Thyroglobulin Antibodies and Tumor Epitope-Specific Cellular Immunity in Papillary Thyroid Cancer.

Papillary thyroid carcinoma (PTC) is characterized by T cell infiltration and frequently by the presence of anti-thyroglobulin antibodies (TgAbs). The role of cellular immunity and of TbAbs in this context is a matter of debate. The aim of our study was to correlate the presence of TgAbs, tumor epitope-specific T cells and the clinical outcome of PTC patients. We studied n=183 consecutive patients with a diagnosis of PTC which were treated with total thyroidectomy plus 131I ablation. During a follow-up of in mean 97 months, most of the PTC patients had no signs of tumor relapse (n=157 patients). In contrast, one patient had serum Tg levels above the detection limit and<1 ng/ml, two patients Tg serum levels≥1 ng/ml and<2 ng/ml and n=23 patients had Tg serum levels≥2 ng/ml. Morphological signs of tumor recurrence were seen in 14 patients; all of these patients had serum Tg levels≥2 ng/ml. Importantly, with the exception of one patient, all TgAb positive PTC patients (n=27) had no signs of tumor recurrence as the serum Tg levels were below the assays functional sensitivities. Tetramer analyses revealed a higher number of tumor epitope-specific CD8+T cells in TgAb positive patients compared to TgAb negative PTC patients. In summary, we show that the occurrence of TgAbs may have an impact on the clinical outcome in PTC patients. This might be due to a tumor epitope-specific cellular immunity in PTC patients.

BRAFV600E and BRAF-WT Specific Antitumor Immunity in Papillary Thyroid Cancer.

One feature of papillary thyroid cancer (PTC) is the frequently present somatic BRAFV600E mutation. PTCs are also characterized by a lymphocytic infiltration, which may correlate with an improved clinical outcome. The objective of the study was the characterization of BRAFV600E specific anti-immunity in PTC patients and correlation analyses with the clinical outcome. Fourteen HLA A2 positive PTC patients were included into the study of whom tumor tissue samples were also available. Of those, 8 PTC patients revealed a somatic BRAFV600E mutation. All PTC patients were also MHC class II typed. Tetramer analyses for detection of MHC class I and MHC class II-restricted, BRAFV600E epitope-specific T cells using unstimulated and peptide-stimulated T cells were performed; correlation analyses between MHC phenotypes, T cell immunity, and the clinical course were performed. In regard to unstimulated T cells, a significantly higher amount of BRAFV600E epitope specific T cells was detected compared to a control tetramer. Importantly, after overnight peptide stimulation a significantly higher number of BRAFV600E positive and BRAF WT epitope-specific T cells could be seen. In regard to the clinical course, however, no significant differences were seen, neither in the context of the initial tumor size, nor in the context of lymph node metastases or peripheral metastastic spread. In conclusion, we clearly demonstrated a BRAF-specific tumor immunity in PTC-patients which is, however, independent of a BRAFV600E status of the PTC patients.

Radioiodine therapy reduces the frequency of circulating tumour cells in patients with differentiated thyroid cancer.

OBJECTIVE: The aim of the study was the quantification of circulating tumour cells (CTCs) in differentiated thyroid cancer (DTC) patients before and 6 weeks after radioiodine therapy (RIT). CONTEXT: Circulating tumour cells (CTCs) were described more recently in cancer patients, mostly correlating with poor outcome and advanced metastases. DESIGN: Peripheral blood for identification and quantification of CTC before RIT or/and 6 weeks after RIT was provided by 55 DTC patients that received RIT for remnant tissue ablation. PATIENTS: 13 follicular thyroid cancer (FTC) patients, 31 papillary thyroid cancer (PTC) patients and 11 patients having the follicular variant PTC (FV-PTC) were included. MEASUREMENTS: Peripheral blood mononuclear cells (PBMCs) were isolated and EpCAM-positive CTCs were counted by immune fluorescent staining. RESULTS: A CTC positivity of 31.8% before RIT could be observed. Six weeks after RIT, the CTC positivity was reduced to 13.6%. Paired data at both time points of blood sampling could be gathered for n = 33 DTC patients. These patients had significantly higher CTC numbers before RIT than 6 weeks afterwards (0.27 ± 0.47 vs 0.05 ± 0.15, P = .0215). Additionally, significantly reduced CTC numbers were also demonstrated in pre-RIT CTC-positive patients (0.88 ± 0.43 vs 0.05 ± 0.16, P = .0039). CONCLUSION: Our results indicate a reducing effect on the number of CTCs by RIT. Therefore, CTC enumeration should be considered as efficient tool for treatment monitoring during RIT.

