Clinical review about TRAb assay's history

Thyroid stimulating receptor autoantibodies

Thyroid-stimulating hormone receptor autoantibodies (TRAbs) play a crucial role as pathogenic antibodies in both the diagnosis and management of Graves' disease (GD). GD, an autoimmune disease resulting from a combination of genetic and environmental factors, is the most common cause of hyperthyroidism. With advancements in technology for TRAb detection and the availability of automated commercial kits, TRAb has become an essential clinical laboratory marker for the diagnosis of GD, as well as extra-thyroidal manifestations like Graves' ophthalmopathy (GO). This article provides a comprehensive review of TRAb, encompassing its clinical assays along with its significance in the clinical setting.

Changes in Clinical Activity, Serum Autoantibody Levels, and Chorioretinal Vessels After Systemic Glucocorticoid Therapy in Thyroid Eye Disease

INTRODUCTION

The aim of this study was to investigate changes in the Clinical Activity Score, serum thyroid-stimulating hormone receptor antibody and thyroid-stimulating immunoglobulin levels, chorioretinal blood vessels, and extraocular muscle thickness in patients with thyroid eye disease following systemic steroid treatment.

METHODS

This prospective observational study enrolled 57 patients with active thyroid eye disease who received systemic intravenous glucocorticoids for 12 weeks. Demographics, clinical activity scores, optical coherence tomography images, and serum thyroid-stimulating immunoglobulin and thyroid-stimulating hormone receptor antibody levels were assessed at baseline, at 6 and 12 weeks after intravenous (IV) GC therapy initiation, and 2 months after IV GC therapy termination. The extraocular muscle thickness, choroidal thickness, and choroidal vascularity index were measured.

RESULTS

The clinical activity scores showed a significant decrease. Serum thyroid-stimulating immunoglobulin levels dropped continuously for 2 months. The thyroid-stimulating hormone receptor antibody level decreased until 12 weeks after treatment but returned to within the normal range in 75% of patients after 77 and 126 days, respectively. The choroidal thickness decreased at all time points. The thickness of the medial and inferior rectus muscles decreased at 2 months after treatment. The clinical activity score decreased to < 3 points in 50% of patients after 78 days.

CONCLUSION

Intravenous glucocorticoid therapy improved the clinical activity score, chorioretinal blood flow, and extraocular muscle thickness. The serum autoantibody levels were normalized in patients with active thyroid eye disease 2 months after IV GC termination. The serum thyroid-stimulating immunoglobulin and thyroid-stimulating hormone receptor antibody levels correlated with restoration of chorioretinal capillary perfusion and improved clinical symptoms and muscle thickness. Non-invasive optical coherence tomography findings and serologic factors predict the response to intravenous glucocorticoid therapy.

Is there an association between endometriosis and thyroid autoimmunity?

OBJECTIVE

It has been suggested that non-uterine endometrial implants can express thyroid-stimulating hormone receptors, thus inducing the formation of thyroid-stimulating immunoglobulin. We aimed to compare the autoantibody positivity in patients with and without endometriosis and to determine whether there is a difference in the incidence of thyroid diseases.

METHODS

This prospective observational study was conducted on 102 women who had been operated on for benign gynecological diseases. Cases enrolling in the study were divided into two groups: the study group with endometriosis (n=51) and the control group without endometriosis (n=51). The blood tests for thyroid-stimulating hormone, free thyroxine (fT4), thyroid-stimulating immunoglobulin, and anti-thyroid peroxidase antibody levels were checked.

RESULTS

The mean thyroid-stimulating immunoglobulin level was found to be higher in the endometriosis group than in the control group. However, this difference was not statistically significant. No significant difference was detected between endometriosis and control groups in terms of anti-thyroid peroxidase antibody and thyroid-stimulating hormone levels. The mean fT4 value (0.97±0.13 ng/dL) of the endometriosis patients was found to be significantly lower than the control group (1.08±0.21 ng/dL) (p=0.002; p<0.05). The mean anti-thyroid peroxidase antibody value of cases with bilateral endometrioma (82.21±252.29 IU/mL) was significantly higher than cases with unilateral endometrioma (15.81±83.13 IU/mL) (p=0.028; p<0.05). There is a positive and significant relationship between the size of endometriosis and anti-thyroid peroxidase antibody values (p=0.011; p<0.05).

CONCLUSION

This study points to an association between endometrioma diameter and anti-thyroid peroxidase antibody values which can be a stepping stone for new studies evaluating this hypothesis further.

Establishment and analytical performance of light-initiated chemiluminescence assay method for detecting thyrotropin receptor antibody

Aim: To evaluate double-antibody competitive light-initiated chemiluminescence assay method for detecting the thyrotropin receptor antibody. Materials & methods: The optimal working concentrations of competitive antibody and rTSHR were confirmed by checkerboard titration. Assay performance was assessed by precision, linearity, accuracy, limit of blank and clinical evaluation. Results: The coefficient of variation for repeatability and intermediate precision was 3.9-5.9 and 0.9-1.3%, respectively. The correlation coefficient was 0.999 by least squares linear fitting in linearity evaluation. The relative deviation ranged from -5.9 to 4.1%, and the limit of blank of the method was 0.13 IU/l. Compared with the Roche cobas system (Roche Diagnostics, Mannheim, Germany), the relationship between the two assays was shown to be significantly correlative. Conclusion: The light-initiated chemiluminescence assay method for detecting thyrotropin receptor antibody is a rapid, novel and accurate method for thyrotropin receptor antibody measurement.

Development and application of animal models to study thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO), also known as Graves' ophthalmopathy, is an autoimmune disease that is usually accompanied by hyperthyroidism. Its pathogenesis involves the activation of autoimmune T lymphocytes by a cross-antigen reaction of thyroid and orbital tissues. The thyroid-stimulating hormone receptor (TSHR) is known to play an important role in the development of TAO. Because of the difficulty of orbital tissue biopsy, the establishment of an ideal animal model is important for developing novel clinical therapies of TAO. To date, TAO animal modeling methods are mainly based on inducing experimental animals to produce anti-thyroid-stimulating hormone receptor antibodies (TRAbs) and then recruit autoimmune T lymphocytes. Currently, the most common methods are hTSHR-A subunit plasmid electroporation and hTSHR-A subunit adenovirus transfection. These animal models provide a powerful tool for exploring the internal relationship between local and systemic immune microenvironment disorders of the TAO orbit, facilitating the development of new drugs. However, existing TAO modeling methods still have some defects, such as low modeling rate, long modeling cycles, low repetition rate, and considerable differences from human histology. Hence, the modeling methods require further innovation, improvement, and in-depth exploration.

Characteristics of Graves' disease in children and adolescents in Nanjing: A retrospective investigation study

Objective

This cross-sectional study analyzed the clinical characteristics of newly diagnosed Graves' disease (GD) in children and adolescents to provide clinical evidence for the early diagnosis of GD.

Method

From 2013 to 2019, information on children and adolescents with newly diagnosed GD admitted to the Department of Endocrinology, Children's Hospital of Nanjing Medical University, was collected, including clinical features and laboratory tests. The data were summarized and statistically analyzed.

Result

This study included 204 cases of newly diagnosed GD, with 158 females and 46 males. The average age at initial diagnosis was 8.9 ± 2.9 years. A total of 132 cases (64.7%) had symptoms before puberty, and 72 cases (35.3%) had symptoms during puberty. Goiter was detected in 193 cases (94.6%). There were 140 cases (68.6%) of exophthalmos, and 21.4% (30/140) were infiltrative. At initial diagnosis, 10 cases (4.9%) reported leukopenia, 18 cases (8.8%) reported neutropenia, and 15 cases (7.4%) reported mild anemia. There was 1 (0.5%) case of thrombocytopenia and 1 (0.5%) case of agranulocytosis. Fifty-four cases (26.5%) had impaired liver function.

