TSH Receptor Autoantibodies Research Articles

A Tear Metabolomic Profile Showing Increased Ornithine Decarboxylase Activity and Spermine Synthesis in Thyroid-Associated Orbitopathy.

About half of patients with Graves’ disease develop an orbitopathy related to an inflammatory expansion of the periorbital adipose tissue and muscles. We used a targeted metabolomic approach measuring 188 metabolites by mass spectrometry to compare the metabolic composition of tears in patients with active (n = 21) versus inactive (n = 24) thyroid-associated orbitopathy. Among the 44 metabolites accurately measured, 8 showed a significant alteration of their concentrations between the two groups. Two short-chain acylcarnitines, propionylcarnitine and butyrylcarnitine, and spermine showed increased concentrations in the tears of patients with active orbitopathy, whereas ornithine, glycine, serine, citrulline and histidine showed decreased concentrations in this group. In addition, the ratio putrescine/ornithine, representing the activity of ornithine decarboxylase, was significantly increased in patients with active compared to inactive orbitopathy (p = 0.0011, fold change 3.75). The specificity of this candidate biomarker was maintained when compared to a control group with unclassified dry eye disease. Our results suggest that the stimulation of ornithine decarboxylase by TSH receptor autoantibodies in orbital fibroblasts could lead to increased synthesis of spermine, through the increased activity of ornithine decarboxylase, that may contribute to periorbital expansion in Graves’ ophthalmopathy.

Relationship between Serum Thyroid-stimulating Hormone Receptor Autoantibodies and Activity and Severity of Thyroid Eye Disease

Purpose: To study the relationship between the levels of serum thyroid-stimulating hormone (TSH)-receptor autoantibodies (TRAbs) and thyroid eye disease (TED) activity and severity scores.Methods: A cross-sectional study was performed. The medical records of 315 patients diagnosed with TED between March 2014 and December 2019 were reviewed. The clinical activity score (CAS) was used to assess TED activity and a modified NOSPECS score was used for severity grading. The serum TRAb level was measured using two assays: a TSHR binding inhibitory immunoglobulin (TBII) assay and thyroid stimulating immunoglobulin (TSI) bioassay.Results: The TBII and TSI assay results were significantly positively correlated with the CAS (R = 0.113 and 0.211, respectively; <i>p</i> < 0.05), modified NOSPECS score (R = 0.173 and 0.316, respectively; <i>p</i> < 0.05), and proptosis (R = 0.136 and 0.167, respectively; <i>p</i> < 0.05). Both assays demonstrated significant differences in the level of TRAb between patients with and without compressive optic neuropathy or corneal epithelial defects.Conclusions: The levels of TRAbs according to both TBII and TSI assays showed significant correlations with clinical signs of corneal involvement, optic neuropathy, and TED activity and severity.

Role of the mononuclear cell infiltrate in Graves' orbitopathy (GO): results of a large cohort study.

The extent to which mononuclear cells and TSH-receptor autoantibodies (TRAb) contribute to Graves' orbitopathy (GO) is not completely defined. Here we investigated the relationship between the immunohistochemical phenotype of orbital infiltrating cells and GO features in a large number of patients. We conducted an observational cohort study in 76 consecutive patients with GO (16 men and 60 women) who underwent orbital decompression over a period of 18 consecutive months. An ophthalmological evaluation was performed in all patients, as well as immunohistochemistry for CD3, CD4, CD8, CD56 (T-cell markers), CD25 (T and B-cell marker), CD20, CD19 (B-cell markers), and CD138 (plasmacell marker) in specimens collected at decompressive surgery. Having established cutoff values for each marker, cell infiltrates were found in 60 patients (78.9%; CD3: 39.4%, CD4 55.2%, CD8 50%, CD56: 0%, CD25: 28.9%, CD20: 51.3%, CD19: 25%, CD138: 26.3%). Eleven (14.4%) stained exclusively for CD138 (plasmacells). Patients with CD4-positive mononuclear cells had a significantly greater GO clinical activity score (CAS) (mean difference 1.07, 95% CI - 0.33 to - 1.82, P = 0.004 by univariate, P = 0.05 by multivariate analysis). CAS as well as the remaining GO features were not affected significantly by the mononuclear cell subpopulations in multivariate analyses. Mononuclear cell infiltrates are present in the majority of GO patients, with a small percentage represented exclusively by plasmacells. CD4 cells exert a major role on GO activity. These findings may represent a further advancement in the comprehension of GO pathogenesis.

