Pathogenesis of thyroid-associated ophthalmopathy: does autoimmunity against calsequestrin and collagen XIII play a role?

Non-coding RNA-mediated epigenetic alterations in Grave's ophthalmopathy: A scoping systematic review

Background

It is becoming more and more apparent that Grave's Ophthalmopathy (GO) pathogenesis may be aided by epigenetic processes such as DNA methylation modifications, histone tail covalent modifications, and non-coding RNA (ncRNA)-based epigenetic processes. In the present study, we aimed to focus more on the miRNAs rather than lncRNAs due to lack of investigations on these non-coding RNAs and their role in GO's pathogenesis.

Methods

A six-stage methodology framework and the PRISMA recommendation were used to conduct this scoping review. A comprehensive search was conducted across seven databases to discover relevant papers published until February 2022. The data extraction separately, and quantitative and qualitative analyses were conducted.

Results

A total of 20 articles were found to meet inclusion criteria. According to the results, ncRNA were involved in the regulation of inflammation (miR-146a, LPAL2/miR-1287-5p axis, LINC01820:13/hsa miR-27b-3p axis, and ENST00000499452/hsa-miR-27a-3p axis), regulation of T cell functions (miR-146a/miR-183/miR-96), regulation of glycosaminoglycan aggregation and fibrosis (miR-146a/miR-21), glucocorticoid sensitivity (miR-224-5p), lipid accumulation and adipogenesis (miR-27a/miR-27b/miR-130a), oxidative stress and angiogenesis (miR-199a), and orbital fibroblast proliferation (miR-21/miR-146a/miR-155). Eleven miRNAs (miR-146a/miR-224-5p/miR-Let7d-5p/miR-96-5p/miR-301a-3p/miR-21-5p) were also indicated to have the capacity to be used as biomarkers.

Conclusions

Regardless of the fact that there is significant documentation of ncRNA-mediated epigenetic dysfunction in GO, additional study is needed to thoroughly comprehend the epigenetic connections concerned in disease pathogenesis, paving the way for novel diagnostic and prognostic tools for epigenetic therapies among the patients.

The Role of TPOAb in Thyroid-Associated Orbitopathy: A Systematic Review

INTRODUCTION

Thyroid-associated orbitopathy (TAO) is one of the most common autoimmune inflammatory disorders of the orbit. The presence of anti-thyroid antibodies is believed to play a role in the pathogenesis and clinical status of the TAO patients. Herein, we review the usefulness of TPOAb as a biomarker for TAO.

METHODS

A systematic search in MEDLINE library was conducted. Results: Twenty studies were included. TPO is expressed in orbital tissues, and the polymorphism rs11675434 SNP has proven to be associated with clinically evident TAO. Studies in pediatric patients have shown a positive correlation between high TPOAb levels and TAO. In contrast, results in adults are inconsistent. Some studies imply a protective role of TPOAb, yet the majority did not find any association. Some authors have suggested an implication of TPOAb in the pathophysiology of TAO in TRAb-negative patients.

CONCLUSIONS

The role of TPOAb in TAO remains unclear and controversial.

Changes of Volume Parameters in the Treatment of Graves Ophthalmopathy by Endoscopic Transethmoidal Decompression of the Orbital Inner Wall Combined with Fat Decompression

Objective

To observe the orbital volume changes and the analysis of surgical effect of Graves orbitopathy (GO) after endoscopic medial wall decompression combined with muscle cone fat.

Methods

Twenty-two patients (30 eyes) with Graves orbital disease who visited the Department of Ophthalmology of Ningbo Medical Center from December 2019 to September 2021 were retrospectively collected. All patients were diagnosed as nonorganic active stage before operation, and all of them received endoscopic transethmoidal decompression of the medial orbital wall combined with intramuscular orbital fat decompression due to decreased vision, visual field defect or color vision disorder, and concomitant proptosis. Regular follow-up after operation. The curative effect is judged according to the degree of improvement of visual acuity, color vision, degree of correction of exophthalmos, diplopia, and other complications at 9 months after operation. Orbital CT combined with computer aided measurement software (Mimics 21) was used to measure the changes of orbital volume before and after exophthalmos surgery. The relationship between the value and eyeball regression is analyzed.