Reply to Drs. Kiaei and Molinaro Regarding the Publication "Comparison of a Bridge Immunoassay with Two Bioassays for Thyrotropin Receptor Antibody Detection and Differentiation".

Dear Editor,Drs. Kiaei and Molinaro 1 put forth two criticisms of the manuscript published by us 2. They state that the experimental design of this study is flawed and that the authors falsely claim that negative Thyretain™ TSI Reporter BioAssay results for two Graves' diseases patients undergoing drug treatments means the absence of stimulating antibodies. To substantiate this claim Drs. Kiaei and Molinaro point out that the manufacturer of the Thyretain TSI Reporter BioAssay clearly states in the package insert that "[t]he effects of various drug therapies on the performance of this Kit have not been established" 1. Second, the package insert explicitly states that "[a] negative result does not exclude the possibility of the presence of TSI" and results of the test should be interpreted in conjunction with information available from other clinical information, such as physical symptoms and thyroid hormone testing, as recommended by the American Thyroid Association (ATA)". Furthermore they state that the "authors of the manuscript did not consider the manufacturer's warning regarding the intended patient population and the ATA guidelines regarding the interpretation of the test results in conjunction with other clinical information. Instead, the authors based their conclusions on the negative Thyretain TSI Reporter BioAssay results and ignored the patients' clinical history of Graves' disease."

Comparison of a Bridge Immunoassay with Two Bioassays for Thyrotropin Receptor Antibody Detection and Differentiation.

A rapid and fully automated chemiluminescent immunoassay for the detection of thyrotropin receptor autoantibodies (TSHR-Ab) based on a bridge technology was compared with two bioassays that measure either stimulating (TSAb) or blocking (TBAb) antibodies for the detection and differentiation of TSHR-Ab. A total of 229 patients with various thyroid disorders [151 with Graves' disease (GD), 35 with Hashimoto's thyroiditis (HT), 32 with nodular goiter, and 11 with thyroid cancer] were included. The bridge immunoassay was performed according to the manufacturer's instructions (cut-off>0.55 IU/l). TSAb and TBAb were measured with reporter bioassays. Blocking activity was defined as percent inhibition of luciferase expression relative to induction with bovine TSH alone (cut-off>34% inhibition). TSAb was reported as percentage of specimen-to-reference ratio (> 140 SRR%). The 3 TSHR-Ab assays were negative in all patients with benign euthyroid nodular goiter and differentiated thyroid cancer. In contrast, in all patients with GD, irrespective of the disease duration, TSHR-Ab positivity was present in 127 of 151 (84%) and 140 (93%) for the bridge assay and TSAb bioassay, respectively (p<0.001). Fifteen of 151 (10%) GD samples were positive in the TSAb bioassay but negative in the bridge assay. The bridge assay and the TSAb bioassay correlated positively (r=0.39, p<0.0001) in patients with GD. Both assays detected TSHR-Ab in all ten untreated hyperthyroid patients with GD. In GD patients with a duration of less than six months, 27/29 (93%) and 28 (97%) were TSHR-Ab positive with the bridge and TSAb bioassay, respectively. In comparison, TSHR-Ab were present in two of 35 (6%) and five (14%) HT patients with the bridge and TSAb bio-assay, respectively. TSHR blocking antibodies were present in one (3%) patient with HT and in two (1%) patients with GD; these two GD patients were also bridge assay positive but TSAb bioassay negative. In conclusion, the bridge immunoassay and both bioassays are highly sensitive for the detection of TSHR-Ab. The bridge assay is, however, also positive in the presence of TSHR blocking antibodies detected in a TBAb bioassay.