Predicting the Course of Graves' Orbitopathy Using Serially Measured TSH-Receptor Autoantibodies by Automated Binding Immunoassays and the Functional Bioassay.

The aim of the study was to investigate the use of serial measurements of TSH-receptor autoantibodies (TRAb) with the newest available assay technology to predict the course of Graves' Orbitopathy (GO) during the first 24 months from disease onset. Serial serum samples from patients with GO (103 mild/135 severe) were collected between 2007 and 2017 and retrospectively analyzed. The course of GO were classified into mild/severe 12 months after manifestation (severe: NOSPECS≥5; mild<5). TRAb were measured with automated binding immunoassays (IU/l): TRAb Elecsys (Cobas, Roche), TRAb bridge assay (IMMULITE, Siemens), and a cell-based bioassay (percent of specimen to reference ratio - SRR%) (Thyretain, Quidel). Variable cut off levels of measured TRAb were calculated at specificity of 90% from receiver operator curve (ROC) analysis for several timepoints during the course of GO. To select one: 5-8 months after first GO symptoms, which is the timepoint for usual referals for treatment mild course could be predicted at cut offs of 1.5 IU/l (Elecsys), 0.8 IU/l (Immulite) and 402% SRR (Thyretain) and the risc of severe course has to be anticipated if TRAb are above 11.6 IU/l (Elecsys), 6.5 IU/l (Thyretain), and 714% SRR (Thyretain). The Thyretain bioassay showed the highest diagnostic sensitivity (using the commercial cut off's) over the entire follow up period. TRAb measurements during the 24-month follow up of GO provide added value to the GO clinical activity and severity scores and should be used especially in the event of an unclear decision-taking situation with regard to therapy.

Evaluation of the application of TSH receptor stimulating autoantibodies and the optimization of detection strategy in Graves’ disease

BackgroundWe evaluated the use of thyroid stimulating immunoglobulin (TSI) assay to optimize the detection strategy for Graves’ disease. MethodsFive hundred and forty-four well characterized serum samples from the Clinical Laboratory of Shanghai Tongren Hospital were collected from August 2019 to April 2020. The serum samples were obtained from 52 untreated GD patients, 155 treated GD patients, 83 patients with Hashimoto's thyroiditis, 70 patients with thyroid nodules, 83 patients with thyroid cancer, and 101 healthy subjects. All samples were evaluated by both TSI assay and TSH receptor autoantibodies (TRAb) assay. Moreover, 23 patients without a distinct thyroid disease diagnosis at the first visit were monitored for 6 months to make a final diagnosis. ResultsThe clinical sensitivity of the TSI and TRAb assays was 98.10% and 94.20% respectively, while the clinical specificity was 92.30% and 96.70% respectively. ROC plot analysis based on sera of UT-GD (newly diagnosed GD patients) revealed an area under the curve (AUC) of 0.974 for the TSI assay. The best cutoff value was 0.58 IU/l (98.0% of sensitivity, 92.8% of specificity). The AUC for the TRAb assay was 0.961. Furthermore, combining TSI and TRAb results, the area under the curve was 0.981. In a pilot study of 23 patients with an uncertain initial diagnosis, the follow-up results showed the clinical diagnosis of 22 out of 23 cases were resolved in agreement with the results obtained by the TSI assay, and one case matched the result obtained by TRAb assay. ConclusionThe TSI assay presents very promising analytical characteristics and could be adopted in clinical practice to improve GD diagnosis. The TSI assay might be better than TRAb assay in initial differential diagnosis of GD from other thyroid diseases.

Graves' Disease during Immune Checkpoint Inhibitor Therapy (A Case Series and Literature Review).