Results

Preoperative exophthalmos ranged from 17.4 mm to 27.6 mm, with an average of (22.08 ± 2.86) mm. The postoperative exophthalmos was 14-25 mm, with an average of (19.52 ± 3.10) mm. Among them, 7 eyes (23.3%) had exophthalmos regression less than 1 mm, 6 eyes (20%) had a regression of 1-2 mm, 7 eyes (23.3%) had a regression of 2-3 mm, 5 eyes (16.7%) had a regression of 3-4 mm, and 5 eyes (16.7%) had a regression of 4-5.3 mm. The exophthalmos after operation was significantly lower than that before operation, and the difference was statistically significant (t = 9.909, P < 0.05). The preoperative orbital volume was 18.6 cm3-25.3 cm3 with an average of (22.39 ± 1.91) cm3. The postoperative orbital volume was 19.8 cm3-26.6 cm3, with an average of (23.89 ± 1.90) cm3.The orbital volume change range is 0.1 cm3-3.8 cm3, and the average orbital volume change is (1.51 ± 1.00) cm3. Compared with preoperative orbital volume, the difference was statistically significant (t = -8.074, P < 0.05).

Conclusion

Endoscopic decompression of the medial orbital wall through the ethmoid approach combined with decompression of the orbital fat within the muscle cone can effectively correct the exophthalmos while decompressing the orbital apex, and it is minimally invasive and has no facial scars. It has the advantages of extremely low incidence of postoperative diplopia and eye shift. There is a significant correlation between orbital volume changes and the regression of exophthalmos, which can provide reference for clinical guidance of surgical methods and prediction of surgical results.

Eye symptoms in patients with benign thyroid diseases

Thyroid diseases may cause a variety of functional and structural body changes, including eye and vision abnormalities, which can have a negative impact on a patient’s well-being. However, only a few studies on the impact of other benign thyroid diseases on the visual process are available in the literature. In this study, using the Polish version of the thyroid-specific quality of life (ThyPROpl) questionnaire, we aimed to determine the self-reported influence of benign thyroid diseases (e.g., nodular goiter, toxic nodular goiter, Graves’ disease, thyroid orbitopathy, Hashimoto’s thyroiditis, and surgical hypothyroidism) on patients’ eyes and vision. This was a prospective study. In total, 374 randomly selected euthyroid patients and 255 control subjects responded to the ThyPROpl questionnaire and the results were evaluated. Nearly 69% of the respondents reported that the most frequent condition was “reduced sight.” Men most often reported wet/tearing eyes (66%). The occurrence of eyelid sacks or swollen eyelids (64%), ophthalmalgia (62%), and eye dryness (61%) was marked almost as often. In total, 29% of the patients reported diplopia, and it was found to be most prevalent among those with thyroid orbitopathy. Other complaints were similarly prevalent among all the subgroups. A positive correlation was also observed between the scores of the “eye symptoms” and other ailments. Except for swelling around the lower eyelids, patients with thyroid diseases more frequently experienced all of the ocular complaints analyzed in this study compared with controls. This study showed that eye complaints are common in patients with benign thyroid diseases and ocular disturbances have a negative impact on the overall quality of life of patients.

