Clinical course of thyroid function and thyroid associated-ophthalmopathy in patients with euthyroid Graves' disease

Long-term surgical outcome and impact on daily life activities of strabismus surgery in thyroid-associated ophthalmopathy with and without previous orbital decompression

BACKGROUNDS

To report the long-term surgical outcomes and the impact on daily life activities of strabismus surgery in patients with Thyroid Associated Orbitopathy (TAO) with and without previous orbital decompression.

METHODS

Patients who underwent strabismus surgery for TAO were retrospectively reviewed. The primary outcome was to evaluate the influence of orbital decompression on the outcomes of TAO related strabismus surgery. Surgical success was defined by the resolution of diplopia and a post-operative deviation < 10 prism diopters (PD). The secondary outcomes were the clinical features, surgical approaches, and impact on daily life activities.

RESULTS

A total of 45 patients were included in the study. The decompression surgery group (DS) included 21 patients (46.7%), whereas the non-decompression surgery group (NDS) patients were 24 (53.3%). The mean follow-up time from the last strabismus surgery was 2,8 years (range 8-200 months). Successful surgical outcome was achieved in 57,1% of patients in the DS, and 75% of patients in the NDS (p = 0,226). DS patients required almost twice the number of surgical interventions for strabismus compared to the NDS (1,95 vs. 1,16 respectively, p = 0,006), a higher number of extraocular muscles recessed in the first surgery (2,67 vs. 1,08 respectively, p < 0.001), and a lower rate of unidirectional surgery compared to NDS (23% vs. 95%, p < 0,001). At the pre-operative assessment, 71.4% of DS patients had eso-hypotropia, while no patients had this type of strabismus in the NDS group (p < 0.001). On the other hand, the hypotropia rate was 79.2% in NDS patients and only 4.8% in DS patients (p < 0.001). Moreover, 21,8% of NDS patients used prism lenses in daily life activities, compared to 42.9% of patients that used prism lenses to reduce the impairment in their daily life activities (p = 0.016).

CONCLUSIONS

The results of our study showed that DS patients required almost twice the number of strabismus surgical procedures, a higher number of extraocular muscles recessed in the first surgery, and an increased need for prism lenses to correct the residual deviation compared to the NDS, but with similar long-term surgical outcomes.

Euthyroid graves' ophthalmopathy in a Chinese population: A cross-sectional follow-up study

OBJECTIVES

A subtype of patients with thyroid eye disease (TED) were found to be euthyroid without prior thyroid dysfunction or treatment, known as Euthyroid Graves' Ophthalmopathy (EGO). We report the prevalence, clinical and serological phenotypes of EGO in a Chinese population.

METHODS

A cross-sectional follow-up study. Ethnic Chinese TED patients were managed at the Thyroid Eye Clinic(TEC), Prince of Wales Hospital and TEC, the Chinese University of Hong Kong between September 2007 and July 2021.

RESULTS

A total of 66 (5%) patients among the 1266 ethnic Han Chinese TED cohort were diagnosed as EGO, and 6 (9%)of them become dysthyroid over an average of 74-month follow-up. EGO patients were associated with a longer duration between onset of the symptoms to our first consultation (P < 0.0001), a higher male-to-female ratio (P = 0.0045) and a higher age of disease onset (P = 0.0092). Family history of thyroid disease was more common in TED patients (P = 0.0216) than in EGO patients. EGO patients were more likely to present unilaterally (P < 0.0001), and they have a larger difference in MRD1 (P < 0.0001), and extraocular motility (P < 0.0001) between the 2 eyes when compared to the TED patients. Notably, the extraocular motility restriction of the worst eye was more affected in EGO patients (P = 0.0113). The percentages of patients who received IVMP, ORT and emergency or elective surgeries(decompression or squint operation) between EGO and TED were similar.

CONCLUSIONS

Understanding the important clinical phenotypes of EGO may help the clinician to make the correct diagnosis. Further study to compare EGO and TED is warranted.

Comparison of two different TSH-receptor antibody assays: A clinical practice study

Background

Graves' disease (GD) is caused by the production of TSH-receptor (TSHR) stimulating auto-antibodies. Over the years various TSHR-antibody (TRAb) detection assays have been developed. Most clinical laboratories use competitive TSH-binding inhibitory immunoglobulin (TBII) assays, which measure the total amount of stimulating and blocking auto-antibodies. Selective detection of TSHR stimulating auto-antibodies (TSI) was previously only possible with functional cell-based bioassays. However, more recently an automated bridge-based binding assay to more specifically measure TSI has become available. The aim of our study was to compare the third-generation automated competitive immunoassay (TBII) with the automated bridge immunoassay (TSI) in clinical practice in an academic thyroid expert center.