Simple SummaryImmune checkpoint inhibitor (ICPi)-induced thyroid dysfunction is a frequent immune-related adverse event (irAE). ICPi-induced thyrotoxicosis is usually the first stage of a biphasic thyroiditis with secondary hypothyroidism, whereas ICPi-induced Graves’ disease (GD), due to the stimulating activity of TSH-receptor autoantibodies, is extremely rare. The aim of this study was to describe the characteristics and evolution of GD during ICPi therapy. We showed that in five patients with induced GD, two patients evolved into classical GD and the three other patients evolved as thyroiditis with short-term thyrotoxicosis and secondary long-term hypothyroidism, with the initial scintigraphic appearance seeming to predict their evolution. Three other patients had a diagnosis of GD before ICPi treatment: all evolved towards definitive hypothyroidism during treatment, without the appearance of irAE. None of the eight patients developed severe hyperthyroidism with life-threatening symptoms, nor significant Graves’ orbitopathy. Use of ICPis in this population with induced or pre-existing autoimmune GD disease therefore appears to be safe.Thyrotoxicosis is an adverse event associated with immune checkpoint inhibitors (ICPis) that occurs in 0.6 to 3.2% of treated patients, depending on ICPi class. Presentation usually consists of a biphasic thyroiditis with transient thyrotoxicosis and secondary hypothyroidism. ICPi-induced Graves’ disease (GD), due to the stimulating activity of TSH-receptor autoantibodies (TRAb), is extremely rare. The aim of this retrospective study was to describe the characteristics and evolution of GD during ICPi therapy. Five among 243 patients followed for ICPi-induced thyrotoxicosis showed TRAb positivity (2% of the cohort). GD occurred quickly after initiation of ICPis; its course was typical for two patients, with prolonged requirement for antithyroid drug treatment (ATD). The three other patients experienced biphasic thyroiditis with secondary hypothyroidism requiring long-term substitution. Three other patients had a diagnosis of GD before starting ICPis; they evolved toward hypothyroidism with early cessation of ATD and long-term substitution treatment during ICPi treatment. None developed significant Graves’ orbitopathy. ICPi treatment was not interrupted for thyroid dysfunction. In conclusion, GD is a rare, immune-related adverse event of ICPis with an unusual course and frequent evolution to biphasic thyroiditis. In the case of ICPi-induced thyrotoxicosis in the presence of TRAb, observing the spontaneous evolution and performing a scintigraphy are useful before starting ATD treatment. Pre-existing GD is not exacerbated by ICPis and tends to evolve towards hypothyroidism. ICPi treatment can be maintained with adequate biochemical surveillance.

Predicting the Relapse of Hyperthyroidism in Treated Graves' Disease with Orbitopathy by Serial Measurements of TSH-Receptor Autoantibodies.

The aim of this study was to investigate the potential of the new TSH-receptor antibody (TRAb) assays to predict remission or relapse of hyperthyroidism in patients with Graves' disease (GD) and Graves' orbitopathy (GO). TRAbs were measured retrospectively in sera from a cohort of GD patients with GO (n=117; remission n=38 and relapse n=79-Essen GO biobank) with automated binding immunoassays: TRAb Elecsys (Cobas Roche) and TRAb bridge assay (IMMULITE, Siemens), and the TSAb (thyroid stimulating Ab) cell-based bioassay (Thyretain, Quidel Corp.). To identify relapse risk/remission of hyperthyroidism patients were followed up at least 10 months after the end of antithyroid drug therapy (ATD) therapy. ROC plot analysis was performed to calculate cut-off levels of TRAb and TSAb for prediction of relapse and remission of hyperthyroidism. Cut-off serum levels are provided for timepoints around 3, 6, 10, and 15 months after the beginning of ATD. Repeated measurements of TRAb increase the rate of relapses predictions to 60% (Elecsys), 70% (IMMULITE), and 55% (Thyretain). Patients with remission have consistently TRAb levels below the cut off for relapse in repeated measurements. The cell-based bioassay was the most sensitive - and continued to be positive during follow up [at 15 months: 90% vs. 70% (IMMULITE) and 65% (Elecsys)]. Identification of relapsing hyperthyroidism is possible with automated immunoassays and cell-based bioassay especially with serial TRAb measurements during the course of ATD therapy. Patient who need eye surgery may profit from an early decision towards definitive treatment.

Modulating gut microbiota in a mouse model of Graves\u2019 orbitopathy and its impact on induced disease