Prognostic factors of restrictive myopathy in thyroid eye disease

To investigate the prognostic factors of extraocular muscle restriction in patients with thyroid eye disease (TED), 65 patients with TED and restrictive myopathy were evaluated. Demographics, clinical activity score (CAS), smoking status, thyroid disease status, thyroid hormone status, thyroid autoantibody status, orbital computed tomography (CT) scan at initial presentation, and treatment regimens were assessed. The movements of the most severely affected extraocular muscles were categorized into five grades. The patients were divided into the improved and the not-improved group based on the improvement in the limitation of the extraocular muscle excursion (LOM) throughout the follow-up, and the groups were compared using clinical factors. The mean LOM significantly improved from 2.3 ± 1.1 to 1.7 ± 1.2 after 1 year of follow-up. The excursion of the most restricted muscle improved in 32 patients but not in 33 patients during the follow-up. The initial concentration of the thyroid-stimulating antibody (TSAb) was significantly lower in the improved (229.3 ± 114.1) than in the not-improved group (345.0 ± 178.6) (P = 0.02) Age, sex, smoking status, CAS, thyroid status, and muscle thickness on the CT scan did not significantly differ in the groups. This study showed that the initial concentration of TSAb is a factor affecting the recovery of restrictive myopathy.

A case report of thyroid-associated Orbitopathy with elevated TPO antibodies

BACKGROUND

Thyroid associated orbitopathy (TAO) is defined as an immune mediated inflammatory process affecting the extraocular muscles, connective and adipose tissue of uncertain etiopathogenesis. TAO are classically described in Grave's disease (GD) however it may occur in euthyroid and hypothyroid patients. Those patients usually test positive for Thyroid Stimulating Hormone receptor antibodies (TRAb). For instance, only few cases of severe Hashimoto's thyroiditis (HT) associated orbitopathy with negative TRAb are reported to date.

CASE PRESENTATION

Herewith we report a rare case of a middle-aged female who presented with bilateral progressive upper and lower palpebral edema and a unilateral marked proptosis associated with asthenia, headache and decrease in visual acuity. Biological investigation was notable for high levels of anti-thyroid peroxidase antibodies (Anti-TPO) in an otherwise euthyroid patient with negative TRAb. Orbital Magnetic resonance imaging revealed edema of the extraocular muscles and inflammation of periorbital soft tissue. The patient received a treatment with intravenous methylprednisolone followed by oral treatment with prednisone. This regimen was both effective and safe with minimal metabolic side effects in our patient.

CONCLUSION

Minor ocular manifestations of HT are common; however, severe sight threatening ophtalmopathy in the absence of TRAb is rare. Multiple differential diagnosis should be considered and investigated before diagnosing this rare entity. Management of similar cases is currently based on reports and no clear guidelines have been elaborated, corticosteroids is the mainstream of treatment with a potential benefit of selenium supplementation in mild to moderate cases.

MicroRNAs and Autoimmune-Mediated Eye Diseases

MicroRNAs (miRNAs) are evolutionarily conserved short non-coding RNAs that act at post-transcriptional regulation of gene expression by destroying target messenger RNA or inhibiting its translation. Recently, miRNAs have been identified as important regulators in autoimmunity. Aberrant expression and function of miRNAs can lead to dysfunction of immune system and mediate autoimmune disorders. Here, we summarize the roles of miRNAs that have been implicated in three representative ocular autoimmune disorders, including autoimmune uveitis, Grave's ophthalmopathy, and Sjögren's syndrome dry eye, and discuss the potential of miRNAs as biomarkers and therapeutic targets for the diagnosis and treatment of these diseases.

Severe unilateral orbitopathy in a patient with Hashimoto's thyroiditis - a case report

Background

Thyroid-associated orbitopathy (TAO) constitutes an immune-mediated inflammation of the orbital tissues of unclear etiopathogenesis. TAO is most prevalent in hyperthyroid patients with Graves’ disease (GD); however, severe cases of orbitopathy associated with Hashimoto’s thyroiditis (HT) have rarely been described.

