Improved prediction of relapse of Graves' thyrotoxicosis by combined determination of TSH receptor and thyroperoxidase antibodies

Influence of Thyroid Peroxidase Antibodies Serum Levels in Graves' Disease: A Retrospective Cohort Study

Purpose Graves' disease (GD) is an autoimmune disorder caused by the presence of antibodies to the thyroid stimulating hormone (TSH) receptor (TRAbs), usually presenting with clinical signs of hyperthyroidism. Previous evidence suggests that higher serum levels of thyroid peroxidase antibodies (TPOAbs) may lead to more sustained remission of hyperthyroidism after treatment with antithyroid drugs (AT). However, doubts about the influence of TPOAbs in Graves' disease outcomes still remain. Methods A retrospective, unicenter cohort study was performed. All patients with GD (TRAbs > 1.58U/L), biochemical primary hyperthyroidism (TSH < 0.4 µUI/mL), and TPOAbs measurement at diagnosis, treated with AT between January 2008 and January 2021, were included for analysis. Results One hundred and forty-two patients (113 women) with a mean age of 52 ± 15 years old were included. They were followed up for 65.4 ± 43.8 months. TPOAbs positivity was present in 71.10% (n=101) of those patients. Patients were treated with AT for a median of 18 (IQR (12; 24)) months. Remission occurred in 47.2% of patients. Patients with remission presented with lower TRAbs and free thyroxine (FT4) levels at the diagnosis. (p-value <0.001, p-value 0.003, respectively). No association was found in the median TPOAbs serum levels of patients who remitted and those who maintained biochemical hyperthyroidism after the first course of AT. Relapse of hyperthyroidism occurred in 54 patients (57.4%). No difference was found in TPOAbs serum levels regarding the patient's relapse. Moreover, a time-based analysis revealed no differences in the relapse rate after 18 months of AT therapy between patients with and without TPOAbs positivity at the diagnosis (p-value 0.176). It was found a weak positive correlation (r=0.295; p-value <0.05) between TRAbs and TPOAbs titters at the moment of Graves' diagnosis. Conclusion In this study, a correlation between TRAbs measurements and TPOAbs titter was described, although no significant association was found between the presence of TPOAbs and the outcomes of patients with GD treated with AT. These results do not support the use of TPOAbs as a useful biomarker to predict remission or relapse of hyperthyroidism in GD patients.

The Clinical Implications of Anti-thyroid Peroxidase Antibodies in Graves’ Disease in Basrah

Background Graves' disease (GD) is an autoimmune disease, with thyrotropin receptor antibodies (TRAbs) being the most important cause in the pathogenesis. The aim of this study is to assess the clinical significance of anti-TPO Abs in GD. Methods A retrospective study was conducted at the Faiha specialized Diabetes, Endocrine, and Metabolism Center (FDEMC) in Basrah during the period between December 2021 and December 2022. A total of 141 patients with GD were involved in this study, and of them, 97 (68.8%) were women. They were divided into two groups: patients with positive and negative anti-TPO Abs groups. Results Positive anti-TPO Abs were seen in 83 patients (58.9%) with GD. Pretreatment-free thyroxine level (ng/dL) was higher in the anti-TPO Abs positive GD patients than in those with negative antibodies (3.7±0.2 versus 3.0±0.2 with a p=0.021). Similarly, higher TRAb titers (IU/ml) at baseline were also seen in patients with positive anti-TPO Abs (9.8±0.7 versus 6.8±0.8) with a p=0.008. Giraffe appearance on thyroid ultrasound was more common in the group with positive anti-TPO Abs as compared to patients with negative anti-TPO Abs: 20 (87.0%) versus 3 (13.0%) with a p=0.005. A higher anti-TPO Abs titer (IU/mL) was associated with a baseline TRAb level of more than 6.4 IU/mL, and giraffe appearance on thyroid ultrasound (206.5±20.0 p-value<0.0001 and 228.0±35.3 p value=0.007, respectively). Conclusion A positive anti-TPO Abs in GD is associated with a high TRAb titer and free T4 level at baseline, as well as a giraffe appearance on thyroid ultrasound.

Clinical significance of thyroglobulin antibodies and thyroid peroxidase antibodies in Graves' disease: a cross-sectional study

PURPOSE

The significance of thyroglobulin antibodies (TgAbs) and thyroid peroxidase antibodies (TPOAbs) in Graves' disease (GD) remains unclear. Therefore, this study aimed to clarify the clinical significance of TgAbs and TPOAbs in GD.

METHODS

A total of 442 patients with GD were recruited and divided into four groups based on TgAb and TPOAb positivity. Their clinical parameters and the characteristics of the groups were compared. Cox proportional hazard regression analysis was performed to assess risk factors for GD remission.