Increased Numbers of Circulating Tumor Cells in Thyroid Cancer Patients.

Circulating tumor cells (CTCs) have been shown to be a valuable prognostic marker for different solid cancers. Within the present study we quantified CTCs in thyroid cancer (TC) patients. Special focus was given to disease-free PTC patients with undetectable serum thyroglobulin (Tg) levels. Altogether, 67 TC patients (33 papillary, 20 follicular, 14 medullary) were included in the study. CTC numbers, which were normalized to 3.3×105 peripheral blood mononuclear cells, were correlated with clinical outcome. TC patients had significantly higher CTC numbers compared to controls. The number of CTCs correlated to the initial tumor stage. Importantly, in comparison to controls, differentiated TC patients with serum Tg levels<0.3 ng/ml (no evidence of tumor recurrence) revealed a significantly higher amount of CTCs, also associated to their former tumor stage. Regarding the tumor-free papillary TC (PTC) patients the number of CTCs additionally correlated to the time point of radioiodine (RI) therapy: PTC patients with RI therapies>8 years before CTC measurement had significantly higher CTC numbers compared to those with RI therapy<8 years ago. We found a clear correlation between the number of CTCs and the tumor stage. Importantly, PTC patients who are in remission may still have increased numbers of CTCs. Follow-up analyses in these patients will reveal whether these data will have a clinical impact.

Measurement of Basal Serum Calcitonin for the Diagnosis of Medullary Thyroid Cancer.

Calcitonin (CT), a tumor marker for medullary thyroid cancer (MTC), can be stimulated with pentagastrin or calcium. Because of the unavailability of pentagastrin, basal CT measurement is frequently used for the preoperative diagnosis of MTC. The aim of the study was to define basal serum calcitonin (bCT) cut-off thresholds for diagnosing MTC. Within a retrospective analysis, 114 patients (51 males) were included fulfilling the criteria of an increased preoperative bCT level (>10 pg/ml) and the criteria of an available postoperative histology analysis. Based on a ROC plot analysis, the cut-off values for the diagnosis of MTC vs. non-malignancy (C cell hyperplasia and goiter) were identified. The most precise bCT thresholds for the identification of MTC were ≥46 pg/ml for males (sensitivity: 93.6%, specificity: 95.0%, PPV: 97%, NPV: 90%) and ≥35 pg/ml for females (sensitivity: 87.3%, specificity: 87.5%, PPV: 98%, NPV: 50%). Using these cut-offs, only 6% of male patients were not identified of having MTC, whereas 5% were false positive (having instead C cell hyperplasia). In females, the discrepancy was higher since 13% of female MTC patients were false negative by using the cut-off of ≥35 pg/ml, and 13% had false positive results (suffering from C cell hyperplasia). Gender-specific bCT cut-offs for the identification of MTC vs. C cell hyperplasia and non-malignancy were defined, which can be used in clinical routine. In female patients, however, the accuracy is much lower compared to males.

Excessive Catecholamine Secretion and the Activation of the Renin-Angiotensin-Aldosterone-System in Patients with Pheochromocytoma: A Single Center Experience and Overview of the Literature.

Catecholamines stimulate renin-secretion in the juxtaglomerular cells of the kidney and a number of case reports suggest an association between pheochromocytoma and activation of the RAAS. Therefore, it could be asked whether patients suffering from pheochromocytoma with high concentrations of circulating catecholamines present with oversecretion of renin and aldosterone. We identified twelve patients with excessive catecholamine secretion due to pheochromocytoma and compared them to a group of twelve patients with essential hypertension (EH) with regard to the activation of the renin-angiotensin-aldosterone-system (RAAS). The PubMed database was screened for studies that investigate the association between pheochromocytoma and activation of the RAAS. The plasma concentrations of metanephrines (19.9-fold) and normetanephrines (29.5-fold) were significantly higher in the pheochromocytoma group than in the EH group. Renin and aldosterone levels were 1.3-fold and 1.6-fold higher, respectively, as compared to the EH group, whereas the differences were not statistically significant. There was no significant correlation between plasma metanephrine or normetanephrine levels and the plasma renin concentration (rs=0.077, rs=0.049, respectively) in our patients. The data from our institution and from review of literature suggest that an association between pheochromocytoma in the context of high plasma catecholamine levels and activation of the RAAS is present. However, results have not been consistent. Thus, other causes of RAAS-activation should be considered also in the presence of pheochromocytoma or reinvestigation for aldosteronism should be offered to such patients after removal of the catecholamine-producing tumour.