BackgroundGraves’ disease (GD) is an autoimmune condition in which autoantibodies to the thyrotropin receptor (TSHR) cause hyperthyroidism. About 50% of GD patients also have Graves’ orbitopathy (GO), an intractable disease in which expansion of the orbital contents causes diplopia, proptosis and even blindness. Murine models of GD/GO, developed in different centres, demonstrated significant variation in gut microbiota composition which correlated with TSHR-induced disease heterogeneity. To investigate whether correlation indicates causation, we modified the gut microbiota to determine whether it has a role in thyroid autoimmunity. Female BALB/c mice were treated with either vancomycin, probiotic bacteria, human fecal material transfer (hFMT) from patients with severe GO or ddH2O from birth to immunization with TSHR-A subunit or beta-galactosidase (βgal; age ~ 6 weeks). Incidence and severity of GD (TSHR autoantibodies, thyroid histology, thyroxine level) and GO (orbital fat and muscle histology), lymphocyte phenotype, cytokine profile and gut microbiota were analysed at sacrifice (~ 22 weeks).ResultsIn ddH2O-TSHR mice, 84% had pathological autoantibodies, 67% elevated thyroxine, 77% hyperplastic thyroids and 70% orbital pathology. Firmicutes were increased, and Bacteroidetes reduced relative to ddH2O-βgal; CCL5 was increased. The random forest algorithm at the genus level predicted vancomycin treatment with 100% accuracy but 74% and 70% for hFMT and probiotic, respectively. Vancomycin significantly reduced gut microbiota richness and diversity compared with all other groups; the incidence and severity of both GD and GO also decreased; reduced orbital pathology correlated positively with Akkermansia spp. whilst IL-4 levels increased. Mice receiving hFMT initially inherited their GO donors’ microbiota, and the severity of induced GD increased, as did the orbital brown adipose tissue volume in TSHR mice. Furthermore, genus Bacteroides, which is reduced in GD patients, was significantly increased by vancomycin but reduced in hFMT-treated mice. Probiotic treatment significantly increased CD25+ Treg cells in orbital draining lymph nodes but exacerbated induced autoimmune hyperthyroidism and GO.ConclusionsThese results strongly support a role for the gut microbiota in TSHR-induced disease. Whilst changes to the gut microbiota have a profound effect on quantifiable GD endocrine and immune factors, the impact on GO cellular changes is more nuanced. The findings have translational potential for novel, improved treatments.4q8n1pZy5-vhe69UMjHMVrVideo abstract

Third generation radioimmunoassay (RIA) for TSH receptor autoantibodies (TRAb) - one step less, similar results?

Aim TSH-receptor (TSHR)-autoantibody (TRAb) is the serological hallmark of Graves’ disease (GD). Recently, 3 rd -generation radioimmunoassays (RIA) employing monoclonal TRAb such as M22 or T7 instead of TSH for the inhibition of human TRAb binding with solid-phase TSHR (coated tubes) have been introduced into laboratory routine. Methods As current assays typically employ a consecutive incubation of patient serum and labelled monoclonal TRAb, automation of TRAb RIA is a challenge. Thus, the assay procedure using human TSHR-coated tubes and the mouse monoclonal TRAb T7 was modified by combining both steps. The novel one-step method was compared with its corresponding consecutive 3 rd -generation RIA by investigating 304 individuals encompassing 102 patients with active GD (GD a ), 43 patients with GD after successful therapy (GD t ), 31 with Hashimoto’s disease (HD), 28 with non-autoimmune thyroid diseases (NAITD) and 100 healthy subjects (HS). Results With the new method, the incubation time was shortened by approximately one hour. Both 3 rd -generation RIAs did not reveal a significantly different assay performance by comparing areas under the curve (AUC) with receiver operating characteristics curve analysis (AUC one-step: 0.94, AUC two-step: 0.96, p > 0.05, respectively). The two-step TRAb RIA demonstrated sensitivity and specificity values of 87.5 % and 96.2 %, respectively, whereas the one-step revealed 84.6 % and 96.2 %, respectively. Conclusion One-step 3 rd -generation RIA may be used for the reliable detection of TRAb. The shorter and easier assay design may improve its use and enable automation in routine nuclear medicine laboratories.

The Role of Nuclear Medicine in the Clinical Management of Benign Thyroid Disorders, Part 1: Hyperthyroidism.