Case presentation

Herewith we report an unusual case of a middle-aged clinically and biochemically euthyroid woman with a stable HT, who developed a severe unilateral left-sided TAO. Thyrotropin receptor antibodies (TRAb) concentration was negative. Intraocular pressure in the left eye was mildly elevated (24 mmHg), while vision acuity was not compromised. Abnormal positioning of the eyeball suggested the extraocular muscles involvement. Unilaterally, von Graefe’s, Stellwag’s, Kocher’s and Moebius' signs were positive. Conjunctival erythema, redness and edema of the eyelid and an enlarged, swollen lacrimal caruncle were visible. She received 4/7 points in the Clinical Activity Scale (CAS) and class IV in the NO SPECS severity scale for the left eye (I-0, II-a, III-0, IV-b, V-0, VI-0). Magnetic resonance imaging (MRI) revealed thickening of the left medial rectus muscle with an increase in T2 signal intensity and prolonged T2 relaxation indicating an active form of TAO. The patient received therapy with glucocorticosteroids intravenously, followed by intramuscular injections with a cumulative dose of 3.24 g of methylprednisolone during a 9-week period with good tolerance. The applied therapy, combined with adequate L-thyroxine substitution, as well as vitamin D and selenium supplementation, resulted in a complete remission of ophthalmic symptoms.

Conclusions

Unilateral exophthalmos in TRAb-negative patients with HT is not a typical manifestation of the disease, and requires a wider differential diagnosis with MRI of the orbits. Scheme of three iv. pulses of methylprednisolone intravenously and the continuation of treatment with im. injections seems to be an effective and safe method of treatment in this group of patients. What is more, adequate vitamin D supplementation and the maintenance of biochemical euthyroidism may help to achieve an ultimate therapeutic effect. Patients with TAO in the course of HT need a careful and continued interdisciplinary approach both ophthalmological and endocrinological. Further studies are needed to elucidate the etiopathogenesis of TAO in TRAb-negative patients.

Biomarker identification of thyroid associated ophthalmopathy using microarray data

AIM

To uncover the underlying pathogenesis of thyroid associated ophthalmopathy (TAO) and explore potential biomarkers of this disease.

METHODS

The expression profile GSE9340, which was downloaded from Gene Expression Omnibus database, included 18 specimens from 10 TAO patients and 8 hyperthyroidism patients without ophthalmopathy. The platform was HumanRef-8 v2 Expression BeadChip. Raw data were normalized using preprocess. Core package and the differentially expressed genes (DEGs) were identified based on t-test with limma package of R. Functional enrichment analyses were performed recruiting the DAVID tool. Based on STRING database, a protein-protein interaction (PPI) network was constructed, from which a module was extracted. The functional enrichment for genes in the module was performed by the BinGO plugin.

RESULTS

In total, 861 DEGs (433 up-regulated and 428 down-regulated) between TAO patients and hyperthyroidism patients without ophthalmopathy were identified. Crucial nodes in the PPI network included TPX2, CDCA5, PRC1, KIF23 and MKI67, which were also remarkable in the module and all enriched in cell cycle process. Additionally, MKI67 was highly correlated with TAO. Besides, the DEGs of GTF2F1, SMC3, USF1 and ZNF263 were predicted as transcription factors (TFs).

CONCLUSION

Several crucial genes are identified such as TPX2, CDCA5, PRC1 and KIF23, which all might play significant roles in TAO via the regulation of cell cycle process. Regulatory relationships between TPX2 and CDCA5 as well as between PRC1 and KIF23 may exist. Additionally, MKI67 may be a potent biomarker of TAO, and SMC3 and ZNF263 may exert their roles as TFs in TAO progression.

A Case of Euthyroid Graves' Ophthalmopathy in a Patient Sero-Negative for TSH Receptor Autoantibody

We report of a case of Graves' ophthalmopathy presented solely with symptoms of the eyes with normal thyroid function tests and negative immunoreactive TSH receptor autoantibody. 40-year-old male was referred to our hospital due to 2-month history of ocular focusing deficit without any signs or symptoms of hyper- or hypothyroidism. Serum thyroid function tests and ^99mTc uptake were both within the normal range. Anti-thyroid autoantibodies were all negative except for the cell-based assay for serum TSH receptor stimulating activity. Since orbital CT scan and MRI gave typical results compatible with Graves' ophthalmopathy, we treated the patients with corticosteroid pulse therapy and orbital radiation therapy, leading to a partial improvement of the symptoms. This case gives insights into the potential pathophysiologic mechanism underlying Graves' ophthalmopathy and casts light upon the difficulties of establishing the diagnosis in a euthyroid case with minimal positive results for anti-thyroid autoantibodies.