Treatment of RET-Positive Advanced Medullary Thyroid Cancer with Multi-Tyrosine Kinase Inhibitors-A Retrospective Multi-Center Registry Analysis.

BACKGROUND: RET (rearranged during transfection) variants are the most prevalent oncogenic events in medullary thyroid cancer (MTC). In advanced disease, multi-tyrosine kinase inhibitors (MKIs) cabozantinib and vandetanib are the approved standard treatment irrespective of RET status. The actual outcome of patients with RET-positive MTC treated with MKIs is ill described. METHODS: We here retrospectively determined the RET oncogene variant status with a targeted DNA Custom Panel in a prospectively collected cohort of 48 patients with advanced MTC treated with vandetanib and/or cabozantinib at four German referral centers. Progression-free survival (PFS) and overall survival (OS) probabilities were estimated using the Kaplan-Meier method. RESULTS: In total, 44/48 (92%) patients had germline or somatic RET variants. The M918T variant was found in 29/44 (66%) cases. In total, 2/32 (6%) patients with a somatic RET variant had further somatic variants, while in 1/32 (3%) patient with a germline RET variant, additional variants were found. Only 1/48 (2%) patient had a pathogenic HRAS variant, and no variants were found in 3 cases. In first-line treatment, the median OS was 53 (95% CI (95% confidence interval), 32-NR (not reached); n = 36), and the median PFS was 21 months (12-39; n = 33) in RET-positive MTC patients. In second-line treatment, the median OS was 18 (13-79; n = 22), and the median PFS was 3.5 months (2-14; n = 22) in RET-positive cases. CONCLUSIONS: RET variants were highly prevalent in patients with advanced MTC. The treatment results in RET-positive cases were similar to those reported in unselected cohorts.

[Graves' Disease]. / Morbus Basedow.

DIAGNOSIS: The diagnosis of Graves' disease is mainly based on ultrasonography and laboratory diagnostics. This includes the determination of the TSH value and the peripheral thyroid hormones. TSH receptor antibody (TRAb) measurement is highly sensitive and specific for the detection of Graves' disease (GD) and helps to distinguish from autoimmune thyroiditis (AIT). However, as recent studies show, some may AIT patients may also reveal TRAb. THERAPY: Current guidelines recommend primarily the use of thiamazol/carbimazole in GD. Due to the comparatively higher hepatotoxicity, propylthiouracil is not recommended as first line therapy. In case of relapse during 12 up to 18 months of antithyroid drug therapy or after a frustrating attempt at cessation, definitive therapy should be considered. Alternatively, in accordance with the current recommendations of the European Thyroid Association, drug therapy may be continued for up to 12 months after initial diagnosis. PREGNANCY: The treatment of active GD during pregnancy is problematic due to diaplacental crossing of peripheral thyroid hormones, TSH receptor stimulating antibodies and antithyroid drugs. According to current guidelines, PTU is recommended during the first 16 weeks of pregnancy, whereas for the 2nd and 3 rd trimester no special recommendations are given. After that, you can choose which antithyroid drug might be used. The aim of antithyroid drug therapy during pregnancy is to achieve a suppressed TSH value together with normal or slightly increased fT4 while using lowest effective dose of antithyroid drug. IMMUNE CHECKPOINT INHIBITORS (ICI): The most common endocrine side effect with this therapy is thyroid dysfunction. Hyperthyroidism; occur most frequently in combination therapy (CTLA-4 / anti-PD-1 therapy) ICI mainly causes destructive thyroiditis with lymphocytic infiltration; GD is absolutely rare in this context and only few cases are described.

