoxicosis, particularly in iodine-deficient regions. The aim of this study was to determine the incidence of iodinated contrast-induced thyrotoxicosis and to determine whether thyrotoxicosis was more common in patients ≥70 years compared to those <70 years of age.

DESIGN

A prospective study of adult patients undergoing an outpatient CT with iodinated contrast was performed.

MEASUREMENTS

Thyroid function tests (TFTs) and urine iodine measurements were performed prior to the scan. TFTs were repeated at 4- and 8-weeks postscan. Changes in TFTs from baseline were analysed.

RESULTS

A total of 102 patients were included in the final analysis. Overall, TSH levels dropped (P = 0·0002), and free T3 (FT3 ) levels increased (P = 0·04) between baseline and week 4 with normalization by week 8; however, these changes were not considered clinically significant. No significant differences in free T4 (FT4 ) occurred in the overall group (P = 0·82). There were no differences in TFTs between baseline and 4 or 8 weeks for those patients aged <70 compared to ≥70 years. Two patients developed new subnormal TSH values. Of these, one had a 90-mm follicular variant papillary thyroid carcinoma diagnosed while the other had a normal thyroid assessment and TSH spontaneously normalized by 12 weeks.

CONCLUSIONS

Only 2% of patients developed subclinical hyperthyroidism following a standard dose of iodinated contrast for CT investigations. Given the low incidence of iodine-induced thyrotoxicosis, there is no indication for routine pre- and post-CT thyroid function testing in our region.

Reconciling the Log-Linear and Non-Log-Linear Nature of the TSH-Free T4 Relationship: Intra-Individual Analysis of a Large Population

CONTEXT

The TSH-T4 relationship was thought to be inverse log-linear, but recent cross-sectional studies report a complex, nonlinear relationship; large, intra-individual studies are lacking.

OBJECTIVE

Our objective was to analyze the TSH-free T4 relationship within individuals.

METHODS

We analyzed data from 13 379 patients, each with six or more TSH/free T4 measurements and at least a 5-fold difference between individual median TSH and minimum or maximum TSH. Linear and nonlinear regression models of log TSH on free T4 were fitted to data from individuals and goodness of fit compared by likelihood ratio testing.

RESULTS

Comparing all models, the linear model achieved best fit in 31% of individuals, followed by quartic (27%), cubic (15%), null (12%), and quadratic (11%) models. After eliminating least favored models (with individuals reassigned to best fitting, available models), the linear model fit best in 42% of participants, quartic in 43%, and null model in 15%. As the number of observations per individual increased, so did the proportion of individuals in whom the linear model achieved best fit, to 66% in those with more than 20 observations. When linear models were applied to all individuals and averaged according to individual median free T4 values, variations in slope and intercept indicated a nonlinear log TSH-free T4 relationship across the population.

CONCLUSIONS

The log TSH-free T4 relationship appears linear in some individuals and nonlinear in others, but is predominantly linear in those with the largest number of observations. A log-linear relationship within individuals can be reconciled with a non-log-linear relationship in a population.

PRACTICAL BARRIERS TO IMPLEMENTATION OF THYROID CANCER GUIDELINES IN THE ASIA-PACIFIC REGION

OBJECTIVE

Numerous published guidelines have described the optimal management of thyroid cancer. However, these rely on the clinical availability of diagnostic and therapeutic modalities. We hypothesized that the availability of medical resources and economic circumstances vary in Asia-Pacific countries, making it difficult to implement guideline recommendations into clinical practice.

METHODS

We surveyed participants at the 2009 and 2013 Congresses of the Association of Southeast Asian Nations Federation of Endocrine Societies by distributing questionnaires to attendees at registration.