Autoantibody against aldehyde dehydrogenase 2 could be a biomarker to monitor progression of Graves' orbitopathy

PURPOSE

This study surveyed the novel autoantigens expressed in the orbital fat tissue of patients with Graves' orbitopathy (GO) and explored the possibility of the autoantibodies against novel autoantigens as biomarkers for GO.

METHODS

We used immuno-proteomic methods to survey novel autoantigens expressed in the orbit fat tissue of GO patients and confirmed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

One protein spot (aldehyde dehydrogenase 2 (ALDH2)) revealed high reactivity with the GO serum than did the healthy control serum and was further verified by ELISA. We found that the plasma anti-ALDH2 antibody level was increased in GO patients compared to healthy control donors. In addition, anti-ALDH2 antibody level was correlated with GO activity classified by clinical activity score(r = 0.588, p < 0.001, using Pearson's correlation).

CONCLUSIONS

These increased levels of anti-ALDH2 antibody in GO serum suggested that ALDH2 could attribute target autoantigen in GO, and anti-ALDH2 autoantibody might serve as a biomarker for GO and help to predict disease activity.

Relationship between Clinical and Immunological Features of Thyroid Autoimmunity and Ophthalmopathy during Pregnancy

Problem. Clinical features of Graves' hyperthyroidism (GH) generally improve during pregnancy and rebound in the postpartum period. It is unclear whether the ophthalmopathy that is associated with GH and, less often, Hashimoto's thyroiditis (HT) changes in parallel with the thyroid associated antibody reactions and clinical features or runs a different course. Method of Study. We retrospectively studied 19 patients with autoimmune thyroid disease over 22 pregnancies: 9 pregnancies with GH and 13 with HT. Ophthalmopathy was defined by NOSPECS class. Results. Thyroid peroxidase (TPO) and thyroglobulin (Tg) antibody titres decreased during pregnancy and rose in the postpartum period. During pregnancy, 5 patients with GH and 4 patients with HT developed mild ophthalmopathy and two patients with GH and HT developed new upper eyelid retraction (UER). In the postpartum period, eye scores improved in 3 patients with GH and 3 with HT, remained stable in two and 5 patients, respectively, and worsened in 2 patients with GH and one with HT. Conclusions. In patients with mild to moderate eye signs associated with GH and HT, the orbital and thyroid reactions ran different courses during pregnancy. Since no patient had severe ophthalmopathy, we cannot draw definitive conclusions from this preliminary study.

Novel single-nucleotide polymorphisms in the calsequestrin-1 gene are associated with Graves' ophthalmopathy and Hashimoto's thyroiditis

BACKGROUND

The eye disorder associated with Graves' disease, called Graves' ophthalmopathy (GO), greatly reduces the quality of life in affected patients. Expression of the calsequestrin (CASQ1) protein in thyroid tissue may be the trigger for the development of eye muscle damage in patients with GO. We determined the prevalence of rs74123279, rs3747673, and rs2275703 single-nucleotide polymorphism (SNPs) in patients with autoimmune thyroid disorders, GO, Graves' hyperthyroidism (GH), or Hashimoto's thyroiditis (HT) and control subjects with no personal or family history of autoimmune thyroid disorders. Furthermore, we measured the concentration of the CASQ1 protein in normal and Graves' thyroid tissue, correlating levels with parameters of the eye signs, CASQ1 antibody levels, and the CASQ1 gene polymorphism rs74123279 and rs2275703.

METHODS

High-quality genomic DNA was isolated from fresh blood samples, assayed for identification of rs74123279, rs3747673, and rs2275703 SNPs in CASQ1 gene by MassARRAY SNP analysis using iPLEX technology of SEQUENOM.