Real-World Efficacy and Safety of Cabozantinib and Vandetanib in Advanced Medullary Thyroid Cancer.

Background: Management of patients with advanced medullary thyroid cancer (MTC) remains a therapeutic challenge. The multi-tyrosine kinase inhibitors (TKIs) vandetanib and cabozantinib have been approved for the treatment of progressive MTC based on prolonged progression-free survival (PFS) in phase 3 clinical trials. Patients and Methods: To evaluate clinical characteristics, treatment regimens, efficacy, and treatment emergent adverse events (TEAEs) of vandetanib and cabozantinib in MTC patients outside clinical trials at four German tertiary care centers. Forty-eight patients diagnosed between 1990 and 2018 were included. PFS and overall survival (OS) probabilities were estimated using the Kaplan-Meier method and compared by log-rank test. Results: The median age at diagnosis was 46 years (15-80 years); a germ line RET (rearranged during transfection) mutation was known in 6 (13%) patients. Thirty-two (67%) patients showed progressive disease before TKI initiation. Forty-seven (98%) patients were treated with vandetanib and 23 (48%) patients with cabozantinib. Vandetanib was first-line treatment in 41 (85%) patients and cabozantinib in 7 (15%) patients. Partial response was the best response in 12 (26%) patients treated with vandetanib and in 5 (22%) patients treated with cabozantinib. Sixteen (34%) patients treated with vandetanib and 3 (13%) patients treated with cabozantinib had stable disease ≥24 weeks. The median PFS for vandetanib and cabozantinib was 17 months [95% confidence interval, CI, 9.3-24.6 months] and 4 months [CI 3.1-4.9 months], respectively. The 6- and 12-month survival rates were 98% and 86% for vandetanib and 78% and 70% for cabozantinib, respectively. The median OS for vandetanib and cabozantinib was 53 months [CI 43.7-62.3 months] and 24 months [CI 5.9-42.1 months], respectively. In vandetanib-treated patients, the PFS and OS were significantly longer in patients aged ≤60 years at TKI initiation and in patients with ≥5 TEAEs. Additionally, the PFS was longer in the absence of bone metastases. In cabozantinib-treated patients, the PFS was significantly longer in patients experiencing TEAEs and in patients aged ≤60 years, and the OS was significantly longer in patients who had TEAEs and in patients with ≥5 TEAEs. Conclusions: Vandetanib and cabozantinib are effective treatment options in the majority of MTC patients. We hypothesize that the poorer prognosis of cabozantinib-treated patients in our retrospective analysis is most likely due to its use as second-line treatment after treatment failure on vandetanib. However, different degrees of efficacy of the two drugs are possible.

FGF-Receptors and PD-L1 in Anaplastic and Poorly Differentiated Thyroid Cancer: Evaluation of the Preclinical Rationale.

Background: Treatment options for poorly differentiated (PDTC) and anaplastic (ATC) thyroid carcinoma are unsatisfactory and prognosis is generally poor. Lenvatinib (LEN), a multi-tyrosine kinase inhibitor targeting fibroblast growth factor receptors (FGFR) 1-4 is approved for advanced radioiodine refractory thyroid carcinoma, but response to single agent is poor in ATC. Recent reports of combining LEN with PD-1 inhibitor pembrolizumab (PEM) are promising. Materials and Methods: Primary ATC (n=93) and PDTC (n=47) tissue samples diagnosed 1997-2019 at five German tertiary care centers were assessed for PD-L1 expression by immunohistochemistry using Tumor Proportion Score (TPS). FGFR 1-4 mRNA was quantified in 31 ATC and 14 PDTC with RNAscope in-situ hybridization. Normal thyroid tissue (NT) and papillary thyroid carcinoma (PTC) served as controls. Disease specific survival (DSS) was the primary outcome variable. Results: PD-L1 TPS≥50% was observed in 42% of ATC and 26% of PDTC specimens. Mean PD-L1 expression was significantly higher in ATC (TPS 30%) than in PDTC (5%; p<0.01) and NT (0%, p<0.001). 53% of PDTC samples had PD-L1 expression ≤5%. FGFR mRNA expression was generally low in all samples but combined FGFR1-4 expression was significantly higher in PDTC and ATC compared to NT (each p<0.001). No impact of PD-L1 and FGFR 1-4 expression was observed on DSS. Conclusion: High tumoral expression of PD-L1 in a large proportion of ATCs and a subgroup of PDTCs provides a rationale for immune checkpoint inhibition. FGFR expression is low thyroid tumor cells. The clinically observed synergism of PEM with LEN may be caused by immune modulation.