Conclusion

GD is more common in female children and adolescents. Parents may ignore their children's hypermetabolic symptoms in the early stages of GD. Routine blood and liver function tests are recommended at initial diagnosis to exclude abnormal hemogram and liver function.

Outcomes of Early-Pregnancy Antithyroid Drug Withdrawal in Graves' Disease: A Preliminary Prospective Follow-Up Study

Objective: The use of antithyroid drugs (ATDs) carries potential risk for teratogenic effects. For women with well-controlled hyperthyroidism on a low dose of ATDs, drug withdrawal upon pregnancy is recommended by international medical guidelines. Therefore, it is necessary to determine the characteristics of patients suitable for ATD withdrawal, subsequent changes in thyroid function after ATD discontinuation, and its impact on pregnancy and offspring outcomes. Methods: This prospective study recruited 63 pregnant women with well-controlled Graves' hyperthyroidism who had stopped ATDs during early pregnancy. Patients were followed up until the end of pregnancy and data on pregnancy outcomes were collected. Results: Overall, 20 patients (31.7%) had rebound of hyperthyroidism. Patients with either subnormal thyrotropin (TSH) levels (TSH <0.35 mIU/L, odds ratio [OR] = 5.12, confidence interval [CI = 1.29-20.34], p = 0.03) or positive thyrotropin receptor antibody (TRAb) (TRAb >1.75 IU/L, OR = 3.79, [CI = 1.17-12.30], p = 0.02) at the time of ATDs withdrawal presented a higher risk of rebound than those with either normal TSH levels or negative TRAb. Patients with both subnormal TSH and positive TRAb at the time of ATD withdrawal were more likely to experience rebound (83.3%, 5/6) than those with both normal TSH and negative TRAb (13%, 3/23, OR = 33.33, [CI = 2.83-392.60], p = 0.003). The prevalence of adverse pregnancy outcomes was significantly higher in patients who experienced rebound compared with those who did not (55.0% vs. 9.3%, OR = 11.92, [CI = 3.08-46.18], p = 0.0002). Conclusions: Subnormal TSH levels and TRAb positivity at the time of ATD withdrawal in early pregnancy may be associated with rebound of Graves' hyperthyroidism. Rebound of hyperthyroidism during pregnancy may increase the risk of adverse pregnancy outcomes. Larger prospective studies are needed to confirm these findings.

The effect of radioiodine treatment on the characteristics of TRAb in Graves' disease

BACKGROUND

Graves' disease (GD) is one of the most common autoimmune thyroid diseases (AITDs) in humans, and thyrotropin receptor antibody (TRAb) is a characterized autoantibody in GD. The use of radioactive iodine therapy (RAI) for GD treatment is increasing.

OBJECTIVES

We studied the biological properties of TRAb and evaluated the effect of RAI therapy on TRAb in GD patients.

METHODS

In total, 225 patients (22 onset GD patients without ¹³¹I therapy, 203 GD patients treated with ¹³¹I therapy) and 20 healthy individuals as normal controls were included in this study. Clinical assessments were performed, and we examined in vitro the biological properties of TRAb in the 22 onset GD patients and 20 controls as well as 84 GD patients with ¹³¹I therapy.

RESULTS

Serum TRAb and thyroid peroxidase antibody (TPOAb) levels increased in the initial year of RAI treatment, and both antibodies decreased gradually after one year. After 5 years from radioiodine treatment, TRAb and TPOAb levels decreased in 88% and 65% of GD patients, respectively. The proportion of patients positive for thyroid-stimulatory antibody (TSAb) was significantly higher in the 7-12-month group, and thyroid-blocking antibody (TBAb) levels were elevated after one year in half of the patients who received ¹³¹I treatment.

CONCLUSIONS

Treatment of GD patients with radioiodine increased TPOAb and TRAb (their main biological properties were TSAbs) within the first year after therapy, and the main biological properties of elevated TRAb were TBAbs after 1 year.

Age Moderates the Impact of TRAbs on Thyroid Hormones and Hepatic Function in Patients with Graves' Disease

Thyrotropin receptor antibodies (TRAbs) play a significant role in the course of hepatic dysfunction (HDF) in patients with Graves' disease (GD). However, few studies have considered the factors that influence the relationships among TRAbs, thyroid hormone levels, and hepatic function in subjects with newly diagnosed GD. Here we investigated the associations of TRAbs with thyroid hormones and hepatic function and assessed potential factors that can influence these associations among patients with GD. A total of 368 patients newly diagnosed with GD were collected in this cross-sectional study. Patients who had received antithyroid drugs, radioactive iodine, or surgery were excluded. Levels of TRAbs and thyroid hormones and hepatic function were recorded. Linear and binary logistic regression analysis models were applied to investigate associations among these variables after adjusting for confounding characteristics. There was a significant difference in TRAbs indices between the HDF and normal hepatic function groups (p <0.05). After adjusting for confounders, the relationship between TRAbs and thyroid hormones was nonlinear, showing a curve with an initial positive slope and a subsequent flattening (p <0.05). Higher TRAbs were associated with HDF [odds ratio (OR) 1.036, 95% confidence interval (CI) 1.018-1.053 per 1-IU/l increase]. These associations were modified by age, but not by gender, smoking status, Graves' orbitopathy, thyroid-peroxidase antibody levels, or thyroglobulin antibody levels. In younger patients, increasing TRAbs were correlated with higher thyroid hormones and HDF (OR 1.034, 95% CI 1.017-1.052) per1-IU/l increase). In older patients, TRAbs were not correlated with thyroid hormones or HDF (OR 1.024, 95% CI 0.993-1.056) per 1-IU/l increase. Age can affect the impact of TRAbs on thyroid hormone levels and hepatic function in GD. TRAb measurement can have good predictive value in younger patients.

Natural autoantibodies to the gonadotropin-releasing hormone receptor in polycystic ovarian syndrome

CONTEXT

Polycystic ovarian syndrome (PCOS) is a complex disease with different subtypes and unclear etiology. Among the frequent comorbidities are autoimmune diseases, suggesting that autoantibodies (aAb) may be involved in PCOS pathogenesis.

OBJECTIVE

As the gonadal axis often is dysregulated, we tested the hypothesis that aAb to the gonadotropin-releasing hormone receptor (GnRH-R) are of diagnostic value in PCOS.

DESIGN

An in vitro assay for quantifying aAb to the GnRH-R (GnRH-R-aAb) was established by using a recombinant fusion protein of full-length human GnRH-R and firefly luciferase. A commercial rabbit antiserum to human GnRH-R was used for standardization. Serum samples of control subjects and different cohorts of European PCOS patients (n = 1051) were analyzed.

RESULTS

The novel GnRH-R-aAb assay was sensitive, and signals were linear on dilution when tested with the commercial GnRH-R antiserum. Natural GnRH-R-aAb were detected in one control (0.25%) and two PCOS samples (0.31%), and 12 samples were slightly above the threshold of positivity. The identification of samples with positive GnRH-R-aAb was reproducible and the signals showed no matrix interferences.

CONCLUSION

Natural GnRH-R-aAb are present in a very small fraction of adult control and PCOS subjects of European decent. Our results do not support the hypothesis that the GnRH-R constitutes a relevant autoantigen in PCOS.