Benign thyroid disorders, especially hyper- and hypothyroidism, are the most prevalent endocrine disorders. The most common etiologies of hyperthyroidism are autoimmune hyperthyroidism (Graves disease, GD), toxic multinodular goiter (TMNG), and toxic thyroid adenoma (TA). Less common etiologies include destructive thyroiditis (e.g., amiodarone-induced thyroid dysfunction) and factitious hyperthyroidism. GD is caused by autoantibodies against the thyroid-stimulating hormone (TSH) receptor. TMNG and TA are caused by a somatic activating gain-of-function mutation. Typical laboratory findings in patients with hyperthyroidism are low TSH, elevated free-thyroxine and free-triiodothyronine levels, and TSH-receptor autoantibodies in patients with GD. Ultrasound imaging is used to determine the size and vascularity of the thyroid gland and the location, size, number, and characteristics of thyroid nodules. Combined with lab tests, these features constitute the first-line diagnostic approach to distinguishing different forms of hyperthyroidism. Thyroid scintigraphy with either radioiodine or 99mTc-pertechnetate is useful to characterize different forms of hyperthyroidism and provides information for planning radioiodine therapy. There are specific scintigraphic patterns for GD, TMNG, TA, and destructive thyroiditis. Scintigraphy with 99mTc-sestamibi allows differentiation of type 1 from type 2 amiodarone-induced hyperthyroidism. The radioiodine uptake test provides information for planning radioiodine therapy of hyperthyroidism. Hyperthyroidism can be treated with oral antithyroid drugs, surgical thyroidectomy, or 131I-iodide. Radioiodine therapy is generally considered after failure of treatment with antithyroid drugs, or when surgery is contraindicated or refused by the patient. In patients with TA or TMNG, the goal of radioiodine therapy is to achieve euthyroid status. In GD, the goal of radioiodine therapy is to induce hypothyroidism, a status that is readily treatable with oral thyroid hormone replacement therapy. Dosimetric estimates based on the thyroid volume to be treated and on radioiodine uptake should guide selection of the 131I-activity to be administered. Early side effects of radioiodine therapy (typically mild pain in the thyroid) can be handled by nonsteroidal antiinflammatory drugs. Delayed side effects after radioiodine therapy for hyperthyroidism are hypothyroidism and a minimal risk of radiation-induced malignancies.

Correlation between serum anti-TSH receptor autoantibodies (TRAbs) and the clinical feature of Graves' orbitopathy.

Graves' orbitopathy (GO) is the most common extrathyroidal manifestation of Graves' disease (GD). Several studies support the involvement of TSH receptor autoantibodies (TRAbs) in the pathogenesis of GO, and a correlation between GO features and TRAbs has been reported, but not confirmed by all studies. Thus, we conducted a cross-sectional investigation to determine whether there is a correlation between TRAbs and the clinical features of GO in an initial phase of the eye disease. Ninety consecutive patients with untreated GO (67 women and 23 men, age 48.9 ± 12.6years) were included. Patients who had received treatments other than anti-thyroid drugs for hyperthyroidism or lubricants for GO were excluded. All patients underwent an endocrinological and ophthalmological evaluation, the latter including exophthalmometry, measurement of eyelid width, clinical activity score (CAS), visual acuity, assessment of diplopia, and NOSPECS score. TRAb levels were measured by a third-generation competitive immunoassay. There was a statistically significant, direct correlation between serum TRAb levels and CAS by linear regression analysis (R = 0.278, P = 0.007). The correlation was confirmed by a multiple regression analysis (R = 0.285; P = 0.006) including age and FT3 levels, which also correlated with CAS. There were no relationships between TRAbs and exophthalmometry, eyelid aperture, degree of diplopia, visual acuity, and NOSPECS score. The levels of TRAb in subjects with a recent-onset, untreated GO are directly correlated with the clinical activity of the disease, confirming a possible role of these antibodies in the pathogenesis ofGO.

Graves' disease.

Graves' disease (GD) is an autoimmune disease that primarily affects the thyroid gland. It is the most common cause of hyperthyroidism and occurs at all ages but especially in women of reproductive age. Graves' hyperthyroidism is caused by autoantibodies to the thyroid-stimulating hormone receptor (TSHR) that act as agonists and induce excessive thyroid hormone secretion, releasing the thyroid gland from pituitary control. TSHR autoantibodies also underlie Graves' orbitopathy (GO) and pretibial myxoedema. Additionally, the pathophysiology of GO (and likely pretibial myxoedema) involves the synergism of insulin-like growth factor 1 receptor (IGF1R) with TSHR autoantibodies, causing retro-orbital tissue expansion and inflammation. Although the aetiology of GD remains unknown, evidence indicates a strong genetic component combined with random potential environmental insults in an immunologically susceptible individual. The treatment of GD has not changed substantially for many years and remains a choice between antithyroid drugs, radioiodine or surgery. However, antithyroid drug use can cause drug-induced embryopathy in pregnancy, radioiodine therapy can exacerbate GO and surgery can result in hypoparathyroidism or laryngeal nerve damage. Therefore, future studies should focus on improved drug management, and a number of important advances are on the horizon.