Methods

A retrospective study in 356 patients with Graves' disease, Graves orbitopathy (GO), and other (thyroid) disease treated in an academic thyroid center was performed. All samples were analyzed for TBII and TSI. For both assays, sensitivity, specificity, positive predictive value (PVV), negative predictive value (NPV) and diagnostic odds ratios were calculated using different cut-offs for negativity.

Results

Using the provided cut-off, the overall sensitivity appeared similar between TBII and TSI, but TSI showed higher overall specificity, PPV, NPV and diagnostic odds ratio. Using two or three times the cut-off for negativity resulted in a decrease in sensitivity, but an increase in specificity and PPV, which was most pronounced for the TBII-assay. Analysis in a subgroup of newly diagnosed treatment naïve GD/GO patients also revealed overall favorable results for the TSI-assay. Increasing the cut-off for negativity resulted in increased specificity for both assays, with similar results using two or three times the cut-off. Most patients with concordant positive results for TBII and TSI suffered from GD or GD + GO (n = 110, 95.6 %), while patients negative for both TBII and TSI mostly suffered from other (thyroid) disease (n = 143, 77.3 %). From patients with positive TBII but negative TSI only 42.1 % had GD/GO (n = 16), whereas 57.9 % (n = 22) had other (thyroid) disease. In contrast, 88.9 % of patients with positive TSI but negative TBII had GD/GO (n = 16), whereas 11.1 % (n = 2) had other (thyroid) disease.

Conclusion

In our academic thyroid center, the diagnostic performance of the TSI-assay outperformed the TBII-assay. Using a higher cut-off value for negativity can be helpful in assessing clinical relevance.

Clinical phenotypes of euthyroid, hyperthyroid, and hypothyroid thyroid-associated ophthalmopathy

OBJECTIVE

To compare the demographic and clinical phenotypes of thyroid-associated ophthalmopathy (TAO) with euthyroidism (Eu-TAO), hyperthyroidism (Hr-TAO), and hypothyroidism (Ho-TAO).

METHODS

We enrolled 2158 TAO patients in this retrospective study and assessed their demographics, clinical manifestations, activity, and severity.

RESULTS

Among the enrolled patients, 526 (24.37%) had Eu-TAO, 1544 (71.55%) had Hr-TAO, and 88 (4.08%) had Ho-TAO. Compared to Hr-TAO (2.02) and Ho-TAO (2.52) patients, Eu-TAO (1.57) patients had the lowest female-to-male ratio (p = 0.026). The mean ages of Eu-TAO, Hr-TAO, and Ho-TAO patients were 43.11 ± 12.05, 42.23 ± 13.63, and 47.39 ± 13.28 years, respectively (p = 0.001). Patients with Eu-TAO had more unilateral involvement (50% vs. 14.38% vs. 21.59%, p < 0.001) than Hr-TAO or Ho-TAO patients. Clinically active TAO patients presented 8.56% in euthyroid vs. 13.86% in hyperthyroid vs. 11.36% in hypothyroid (p = 0.006). Regarding the severity of the European Group on Graves' Orbitopathy (EUGOGO) classification among euthyroid, hyperthyroid, and hypothyroid patients, mild TAO was present in 67.68, 54.27, and 72.72% of participants, moderate-to-severe TAO in 31.18, 42.49, and 26.14%, and sight-threatening TAO in 1.14, 3.24, and 1.14%, respectively. Eu-TAO was positively correlated with unilateral involvement (OR = 5.671, p < 0.001) and age (OR = 1.013, p = 0.003) and negatively correlated with the female-to-male ratio (OR = 0.656, p < 0.001) and TAO severity (OR = 0.742, p < 0.01).

CONCLUSIONS

Eu-TAO patients are older and less likely to be female, and show more unilateral and milder clinical phenotypes than hyper/hypothyroid TAO patients.

Clinical relevance of thyroid-stimulating immunoglobulin as a biomarker of the activity of thyroid eye disease

BACKGROUND/OBJECTIVES

Although it has been reported that thyroid-stimulating immunoglobulin (TSI) is associated with the clinical characteristics of thyroid eye disease (TED), there is a paucity of literature regarding the role of TSI in diagnosing active TED. This study investigated the relationship between the level of TSI and the activity of TED and assessed the cut-off value of TSI discriminating active TED from inactive TED.