Real-World Efficacy and Safety of Multi-Tyrosine Kinase Inhibitors in Radioiodine Refractory Thyroid Cancer.

Background: The management of patients with locally advanced or metastatic differentiated thyroid cancer (DTC) that is refractory to radioiodine (RAI) remains a therapeutic challenge. The multi-tyrosine kinase inhibitors (TKIs) sorafenib and lenvatinib have been approved based on phase 3 clinical trials. Patients and Methods: We aimed at describing the efficacy and safety of TKI treatment of RAI-refractory DTC in a real-world setting at six German referral centers. One hundred and one patients with locally advanced or metastatic RAI-refractory DTC treated with sorafenib, lenvatinib, and/or pazopanib were included. Progression-free survival (PFS) and overall survival (OS) probabilities were estimated by using the Kaplan-Meier method. Results: Ninety-seven of 101 patients had progressive disease before TKI initiation. The median PFS for first-line treatment with sorafenib (n = 33), lenvatinib (n = 53), and pazopanib (n = 15) was 9 (95% confidence interval 5.2-12.8), 12 (4.4-19.6), and 12 months (4.4-19.6), respectively. The median OS for first-line treatment was 37 (10-64) for sorafenib, 47 (15.5-78.5) for lenvatinib, and 34 months (20.2-47.8) for pazopanib. Serious complications (e.g., hemorrhage, acute coronary syndrome, and thrombosis/venous thromboembolism) occurred in 16 out of 75 (21%) patients taking lenvatinib, in 3 out of 42 (7%) patients taking sorafenib, and in 3 out of 24 (13%) patients taking pazopanib. Conclusions: Sorafenib, lenvatinib, and pazopanib are effective treatment options in the majority of patients with RAI-refractory DTC. The PFS and six-month survival rate in patients treated with lenvatinib und pazopanib appear to compare favorably with sorafenib in the first-line treatment setting. However, a more advanced disease stage at treatment initiation in sorafenib- and pazopanib-treated patients in the era before TKI-approval and the retrospective nature of this study precludes a direct comparison of TKIs.

[Update Graves' disease 2019]. / Update Morbus Basedow.

DIAGNOSIS: Also accordingly to the recent European Thyroid Association Guidelines 2018, TSH receptor antibody (TRAb) measurement is highly sensitive and specific for the detection of Graves' disease (GD) and to distinguish from autoimmune thyroiditis (AIT). Bioassays are used for distinguishing stimulating from blocking antibodies and are used for scientific questions. THERAPY: According to the current guidelines - and with exception for pregnant women - the use of thiamazol/carbimazole is generally favored from propylthiouracil (PTU). In case of relapse or missing remission after 12 up to 18 months antithyroid drug therapy, thyroid ablative therapy including radioiodine therapy or thyroidectomy, respectively, should be performed. PROGNOSIS: TRAb measurement can also be used for outcome prediction. PREGNANCY: Recently the American Thyroid Association published a new guideline for the management of thyroid disease during pregnancy. According to this, during the first 16 weeks of pregnancy PTU is preferred for the treatment of GD with hyperthyroidism. After the 16th week of pregnancy, there is no clear recommandation which antithyroid drug should be used. The general aim is to reach a maternal serum T4 at the upper serum range or moderately above the reference range with the lowest effective dose of an antithyroid drug. ENDOCRINE OPHTHALMOPATHY: As recently shown, Graves' ophthalmopathy improves significantly following the treatment with the monoclonal antibody teprotumumab which inhibits the IGF 1 receptor. This therapy is, however, not been approved in Germany.