SUN-LB78 Hyperfunctioning Papillary Thyroid Carcinoma With a BRAF Mutation

Background: Hyperfunctioning papillary thyroid carcinoma (PTC) is a rare tumor and accounts for less than 0.1% of all thyroid tumors. Information about its driver mutations is limited. Our literature search yielded 16 cases wherein a mutational analysis was conducted. Thyrotropin receptor (TSHR) mutations were identified in 11 of these cases. One case revealed a combination of TSHR and KRAS mutations. No mutations were identified in the other four cases. BRAFV600E is a prominent oncogene in PTC; however, hyperfunctioning PTC with this mutation has not yet been reported. Clinical Case: In a 48-year-old man, ultrasonography (US) during an annual medical checkup revealed a nodule at the right lobe of the thyroid gland. He visited the outpatient clinic for further evaluation. Thyroid function tests indicated that he was hyperthyroid with TSH level of 0.01 mIU/L (reference range: 0.05-5.00), free thyroxine level of 1.8 ng/dL (reference range: 0.9-1.7), and free triiodothyronine level of 4.3 pg/mL (reference range: 2.3-4.0). Serum thyroglobulin was 62.1 ng/mL (reference range: <33.7) and TSHR autoantibodies (TRAb) was <0.8 IU/L (reference range: <2.0 IU/L). B-mode US revealed a hypoechoic, heterogeneous nodule with largest diameter of 25 mm, and it had a jagged border and microcalcification. Color Doppler US revealed increased intranodular vascularity. The 99mTc thyroid scintigram revealed a round, right-sided focus of tracer uptake by the nodule with suppression in the remainder of the gland. These findings were consistent with an autonomously-functioning thyroid nodule. The patient underwent total thyroidectomy because fine-needle aspiration cytology revealed a malignant cytological diagnosis. The histopathological diagnosis of the patient was PTC, tall cell variant, pT2, pEx0, pN1b, and M0. Subsequent mutational analysis of BRAF (exon 15), TSHR (exons 9 and 10), GNAS (exons 7-10), KRAS, NRAS, HRAS (codons 12, 13, and 61), and TERT promoter (C250T and C228T) only identified a heterozygous point mutation in BRAFV600E in tissue samples. Conclusion: We report for the first time a case of hyperfunctioning papillary thyroid carcinoma with a BRAF mutation.

Practical applications of studies on the TSH receptor and TSH receptor autoantibodies

Studies on the TSH receptor (TSHR) have numerous practical applications in vitro and in vivo. For example human monoclonal autoantibodies (MAbs) to the TSHR are useful reagents for in vitro diagnostics. Measurement of TSHR autoantibodies (TRAbs) is helpful in diagnosis and management of autoimmune thyroid disease. Currently available highly sensitive and specific assays to measure TRAbs use the human TSHR MAb M22 instead of the TSH. Furthermore, preparations of the human TSHR MAb M22 are useful as the World Health Organisation International Standard for thyroid stimulating antibody and for calibration of the assays for measuring TRAbs. Preparations of thermostabilised TSHR extracellular domain have recently become available and this is likely to have an impact on improvements in specificity testing for TRAb assays. In addition the stable TSHR preparations have practical application for specific immunoadsorption of patient serum TRAbs. Human TSHR MAbs also have promising prospects as new therapeutics. Autoantibodies with TSHR antagonistic activities are “natural” inhibitors of TSHR stimulation and are expected to be helpful in controlling TSHR activity in patients with Graves’ disease, Graves’ ophthalmopathy and thyroid cancer.

Alternating Hyperthyroidism and Hypothyroidism in Graves’ Disease: A Case Report and Literature Review

Background: Alternating thyroid function between hypo- and hyperthyroidism is a very rare phenomenon attributed to the switch between the types of thyroid stimulating hormone receptor autoantibodies; thyroid stimulating antibody and thyroid stimulating hormone blocking antibody. Case Presentation: We report an 18 years old male who presented with hyperthyroidism attributed to Graves’ disease. He was treated with antithyroid medication. During follow up, his thyroid function was switching between hyper- and hypothyroidism which was difficult to treat with antithyroid medication. His laboratory investigations revealed high thyroid stimulating immunoglobulin and TSH binding inhibitory immunoglobulin. Due to the difficultly of managing him with antithyroid medication, he was offered a definitive management for his Graves’ disease. Conclusion: This case demonstrates a rare challenging presentation of Graves’ disease. Patients presenting with fluctuation in thyroid function between hyper-and hypothyroidism need a definitive management for Graves’ disease.

