Treating the thyroid in the presence of Graves' ophthalmopathy

Advancing thyroid disease research: The role and potential of zebrafish model

Thyroid disorders significantly affect human metabolism, cardiovascular function, skeletal health, and reproductive systems, presenting a complex challenge due to their multifactorial nature. Understanding the underlying mechanisms and developing novel therapeutic approaches require appropriate models. Zebrafish, with their genetic tractability, short life cycle, and physiological relevance, have emerged as a valuable model for investigating thyroid diseases. This review provides a comprehensive analysis of the zebrafish thyroid gland's structure and function, explores its application in modeling thyroid pathologies such as hypothyroidism, hyperthyroidism, and thyroid cancer, and discusses current limitations and possible improvements. Furthermore, it outlines future directions for zebrafish-based research, focusing on enhancing the model's relevance to human thyroid disease and its potential to expedite the development of clinical therapies.

Medical and surgical treatment of thyroid eye disease

Thyroid eye disease is an autoimmune inflammatory disease strongly associated with thyroid disease, principally Graves disease. It can range from mild disease requiring observation or symptomatic treatments only, through to sight-threatening disease requiring major drug therapy and orbital surgery. Severity is graded by the NOSPECS system and activity by the clinical activity score (CAS) to assist in treatment selection. Non-surgical management can extend from observation alone to minor therapy such as oral selenium, then glucocorticoid therapy, cyclosporin, mycophenolate, rituximab, immunoglobulin, teprotumumab, and orbital radiotherapy. High-dose intravenous methylprednisolone therapy is used in active vision-threatening disease with early use of tarsorrhaphy and orbital decompression. Inactive but moderate to severe disease may be treated by orbital decompression, strabismus and eyelid surgery. Systematic assessment and management by both an endocrinologist and ophthalmologist to achieve and maintain euthyroidism and select and sequence treatments according to activity and severity of thyroid eye disease gives the best results for quality of life and vision.

A systematic review of euthyroid Graves' disease (Review)

Euthyroid Graves' Disease (EGD) is a challenging pathology, due to its atypical clinical manifestations and the absence of abnormal thyroid function. Typically, thyroid ophthalmopathy is associated with elevated thyroid hormone levels and with the presence of thyrotropin receptor antibodies (TRAb) but a low percentage of patients remain euthyroid without developing hyperthyroidism during long-term follow-up periods. Although it is considered a different pathology, it shares a lot of similarities with Graves' disease, rendering the diagnosis more difficult. It is also important to note that ophthalmopathy may be the first clinical manifestation of Graves' disease and that thyroid function examinations do not present abnormalities over a long period. Treatment choices for euthyroid disease do not differ from those described in Graves' ophthalmopathy. However, it is considered that since euthyroid patients develop milder ophthalmic symptoms and their clinical activity score is lower, they tend to have better responses to treatment. Moreover, atypical sight-threatening cases such as exposure keratopathy and dysthyroid optic neuropathy with variable responses to therapy also exist. Disease management consists of a favorable collaboration between ophthalmologists and endocrinologists because patients with EGD can develop thyroid abnormalities over time. In conclusion, the diagnosis of EGD is difficult, clinical manifestations and evolution are variables depending on several factors, including the heterogeneity of TRAb. This review aimed to identify the characteristics of this disease by reviewing the clinical studies and case reports published in previous years.

Insulin-like Growth Factor-I Receptor and Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is a complex disease process presumed to emerge from autoimmunity occurring in the thyroid gland, most frequently in Graves disease (GD). It is disfiguring and potentially blinding, culminating in orbital tissue remodeling and disruption of function of structures adjacent to the eye. There are currently no medical therapies proven capable of altering the clinical outcome of TAO in randomized, placebo-controlled multicenter trials. The orbital fibroblast represents the central target for immune reactivity. Recent identification of fibroblasts that putatively originate in the bone marrow as monocyte progenitors provides a plausible explanation for why antigens, the expressions of which were once considered restricted to the thyroid, are detected in the TAO orbit. These cells, known as fibrocytes, express relatively high levels of functional TSH receptor (TSHR) through which they can be activated by TSH and the GD-specific pathogenic antibodies that underpin thyroid overactivity. Fibrocytes also express insulin-like growth factor I receptor (IGF-IR) with which TSHR forms a physical and functional signaling complex. Notably, inhibition of IGF-IR activity results in the attenuation of signaling initiated at either receptor. Some studies suggest that IGF-IR-activating antibodies are generated in GD, whereas others refute this concept. These observations served as the rationale for implementing a recently completed therapeutic trial of teprotumumab, a monoclonal inhibitory antibody targeting IGF-IR in TAO. Results of that trial in active, moderate to severe disease revealed dramatic and rapid reductions in disease activity and severity. The targeting of IGF-IR with specific biologic agents may represent a paradigm shift in the therapy of TAO.

