The role of laboratory medicine in the diagnosis of the hyperthyroidism

Advances in Thyroid Function Tests: Precision Diagnostics and Clinical Implications

This narrative review explores the evolving field of thyroid function testing, explicitly highlighting the significance of precision diagnostics and their substantial impact on clinical practice. Commencing with a comprehensive examination of the historical progression of thyroid diagnostics, the discourse proceeds to explore recent developments, highlighting the paramount importance of accuracy in testing methods. The primary issue under consideration is the crucial requirement for accuracy in the field of therapeutic practice. The review critically examines the problems related to the interpretation, standardization, and ethical considerations in examining advanced laboratory techniques, novel biomarkers, and state-of-the-art technologies like immunoassays, molecular testing, and automation. The focus on the paradigm shift towards precision diagnostics brings attention to the complex connection between test results and their direct influence on patient care. This investigation expands upon the incorporation of imaging and molecular diagnostics, highlighting the rising significance of precision in customizing treatment strategies. In summary, the study provides a prospective viewpoint, recognizing the persistent obstacles and highlighting the want for dependable, uniform methodologies in thyroid diagnostics. This narrative's primary objective is to guide physicians, researchers, and stakeholders in effectively navigating the intricate nature of contemporary thyroid function tests, with a particular emphasis on resolving the fundamental issue of precision.

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.

New-onset and relapsed Graves' disease following COVID-19 vaccination: a comprehensive review of reported cases

Global Coronavir us disease 2019 (COVID-19) vaccination efforts are being intensified to combat the pandemic. As the frequency of immunization against COVID-19 has increased, some adverse effects related to vaccination have emerged. Within this context, this article reviewed 62 Graves' disease (GD) cases following COVID-19 vaccination, to probe the potential association between the vaccination and the onset of GD. A comprehensive search of the PubMed, Web of Science, and Scopus databases was conducted to collect GD cases following COVID-19 vaccination up to June 7, 2023. Among the 62 GD cases included in this review, there were 33 (53.2%) new-onset GD and 10 (16.1%) relapsed GD patients following mRNA vaccination, 14 (22.6%) new-onset GD and 4 (6.5%) relapsed GD patients following viral vector vaccination, and 1 (1.6%) relapsed GD patients following inactivated vaccination. Median durations to symptoms onset for new-onset and relapsed GD were 12 (range: 1-60) and 21 (range: 5-30) days following mRNA vaccination, while 7 (range: 1-28) and 14 (range: 10-14) days following viral vector vaccination, respectively. While the definitive pathogenesis of GD following COVID-19 vaccination remains unclear, it might be associated with cross-immune responses triggered by molecular mimicry, and an adjuvant-induced autoimmune/inflammatory syndrome. However, due to the limited number of observed GD cases following COVID-19 vaccination and the lack of systematic experimental studies, a causal relationship between COVID-19 vaccination and the onset of GD has not been definitively confirmed. It should be highlighted that most of GD patients following COVID-19 vaccination experienced positive outcomes after treatment. In the broader context of ending the COVID-19 pandemic and reducing mortality rates, the benefits of COVID-19 vaccination significantly outweigh mild risks such as treatable GD. Adherence to the COVID-19 vaccination schedule is therefore imperative in effectively managing the pandemic.

Comparison Between Thyroid Stimulating Immunoglobulin and TSH-Receptor Antibodies in the Management of Graves' Orbitopathy

OBJECTIVES

TSH-receptor antibodies (TRAb) targeting the TSH receptor (TSH-R) induce hyperthyroidism in Graves´ disease (GD). Graves´ orbitopathy (GO) is influenced by stimulation of the TSH-R in the orbita. GO has been, among other factors, linked to high TRAb levels. Thyroid stimulating immunoglobulins (TSI) is a relatively new method for assessing TSH-receptor antibodies. The aim of this study was to investigate the role of TSI in the management of GO.

METHODS

Patients with newly diagnosed GD (n=30, median age 55 years (range 35-72), 29 women) received pharmacological therapy (methimazole+++thyroxine) for up to 24 months. GO was identified by clinical signs and symptoms. Eleven patients had GO at diagnosis, and another six developed GO during treatment. Blood samples for TSI and other thyroidal biomarkers were obtained at baseline and on five occasions during the 24-month follow-up. Twenty-two subjects completed the drug regimen without surgery or radioiodine treatment.

RESULTS

At baseline, TSI was highly correlated with TRAb (r _s =0.64, p<0.001), and both assays similarly correlated to fT3 values. TSI and TRAb did not differ significantly between GO and non-GO patients for visit v1 (n=30, 17 GO during the whole study) or at follow-up (n=22, 12 GO during the whole study). During follow-up, levels of TSI and TRAb decreased and normalized in both groups.

CONCLUSION

The present study does not support any added benefit of TSI compared to TRAb for the prediction and management of GO.