The role of laboratory medicine in the diagnosis of the hyperthyroidism

Hyperthyroidism is a clinical condition characterized by inappropriately high synthesis and secretion of thyroid hormones by the thyroid gland. It has multiple aetiologies, manifestations and potential therapies. Graves' disease is the most common form of hyperthyroidism, due to the production of autoantibodies against thyrotropin receptor, capable of over-stimulating thyroid function. A reliable diagnosis of hyperthyroidism can be established on clinical grounds, followed by the evaluation of serum thyroid function tests (thyrotropin first and then free thyroxine, adding the measurement of free triiodothyronine in selected specific situations). The recent guidelines of both the American and European Thyroid Associations have strongly recommended the measurement of thyrotropin receptor autoantibodies for the accurate diagnosis and management of Graves' disease. If autoantibody test is negative, a radioiodine uptake should be performed. Considering the most recent laboratory improvements, binding assays can be considered the best first solution for the measurement of thyrotropin receptor autoantibodies in diagnosis and management of overt cases of Graves' disease. In fact, they have a satisfactory clinical sensitivity and specificity (97.4% and 99.2%, respectively) being performed in clinical laboratories on automated platforms together with the other thyroid function tests. In this setting, the bioassays should be reserved for fine and complex diagnoses and for particular clinical conditions where it is essential to document the transition from stimulating to blocking activity or vice versa (e.g. pregnancy and post-partum, related thyroid eye disease, Hashimoto's thyroiditis with extrathyroidal manifestations, unusual cases after LT4 therapy for hypothyroidism or after antithyroid drug treatment for Graves' disease). Undoubtedly, technological advances will help improve laboratory diagnostics of hyperthyroidism. Nevertheless, despite future progress, the dialogue between clinicians and laboratory will continue to be crucial for an adequate knowledge and interpretation of the laboratory tests and, therefore, for an accurate diagnosis and correct management of the patient.

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, 3rd-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 3rd-generation RIA by investigating 304 individuals encompassing 102 patients with active GD (GDa), 43 patients with GD after successful therapy (GDt), 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 3rd-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 3rd-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.

Non-Conventional Clinical Uses of TSH Receptor Antibodies: The Case of Chronic Autoimmune Thyroiditis

Anti TSH receptor antibodies (TSHrAb) are a family of antibodies with different activity, some of them stimulating thyroid function (TSAb), others with blocking properties (TBAb), it is a common finding that antibodies with different function might coexist in the same patient and can modulate the function of the thyroid. However, most of the labs routinely detect all antibodies binding to the TSH receptor (TRAb, i.e. TSH-receptor antibodies detected by binding assay without definition of functional property). Classical use of TSHr-Ab assay is in Graves' disease where they are tested for diagnostic and prognostic issues; however, they can be used in specific settings of chronic autoimmune thyroiditis (CAT) as well. Aim of the present paper is to highlight these conditions where detection of TSHr-Ab can be of clinical relevance. Prevalence of TSHrAb is different in in the 2 main form of CAT, i.e. classical Hashimoto's thyroiditis and in atrophic thyroiditis, where TBAb play a major role. Simultaneous presence of both TSAb and TBAb in the serum of the same patient might have clinical implication and cause the shift from hyperthyroidism to hypothyroidism and vice versa. Evaluation of TRAb is recommended in case of patients with Thyroid Associated Orbitopathy not associated with hyperthyroidism. At present, however, the most relevant recommendation for the use of TRAb assay is in patients with CAT secondary to a known agent; in particular, after treatment with alemtuzumab for multiple sclerosis. In conclusion, the routine use of anti-TSH receptor antibodies (either TRAb or TSAb/TBAb) assay cannot be suggested at the present for diagnosis/follow up of patients affected by CAT; there are, however, several conditions where their detection can be clinically relevant.

The Clinical Value and Variation of Antithyroid Antibodies during Pregnancy

Antithyroid antibodies, which include thyroid-stimulating hormone receptor antibodies (TRAbs), thyroid peroxidase antibodies (TPOAbs), and thyroid globulin antibodies (TgAbs), are widely known for their tight association with thyroid autoimmune diseases. The variation in all three kinds of antibodies also showed different trends during and after pregnancy (Weetman, 2010). This article reviewed the the physiological changes, while focusing on the variation of thyroid antibodies concentration in women during and after pregnancy, and adverse consequences related to their elevation. Since abnormal elevations of these antithyroid antibodies may lead to adverse outcomes in both mothers and fetuses, special attention must be paid to the titer of the antibodies during pregnancy. The molecular mechanisms of the variations in those antibodies have yet to be explained. The frequency and timing of thyroid antibody measurement, as well as different reference levels, also remain to be elucidated.

Remission Rate of Graves' Disease and the Trend of Changes in Serum TSH Receptor Antibodies in Prolonged Antithyroid Drug Treatment

Context: Graves’ disease is an autoimmune disease caused by thyrotropin receptor antibodies (TRAb). These antibodies can be measured and used for the diagnosis, prediction of remission, and risk of Graves’ orbitopathy development. There are three treatments for Graves’ disease that have remained unchanged for the last 75 years: Antithyroid drugs, radioiodine, and surgery. Antithyroid drugs are the first treatment option worldwide and are usually used for 12 - 18 months. Recent reports suggest the use of antithyroid drugs for more than 18 months with better outcomes. This review focuses on two aspects of treatment with antithyroid drugs: The impact of using antithyroid drugs for more than 12 - 18 months on remission rates and the trend of TRAb during prolonged antithyroid drug treatment. Evidence Acquisition: A review was performed in Medline on the published work regarding the duration of ATD treatment and remission of Graves' disease and also ATD treatment and TRAb status during the 1990 - 2019 period. Results: Remission rates are variable (30% - 80%), and many clinical and genetic factors serve as predictors. The long-term use of antithyroid drugs appears to increase remission rates. TRAb values usually decline during ATD treatment, but the trend could occur in two ways: Becoming negative or showing a fluctuating pattern. However, approximately 10% of the patients will remain TRAb-positive after five years of treatment with antithyroid drugs. Conclusions: Antithyroid drugs can be used for long periods with an increase in remission rates, and a gradual decrease in TRAb levels, with the disappearance of TRAb in 90% of the patients after 60 months.

General properties of autoimmune thyroid diseases and associated morbidities

Background Autoimmune thyroid diseases (ATDs) can be classified into two basic diseases: Graves' disease (GD) and Hashimoto's thyroiditis (HT). Here, we review the effectiveness of laboratory and imaging methods used for the early diagnosis of ATD and draw attention to methods that may improve screening. Methods Retrospective data of 142 patients diagnosed with ATD between January 2010 and December 2015 at our paediatric endocrinology clinic were used. Sociodemographic characteristics, clinical findings, treatments and follow-up data of patients were statistically evaluated. Results Of the ATD cases, 81% (n = 115) were female. The median age was 12.5 ± 3.5 (range 1-17) years and 91% (n = 129) of patients were in puberty. There was a significant positive correlation between the height (standard deviation score) and follow-up time for patients with HT (r = 0.156, p < 0.01). Thyroglobulin antibody (TgAb) positivity was found in 75% (45/60) of females with a positive maternal ATD history (p = 0.045). Thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4) values were significantly altered during the treatment follow-up period in female patients with GD and HT, while only fT4 values were found to be significantly altered in boys with HT. Conclusion Although GD and HT have similar mechanisms, they differ in terms of treatment duration and remission and relapse frequencies. Ultrasonography (USG) screening is a non-invasive procedure that is suitable for all patients with ATD. Based on our results, TgAb could be useful in the screening of girls with a history of maternal ATD.

A novel third-generation TSH receptor antibody (TRAb) enzyme-linked immunosorbent assay based on a murine monoclonal TSH receptor-binding antibody

TSH receptor (TSHR) autoantibody (TRAb) is the serological hallmark of Graves' disease (GD). Third-generation enzyme-linked immunosorbent assays (ELISAs) using monoclonal TRAbs instead of TSH have been found useful for TRAb analysis recently. For the first time, a mouse monoclonal antibody (mAb) against TSHR was analyzed for TRAb detection and compared with human mAb M22 and TSH by the same competitive binding assay technique. A mouse monoclonal antibody (T7) binding to the TSH receptor and inhibiting TSH binding was generated and used for TRAb analysis in a third-generation ELISA. Obtained TRAb levels were compared with a second-generation TRAb assay employing bovine TSH and a third-generation assay with human mAb M22 as TSHR-binding reagents by investigating 89 patients with GD, 56 with Hashimoto's thyroiditis (HT), 73 with non-autoimmune thyroid diseases, 17 with rheumatoid arthritis, and 100 healthy subjects. The T7-based TRAb ELISA did not reveal a significantly different assay performance (area under the curve [AUC]) in contrast to the TSH and M22-based TRAb ELISAs by receiver operating characteristic (ROC) curve analysis (AUC-T7 0.967, AUC-TSH 0.972, AUC-M22 0.958, p > 0.05, respectively). After adjustment of cutoffs by ROC, all three TRAb ELISAs demonstrated sensitivities and specificities above 89.9% and 96.0%, respectively. Both third-generation TRAb ELISAs showed a tendency for a higher prevalence of TRAb positives in HT in contrast to the second-generation ELISA. Mouse mAbs against the TSHR may be used for the reliable detection of TRAb by third-generation TRAb ELISA. The earlier reported higher sensitivity of third-generation TRAb ELISA in GD needs to be considered in the context of a slightly lower specificity regarding HT.