Total thyroidectomy (Tx) versus thionamides (antithyroid drugs) in patients with moderate-to-severe Graves' ophthalmopathy - a 1-year follow-up: study protocol for a randomized controlled trial

Background

Graves’ disease (GD) is characterized by thyrotoxicosis and goiter and arises through circulating autoantibodies that bind to, and stimulate, the thyroid hormone receptor (TSHR). A temporal relation between the onset of hyperthyroidism and the onset of ophthalmopathy, a common extrathyroidal manifestation, has been demonstrated. Graves’ ophthalmopathy (GO) is typically characterized by an inflammation and expansion of the extraocular muscles and an increase in retroorbital fat. There are currently three forms of therapies offered for hyperthyroidism caused by Graves’ disease: antithyroid drugs (ATD) (thionamides), radioiodine ablation (RAI) and thyroidectomy (Tx). To date, there is no clear recommendation on the treatment of Graves’ disease and GO, mainly due to the individuality of the disease in each patient. The aim of the study is to examine the difference in the outcome of GO in patients with moderate-to-severe GO who receive Tx versus further ATD after suffering their first relapse of GO, or in which GO stays the same following the initial decrease in ATD therapy after 6 months.

Methods/Design

This prospective randomized clinical trial with observer-blinded analysis will analyze 60 patients with moderate-to-severe GO who receive Tx versus ATD without surgery. Main outcome variables include: muscle index measurements via ultrasound and thyroid antibody levels. Additional outcome variables include: Clinical Activity Score (CAScore), NOSPECS score, superonasal index measurements via ultrasound, and quality of life score.

Discussion

This study should allow for better therapeutic choices in patients with moderate-to-severe GO. In addition, it should demonstrate whether the outcome of GO in patients with moderate-to-severe GO is better in those who receive early Tx versus further ATD. Furthermore, this study will aim to establish a standard glucocorticoid scheme before and after Tx in patients with moderate-to-severe EO.

Trial registration

Eudra-CT: 2015–003515-38; Medical University of Vienna Protocol Record 1839/2015.

Date of Ethics Committee approval: 19 January 2017.

Registered on 27 January 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2876-0) contains supplementary material, which is available to authorized users.

[Graves' ophthalmopathy]

Graves' orbitopathy (GO) is the main extrathyroidal manifestation of Graves' disease and the full clinical picture can impair the quality of life of the patients considerably. Active inflammation can often be effectively treated by intravenous steroids/immunosuppression, however does not lead to full remission, since inflammation rather quickly results in irreversible fibrosis and increase of orbital fat. Very important is the control of risk factors (smoking cessation, good control of thyroid function, selenium supplementation) to prevent progression to severe stages. Treatment should rely on a thorough assessment of activity and severity of GO. Rehabilitative surgery (orbital decompression, squint surgery, eyelid surgery) is needed in many patients to restore function and appearance. Anti-thyroid-stimulating hormone (TSH) receptor antibodies do specifically occur in these patients and correlate to the course of thyroid and eye disease. The levels of these antibodies can be used for treatment decisions at certain time points of the disease.

Complications in head and neck surgery

Head and neck anatomy is topographically complex and the region is densely populated by vital nerves and vascular and lymphatic structures. Injury to many of these structures is associated with significant morbidity and may even be fatal. A thorough knowledge of regional anatomy is imperative and complications need to be managed in a thoughtful directed manner. The pediatric surgeon may be called upon to address both congenital and acquired conditions and should be prepared to encounter reoperative fields after failed initial surgery. This review summarizes the current literature on four frequently encountered surgical conditions of the head and neck: branchial cleft anomalies, thyroglossal duct cyst, thyroid disease, and lymphatic malformations, with a focus on the prevention and treatment of complications.

A questionnaire survey on the management of Graves' orbitopathy in China: A comparison with Europe and Latin-America

OBJECTIVE

Management of Graves' orbitopathy (GO) continues to be a challenge to clinical endocrinologists. In the last few years, surveys on GO management have succeeded in elucidating trends in Europe and Latin America. To determine how endocrinologists in China assess and treat patients with GO and gain insight into how to make the management of this disease more uniform and standardized.

METHODS

Based on the questionnaire used in the European survey on GO, a questionnaire in China was drafted and circulated to the members of Chinese Society of Endocrinology (CSE) during the annual meeting.

RESULTS

A total of 124 valid responses were analysed. Almost all respondents (94.4%) claimed that a multidisciplinary approach for GO management was valuable. Over 80% of the participants advocated the assessment of exophthalmometry, vision, visual fields by perimetry, eye movements, and fundoscopy. Glucocorticoids were preferred as the first-line therapy by 92.7% of respondents, among them, 59.7% choose the intravenous route. The treatment strategy for GO with intravenous glucocorticoids therapy still remains debatable. Anti-thyroid drugs (ATDs) were the most common choice (72.6%) for first-line therapy of coexisting hyperthyroidism. Treatment options for GO were very similar among Chinese, Latin-American and European respondents, whereas radioactive iodine and surgical treatment were more often indicated for co-existing hyperthyroidism in China.