Graves' disease in clinical perspective.

Graves' disease (GD) is the most common cause for hyperthyroidism in iodine-replete areas. The disease is caused by the appearance of stimulating TSH receptor autoantibodies (TRAb) leading to hyperthyroidism. Blocking and neutral TRAb have, however, also been described. TRAb can be measured either by competition assays, assays using a bridge technology or bioassays (for discriminating stimulating vs. blocking antibodies). Therapy of GD with antithyroid drugs belonging to the group of thionamides is the first-line treatment to be continued for 12 up to 18 months. In case of relapse, thyroid ablative therapy including radioiodine therapy or thyroidectomy, respectively, should be performed. Risk factors for relapse are a large thyroid volume, persistence of high TRAb serum titer, smoking, and others. Within this review, we will give insights into the pathogenesis of GD including the pathogenesis of Graves' ophthalmopathy. We also describe recent developments of TRAb measurement, which is used for the diagnosis of GD as well as for outcome prediction. Finally, we discuss therapy aspects as well as the important issue of GD and pregnancy.

TSH-receptor autoantibodies: pathophysiology, assay methods, and clinical applications.

TSH receptor antibodies (TRAbs) are characteristic indicators for the common autoimmune thyroid disease Graves disease (GD). In almost all patients stimulating TRAbs are found leading to hyperthyroidism as these antibodies act in an agonistic manner to TSH. Besides stimulating TRAbs, other TRAbs are also frequently found leading to inhibition of TSH receptor signaling (blocking TRAbs) or to the activation of different signaling cascades resulting in e.g. thyrocyte apoptosis (cleavage antibodies). Patients' sera may contain all three types of TRAbs. Dependent on the activity of these particular TSHR autoantibodies clinical symptoms might change. Within this review we summarize current genetic and environmental factors that are generally accepted for GD's etiology. Binding sides to the TSH receptor as well as the resulting signaling cascades are described just as the current used assay methods for TRAb measurement. Finally, we illustrate the clinical impact of TRAbs in the follow-up of GD patients with special focus on GD patients suffering from Graves' ophthalmopathy.

Epitope-Specific Antitumor Immunity Suppresses Tumor Spread in Papillary Thyroid Cancer.

Context: Papillary thyroid cancer (PTC) is characterized by a lymphocytic infiltration. PTC patients with lymphocytic infiltration may have a better clinical outcome. Objective: Characterization of tumor epitope-specific immunity and correlation analyses with the clinical outcome. Patients: 150 PTC patients; 40 Hashimoto thyroiditis (HT) patients; 21 healthy controls; 27,239 healthy whites (for HLA typing). Main Outcome Measures: HLA class I restricted thyroperoxidase (TPO) and thyroglobulin (Tg) epitope-specific T cells (tetramer analyses), correlation analyses between HLA class II phenotypes, T cell immunity, and the clinical course. Results: The frequency of TPO- and Tg-specific CD8+ T cells in PTC patients was largely increased compared with healthy controls (TPO and Tg, P < 0.005 and P < 0.005) and was similar to those in HT patients. HLA-DQB1*03-positive PTC patients had a significantly lower risk [risk ratio (RR), 0.170; 95% confidence interval (CI), 0.037 to 0.755; P < 0.05] and HLA-DRB1*03-positive and HLA-DQB1*02-positive PTC patients a significantly higher risk (HLA-DRB1*03: RR, 4.400; 95% CI, 1.378 to 14.05; P < 0.05; HLA-DQB1*02: RR, 3.692; 95% CI, 1.102 to 12.38; P < 0.05) for distant metastases, compared with patients with other haplotypes. HLA-DQB1*03-positive PTC patients revealed an increased responsiveness of tumor epitopes in vitro. These tumor epitope-specific CD8+ T cells were also found in lymph node metastases of HLA-DQB1*03-positive PTC patients. Conclusion: We demonstrate a tumor epitope-specific immunity in PTC patients and the protective role of HLA-DQB1*03 against metastatic spread. These results have direct implications for new treatment options with immune checkpoint inhibitors.