Age May Influence the Impact of TRAbs on Thyroid Function and Relapse-Risk in Patients With Graves Disease

CONTEXT

Thyrotropin receptor antibodies (TRAbs) play a crucial role in the pathogenesis of Graves disease (GD). However, factors that influence the association of TRAbs with thyroid hormones and relapse risk in GD remain unclear.

OBJECTIVE

We investigated the associations of TRAbs at diagnosis with thyroid hormones and relapse risk and potential factors that can influence these associations in GD.

DESIGN AND SETTING

A prospective study in an endocrine center in England.

PATIENTS AND MAIN OUTCOME MEASURES

Three hundred eighty-four consecutive patients with GD who had measurements of TRAbs and thyroid hormones at diagnosis. The association of TRAbs with thyroid hormones and relapse risk was assessed through linear regression and Cox proportional hazard models, adjusted for confounders.

RESULTS

TRAbs were nonlinearly associated with thyroid hormones, following a curve with an initial positive slope and a subsequent flattening (P < 0.0001). Higher TRAbs were associated with greater relapse risk [hazard ratio (HR), 1.05 (95% CI, 1.02 to 1.08) per 1-U/L increase]. These associations were modified by age, but not by sex, race, smoking, or thyroid peroxidase antibody levels. In younger participants, increasing TRAbs were associated with higher thyroid hormones and greater relapse risk [HR, 1.13 (95% CI, 1.04 to 1.23) per 1-U/L increase]. In older participants, TRAbs were not associated with thyroid hormones or relapse risk [HR, 0.99 (95% CI, 0.93 to 1.05) per 1-U/L increase.

CONCLUSIONS

In GD, age can influence the effect of TRAbs on thyroid function and relapse risk. TRAbs at diagnosis have better predictive value in younger patients with GD.

Association between systemic lupus erythematosus and thyroid dysfunction: a meta-analysis

INTRODUCTION

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease, the pathogenesis of which remains elusive. The deficiency or excess of thyroid hormone is defined as thyroid dysfunction, including (subclinical) hypothyroidism and (subclinical) hyperthyroidism. Autoimmune factors are likely to be relevant to the development of SLE and thyroid dysfunction. Recently, many studies have indicated that the prevalence of thyroid dysfunction is higher in SLE patients than in the general population. The objective of our study was to perform a systematic review and meta-analysis to find out the relationship between SLE and thyroid dysfunction.

METHODS

Literature databases were searched, including PubMed, Embase, Web of science, Cochrane, CNKI, CHINESE WANFANG, China Science and Technology Database (VIP). Studies comparing presence of thyroid dysfunction in SLE patients to healthy controls were extracted. All the statistical analyses were performed with STATA 12.0 software.

RESULTS

Ten studies with 10,500 SLE patients and 44,170 healthy controls were included in this study. The meta-analysis results showed that the prevalence of (subclinical) hypothyroidism in SLE patients was higher than in the healthy controls (hypothyroidism: OR = 2.93, 95% CI = 1.81-4.75; subclinical hypothyroidism: OR = 5.67, 95% CI = 3.50-9.18). No statistical difference of (subclinical) hyperthyroidism was found between SLE patients and controls.

CONCLUSION

Our meta-analysis suggests that SLE is significantly associated with increased risk of (subclinical) hypothyroidism, but it has little influence on (subclinical) hyperthyroidism.

Thyrotropin Receptor Blocking Antibodies

Autoantibodies (Ab) against the thyroid-stimulating hormone receptor (TSHR) are frequently found in autoimmune thyroid disease (AITD). Autoantibodies to the TSHR (anti-TSHR-Ab) may mimic or block the action of TSH or be functionally neutral. Measurement of anti-TSHR-Ab can be done either via competitive-binding immunoassays or with functional cell-based bioassays. Antibody-binding assays do not assess anti-TSHR-Ab functionality, but rather measure the concentration of total anti-TSHR binding activity. In contrast, functional cell-based bioassays indicate whether anti-TSHR-Ab have stimulatory or blocking activity. Historically bioassays for anti-TSHR-Ab were research tools and were used to study the pathophysiology of Graves' disease and Hashimoto's thyroiditis. In the past, bioassays for anti-TSHR-Abs were laborious and time-consuming and varied widely in performance from laboratory to laboratory. Recent advances in the development of cell-based assays, including the application of molecular engineering, have led to significant improvements that have enabled bioassays to be employed routinely in clinical laboratories. The prevalence and functional significance of TSHR blocking autoantibodies (TBAb) in autoimmune hypothyroidism has been less well investigated compared to TSHR stimulating Ab. There is an increasing body of data, however, that demonstrate the clinical utility and relevance of TBAb, and thus the importance of TBAb bioassays, in the diagnosis and management of patients with AITD. In the present review, we summarize the different methods used to measure TBAb, and discuss their prevalence and clinical relevance.

Nivolumab-induced thyroid dysfunction lacking antithyroid antibody is frequently evoked in Japanese patients with malignant melanoma

BACKGROUND

Nivolumab, an anti-programmed cell death-1 monoclonal antibody, has improved the survival of patients with malignant melanoma. Despite its efficacy, nivolumab inconsistently induces thyroid dysfunction as an immune-related adverse event (irAE). This study aimed to evaluate nivolumab-induced thyroid dysfunction to determine the risks and mechanisms of thyroid irAEs.

METHODS

After excluding 10 patients, data of 24 patients with malignant melanoma (aged 17-85 years; 54% female) were retrospectively analyzed.

RESULTS

Thyroid irAEs were observed in seven patients (29%). Three patients had hypothyroidism after preceding transient thyrotoxicosis, and the other four patients had hypothyroidism without thyrotoxicosis. Levothyroxine-Na replacement was required in three patients. Antithyroid antibody (ATA) titer was elevated in one of four assessable patients. The average (±SD) time to onset of thyroid irAE was 33.6 (±21.9) weeks. The administration period of nivolumab was longer in patients with thyroid irAEs than in those without thyroid irAEs (P < 0.01). There were no significant differences between patients with and without thyroid irAEs regarding age, sex, tumor stage, response to nivolumab therapy, baseline thyroid function, antithyroid peroxidase antibody (anti-TPO Ab) and antithyroglobulin antibody (anti-Tg Ab).

CONCLUSIONS

Thyroid dysfunction was a common irAE of nivolumab in malignant melanoma. Neither anti-TPO Ab nor anti-Tg Ab was associated with the risk for nivolumab-induced thyroid dysfunction. A conventional ATA-independent mechanism might be involved in thyroid irAEs. Further studies are required to clarify the mechanism and identify the predictive factors of thyroid irAEs.