METHODS

This cross-sectional study included 101 patients with TED. TSI was quantitatively measured with a cell-based bioassay using a chimeric TSH receptor and a cyclic adenosine monophosphate response element-dependent luciferase. The association between TSI and a variety of demographic and clinical features of TED was analysed. Multivariate regression analysis was performed to determine possible independent factors affecting the level of TSI.

RESULTS

TSI level was higher in males than in females (p = 0.023) and smokers than in nonsmokers (p = 0.004). TSI level was inversely correlated with the duration of ocular symptoms (r = -0.295, p = 0.003). The level of TSI was also significantly different when compared to the thyroid function (p = 0.003), TED activity (p < 0.001), and TED severity (p = 0.001). Multivariate regression analysis revealed a significant relationship between TED activity and thyroid function jointly and the TSI level. The cut-off level of TSI for predicting active TED was a specimen-to-reference ratio of 406.7 (p < 0.001, area under the curve = 0.847, sensitivity 77.4%, specificity 81.3%).

CONCLUSIONS

TSI was a functional biomarker strongly associated with TED activity even after being adjusted by other clinical characteristics. Serum TSI level may help identify patients with active TED in clinics.

Thyroid autoantibodies

Thyroid-stimulating hormone (TSH) receptor antibody (TSH-R-Ab or TRAb) testing plays a pivotal role in arriving at the aetiological diagnosis in patients with thyrotoxicosis. A positive test establishes the diagnosis of Graves' disease (GD) while a negative result in conjunction with imaging studies supports other possible aetiologies. In patients with GD, TRAb levels at diagnosis and at the time of withdrawal of antithyroid drugs can identify patients who are unlikely to achieve remission and guide clinical management decisions. We provide an algorithm that incorporates TRAb in the decision-making process for the management of thyrotoxicosis. The utility of TRAb in predicting the risk of fetal and neonatal thyroid dysfunction is established and widely accepted in guidelines. TRAb may also help in the diagnosis of Graves' orbitopathy, especially in euthyroid or hypothyroid patients and its role in guiding its management is evolving as a useful adjunct to the clinical parameters used in making therapeutic decisions.Anti-thyroid peroxidase antibodies (TPOAb) and anti-thyroglobulin antibodies (TgAb) indicate thyroid autoimmunity. The most common use of TPOAb is to identify patients at a higher risk of progression to treatment-requiring hypothyroidism. They also aid the diagnosis of immune thyroiditis and Hashimoto's encephalopathy. Thyroglobulin measurement is used to help guide differentiated thyroid cancer treatment. TgAb is used as an accompanying test with thyroglobulin measurement as its presence can interfere with the thyroglobulin assay. A negative TgAb result reduces the likelihood of, but does not exclude, interference with thyroglobulin assay.

A review of TSHR- and IGF-1R-related pathogenesis and treatment of Graves' orbitopathy

Graves' orbitopathy (GO) is an organ-specific autoimmune disease, but its pathogenesis remains unclear. There are few review articles on GO research from the perspective of target cells and target antigens. A systematic search of PubMed was performed, focusing mainly on studies published after 2015 that involve the role of target cells, orbital fibroblasts (OFs) and orbital adipocytes (OAs), target antigens, thyrotropin receptor (TSHR) and insulin-like growth factor-1 receptor (IGF-1R), and their corresponding antibodies, TSHR antibodies (TRAbs) and IGF-1R antibodies (IGF-1R Abs), in GO pathogenesis and the potentially effective therapies that target TSHR and IGF-1R. Based on the results, OFs may be derived from bone marrow-derived CD34+ fibrocytes. In addition to CD34+ OFs, CD34- OFs are important in the pathogenesis of GO and may be involved in hyaluronan formation. CD34- OFs expressing Slit2 suppress the phenotype of CD34+ OFs. β-arrestin 1 can be involved in TSHR/IGF-1R crosstalk as a scaffold. Research on TRAbs has gradually shifted to TSAbs, TBAbs and the titre of TRAbs. However, the existence and role of IGF-1R Abs are still unknown and deserve further study. Basic and clinical trials of TSHR-inhibiting therapies are increasing, and TSHR is an expected therapeutic target. Teprotumumab has become the latest second-line treatment for GO. This review aims to effectively describe the pathogenesis of GO from the perspective of target cells and target antigens and provide ideas for its fundamental treatment.