CONCLUSION

The appropriate treatment for patients with GO is controversial even among thyroid specialists. Further training of thyroid specialists, easier access of patients to multidisciplinary centres and establishment of practice guidelines are required for the management of this condition in China.

Radioiodine ablation of postsurgical thyroid remnants after treatment with recombinant human TSH (rhTSH) in patients with moderate-to-severe graves' orbitopathy (GO): a prospective, randomized, single-blind clinical trial

CONTEXT

Recent evidence suggests thyroidectomy (Tx) followed by radioiodine remnant ablation to be beneficial to Graves' orbitopathy (GO) patients.

OBJECTIVE

The aim of the study was to evaluate the effect of (131)I thyroid ablation after recombinant human TSH stimulation in patients with moderate-to-severe GO.

DESIGN, PATIENTS, AND INTERVENTIONS

The study was prospective, randomized, and single-blind, and it included 40 consecutive patients with moderate-to-severe GO randomized into: 1) a Tx-radioactive iodine (RAI) group (20 subjects who underwent total-Tx and (131)I ablation after recombinant human TSH stimulation); and 2) a Tx group (20 subjects who underwent total-Tx alone).

OUTCOME MEASURES

The overall GO outcome 12 months after Tx/radioiodine ablation was the main measure.

RESULTS

GO evaluation at the end of iv glucocorticoids showed eye disease to be improved in 65% of the Tx-RAI group and 60% of the Tx group patients. At 6 and 12 months, no further changes in the GO outcome could be observed in the Tx-RAI group. Conversely, five patients from the Tx group exhibited a deterioration in GO. At 12 months, GO was found to be improved in 70% of the Tx-RAI and 20% of the Tx group patients, the latter being found to be stable (55%) or worse (25%) than at baseline evaluation. At 12 months, GO was found to be inactive in a significantly higher percentage of patients in the Tx-RAI than in the Tx group (75 vs 30%; P < .01).

CONCLUSIONS

Postoperative radioiodine ablation proved more effective than Tx alone in inducing earlier and steadier GO improvement in patients with moderate-to-severe GO treated with iv glucocorticoids over a 24-month follow-up period.

Orbital decompression for thyroid-associated orbitopathy in England: trends over time and geographical variation

AIMS

The aims of this study were to examine trends over time and geographical variation in the annual incidence of surgical orbital decompression for thyroid-associated ophthalmopathy (TAO) in England.

METHODS

Data on hospital admissions for orbital decompression surgery in patients with thyroid disease were analysed using English national Hospital Episode Statistics for admissions from 1991-2011.

RESULTS

Annual rates of orbital decompression surgery performed for patients with thyroid disease increased from 0.06 (95% confidence interval, 0.04--0.09) per 100,000 population in 1991, to 0.62 (0.54--0.67) in 2008, and then fell to 0.56 (0.48--0.60) in 2011. The surgical rate was highest in women aged 45--64 years. Geographical analysis showed significant variation across strategic health authority areas in surgical rates, from 0.22 (0.14-0.35) to 1.04 (0.79-1.34) people per 100,000 population per year in 2007-2011.

CONCLUSION

The incidence of orbital decompression surgery performed annually in England has increased substantially over the past two decades, but peaked in 2008 and decreased since then. Significant geographical variation exists in surgical rates. Potential reasons for the decline include improved management of thyroid disease itself, but altered threshold in medical versus surgical management of TAO may also have played a role. The Amsterdam Declaration and EUGOGO treatment guidelines may also have influenced decisions about whether to operate on these patients.

Radioiodine therapy in benign thyroid diseases: effects, side effects, and factors affecting therapeutic outcome

Radioiodine ((131)I) therapy of benign thyroid diseases was introduced 70 yr ago, and the patients treated since then are probably numbered in the millions. Fifty to 90% of hyperthyroid patients are cured within 1 yr after (131)I therapy. With longer follow-up, permanent hypothyroidism seems inevitable in Graves' disease, whereas this risk is much lower when treating toxic nodular goiter. The side effect causing most concern is the potential induction of ophthalmopathy in predisposed individuals. The response to (131)I therapy is to some extent related to the radiation dose. However, calculation of an exact thyroid dose is error-prone due to imprecise measurement of the (131)I biokinetics, and the importance of internal dosimetric factors, such as the thyroid follicle size, is probably underestimated. Besides these obstacles, several potential confounders interfere with the efficacy of (131)I therapy, and they may even interact mutually and counteract each other. Numerous studies have evaluated the effect of (131)I therapy, but results have been conflicting due to differences in design, sample size, patient selection, and dose calculation. It seems clear that no single factor reliably predicts the outcome from (131)I therapy. The individual radiosensitivity, still poorly defined and impossible to quantify, may be a major determinant of the outcome from (131)I therapy. Above all, the impact of (131)I therapy relies on the iodine-concentrating ability of the thyroid gland. The thyroid (131)I uptake (or retention) can be stimulated in several ways, including dietary iodine restriction and use of lithium. In particular, recombinant human thyrotropin has gained interest because this compound significantly amplifies the effect of (131)I therapy in patients with nontoxic nodular goiter.