Persistent Graves’ hyperthyroidism despite rapid negative conversion of thyroid-stimulating hormone-binding inhibitory immunoglobulin assay results: a case report

Background

Case presentation

Conclusions

Stimulating TSH receptor autoantibodies immunoassay: analytical evaluation and clinical performance in Graves’ disease

Background

Thyroid-stimulating hormone (TSH) receptor (TSHR) autoantibodies (TRAbs) are a heterogeneous group of antibodies (Abs) with different functionalities. Among all TRAbs, only the stimulating ones (S-TRAbs) are considered as the pathogenetic marker of Graves’ disease (GD). To date, the methods available for TRAbs testing are based on immunoassays (IMAs) which detect total serum TRAbs or bioassays which are not suitable in clinical practice, even though they discern Abs functionality. The aim of our work was to evaluate the analytical and clinical performance of a very recent IMA (Immulite TSI method), supposed to test only the serum concentration of S-TRAbs, in comparison with a current method for total TRAbs (Roche/Elecsys IMA).

Methods

We evaluated serum samples of 145 subjects: 46 with untreated (GD), 36 with chronic autoimmune thyroiditis, 3 with atrophic thyroiditis, 10 with multinodular non-toxic goiter and 50 healthy subjects.

Results

The method showed an optimal analytical sensitivity and high precision levels (LoB: 0.04 UI/L, LoD:0.07 UI/L, LoQ:0.14 UI/L, intra-assay CV: 4.2–5.9%, inter-assay: 4.5–7.2%). By receiver operating characteristics curve analysis, we obtained a value of 0.57 (sensitivity: 98.0%, specificity: 99.9%) as the best cut-off to distinguish GD, apart from four cases. Passing Bablok regression and Bland Altman analysis pointed out a good correlation and agreement with Roche method (R2 = 0.98, slope = 1.03, bias = −2.70).

Conclusions

The new method presents very promising analytical characteristics and could be adopted in clinical practice for GD diagnosis. Moreover, the test allows to accurately detect very low values of analyte with a further clinical utility in detecting earlier possible relapses.

Epidemiology, management and outcomes of Graves' disease-real life data

PURPOSE

Treatment options in Graves' disease are clearly defined, but management practices and the perceptions of success are varied. The outcomes of treatment in large consecutive cohorts of Graves' disease have not been well characterised. The study describes the epidemiology, management strategies and medium term outcomes following anti-thyroid drug treatment, radio-iodine ablation and surgery in Graves' disease.

METHODS

All patients (n = 659) who received treatment for a new diagnosis of Graves' disease in secondary care over a 5 year period were included with a median (interquartile range) follow-up of 42.9 (29-57.5) months.

RESULTS

The age adjusted incidence of adult onset Graves' disease in Sheffield, UK was 24.8 per 100,000 per year. Excluding 35 patients lost to follow-up, 93.1% (n = 581) were controlled on anti-thyroid drug treatment. Of these, 73.6% went into remission following withdrawal of anti-thyroid drugs; 5.2% were still undergoing initial therapy; 13.3% lost control whilst on anti-thyroid drugs; and 7.9% went on to have either surgery or radio-iodine ablation whilst controlled on anti-thyroid drugs. Of the 428 patients who achieved remission, 36.7% relapsed. Of 144 patients who had radio-iodine ablation treatment, 5.6% relapsed and needed further treatment. Of 119 patients having surgery, 5.2% had long-term hypoparathyroidism and none had documented long-term recurrent laryngeal nerve palsy.

CONCLUSIONS

In the follow-up, 39.9% of patients underwent surgery or radio-iodine ablation with little morbidity. Up to two-thirds of patients who achieved remission did not relapse. Data on effectiveness and risks of treatments for Graves' disease presented in this study will help clinicians and patients in decision making.

Measuring TSH receptor antibody to influence treatment choices in Graves' disease

TSH receptor antibody (TRAb) plays a key role in the pathogenesis of Graves' disease (GD), and its levels correlate with the clinical course. The second- and third-generation TRAb assays have >95% sensitivity and specificity for the diagnosis of GD and have improved the utility of TRAb to predict relapse. TRAb levels decline with antithyroid drug (ATD) therapy and after thyroidectomy. Its level increases for a year following radioactive iodine (RAI) therapy, with a gradual fall thereafter. TRAb level >12 IU/l at diagnosis of GD is associated with 60% risk of relapse at 2 years and 84% at 4 years. The prediction of risk of relapse improves further to >90% with TRAb >7·5 IU/l at 12 months or >3·85 IU/l at cessation of ATD therapy. TRAb tests are not expensive, and hence, TRAb measurements at presentation, after 12 months and/or 18 months (at cessation) of ATD therapy, could potentially guide treatment choices in GD. Elevated TRAb favours definitive treatment in the form of RAI or thyroidectomy, depending on the presence or absence of moderate-to-severe Graves' ophthalmopathy (GO) and the ability to comply with radiation protection requirements. Use of ATDs in early pregnancy is associated with increased risk of congenital anomalies; early ablative treatment (RAI/surgery) should be considered in women of childbearing age at higher risk of relapse of GD. TRAb ≥5 IU/l in pregnant women with current or previously treated GD is associated with increased risk of foetal and neonatal thyrotoxicosis, and hence needs close monitoring. TRAb levels parallel the course of GO, and elevated TRAb is an indication for steroid prophylaxis to prevent progression of GO with RAI therapy.

DYNAMIC CHANGES OF TRAb AND TPOAb AFTER RADIOIODINE THERAPY IN GRAVES' DISEASE

Context

To analyze the dynamic changes of serum thyrotrophin receptor antibody (TRAb) and thyroid peroxidase antibody (TPOAb) in Graves' disease (GD) patients before and after radioactive iodine (RAI) treatment and to investigate if TRAb and TPOAb play a role in the occurrence of early hypothyroidism after ¹³¹I therapy for Graves' hyperthyroidism.

Subjects and Methods

A total of 240 patients newly diagnosed with GD were selected to study. A clinical and laboratory assessment was performed before and at 3, 6, and 12 months after ¹³¹I therapy. Chemiluminescent immunoassays were used to detect serum free triiodothyronine (FT3), free thyroxine (FT4), sensitive thyroid-stimulating hormone (TSH) and TPOAb concentration. Radio-receptor assay was used to measure serum TRAb concentration. According to the early onset of hypothyroidism in a year after RAI therapy, patients were divided into early hypothyroidism group (group A) and non-early hypothyroidism group (group B).

Results

In both groups, serum TRAb and TPOAb increased at 3 months, reached the highest level at 6 months and returned to the baseline at 12 months after RAI therapy. TRAb showed a significant difference between the two groups at 6 months (P<0.01). Serum TPOAb in group A was higher than that in group B before and at 3, 6, 12 months after RAI therapy (P<0.05).

Conclusions

Serum TRAb and TPOAb are closely related to the occurrence of the early hypothyroidism, and play an important role in judging prognosis after ¹³¹I treatment in Graves' disease.

An Advantageous Role of Spectral Doppler Sonography in the Evaluation of Thyroid Dysfunction During the Postpartum Period

OBJECTIVES

To evaluate the diagnostic value of spectral Doppler sonography in women with thyroid dysfunction during the first postpartum year.

METHODS

This prospective observational clinical study included 83 consecutive untreated women: 32 with hyperthyroid postpartum thyroiditis, 32 with hypothyroid postpartum thyroiditis, and 19 with Graves disease, which first appeared within 12 months after delivery. Thyrotropin, free thyroid hormones, thyroid peroxidase antibodies, thyroglobulin antibodies, and thyrotropin receptor antibodies were measured. With a 7.5-MHz linear transducer, we measured the thyroid volume and peak systolic velocity (PSV) at the level of intrathyroid arteries.

RESULTS

Hyperthyroid postpartum thyroiditis appeared significantly earlier (mean ± SD, 4.4 ± 1.9 months after delivery) than hypothyroid postpartum thyroiditis (6.5 ± 2.1 months) and Graves disease (7.2 ± 2.7 months; P< .001). The thyroid volume in hyperthyroid postpartum thyroiditis (9.7 ± 6.3 mL) was significantly lower than in hypothyroid postpartum thyroiditis (14.7 ± 10.2 mL; P = .030) and Graves disease (19.4 ± 10.2 mL; P< .001). The PSV in hyperthyroid postpartum thyroiditis (9.4 ± 3.4 cm/s) was significantly lower than in hypothyroid postpartum thyroiditis (14.4 ± 3.9 cm/s; P < .001) and Graves disease (19.8 ± 7.0 cm/s; P < .001). With a cutoff level of 15 cm/s, the sensitivity and specificity of the PSV as a predictor of the correct diagnosis in hyperthyroid postpartum women were 94.7% and 96.8%, respectively. A multinomial logistic regression revealed PSV and the time after delivery at which the disorders presented as independent predictors of the differentiation between hyperthyroid postpartum thyroiditis and Graves disease (P = .003; P = .022).