Association of clinical course with thyroid-stimulating immunoglobulin in Graves’ ophthalmopathy in Mongolians

Graves’ ophthalmopathy (GO) is a complex inflammatory condition affecting the orbit and is often associated with Graves’ disease (GD). This study aims to determine the levels of thyroid-stimulating immunoglobulin (TSI) and thyroid-stimulating hormone receptor autoantibody (TSHR-ab) in the serum of patients with GO, compare it with the GD, and determine whether there is a correlation with the clinical course of GO. The cross-sectional study included 82 patients with GO, 81 patients with GD, and 75 healthy subjects. The ocular manifestations of GO were identified and evaluated by the clinical activity score (CAS) and severity of GO using the European Group of Graves’ Orbitopathy (EUGOGO). TSI and TSHR-ab levels in the serum of participants were determined with ELISA kits and correlated with clinical findings. A total of 238 participant’s data were analyzed. There were 14 patients (17%) with unilateral GO. The most common ocular signs were eyelid retraction 68 (82.3%) and proptosis 61 (74.4%). The mean CAS score was 2.65±1.64 in GO patients and was higher in men than women (P = 0.008). The mean of TSI was 37.95±35.41 in GO, 14.16±15.67 in GD, and 4.33±2.94 in healthy controls (P<0.0001). The TSI was significantly higher in patients with GO than in those with GD (P<0.0001). There were no correlations between TSI and TSHR-ab levels and CAS scores. However, we observed a correlation between the TSI level and the severity of GO (P = 0.023). The area under the ROC curve (AUC) of TSI was 0.933 and selected 14.1 IU/ml was the optimal cutoff value (98.78% of sensitivity, 83.97% of specificity). Our study showed that TSI is significantly related to GO and the severity of GO. Therefore, TSI can be used as a predictor of severe GO to help in prognostication, follow-up and treatment planning.

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.

An Interesting Case of Euthyroid Graves' Ophthalmopathy, With Negative Thyroid-Stimulating Hormone Receptor Antibodies

Thyroid eye disease (TED), also known as Graves' orbitopathy or ophthalmopathy (GO) or Graves' eye disease, is an autoimmune condition of the retroocular tissues associated with Graves' disease. In isolated GO, the patient can present without thyroid hormone dysfunction or systemic symptoms of Graves' disease, in which case it is called euthyroid Graves' ophthalmopathy (EGO). It is very rare for this condition to have negative thyroid-stimulating hormone receptor (TSHR) autoantibodies, and we present such a rare case of a young female, who had progressive bilateral vision loss, intermittent left-sided retroocular headache, and severe bilateral proptosis. The patient was diagnosed with EGO based on multidisciplinary consults, diagnostic orbital magnetic resonance imaging (MRI) results, and a good response to treatment with intravenous steroids. Later, the patient was followed as an outpatient and treated with thyroid orbitopathy-specific immunotherapy with teprotumumab. The patient's response to teprotumumab was excellent and caused significant improvement in visual acuity, proptosis, and chemosis. This adds valuable literature to the medical field and gives insight to clinicians to consider the diagnosis of GO even with seronegative TSHR autoantibodies and euthyroid hormone status. It also adds to the understanding of the complex pathophysiology of this rare condition.

Beyond classic concepts in thyroid homeostasis: Immune system and microbiota

It has long been known that thyroid hormones have implications for multiple physiological processes and can lead to serious illness when there is an imbalance in its metabolism. The connections between thyroid hormone metabolism and the immune system have been extensively described, as they can participate in inflammation, autoimmunity, or cancer progression. In addition, changes in the normal intestinal microbiota involve the activation of the immune system while triggering different pathophysiological disorders. Recent studies have linked the microbiota and certain bacterial fragments or metabolites to the regulation of thyroid hormones and the general response in the endocrine system. Even if the biology and function of the thyroid gland has attracted more attention due to its pathophysiological importance, there are essential mechanisms and issues related to it that are related to the interplay between the intestinal microbiota and the immune system and must be further investigated. Here we summarize additional information to uncover these relationships, the knowledge of which would help establish new personalized medical strategies.