RESULTS

DNA samples from 300 patients and 106 control subjects (100 males, 306 females) with GO (n=74), GH (n=130), HT (n=96) and control subjects (n=106) were genotyped for the SNPs rs74123279, rs3747673 (n=405), and rs2275703 (n=407). The SNP rs74123279, rs3747673, and rs2275703 were identified as 1) common homozygous or wild type, 2) heterozygote, and 3) rare homozygous. Minor allele frequency for rs74123279, rs3747763, and rs2275703 were 21%, 40%, and 44%, respectively. Multiple comparisons of genotype frequency for rs74123279, rs3747763, and rs2275703 in the GO, GH, HT, and control groups showed P=0.06, 0.641, and 0.189, respectively. These results were substantiated by multiple comparison of alleles frequency for rs74123279, rs3838216, rs3747763, and rs2275703 in the GO, GH, HT, and control groups showed, P=0.36, 0.008, 0.66, and 0.05, respectively. Pairwise analysis of alleles frequency distribution in patients with GO showed significant probability for rs2275703, P=0.008.

CONCLUSION

Based on their evolutionary conservation and their significant prevalence, we suggest that CASQ1 gene SNPs rs74123279, rs3838216, and rs2275703 may be considered as genetic markers for GO.

An overview of thyroid eye disease

Thyroid eye disease (also known as Graves’ ophthalmopathy) is a complex orbital inflammatory disease, which can be sight threatening, debilitating and disfiguring. This overview discusses the epidemiology, risk factors, pathogenesis, presentation, ophthalmic clinical features, investigations and treatment of thyroid eye disease.

Update on advanced imaging options for thyroid-associated orbitopathy

Thyroid-associated orbitopathy (TAO) is a diverse spectrum of signs and symptoms that appears to have immunologic and pathologic causative factors as diverse as its clinical presentations. Lymphocytes, hormones, and cytokines affect orbital fibroblasts and other similar cells, which exert their effects on orbital tissues, including the extraocular muscles, orbital fat, and optic nerve. This complicated inflammatory cascade and the myriad of clinical findings that result contributes to the active phase of TAO. The distinction between the active and inactive phases of TAO is an important one, as the proper treatment will depend on the disease phase and degree thereof. Several clinical grading scales and scores have been established to help qualify and quantify the disease severity. Aiding clinical exam and acumen, proper and reproducible imaging of the orbit and ocular adnexa is incredibly important to the management of TAO. Orbital ultrasound, computed tomography, magnetic resonance imaging, and scintigraphy each have unique abilities, including quantifying orbital changes, assessing disease activity, correlating orbital findings with clinical changes, guiding appropriate treatment, and monitoring therapeutic responses. Further, study ease, accessibility, cost, sensitivity, specificity, reproducibility, and risks are all important considerations in picking the right test with which to diagnose and follow TAO. This analysis will provide a review of orbital imaging for TAO, including the mechanism of each imaging technique as well as their rationales, advantages, disadvantages, and utilities.

Rituximab therapy in steroid-resistant severe hypothyroid Grave's ophthalmopathy

Association of Grave's ophthalmopathy with hyperthyroidism is well known, and it has also been reported in euthyroid or hypothyroid autoimmune thyroiditis, which rarely requires treatment. Here, we report a case of bilaterally symmetrical severe corticosteroid-resistant hypothyroid Grave's ophthalmopathy successfully treated with rituximab.

Eye findings and immunological markers in probands and their euthyroid relatives from a single family with multiple cases of thyroid autoimmunity

Background

Ophthalmopathy is a common manifestation of Graves’ disease (GD) occurring in up to 50% of patients. Mild eye signs are also common in patients with Hashimoto’s thyroiditis. Whilst a genetic predisposition to GD has been demonstrated this is not the case for the ophthalmopathy which often runs a separate course.

Objective

We determined the prevalences of eye and eyelid signs and positive thyroid and orbital antibody tests in first and second degree relatives from a single family with multiple cases of Graves’ disease, ophthalmopathy and Hashimoto’s thyroiditis.