CONCLUSIONS

Spectral Doppler sonography was shown to be a useful and accurate method for thyroid dysfunction evaluation during the postpartum period.

Usefulness of Measuring Thyroid Stimulating Antibody at the Time of Antithyroid Drug Withdrawal for Predicting Relapse of Graves Disease

BACKGROUND

Hyperthyroidism relapse in Graves disease after antithyroid drug (ATD) withdrawal is common; however, measuring the thyrotropin receptor antibody (TRAb) at ATD withdrawal in order to predict outcomes is controversial. This study compared measurement of thyroid stimulatory antibody (TSAb) and thyrotropin-binding inhibitory immunoglobulin (TBII) at ATD withdrawal to predict relapse.

METHODS

This retrospective study enrolled patients with Graves disease who were treated with ATDs and whose serum thyroid-stimulating hormone levels were normal after receiving low-dose ATDs. ATD therapy was stopped irrespective of TRAb positivity after an additional 6 months of receiving the minimum dose of ATD therapy. Patients were followed using thyroid function tests and TSAb (TSAb group; n=35) or TBII (TBII group; n=39) every 3 to 6 months for 2 years after ATD withdrawal.

RESULTS

Twenty-eight patients (38%) relapsed for a median follow-up of 21 months, and there were no differences in baseline clinical characteristics between groups. In the TSAb group, relapse was more common in patients with positive TSAb at ATD withdrawal (67%) than patients with negative TSAb (17%; P=0.007). Relapse-free survival was shorter in TSAb-positive patients. In the TBII group, there were no differences in the relapse rate and relapse-free survivals according to TBII positivity. For predicting Graves disease relapse, the sensitivity and specificity of TSAb were 63% and 83%, respectively, whereas those of TBII were 28% and 65%.

CONCLUSION

TSAb at ATD withdrawal can predict the relapse of Graves hyperthyroidism, but TBII cannot. Measuring TSAb at ATD withdrawal can assist with clinical decisions making for patients with Graves disease.

Graves Disease Is Associated With Endometriosis: A 3-Year Population-Based Cross-Sectional Study

The aim of this cross-sectional study was to compare the prevalence of thyroid diseases between women with and without endometriosis.We established the endometriosis group according to diagnosis codes, surgery codes, and gonadotropin-releasing hormone agonist codes using the Korean Health Insurance Review and Assessment Service-National Inpatients Sample (HIRA-NIS) from 2009 to 2011. Four controls were randomly matched to each endometriosis case. Thyroid disease cases were selected using the thyroid disease diagnosis code (E0X).Among the 1,843,451 women sampled, 5615 had endometriosis; 22,460 controls were matched to the endometriosis cases. After adjustment for age and sampling year, Graves disease was associated with endometriosis (odds ratio [OR]: 2.52; 95% CI: 1.30-4.88; P < 0.01), while hypothyroidism was not (OR: 1.17; 95% CI: 0.90-1.52; P = 0.25). Autoimmune hypothyroidism was also not associated with endometriosis (OR: 1.61; 95% CI: 0.88-2.94; P = 0.12).This study revealed an association between Graves disease and endometriosis.

Severe unsuspected maternal hypothyroidism discovered after the diagnosis of thyrotropin receptor-blocking antibody-induced congenital hypothyroidism in the neonate: failure to recognize and implications to the fetus

BACKGROUND

Whereas most adequately treated children with congenital hypothyroidism (CH) do well neurodevelopmentally, when both the maternal and fetal thyroid glands are compromised, significant cognitive delay can occur despite early and aggressive postnatal therapy. Maternal thyrotropin-stimulating hormone receptor (TSHR)-blocking antibodies (Abs) can be transmitted to the fetus and cause combined maternal-fetal hypothyroidism. Current guidelines recommend their measurement only if mothers have known autoimmune thyroid disease, there is a history of a previously affected sibling, or when transient CH is suspected.

RESULTS

We report 3 infants in whom the diagnosis of maternal hypothyroidism was not known and was identified only after CH was diagnosed in their babies. One of these infants had developmental delay despite rapid normalization of thyroid function postnatally. All 3 mothers had potent TSHR Abs in serum, but thyroid peroxidase Abs and thyroglobulin Abs were detectable in only 2 of them.

CONCLUSIONS

TSHR-blocking Ab-induced CH should be suspected in any baby with CH irrespective of the known family history, especially if the hypothyroidism is severe and a eutopic thyroid gland is demonstrated on imaging. Measurement of TSHR Abs is necessary to establish the diagnosis; the presence of other thyroid Abs is insufficiently sensitive and may miss some cases.

"Orbiting around" the orbital myositis: clinical features, differential diagnosis and therapy

Orbital myositis (OM) is a rare disease whose clinical heterogeneity and different treatment options represent a diagnostic and therapeutic challenge. We aim to review the state of knowledge on OM, also describing a cohort of patients diagnosed in our centre, to highlight some remarkable clinical features. A literature review was conducted in PubMed and Medline databases. The herein described cohort is composed of seven OM patients, diagnosed according to clinical, laboratory and neuroradiological features, whose clinical data were retrospectively analysed. OM is a non-infectious, inflammatory process primarily involving extraocular eye-muscles. It typically presents as an acute to sub-acute, painful ophthalmoplegia with signs of ocular inflammation, but atypical cases without pain or with a chronic progression have been described. The wide range of OM mimicking diseases make a prompt diagnosis challenging but orbit MRI provides valuable clues for differential diagnosis. Timely treatment is greatly important as OM promptly responds to steroids; nevertheless, partial recovery or relapses often occur. In refractory, recurrent or steroid-intolerant cases other therapeutic options (radiotherapy, immunosuppressants, immunoglobulins) can be adopted, but the most effective therapeutic management is yet to be established. In this review, we provide a detailed clinical description of OM, considering the main differential diagnoses and suggesting the most useful investigations. In light of the currently available data on therapy efficacy, we propose a therapeutic algorithm that may guide neurologists in OM patients' management.

Autoantibodies to asialoglycoprotein receptor (ASGPR) in patients with autoimmune liver diseases

BACKGROUND

The liver asialoglycoprotein receptor (ASGPR) is the only organ-specific autoantigenic target in autoimmune hepatitis (AIH) patients and corresponding autoantibodies (Abs) have been suggested aiding in the serology of autoimmune liver diseases (ALD).

METHODS

A novel enzyme-linked immunosorbent assay (ELISA) employing purified rabbit ASGPR was used to detect ASGPR Abs in patients with ALD and controls. ASGPR Ab was determined in sera from 172 patients with AIH type 1, AIH type 2 (n=42), primary biliary cirrhosis (PBC) (n=113), cryptogenic liver disease (n=30), toxic liver disease (n=11), primary sclerosing cholangitis (PSC) (n=27), HCV infection (n=25), non-alcoholic steatohepatitis (n=43) and 100 blood donors. ASGPR Ab positivity was compared with AIH-related Abs (ANA, ASMA, Abs to LKM-1, LC-1, and SLA/LP) in patients with AIH.

RESULTS

Patients with AIH-1 and AIH-2 demonstrated an ASGPR Ab prevalence of 29.1% and 16.7%, respectively. ASGPR Ab positivity in patients with AIH-1 and AIH-2 was not significantly different to those in patients with PSC and HCV (p>0.05, respectively). ASGPR Ab levels in all study cohorts were significantly different with the highest medians in patients with AIH, PSC, and HCV infection (p<0.0001). ASGPR Ab can be found as only AIH-specific Ab determined by LIA and ELISA in 24.4% of AIH patients (48/197).