Reduced Retinal Microvascular Density Related to Activity Status and Serum Antibodies in Patients with Graves’ Ophthalmopathy

ABSTRACTObjective: To investigate changes in retinal capillary density (RCD) that occur in Graves’ ophthalmopathy (GO) and explore their association with the clinical manifestations for GO.Material and Methods: A total of 125 participants (93 GO patients and 32 normal subjects) were enrolled. All participants underwent ophthalmology and endocrinology examinations. Retinal microvasculature was imaged by spectral domain optical coherence tomographic angiography (OCT-A). The RCDs in the superficial and deep retinal capillary plexuses (SRCP and DRCP) were quantified by the custom software from the OCT-A images, which were divided into total annular zones (TAZ) and four quadrants. Multiple linear regression analysis was used to explore the associations between RCD and the relevant factors.Results: Significant reduction was seen in the TAZ zone in SRCP and DRCP of GO group (P < .05) when compared to the healthy subjects; significant differences remained after adjustment of vascular relevant factors. According to the univariate analysis, the relevant factors of higher IOP, larger proptosis, higher clinical activity scoring (CAS), thyroid stimulating hormone-receptor autoantibodies (TRAb), and 131I therapy were significantly associated with decreased RCDs in GO patients (P < .05). Multivariate linear regression analysis showed that CAS and TRAb were the most important relevant factors for decreased RCDs.Conclusions: The RCD of GO patients was significantly decreased compared to the healthy controls. The activity status and serum antibodies associated with GO were the relevant factors for reduced RCD.

Experimental Reproduction of Dynamic Fluctuation of TSH Receptor-Binding Antibodies Between Stimulation and Inhibition.

ContextHyperthyroidism in Graves disease (GD) is caused by autoantibody stimulation of the TSH receptor (TSHR). TSHR autoantibody (TSHR-Ab) activity is measured routinely by inhibition of labeled ligand (TSH or M22) binding to the TSHR [TSH-binding inhibitory immunoglobulins (TBIIs)] or by stimulation of cAMP production in isolated cells [TSH receptor–stimulating antibodies (TSAbs)]. Usually, measurements of TSHR-Abs by TBIIs agree reasonably well with TSAb values at least in the setting of hyperthyroidism, and both measurements tend to change in parallel during treatment with some exceptions. In this study, we describe three unusual cases, which illustrate nearly pure stimulating, blocking, or neutral properties of TSHR-Abs.ObjectiveWhether patient serum TSHR-Abs can be reproduced by mixtures of human monoclonal autoantibodies to the TSHR was studied because the sera in most patients show moderate properties having both of TBII and TSAb activities.DesignWe compared the TBII and TSAb activities of serum from four unusual patients in detail with mixtures of human monoclonal TSHR-Abs (mAbs) M22 (stimulating), K1-18 (stimulating), and K1-70 (blocking).ResultsCharacteristic of a patient’s serum was similar to M22 or K1-18, another was similar to K1-70, whereas another was similar to a mixture of K1-70 and M22 (or K1-18). Additionally, some patients seemed to have neutral TSHR-Abs in their sera.ConclusionsOur studies suggest that the characteristics of TSHR-Abs in the patient serum can be mimicked by mixtures of human mAbs to the TSHR, stimulating, blocking, and neutral if any.

Exophthalmos and multinodular goitre, an unusual combination.

SummaryMultinodular goitre is not associated with eye disease, unless in a rare case of Marine–Lenhart syndrome where it coexists with Grave’s disease. Therefore, other causes of exophthalmos need to be ruled out when the eye disease is seen in a patient with multinodular goitre. Confusion can arise in patients with features suggestive of Graves’ ophthalmopathy in the absence of thyroid-stimulating hormone receptor autoantibodies and no evidence of other causes of exophthalmos. We present a case of multinodular goitre in a patient with exophthalmos which flared up after iodine contrast-based study. A 61-year-old Australian presented with a pre-syncopal attack and was diagnosed with toxic multinodular goitre. At the same time of investigations, to diagnose the possible cause of the pre-syncopal attack, computerised tomographic (CT) coronary artery angiogram was requested by a cardiologist. A few days after the iodine contrast-based imaging test was performed, he developed severe eye symptoms, with signs suggestive of Graves’ orbitopathy. MRI of the orbit revealed features of the disease. Although he had pre-existing eye symptoms, they were not classical of thyroid eye disease. He eventually had orbital decompressive surgery. This case poses a diagnostic dilemma of a possible Graves’ orbitopathy in a patient with multinodular goitre.Learning points:Graves’ orbitopathy can occur in a patient with normal autothyroid antibodies. The absence of the thyroid antibodies does not rule out the disease in all cases.Graves’ orbitopathy can coexist with multinodular goitre.Iodine-based compounds, in any form, can trigger severe symptoms, on the background of Graves’ eye disease.