RESULTS

The free triiodothyronine (FT3) level was significantly higher in groups positive for TgAbs and TPOAbs than in the other groups. The FT3 to free thyroxine (FT4) (FT3/FT4) ratio was significantly higher and thyrotropin-stimulating hormone (TSH) receptor antibodies (TRAbs) were significantly lower in the TgAb+/TPOAb- group. Time to FT4 recovery was significantly shorter for groups negative for TPOAbs, whereas time to TSH recovery was significantly longer for groups positive for TPOAbs. Cox proportional hazard regression analysis revealed that TgAb positivity, prolonged treatment duration with antithyroid drugs, and Graves' ophthalmopathy treated with methylprednisolone were significantly associated with GD remission and that a smoking history, elevated FT3/FT4 ratio, and treatment with propylthiouracil hindered GD remission.

CONCLUSION

The contributions of TgAbs and TPOAbs to GD pathogenesis differ. Patients positive for TgAbs develop GD with lower TRAb titers and undergo earlier remission than those negative for TgAbs. Patients positive for TPOAbs develop GD with high TRAb titers and need a long time to achieve remission.

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.

Serum TSH level as predictor of Graves' disease recurrence following antithyroid drug withdrawal: A systematic review

Graves’ disease (GD) has a high recurrence rate despite various and adequate treatment. Numerous studies have been performed to identify the predictor of disease recurrence. This report aims to investigate the role of thyroid stimulating hormone (TSH) level as a thyrotropin in predicting the recurrence of Graves’ disease within 1 to 2 years following antithyroid drug (ATD) withdrawal. Literature searching was conducted on PubMed, Scopus, Cochrane, Proquest, EBSCO in August 2019 and Google Scholar in October 2020. The study criteria include the study that evaluates TSH level 4 weeks following ATD withdrawal, with subjects ≥18 years old who are retrospectively or prospectively followed up after 1 to 2 years following ATD withdrawal. Four eligible studies were selected based on inclusion/exclusion criteria, all of which measured TSH level at 4 weeks following ATD withdrawal. All studies had 1 to 2 years follow up. One study was an RCT, two studies were done in prospective cohort and another in retrospective cohort. All studies had comparable validity and applicability. Three out of four studies suggested that low TSH level measured 4 weeks following treatment withdrawal was associated with higher risk of disease recurrence. In conclusion, low TSH level obtained 4 weeks after ATD withdrawal was associated with higher rate of recurrence rate in GD.

Changes in Thyroid Peroxidase and Thyroglobulin Antibodies Might Be Associated with Graves' Disease Relapse after Antithyroid Drug Therapy

BACKGROUND

Graves' disease (GD) is an autoimmune thyroid disorder caused by antibodies stimulating the thyrotropin (TSH) receptor. TSH receptor antibody (TRAb) measurement is useful for predicting GD relapse after antithyroid drug (ATD) treatment. However, the association of other thyroid autoantibodies with GD relapse remains obscure.

METHODS

This retrospective study enrolled patients with GD who were initially treated with ATD. TRAb, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) were measured at the initial diagnosis and at the time of ATD discontinuation.

RESULTS

A total of 55 patients were enrolled. The mean age was 49.7 years, and 39 patients (70.9%) were female. Antibody positivity at diagnosis was 90.9%, 69.1%, and 61.9% for TRAb, TPOAb, TgAb, respectively. Median ATD treatment period was 15.1 months. At the time of ATD withdrawal, TRAb titers decreased uniformly overall. Conversely, TPOAb and TgAb showed various changes. After withdrawal of ATD, 19 patients (34.5%) experienced relapse. No clinical features or laboratory results were significantly related to relapse in the overall patient group. However, in the TPOAb positive group at diagnosis, increasing titer of TPOAb or TgAb after ATD treatment was significantly and independently related to relapse free survival (TPOAb: hazard ratio [HR], 17.99; 95% confidence interval [CI], 1.66 to 195.43; P=0.02) (TgAb: HR, 5.73; 95% CI, 1.21 to 27.26; P=0.03).

CONCLUSION

Changes in TPOAb or TgAb titers during treatment might be useful for predicting relapse after ATD treatment in patients with positive TPOAb at diagnosis.

Clinical, Hormonal, and Ultrasound Characteristics of Patients with Newly Diagnosed Graves’ Disease And Different Thyroid Antibody Profiles

Objective: Graves’ disease (GD) is characterized by elevated TSH-receptor antibodies (TRAb) and less often – thyroid peroxidase (TPOAb) and thyroglobulin antibodies (TgAb). Our aim was to examine the hormonal and ultrasound characteristics of patients with newly diagnosed GD with differing positive thyroid antibodies.