CONCLUSIONS

The novel ASGPR Ab ELISA is a specific diagnostic tool for ASGPR Ab detection in AIH. In addition to AIH, patients with PSC can demonstrate elevated ASGPR Ab amongst those with ALD suggesting a tolerance break to ASGPR in PSC.

Antithyroid peroxidase antibody positivity is associated with lower incidence of metastasis in breast cancer

Thyroid extracts were first used to treat patients with metastatic breast cancer over a century ago. Since then, a number of studies have investigated the association between thyroid disorders and breast cancer. The presence of antibodies to thyroid peroxidase (TPOab) was recently reported to be associated with improved outcome in these patients. The aim of the present study was to evaluate the association between TPOab positivity and clinicopathological characteristics in breast cancer patients. The study included 318 newly diagnosed cases of breast cancer treated at Ondokuz Mayis University Hospital, Samsun, Turkey, between 2008 and 2012. Serum thyroid-stimulating hormone, free triiodothyronine and free thyroxine levels were measured at the time of diagnosis. Of the 318 patients, 253 were considered to be TPOab-negative (TPOab ≤34 IU/ml) and 65 TPOab-positive (TPOab >34 IU/ml). No cases with distant metastases were found in the TPOab-positive group. However, 20 (7.9%) of the 253 patients displayed distant metastases in the TPOab-negative group (P=0.01). Therefore, TPOab positivity was found to be associated with a lower incidence of metastasis in breast cancer patients.

High cut-off value of a chimeric TSH receptor (Mc4)-based bioassay may improve prediction of relapse in Graves' disease for 12 months

There are scarce reports regarding a functional prognostic value of thyroid-stimulating autoantibody (TSAb) levels using a thyroid-stimulating hormone receptor chimera (Mc4) in Graves' disease (GD) in iodine sufficient area. The aim of this study was to investigate whether Mc4-TSAb can predict GD remission/relapse after antithyroid drug (ATD) treatment and to compare Mc4-TSAb with a binding assay using M22 monoclonal antibody (M22-TRAb) in GD patients. We retrospectively reviewed the results of M22-TRAb and Mc4-TSAb in GD patients treated with ATD for 12 months. GD patients who underwent ATD treatment for at least 12 months were included. We compared the predictive values of M22-TRAb and Mc4-TSAb for GD remission and relapse. Of the 92 patients, 60 (65.2%) achieved remission and 32 (34.8%) relapsed within 12 months. In receiver operating characteristic analysis, there were no significant differences in the area under the curves (AUCs) between Mc4-TSAb [AUC=0.79 (95% CI 0.69-0.89)] and M22-TRAb [AUC=0.69 (95% CI 0.58-0.81)]. The optimal predictive cut-off values of M22-TRAb and Mc4-TSAb were 2.23 IU/L and 230%, respectively. At a high Mc4-TSAb cut-off, the better specificity of 85.0% and positive predictive value (PPV) of 69.0% were shown compared with those at the best cut-off for M22-TRAb. In conclusion, a high cut-off for an Mc4 assay may improve the predictive value of relapse with superior specificity and PPV compared with M22-TRAb in treated GD.

Applications of cell-based bioassays measuring the induced expression of endogenous genes

Cell-based bioassays are used to determine the biological activity of complex biotherapeutic products, to assign potency and to assure the quality and consistency of the manufacturing process. Clinically, these assays are used to assess bioactivity in patient samples, particularly for the detection of antidrug neutralizing antibodies. Owing to their versatility, cellular assays that measure endogenous gene expression by quantitative reverse transcription PCR offer a rapid and automatable alternative to assays measuring functional, late-stage responses. Notably, detection of immediate early gene expression represents a direct response of the cell to receptor ligation by the biotherapeutic. We review current developments in the use of this approach and demonstrate its application to the detection of receptor-binding autoantibodies using, as a case study, the detection of autoantibodies to the thyroid-stimulating hormone receptor.

Diagnosis and classification of Graves' disease

Graves' disease (GD) is an autoimmune disorder involving the thyroid gland, typically characterized by the presence of circulating autoantibodies that bind to and stimulate the thyroid hormone receptor (TSHR), resulting in hyperthyroidism and goiter. Organs other than the thyroid can also be affected, leading to the extrathyroidal manifestations of GD, namely Graves' ophthalmopathy, which is observed in ~50% of patients, and Graves' dermopathy and acropachy, which are quite rare. Presumably, the extrathyroidal manifestations of GD are due to autoimmunity against antigens common to the thyroid and other affected organs. Although its exact etiology remains to be completely understood, GD is believed to result from a complex interaction between genetic susceptibility and environmental factors. Clinically, GD is characterized by the manifestations of thyrotoxicosis as well as by its extrathyroidal features when present, the latter making the diagnosis almost unmistakable. In the absence of ophthalmopathy, the diagnosis is generally based on the association of hyperthyroidism and usually diffuse goiter confirmed with serum anti-TSHR autoantibodies (TRAbs). Hyperthyroidism is generally treated with anti-thyroid drugs, but a common long term treatment strategy in patients relapsing after a course of anti-thyroid drugs (60-70%), implies the use of radioactive iodine or surgery.

[Hyperthyroidism]

Thyrotoxicosis is mainly caused by autonomous adenomas of the thyroid gland and by Graves' disease. A less frequent cause for thyrotoxicosis is Hashimoto's thyroiditis. Thyrotoxicosis in autonomous adenomas and Graves' disease is caused by an increased thyroid hormone production whereas hyperthyroidism in Hashimoto's thyroiditis results from destruction of the thyroid gland. Drug therapy depends on the cause of the disease. Autonomous adenomas and Graves' disease are treated with methimazole and potentially with β-blockers. Regarding thyroid ablative therapy, radioiodine is mostly preferred compared to thyroidectomy. Drug therapy of Hashimoto's thyroiditis is purely symptomatic using β-blockers and rarely corticosteroids. Hyperthyroidism in pregnancy is a major issue and pregnant women in the first trimester are treated with propylthiouracil (PTU) whereas women in the second and third trimesters are treated with methimazole. The aim is to maintain the serum fT4 levels within the upper normal range.

Functional expression of thyroid-stimulating hormone receptor on nano-sized bacterial magnetic particles in Magnetospirillum magneticum AMB-1

The measurement of autoantibodies to thyroid-stimulating hormone receptor (TSHR) is important for the diagnosis of autoimmune thyroid disease such as Graves' disease (GD). Although TSHR from porcine thyroid membrane is commonly used for the measurement of TSHR autoantibodies (TRAb), recombinant human TSHR (hTSHR) remains ideal in terms of stable supply and species identity. Here we set out to express recombinant hTSHR on the lipid-bilayer surface of magnetic nanoparticles from a magnetotactic bacterium, Magnetospirillum magneticum AMB-1. Using a tetracycline-inducible expression system, we successfully overexpressed functional hTSHR on bacterial magnetic particles (BacMPs) in AMB-1 via an anchor protein specific for BacMPs. The overexpressed hTSHR was membrane integrated and possessed both ligand and autoantibody binding activity. Our data suggest that hTSHR-displayed BacMPs have potential as novel tools for ligand-receptor interaction analysis or for TRAb immunoassay in GD patients.

Clinical review: Clinical utility of TSH receptor antibodies

CONTEXT

TSH receptor antibodies (TRAb) cause Graves' disease (GD) hyperthyroidism. Widely available TRAb measurement methods have been significantly improved recently. However, the role of TRAb measurement in the differential diagnosis of hyperthyroidism, the prediction of remission of GD hyperthyroidism, the prediction of fetal/neonatal thyrotoxicosis, and the clinical assessment of Graves' ophthalmopathy (GO) are controversial.