Design

The study cohort comprised 16 subjects from the same family, 4 probands namely, 3 with GD and one with Hashimoto’s thyroiditis and hypothyroidism and 12 of their euthyroid first or second degree relatives. We measured antibodies against calsequestrin (CASQ1) and collagen XIII in an enzyme-linked-immunosorbent assays and TSH-Receptor (TSH-R) antibodies as i) TSH-R binding inhibiting immunoglobulin (TBII) and ii) thyroid stimulating immunoglobulin (TSI). Eye signs were classified and quantified using the clinical activity score (CAS), NOSPECS classes, Nunery types 1 and 2 and the margin-reflex-distance (MRD) as a measure of upper eyelid retraction (UER).

Main outcomes

Whilst significant ophthalmopathy was uncommon in the relatives, mild eye signs, in particular UER, were demonstrated in about a third of them. The presence of eye signs was moderately, but not significantly, associated with the detection of CASQ1 and collagen XIII antibodies, but not TSH-R antibodies.

Conclusion

Our study demonstrates a significant prevalence of positive orbital antibody tests and ophthalmopathy in probands with thyroid autoimmunity and their euthyroid relatives, favouring a role of genetic factors in the development of ophthalmopathy in patients with thyroid autoimmunity.

Determinants of extraocular muscle volume in patients with graves' disease

Background. To examine factors contributing to extraocular muscle (EOM) volume enlargement in patients with Graves' hyperthyroidism. Methods. EOM volumes were measured with orbital magnetic resonance imaging (MRI) in 39 patients with recently diagnosed Graves' disease, and compared to EOM volumes of 13 normal volunteers. Thyroid function tests, uptake on thyroid scintigraphy, anti-TSH-receptor antibody positivity and other parameters were then evaluated in patients with EOM enlargement. Results. 31/39 patients had one or more enlarged EOM, of whom only 2 patients had clinical EOM dysfunction. Compared to Graves' disease patients with normal EOM volumes, those with EOM enlargement had significantly higher mean serum TSH (0.020 ± 0.005 versus 0.007 ± 0.002 mIU/L; P value 0.012), free-T4 (52.9 ± 3.3 versus 41.2 ± 1.7 pmol/L; P value 0.003) and technetium uptake on thyroid scintigraphy (13.51 ± 1.7% versus 8.55 ± 1.6%; P value 0.045). There were no differences between the 2 groups in anti-TSH-receptor antibody positivity, the proportion of males, tobacco smokers, or those with active ophthalmopathy. Conclusions. Patients with recently diagnosed Graves' disease and EOM volume enlargement have higher serum TSH and more severe hyperthyroidism than patients with normal EOM volumes, with no difference in anti-TSH-receptor antibody positivity between the two groups.

Severe thyroid-associated orbitopathy in Hashimoto's thyroiditis. Report of 2 cases

Thyroid-associated orbitopathy (TAO) is characterized by immune-mediated inflammation of the extraocular muscles surrounding orbital connective tissue and adipose tissue. Severe orbitopathy related to autoimmune thyroid disease often occurs in patients with Grave's disease, but it is rare in patients with Hashimoto's thyroiditis. The pathogenesis of TAO is unclear. Several studies have noted a strong correlation between the levels of antibodies to thyrotropin receptor antibody (TRAb) and TAO in Graves' disease. Mild upper eyelid retraction has been reported to be common in Hashimoto's thyroiditis patients, however severe orbitopathy is rare. We report two cases of severe TAO in patients with Hashimoto's thyroiditis who required systemic glucocorticoid therapy and orbital irradiation to treat the TAO. The activity of the TAO was high in both patients, because their clinical activity scores (CAS) for the orbitopathy were high, and magnetic resonance imaging (MRI) showed enlargement of the extraocular muscles and an increase in T2 signal intensity and prolonged T2 relaxation time which indicate an active stage of inflammation. We tested the presence of TRAb by three different assays and were negative in both patients. Since the eye muscle damage cannot be due to TSH receptor antibodies, other pathogenetic mechanisms may be responsible for the orbitopathy in patients with Hashimoto's thyroiditis.