Materials and Methods: This study included 249 patients with newly diagnosed GD (191 women, 58 men). 40.2% of them had Graves’ ophtalmopathy. The serum levels of TSH, free T4, free T3, TRAb, TPOAb, and TgAb were measured with third generation ECLIA assays (Roche Diagnostics, Switzerland). Thyroid ultrasound was performed with a Fukuda-Denshi 550 device (Fukuda Corp., Japan) and an Ultrasonix device (Ultrasonix Medical Corp., Canada). Statistical analyses were done using the SPSS 23.0 statistical package (Chicago, IL).

Results: 64% of the patients were TPOAb+ and 36% − TgAb+. One third were only TRAb+, 1/3 had two positive antibodies (TRAb + second antibody) and 1/3 – all three positive antibodies. Patients with more positive antibodies tended to be younger, had higher fT4, TRAb levels, thyroid volume but rarely had nodules on US and accompanying GO. Positive TPOAb antibodies were found in younger patients, with higher fT4 and TRAb levels, higher thyroid volume and lower prevalence of nodules and GO. The same trends were found in patients with positive TgAb.

Conclusion: The different characteristics of GD patients with varying thyroid antibody profiles may be due to a variation in the pathogenesis of the disease. An individualized clinical approach may be suitable in those cases.

Graves' Disease: Can It Be Cured?

Whether or not Graves' hyperthyroidism can be really cured, depends on the definition of "cure." If eradication of thyroid hormone excess suffices for the label "cure," then all patients can be cured because total thyroidectomy or high doses of ¹³¹I will abolish hyperthyroidism albeit at the expense of creating another disease (hypothyroidism) requiring lifelong medication with levothyroxine. I would not call this a "cure," which I would like to define as a state with stable thyroid stimulating hormone (TSH), free thyroxine, and triiodothyronine serum concentrations in the normal range in the absence of any thyroid medication. Surgery and radioiodine are unlikely to result in so-defined cures, as their preferable aim as stated in guidelines is to cause permanent hypothyroidism. Discontinuation of antithyroid drugs is followed by 50% recurrences within 4 years; before starting therapy the risk of recurrences can be estimated with the Graves' Recurrent Events After Therapy (GREAT) score. At 20-year follow-up about 62% had developed recurrent hyperthyroidism, 8% had subclinical hypothyroidism, and 3% overt hypothyroidism related to TSH receptor blocking antibodies and thyroid peroxidase antibodies. Only 27% was in remission, and might be considered cured. If the definition of "cure" would also include the disappearance of thyroid antibodies in serum, the proportion of cured patients would become even lower.

PREDICTION OF RELAPSE FROM HYPERTHYROIDISM FOLLOWING ANTITHYROID MEDICATION WITHDRAWAL USING TECHNETIUM THYROID UPTAKE SCANNING

OBJECTIVE

Technetium thyroid uptake (TTU) is not inhibited by antithyroid drugs (ATD) and reflects the degree of thyroid stimulation. We intended to predict the relapse rate from hyperthyroidism based on TTU measurement.

METHODS

Out of 44 initially enrolled subjects, 38 patients aged 41.6 ± 14.6 with Graves disease (duration: 84 ± 78 months) completed the study. TTU was performed with 40-second imaging of the neck and mediastinum 20 minutes after injection of 1 mCi technetium-99m pertechnetate. TTU was measured as the percentage of the count of activity accumulated in the thyroidal region minus the mediastinal background uptake to the count of 1 mCi technetium-99m under the same acquisition conditions. Then methimazole was stopped and patients were followed. The optimal TTU cutoff value for Graves relapse prediction was calculated using Youden's J statistic.

RESULTS

Hyperthyroidism relapsed in 11 (28.9%) patients 122 ± 96 (range: 15-290) days post-ATD withdrawal. The subjects in remission were followed for 209 ± 81 days (range: 88-390). TTU was significantly higher in patients with forthcoming relapse (12.0 ± 8.0 vs. 3.9 ± 2.0, P = .007). The difference was significant after adjustment for age, sex, history of previous relapse, disease duration, and thyroid-stimulating hormone (TSH) levels before withdrawal. The area under the receiver operative characteristic (ROC) curve was 0.87. The optimal TTU cutoff value for classification of subjects with relapse and remission was 8.7 with sensitivity, specificity, and positive and negative predictive value of 73%, 100%, 100%, and 90%, respectively (odds ratio [OR] = 10.0; 95% confidence interval [CI]: 3.4-29.3).