RESULTS

Responses were obtained from 268 respondents in 2009 and 163 respondents in 2013. Similar to the high prevalence of low-risk thyroid cancer observed in the Surveillance, Epidemiology, and End Results database, across the Asia-Pacific countries surveyed in 2009 and 2013, 50 to 100% of the respondents from the Philippines, Malaysia, Singapore, China, Taiwan, Thailand, Hong Kong, Korea, and Sri Lanka reported that more than 50% of the patients had low-risk thyroid cancer on follow-up. Importantly, there was much variation with regards to the perceived availability of investigation and treatment modalities.

CONCLUSION

We found a wide variation in clinicians' perception of availability of diagnostic and therapeutic modalities in the face of a rise in thyroid cancer incidence and thyroid cancer management guidelines that emphasized their importance. The lack of availability of management tools and treatments will prove to be a major barrier to the implementation of thyroid cancer management guidelines in Southeast Asia, and likely in other parts of the world as well.

A statistical basis for harmonization of thyroid stimulating hormone immunoassays using a robust factor analysis model

BACKGROUND

Between-method equivalence ideally is achieved by calibration against an SI-traceable reference measurement procedure. For measurement of thyroid stimulating hormone (TSH), it is unlikely to accomplish this goal in mid-term. Therefore, we investigated a statistical alternative based on a factor analysis (FA) model.

METHODS

The FA model was applied to TSH results for 94 samples generated by 14 immunoassays (concentration range: 0.0005-78 mIU/L). The dataset did not fulfill the assumption of a homogeneous sample from an elliptically symmetric distribution, and, therefore, required standardization prior to application of the FA model. As outliers and missing values also occurred, the key quantities of the FA model had to be estimated with a method that can handle these complications. We selected a robust alternating regressions (RAR) method, which replaces in the minimization criterion of the fitting process the squared differences between results xij and model fit x^ij ${\hat x_{ij}}$ by a weighted absolute difference. The weights are adaptively determined in successive regressions, which down weighs the outliers. The weights for missing values are set to zero.

RESULTS

The quality of the estimated targets was reflected by their central position in the distributions, and description of the relationship between results and targets by a simple two-parameter regression equation with high correlation coefficients and low SDs of the percentage-residuals. Mathematical recalibration eliminated the method differences and improved the between-method CV from 11% to 6%.

CONCLUSIONS

RAR applied to a multimethod comparison dataset hampered by outliers and missing values, is fit to the purpose of harmonization.

[FT4 immunoassay interference : A case report]

Measurement of thyrotropin and free thyroxin made using immunoassays are usually needed in clinical endocrinology. Here, we report a case of a patient with type 2 diabetes who presented a weight loss. To eliminate hyperthyroidism, thyroid function tests were performed. Free thyroxin (FT4) was decreased using two automated immunoassays TOSOH AIA 1800 and Roche ELECSYS 2010, with a normal thyrotropin value. Thyroid function tests repeated a month later were normal. The patient's history revealed contact with sheep, which may partly explain the interference. Investigations into the patient's serum were carried out using both the PEG test and dilution test. Interference factors were probably antibodies. Despite progress in immunoassays, we should be aware of interference occurrence since it can lead to false results, unnecessary investigations and incorrect treatment. Thus, simple tests must be carried out as if interference in immunoassays were suspected. Dilutions and PEG tests are generally performed as first line investigations.

Thyroid hormone levels and incident chronic kidney disease in euthyroid individuals: the Kangbuk Samsung Health Study

BACKGROUND

Overt and subclinical hypothyroidism are associated with higher levels of serum creatinine and with increased risk of chronic kidney disease (CKD). The prospective association between thyroid hormones and kidney function in euthyroid individuals,however, is largely unexplored.

METHODS

We conducted a prospective cohort study in 104 633 South Korean men and women who were free of CKD and proteinuria at baseline and had normal thyroid hormone levels and no history of thyroid disease or cancer. At each annual or biennial follow-up visit, thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxin (FT4) levels were measured by radioimmunoassay. The study outcome was incident CKD, defined as an estimated glomerular filtration rate (eGFR)<60 ml/min/1.73 m2 based on the Chronic Kidney Disease Epidemiology Collaboration creatinine equation.