Clinical presentation, treatment and outcome of anaplastic thyroid carcinoma: results of a multicenter study in Germany.

CONTEXT: Anaplastic thyroid carcinoma (ATC) is an orphan disease and confers a dismal prognosis. Standard treatment is not established. OBJECTIVE: The aim of this study is to describe clinical characteristics, current treatment regimens and outcome of ATC and to identify clinical prognostic markers and treatment factors associated with improved prognosis. DESIGN: Retrospective cohort study at five German tertiary care centers. PATIENTS AND METHODS: Totally 100 ATC patients diagnosed between 2000 and 2015 were included in the analysis. Disease-specific overall survival (OS) was compared with the Kaplan-Meier method and log-rank test; Cox proportional hazard model was used to identify risk factors. RESULTS: The 6-month, 1-year and 5-year disease-specific OS rates were 37, 28 and 5%, respectively. Stage-dependent OS at 6 months was 78, 54 and 18% for stage IVA, B and C, respectively. 29% patients survived >1 year. Multivariate analysis of OS identified age ≥70 years, incomplete local resection status and the presence of distant metastasis as significant risk factors associated with shorter survival. Radical surgery (hazard ratio [HR] 2.20, 95% confidence interval (CI) 1.19-4.09, P = 0.012), external beam radiation therapy (EBRT) ≥40 Gy (HR = 0.34, 0.15-0.76, P = 0.008) and any kind of chemotherapy (CTX) (HR = 11.64, 2.42-60.39, P = 0.003) were associated with longer survival in multivariate analyses adjusted for age and tumor stage. A multimodal treatment regimen was significantly associated with a survival benefit (HR = 1.04, 1.01-1.08, P < 0.0001) only in IVC patients. CONCLUSION: Disease-specific OS is still poor in ATC. Treatment factors associated with improved OS provide a rationale to devise treatment pathways for routine care. Collaborative research structures should be aimed to advance treatment of ATC.

Enhanced iodine supplementation alters the immune process in a transgenic mouse model for autoimmune thyroiditis.

BACKGROUND: The impact of excessive iodine intake on the development of autoimmune thyroiditis (AIT) is still under debate. Transgenic, antibody-devoid TAZ10 mice spontaneously develop AIT due to autoreactive thyroperoxidase-specific T cells. In this model, development of AIT is determined by a T cell infiltration of the thyroid gland leading to an elevation of serum thyrotropin (TSH) levels and significant weight gain. In the present study we investigated the impact of moderate and high iodine supplementation on the course of disease in these mice, which are immunologically prone to AIT. METHODS: In addition to normal nutrition, mice were supplemented for 20 weeks with 2.5 µg versus 5 µg iodine per milliliter drinking water, which corresponds to a human daily iodine supplementation of 150 µg, 315 µg, and 615 µg iodine. AIT-defining parameters (weight gain, elevation of serum TSH levels, cellular infiltration of the thyroid) and immunologic effects were analyzed. RESULTS: No significant differences were displayed when comparing weight and serum TSH levels in the iodine-supplemented versus control groups. Increased thyroid infiltrates with CD8⁺ T cells were detected by fluorescein-activated cell sorter (FACS) and immunofluorescence staining in mice supplemented with elevated iodine amounts (315 µg and 615 µg iodine per day, respectively). Immunologic monitoring revealed selective changes in immune cell frequencies (CD8⁺ and regulatory T cells, natural killer [NK] cells) and cytokine production (interferon-γ, interleukin-1α, and interleukin-17), however, without affecting the overall immune balance. CONCLUSION: Our results demonstrate that elevated iodine supplementation has no physical impact on the course of disease in transgenic, antibody-devoid TAZ10 mice, which are immunologically prone to AIT.