CONCLUSION

TTU evaluation in hyperthyroid patients receiving antithyroid medication is an accurate and practical method for predicting relapse after ATD withdrawal.

ABBREVIATIONS

ATD = antithyroid drugs RIU = radio-iodine uptake TSH = thyroid-stimulating hormone TSI = thyroid-stimulating immunoglobulin TTU = technetium thyroid uptake.

Inverse Relationship Between Organ-Specific Autoantibodies and Systemic Immune Mediators in Type 1 Diabetes and Type 2 Diabetes: Action LADA 11

OBJECTIVE

We related organ-specific autoantibodies, including diabetes-associated autoantibodies (DAAs) and non-DAAs to systemic cytokines/chemokines in type 1 and type 2 diabetes.

RESEARCH DESIGN AND METHODS

From the European Action LADA (latent autoimmune diabetes in adults) cohort, patients with adult-onset type 1 diabetes (n = 80, of whom 50 had LADA and 30 had classic type 1 diabetes) and type 2 diabetes (n = 626) were analyzed for DAAs (GAD antibody [GADA], IA-2 antigen, islet cell antibody, and zinc transporter T8), non-DAAs (transglutaminase, thyroid peroxide autoantibodies, parietal cell antibodies), and 10 immune mediator concentrations (measured by LUMINEX).

RESULTS

Type 1 diabetes patients (whether having classic type 1 diabetes or LADA), apart from their clinical phenotype, could not be distinguished by either autoantibodies (both DAAs and non-DAAs) or immune mediators. In type 1 diabetes, most immune mediators (9 of 10) were negatively correlated with DAA titers. Type 2 diabetes patients, who by definition were without DAAs, had fewer non-DAAs (P < 0.0005), but had higher levels of proinflammatory immune mediators, especially compared with patients with type 1 diabetes who had high GADA titers (interleukin [IL]-6 [P < 0.001], soluble E-selectin [P < 0.01], and IL-1 receptor antagonist [P = 0.052], for trend).

CONCLUSIONS

Patients with type 1 diabetes had more DAAs and non-DAAs than did those with type 2 diabetes, whereas the frequency and nature of these autoantibodies was broadly similar in classic type 1 diabetes and LADA. Systemic immune mediator levels, in the main, were negatively correlated with DAA titers, and, for some, were higher in patients with type 2 diabetes, especially when compared with patients who had high GADA titers. Differences in the clinical classification of diabetes are associated with graded differences in adaptive and innate immune reactivity.

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.

Thyroid peroxidase autoantibodies are associated with a lesser likelihood of late reversion to hyperthyroidism after successful non-ablative treatment of Graves' disease in Croatian patients

BACKGROUND

Thyroid peroxidase autoantibodies (TPOAbs) are frequently observed in Graves' disease (GD) and tend to persist in patients even after successful treatment with antithyroid drugs. However, there is a lack of consistent data regarding the prognostic significance of TPOAbs during and after non-ablative treatment for Graves' hyperthyroidism.

AIM

To assess the prognostic value of TPOAbs on the long-term outcome of GD patients, who were in remission after the use of antithyroid drugs (block-and-replace regimen).

SUBJECTS

100 remitters were retrospectively investigated for factors associated with the 5-year course of disease recurrence and compared to 60 age/sex-matched patients with intractable GD.

RESULTS

Mild hyperthyroidism, low baseline thyroid-stimulating antibodies levels, and small goiters were predictive of remission. Once attained, the remission was shorter in younger patients, patients with declining post-treatment TSH values, and negative baseline TPOAb levels. The 5-year cumulative incidence of relapse incrementally increased from 24 to 44 to 70 % across decreasing TPOAb tertiles (log-rank, p = 0.00056; the lower tertile representing TPOAb-negative cases). The age-of-onset (p = 0.034), and the baseline TPOAb value [upper tertile, hazard ratio (HR) 0.25; 95 % confidence interval, 0.11-0.59; p = 0.0014; middle tertile, HR 0.47 (0.24-0.9); p = 0.024; Cox regression] were inversely associated with late (>12 months) relapse rates in a level-dependent manner. In contrast, serum logTSH measured 6 months after drug discontinuation was inversely associated with hazard rates at all time points (p = 0.0005).

CONCLUSION

Baseline TPOAb positivity is an independent indicator of long-term remission in GD patients who have been successfully treated, but the mechanism of action and causal relations remain unknown.