Nanoparticles Bearing TSH Receptor Protein and a Tolerogenic Molecule Do Not Induce Immune Tolerance but Exacerbate Thyroid Autoimmunity in hTSHR/NOD.H2h4 Mice.

Transgenic NOD.H2h4 mice that express the human (h) TSHR A-subunit in the thyroid gland spontaneously develop pathogenic TSHR autoantibodies resembling those in patients with Graves disease. Nanoparticles coupled to recombinant hTSHR A-subunit protein and a tolerogenic molecule (ligand for the endogenous aryl-hydrocarbon receptor; ITE) were injected i.p. four times at weekly intervals into hTSHR/NOD.H2h4 mice with the goal of blocking TSHR Ab development. Unexpectedly, in transgenic mice, injecting TSHR A-subunit-ITE nanoparticles (not ITE-nanoparticles or buffer) accelerated and enhanced the development of pathogenic TSHR Abs measured by inhibition of TSH binding to the TSHR. Nonpathogenic TSHR Abs (ELISA) were enhanced in transgenics and induced in wild-type littermates. Serendipitously, these findings have important implications for disease pathogenesis: development of Graves TSHR Abs is limited by the availability of A-subunit protein, which is shed from membrane bound TSHR, expressed at low levels in the thyroid. The enhanced TSHR Ab response following injected TSHR A-subunit protein-nanoparticles is reminiscent of the transient increase in pathogenic TSHR Abs following the release of thyroid autoantigens after radio-iodine therapy in Graves patients. However, in the hTSHR/NOD.H2h4 model, enhancement is specific for TSHR Abs, with Abs to thyroglobulin and thyroid peroxidase remaining unchanged. In conclusion, despite the inclusion of a tolerogenic molecule, injected nanoparticles coated with TSHR A-subunit protein enhanced and accelerated development of pathogenic TSHR Abs in hTSHR/NOD. NOD.H2h4 These findings emphasize the need for sufficient TSHR A-subunit protein to activate the immune system and the generation of stimulatory TSHR Abs in genetically predisposed individuals.

MON-593 Thyrotropin Receptor Stimulating Immunoglobulin: Clinical Utility in Graves' Disease Diagnosis

Introduction: Thyroid stimulating hormone receptor autoantibodies (TRAb) are a diagnostic hallmark of Graves' disease (GD) and their clinical performance have been extensively reported in the medical literature. One of the three subtypes of TRAb is stimulating (S-TRAb), which leads to unregulated thyroid hormone production by activating the TSH receptor on thyroid follicular cells. The aim of our study was to assess the clinical utility and accuracy of the immunoassay Siemens/Immulite TSI, that supposedly measures only S-TRAb and compare it with Roche/Cobas method which measures total TRAb, in the diagnosis of GD. Methods: We performed a prospective study, evaluating serum samples of 107 patients, between January and September of 2018: 36 with untreated GD (group 1) and 76 control subjects [group 2 - 40 with euthyroid multinodular goiter (EMNG), 24 with autoimmune thyroiditis (AIT) and 12 with toxic multinodular goiter (TMNG)]. GD was diagnosed according to the American Thyroid Association guidelines. Statistical analysis was performed using independent samples t-test. Results: Median value of TRAb and S-TRAb in group 1 patients was 13.3 (cut-off <1.7 UI/L) and 7.3 (cut-off <0.55 UI/L), respectively, versus 0.4 and 0.12 in group 2, respectively. In group 2, patients with TMNG had higher TRAb levels than patients with MNG and AIT (0.96 versus 0.48 and 0.49, respectively; p=0.011), but similar levels of TSI (0.14, 0.16 and 0.1, respectively; p=0.246).By receiver operating characteristics curve analysis, we obtained a TRAb value of 1.75 UI/L (sensitivity 97.8%; specificity 97.4%) and S-TRAb value of 0.75 UI/L (sensitivity 100%; specificity 98.7%) as the best cut-off values to diagnose GD. S-TRAb levels were positive in all GD patients and negative in all but one control (sensitivity 100%; specificity 98.7%), whereas TRAb were positive in all but one patient with GD and negative in all but two controls (sensitivity 96.8%; specificity 98.1%). Discussion:There are very few studies regarding the diagnostic utility and accuracy of S-TRAb in GD diagnosis. It has a very similar diagnostic accuracy compared to TRAb, but it could be useful in particular cases, as it has a slightly higher sensitivity and specificity and can accurately detect very low values of analyte.