RESULTS

After a median follow-up of 3.5 years, 1032 participants developed incident CKD.There was a positive association between high-normal levels of TSH and increased risk of incident CKD. In fully-adjusted models including baseline eGFR, the hazard ratio comparing the highest vs the lowest quintiles of TSH was 1.26 [95% confidence interval (CI) 1.02 to 1.55; P for linear trend=0.03]. In spline models, FT3 levels below 3 pg/ml were also associated with increased risk of incident CKD. There was no association between FT4 levels and CKD.

CONCLUSIONS

In a large cohort of euthyroid men and women, high levels of TSH and low levels of FT3, even within the normal range, were modestly associated with an increased risk of incident CKD.

Label-free and rapid electrical detection of hTSH with CMOS-compatible silicon nanowire transistor arrays

Now a human thyroid stimulating hormone (hTSH) assay has been considered as a screening tool for thyroid disease. However, some existing methods employed for in-hospital diagnosis still suffer from labor-intensive experimental steps, and expensive instrumentation. It is of great significance to meet the ever growing demand for development of label-free, disposable, and low-cost productive hTSH detection biosensors. Herein, we demonstrate a novel sensing strategy for highly sensitive and selective immunodetection of hTSH by using a CMOS-compatible silicon nanowire field effect transistor (SiNW-FET) device. The SiNW chips were manufactured by a top-down approach, allowing for the possibility of low-cost and large-scale production. By using the antibody-functionalized SiNW-FET nanosensors, we performed the label-free and rapid electrical detection of hTSH without any nanoparticle conjugation or signal amplifications. The proposed SiNW biosensor could detect hTSH binding down to a concentration of at least 0.02 mIU/L (0.11 pM), which is more sensitive than other sensing techniques. We also investigated the influence of Debye screening with varied ionic strength on hTSH detection sensitivity, and real-time measurements on various concentrations of the diluted buffer. The simple, label-free, low-cost, and miniaturized SiNW-FET chip has a potential perspective in point-of-care diagnosis of thyroid disease.

Thyrotropin isoforms: implications for thyrotropin analysis and clinical practice

Serum thyrotropin (TSH) is considered the single most sensitive and specific measure of thyroid function in the general population owing to its negative logarithmic association with free triiodothyronine and free thyroxine concentrations. It is therefore often the test of choice for screening, diagnosis, and monitoring of primary hypothyroidism. Serum TSH concentrations can be analyzed quantitatively using third-generation immunoassays, whereas its bioactivity can be measured by TSH activity assays in cell culture. Theoretically, if serum TSH concentrations are directly related to TSH activity, the two tests should yield comparable results. However, on occasion, the results are discordant, with serum concentrations being higher than TSH biological activity. This review focuses on the dissociation between the clinical state and serum TSH concentrations and addresses clinically important aspects of TSH analysis.

A digital microfluidic electrochemical immunoassay

Digital microfluidics (DMF) has emerged as a popular format for implementing quantitative immunoassays for diagnostic biomarkers. All previous reports of such assays have relied on optical detection; here, we introduce the first digital microfluidic immunoassay relying on electrochemical detection. In this system, an indium tin oxide (ITO) based DMF top plate was modified to include gold sensing electrodes and silver counter/pseudoreference electrodes suitable for in-line amperometric measurements. A thyroid stimulating hormone (TSH) immunoassay procedure was developed relying on magnetic microparticles conjugated with primary antibody (Ab1). Antigen molecules are captured followed by capture of a secondary antibody (Ab2) conjugated with horseradish peroxidase enzyme (HRP). HRP catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) which can be detected amperometrically. The limit of detection of the technique (2.4 μIU mL(-1)) is compatible with clinical applications; moreover, the simplicity and the small size of the detector suggest utility in the future for portable analysis.