The role of thyrotrophin receptor antibody assays in graves' disease

Thyrotrophin receptor antibodies (TRAb) exist as stimulating or blocking antibodies in the serum (neutral TRAb have been identified recently). The clinical features of GD occur when stimulating TRAb predominate. But the relationship of TRAb to clinical phenotype and outcome is not clear when current assay methods are used. Therefore no consensus exists about its utility in diagnosing and predicting outcome in GD. The most commonly used TRAb assays, measure thyroid binding inhibiting immunoglobulins (TBII or “receptor assays”) and don't differentiate between stimulating and blocking antibodies. However, the more expensive, technically demanding and less freely available “biological assays” differentiate between them by their ability to stimulate cyclic AMP or failure to do so. Failure to differentiate between TRAb types and its heterogeneous molecular and functional properties has limited TBII use to GD diagnosis and differentiating from other forms of thyrotoxicosis. The current 2nd-3rd generation receptor assays are highly sensitive and specific when used for this purpose. TRAb assays should also be done in appropriate pregnant women. Current data do not support its use in outcome prediction as there is a significant variability of assay methodology, population characteristics and study design in published data, resulting in a lack of consensus.

[Graves' ophthalmopathy from the internist's perspective]

Graves' orbitopathy (GO) is the most frequently observed extrathyroidal manifestation of Graves' disease occurring in up to 40% of patients. Most patients with Graves' orbitopathy are tested positive for TSH receptor autoantibodies (TRAb), which are pathognomonic for Graves' disease and also play a central pathogenetic role in the development of GO. For the diagnosis of Graves' disease, symptoms of hyperthyroidism, low TSH and high fT3 and/or fT4 levels and positive TRAbs are typical. All patients with Graves' disease must be regularly examined for extrathyroidal manifestations, especially for Graves' orbitopathy. For hyperthyroidism, treatment with antithyroidal drugs, such as thiamazole or propylthiouracil is initiated to quickly restore euthyroidism, which also frequently leads to improvement of Graves' orbitopathy. Smoking cessation is also heavily mandated. In cases of relapse or ineffective antithyroidal treatment, radioiodine therapy or thyroid surgery is a further definitive therapeutic option to treat hyperthyroidism. The management of Graves' orbitopathy remains clinically challenging and demands involvement of a multidisciplinary team including endocrinologists, ophthalmologists, surgeons, radiotherapists and nuclear medicine specialists.

Clinical value of the first automated TSH receptor autoantibody assay for the diagnosis of Graves' disease (GD): an international multicentre trial

BACKGROUND

Most recently, a new rapid and fully automated electrochemiluminescence immunoassay for the determination of TSH receptor autoantibodies (TRAb) based on the ability of TRAb to inhibit the binding of a human thyroid-stimulating monoclonal antibody (M22) has been established.

OBJECTIVE

To evaluate this assay system in clinical routine based on an international multicentre trial and to compare the results with other established TRAb assays.

PATIENTS AND MEASUREMENTS

Totally 508 Graves' disease (GD), 142 autoimmune thyroiditis, 107 subacute thyroiditis, 109 nonautoimmune nodular goitre, 23 thyroid cancer patients and 446 normal controls were retrospectively evaluated.

RESULTS

ROC plot analysis revealed an area under curve of 0.99 (95% CI: 0.99-1.0) indicating a high assay sensitivity and specificity. The highest sensitivity (99%) and specificity (99%) was seen at a cut-off level of 1.75 IU/l. Here, the calculated positive predictive value was 95%, whereas the negative predictive value was 100%. Applying the ROC plot-derived cut-off of 1.75 IU/l we found a sensitivity for TRAb positivity within the group of newly diagnosed GD patients of 97% which is in accordance to the sum of different nonautomated porcine TSH receptor-based assays with a sensitivity of 94% indicating an excellent analytical performance of the new assay format. Detailed comparison of the automated and the sum of manual assays revealed a near identical specificity.

CONCLUSION

Our results demonstrate that this new assay system has a high sensitivity for detecting GD and specificity for discriminating from other thyroid diseases. This assay may represent the future technology for rapid fully automated TRAb detection.

Treatment of Graves' hyperthyroidism: evidence-based and emerging modalities

Currently there are three well-established treatment options for hyperthyroid Graves' disease (GD): antithyroid drug therapy with thionamides (ATD), radioactive iodine treatment with (131)I, and thyroid surgery. This article reviews the current evidence so the reader can evaluate advantages and disadvantages of these treatment modalities. Surgery is rarely used, except for patients who have a large goiter or ophthalmopathy. Fewer than 50% of patients treated with ATD remain in long-term remission. Therefore, radioactive iodine is used increasingly. No data as yet support the routine use of biologic therapies (eg, rituximab). Prospective, randomized studies comparing available and any novel therapeutic options for GD are needed. The focus of these studies should include, but not be limited to, cost and quality of life.