EVIDENCE ACQUISITION

We reviewed and analyzed the literature reporting primary data on the clinical use of TRAb. We focused our analyses on clinical studies analyzing third-generation TRAb assays.

EVIDENCE SYNTHESIS

The performance of TRAb in the differential diagnosis of overt hyperthyroidism is excellent, with sensitivity and specificity in the upper 90%. TRAb can accurately predict short-term relapses of hyperthyroidism after a course of antithyroid drugs but are less effective in predicting long-term relapses or remissions. Pregnancies in women with GD with negative TRAb are highly unlikely to result in fetal hyperthyroidism, whereas high titers of TRAb in pregnancy require careful fetal monitoring. GD patients with GO frequently have high TRAb levels. However, there are insufficient data to use the test to predict the clinical course of GO and response to treatment.

CONCLUSIONS

Third-generation TRAb assays are suitable in the differential diagnosis of hyperthyroidism. In GD, TRAb should be tested before deciding whether methimazole can be stopped. TRAb should be used in pregnant women with GD to assess the risk of fetal thyrotoxicosis. The use of TRAb in GO requires further studies.

Incidence rate and clinical features of hyperthyroidism in a long-term iodine sufficient area of Sweden (Gothenburg) 2003-2005

OBJECTIVES

To study hyperthyroidism in long-term iodine sufficiency (IS), as iodine supply affects its occurrence.

DESIGN

Prospective descriptive study.

PATIENTS

In 2003-2005, all referred cases of subclinical (SH) and overt hyperthyroidism (OH) were registered at diagnosis from a population (n = 631 239) in Gothenburg, Sweden.

MEASUREMENTS

Information on age, gender, smoking, thyroid associated ophthalmopathy (TAO), thyroid hormones and TSH receptor antibodies (TRab) was collected. Incidences were calculated. SH and OH cases with Graves' disease (GD), toxic multinodular goiter (TMNG) and solitary toxic adenoma (STA) were compared. In GD, TRab+ and TRab- cases and patients with (TAO+) and without TAO (TAO-) were compared.

RESULTS

The total incidence (n/100 000/year) of hyperthyroidism was 27·6; OH 23·8; SH 3·8; GD 21·4; TMNG 4·3; and STA 1·8. SH was more common among TMNG (40·2%) and STA (45·7%) than in GD (5·9%). SH-GD patients were older, more often smokers and had lower TRab levels than OH-GD patients. FreeT4 and T3 levels in GD were higher than in TMNG and STA. FreeT4, T3 and TRab decreased with age in patients with GD, P < 0·0001. TRab- patients had lower T3 than TRab+ patients, P < 0·001. TRab was positively correlated to FreeT4, P < 0·0001. TAO occurred in 20% of patients with GD. TAO+ patients were younger than TAO- patients. Smokers did not have more TAO.

CONCLUSION

The total incidence of hyperthyroidism was low. GD dominated with an age-related decline of thyroid hormones and TRab levels. The spectrum of hyperthyroidism in this long-term IS area may represent the future situation for countries with shorter history of IS.

Thyroid autoantibodies in pregnancy: their role, regulation and clinical relevance

Autoantibodies to thyroglobulin and thyroid peroxidase are common in the euthyroid population and are considered secondary responses and indicative of thyroid inflammation. By contrast, autoantibodies to the TSH receptor are unique to patients with Graves' disease and to some patients with Hashimoto's thyroiditis. Both types of thyroid antibodies are useful clinical markers of autoimmune thyroid disease and are profoundly influenced by the immune suppression of pregnancy and the resulting loss of such suppression in the postpartum period. Here, we review these three types of thyroid antibodies and their antigens and how they relate to pregnancy itself, obstetric and neonatal outcomes, and the postpartum.

Analytical performance and clinical utility of a bioassay for thyroid-stimulating immunoglobulins

The analytical performance and the clinical utility of a thyrotropin receptor (TSHR)-stimulating immunoglobulin (TSI) bioassay were compared with those of a TSHR-binding inhibitory immunoglobulin (TBII) assay. Limits of detection (LoD) and quantitation (LoQ), assay cutoff, and the half-maximal effective concentration (EC(50)) were measured. Dilution analysis was performed in sera of hyperthyroid patients with Graves disease (GD) during antithyroid treatment (ATD). Titer was defined as the first dilution step at which measurement of TSI or TBII fell below the assay cutoff. The LoD, LoQ, cutoff, and EC(50) of the bioassay were 251-, 298-, 814-, and 827-fold lower than for the TBII assay. There were 22%, 42%, 23%, and 14% more positive samples in the TSI bioassay at dilutions of 1:3, 1:9, 1:27, and 1:81 (P < .0001), respectively. Responders to ATD demonstrated marked differences in titers compared with nonresponders. The bioassay detected lower levels of TSHR autoantibodies, and the dilution analysis provided similar predictive values of both assays in GD.

A patient with Graves' disease showing only psychiatric symptoms and negativity for both TSH receptor autoantibody and thyroid stimulating antibody

Background

Both thyroid stimulating hormone (TSH) and thyroid stimulating antibody (TSAb) negative Graves’s disease (GD) is extremely rare. Here we present such a patient.

Case presentation

The patient was a 76-year-old woman who was diagnosed as having schizophrenia forty years ago. She did not show characteristic symptoms for hyperthyroidism, such as swelling of thyroid, exophthalmos, tachycardia and tremor, however, she showed only psychomotor agitation. Serum free triiodothyronine and free thyroxine levels were elevated and TSH level was suppressed, suggesting the existence of hyperthyroidism. However, both the first generation TSH receptor autoantibody (TRAb1) and the thyroid stimulating autoantibody (TSAb) were negative. Slightly increased blood flow and swelling was detected by thyroid echography. Thyroid scintigraphy demonstrated diffuse and remarkably elevated uptake of ¹²³I uptake. Finally, we diagnosed her as having GD. She was treated by using methimazole, and hyperthyroidism and her psychiatric symptoms were promptly ameliorated.

Discussion

We experienced a patient with GD who did not show characteristic symptoms except for psychiatric symptoms, and also showed negativity for both TRAb1 and TSAb. Thyroid autoantibody-negative GD is extremely rare. Thyroid scintigraphy was useful to diagnose such a patient.

Anti-thyroid peroxidase antibodies are associated with the absence of distant metastases in patients with newly diagnosed breast cancer

BACKGROUND

The presence of thyroid peroxidase antibodies (TPOab) are reported to be associated with improved outcome among breast cancer patients. We evaluated the correlation between TPOab and diagnostic parameters among newly diagnosed breast cancer patients.

METHODS

Three hundred and fourteen newly diagnosed patients with breast cancer, diagnosed and treated in Bethesda Essen between January 2002 and June 2006, were included in this study; 258 (82.2%) without TPOab (≤100 IU/mL) and 56 (17.8%) with TPOab (>100 IU/mL). Blood analysis was performed to measure serum levels of carcinoembryonic antigen (CEA), cancer antigen 15-3 (CA-15-3), free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH) and TPOab by radioimmunoassay. Data regarding age, tumor size, grading, TNM classification, receptor status, lymph node, and distant metastases were collected and analyzed from patient reports. Statistics were performed using Pearson’s χ2-test and logistic regression analysis.

RESULTS

There were no incidences of distant metastasis among 56 patients with TPOab, whereas 17 (6.6%) of 258 cases without TPOab displayed distant metastases (p=0.04). Logistic regression showed an inverse association of TPOab with CA-15-3 and CEA levels (p<0.001, respectively). Both groups, with and without TPOab, revealed no significant differences with respect to age, tumor size, grading, TNM classification, fT3, fT4, and receptor status. TPOab positive patients had higher TSH levels (2.55±3.58), compared to TPOab negative cases (1.20±1.15) (p<0.001).

CONCLUSIONS

TPOab occurrence is associated with significantly lower frequency of distant metastases in breast cancer. TPOab level inversely correlates with the conventional tumor markers CA-15-3 and CEA.