A Promising Mouse Model of Graves' Orbitopathy Induced by Adenovirus Expressing Thyrotropin Receptor A Subunit

Background: Graves' orbitopathy (GO) is the most common and serious manifestation of Graves' disease (GD). It is characterized by orbital inflammation and tissue remodeling. Although several GO models have been reported, most lack a full assessment or mechanistic evaluation. Here, we established a promising mouse model mimicking many aspects of human GO with a frequency of 70% and characterized the key role of T cells in the progression of GO. Methods: An adenovirus expressing the human thyrotropin (TSH) receptor A subunit (Ad-TSHRA) was injected in the muscles of female BALB/C mice nine times to induce GO. At predetermined time points, histological examinations of retrobulbar tissues and thyroid glands were performed to dynamically monitor changes; serum autoantibodies and total thyroxine levels were examined to evaluate thyroid function. Flow cytometry of CD4+ T cell subgroups and RNA sequencing (RNA-Seq) of splenocytes were also performed to explore the underlying mechanism. Results: After nine injections, 7 of 10 mice challenged with Ad-TSHRA developed the orbital changes associated with GO. Seven mice manifested retrobulbar fibrosis, and four mice showed adipogenesis. Exophthalmia, conjunctival redness, and orbital lymphocyte infiltration were also observed in a subset of mice. The orbitopathy was first detected after seven injections and followed the hyperplastic change observed in thyroids after four injections. Flow cytometry revealed increased proportions of Th1 cells and decreased proportions of Th2 cells and regulatory T (Treg) cells in the splenocytes of GO mice. This change in CD4+ T cell subgroups was confirmed by orbital immunohistochemical staining. Genes involved in T cell receptor signaling, proliferation, adhesion, inflammation, and cytotoxicity were upregulated in GO mice according to the RNA-Seq; a trend of upregulation of these GO-specific genes was observed in mice with hyperthyroidism without orbitopathy after four injections. Conclusions: A GO mouse model was successfully established by administering nine injections of Ad-TSHRA. The model was achieved with a frequency of 70% and revealed the importance of T cell immunity. A potential time window from Graves' hyperthyroidism to GO was presented for the first time. Therefore, this model could be used to study the pathogenesis and novel treatments for GO.

Is There Evidence for IGF1R-Stimulating Abs in Graves' Orbitopathy Pathogenesis?

In this review, we summarize the evidence against direct stimulation of insulin-like growth factor 1 receptors (IGF1Rs) by autoantibodies in Graves’ orbitopathy (GO) pathogenesis. We describe a model of thyroid-stimulating hormone (TSH) receptor (TSHR)/IGF1R crosstalk and present evidence that observations indicating IGF1R’s role in GO could be explained by this mechanism. We evaluate the evidence for and against IGF1R as a direct target of stimulating IGF1R antibodies (IGF1RAbs) and conclude that GO pathogenesis does not involve directly stimulating IGF1RAbs. We further conclude that the preponderance of evidence supports TSHR as the direct and only target of stimulating autoantibodies in GO and maintain that the TSHR should remain a major target for further development of a medical therapy for GO in concert with drugs that target TSHR/IGF1R crosstalk.

Non-specific orbital inflammation: Current understanding and unmet needs

Non-specific orbital inflammation (NSOI) is a noninfectious inflammatory condition of the orbit. Although it is generally considered the most common diagnosis derived from an orbital biopsy, it is a diagnosis of exclusion, meaning that the diagnosis requires exclusion of a systemic process or another identifiable etiology of orbital inflammation. The clinical diagnosis of NSOI is ill-defined, but it is typically characterized by acute orbital signs and symptoms, including pain, proptosis, periorbital edema, chemosis, diplopia, and less commonly visual disturbance. NSOI poses a diagnostic and therapeutic challenge: The clinical presentations and histological findings are heterogeneous, and there are no specific diagnostic criteria or treatment guidelines. The etiology and pathogenesis of NSOI are poorly understood. Here we recapitulate our current clinical understanding of NSOI, with an emphasis on the most recent findings on clinical characteristics, imaging findings, and treatment outcomes. Furthermore, gene expression profiling of NSOI and its implications are presented and discussed.

Type 2 Autoimmune Polyglandular Syndrome Presenting with Hyperpigmentation and Amenorrhea

A 36-year-old female presented with lethargy, anorexia, nausea, hyperpigmentation, weight loss and amenorrhea for six months. On examination, she had hyperpigmentation of face, hands and oral mucosa. Investigations revealed adrenal insufficiency and subclinical hyperthyroidism with elevated anti-thyroid peroxidase antibodies. Adrenal insufficiency in combination with Grave's disease and/or type 1 diabetes mellitus occurs in type 2 autoimmune polyglandular syndrome. It is a polygenic disorder occurring due to mutations in the human leukocyte antigen complex on chromosome 6. The patient was treated with oral hydrocortisone which led to improvement in all the symptoms.