A Prospective, Randomized, Double-blind, Placebo-controlled Study of Orbital Radiotherapy for Graves' Ophthalmopathy.

CONTEXT: Although widely used for more than 85 years, the efficacy of radiotherapy for Graves' ophthalmopathy (GO) has not been established convincingly. OBJECTIVE: To evaluate the efficacy of radiotherapy for GO. DESIGN: Prospective, randomized, internally controlled, double-blind clinical trial in a tertiary care academic medical center. PARTICIPANTS: The patients were ethnically diverse males and females over age 30 seen in a referral practice. The patients had moderate, symptomatic Graves' ophthalmopathy (mean clinical activity score, 6.2) but no optic neuropathy, diabetes, recent steroid treatment, previous decompression, or muscle surgery. Forty-two of 53 consecutive patients were enrolled after giving informed consent and fulfilling study entry criteria. Eleven eligible patients declined to participate because of inconvenience, desire for alternative therapy, or concern about radiation. INTERVENTION: One randomly selected orbit was treated with 20 Gy of external beam therapy; sham therapy was given to the other side. Six months later, the therapies were reversed. MAIN OUTCOME MEASURES: Every 3 months for 1 year, we measured the volume of extraocular muscle and fat, proptosis, range of extraocular muscle motion, area of diplopia fields, and lid fissure width. Effective treatment for GO will modify one or more of these parameters. RESULTS: No clinically or statistically significant difference between the treated and untreated orbit was observed in any of the main outcome measures at 6 months. At 12 months, muscle volume and proptosis improved slightly more in the orbit that was treated first. CONCLUSIONS: In this group of patients, representative of those for whom radiotherapy is frequently recommended, we were unable to demonstrate any beneficial therapeutic effect. The slight improvement noted in both orbits at 12 months may be the result of natural remission or of radiotherapy, but the changes are of marginal clinical significance.

Clinical Experience with Rituximab and Intravenous Immunoglobulin for Pretibial Myxedema: A Case Series.

Background: Severe pretibial myxedema (PTM) can be difficult to manage, highlighting the need to investigate newer therapies. Rituximab (RTX) and intravenous immunoglobulin (IVIg) have been tried in Graves' orbitopathy. Since PTM and orbitopathy share a similar underlying pathophysiology, this study aimed to explore these therapies for progressive PTM. Methods: The electronic database was screened for PTM patients evaluated at the Mayo Clinic, Rochester, from 2002 to 2016, and three patients who received IVIg and five who received RTX are reported. PTM pattern was classified as non-pitting edema, plaque and induration, nodular/nummular, and elephantiasis. PTM was confirmed by biopsy in six patients. Results: The patients' median age was 53.8 years, 75% were female, and all but one patient were either active or former smokers. All patients were euthyroid and had progressed despite various therapies prior to starting these agents. Six patients had a plaque and induration pattern, and two had a nodular pattern with elephantiasis. After therapy, six (75%) patients had PTM stability or improvement both subjectively and objectively (80% with RTX and 66% with IVIg). The three patients (one in the IVIg group and two in the RTX group) who had subjective improvement had a plaque pattern. One patient with elephantiasis had a transient response to IVIg and another had stability after RTX. Thyrotropin receptor antibody values and orbitopathy also improved in patients who demonstrated PTM improvement. No serious adverse events were reported, but one patient each had transient hypertension and injection-site thrombophlebitis after IVIg. Conclusions: Immunomodulation therapy was followed by PTM improvement or stability in most patients, with a slightly better response after RTX compared to IVIg. A validated response assessment instrument and larger series of patients are required to determine if the underlying disease process could be curtailed with these agents.

Comparative Effectiveness of Treatment Choices for Graves' Hyperthyroidism: A Historical Cohort Study.

BACKGROUND: The optimum therapy for Graves' disease (GD) is chosen following discussion between physician and patient regarding benefits, drawbacks, potential side effects, and logistics of the various treatment options, and it takes into account patient values and preferences. This cohort study aimed to provide useful information for this discussion regarding the usage, efficacy, and adverse-effect profile of radioactive iodine (RAI), antithyroid drugs (ATDs), and thyroidectomy in a tertiary healthcare facility. METHODS: The cohort included consecutive adults diagnosed with GD from January 2002 to December 2008, who had complete follow-up after treatment at the Mayo Clinic, Rochester, Minnesota. Data on treatment modalities, disease relapses, and adverse effects were extracted manually and electronically from the electronic medical records. Kaplan-Meier analyses were performed to evaluate the association of treatments with relapse-free survival. RESULTS: The cohort included 720 patients with a mean age of 49.3 years followed for a mean of 3.3 years. Of these, 76.7% were women and 17.1% were smokers. The initial therapy was RAI in 75.4%, ATDs in 16.4%, and thyroidectomy in 2.6%, while 5.6% opted for observation. For the duration of follow-up, ATDs had an overall failure rate of 48.3% compared with 8% for RAI (hazard ratio = 7.6; p < 0.0001). Surgery had a 100% success rate; 80% of observed patients ultimately required therapy. Adverse effects developed in 43 (17.3%) patients treated with ATDs, most commonly dysgeusia (4.4%), rash (2.8%), nausea/gastric distress (2.4%), pruritus (1.6%), and urticaria (1.2%). Eight patients treated with RAI experienced radiation thyroiditis (1.2%). Thyroidectomy resulted in one (2.9%) hematoma and one (2.85%) superior laryngeal nerve damage, with no permanent hypocalcemia. CONCLUSIONS: RAI was the most commonly used modality within the cohort and demonstrated the best efficacy and safety profile. Surgery was also very effective and relatively safe in the hands of experienced surgeons. While ATDs allow preservation of thyroid function, a high relapse rate combined with a significant adverse-effect profile was documented. These data can inform discussion between physician and patient regarding choice of therapy for GD.

Riedel's thyroiditis association with IgG4-related disease.

CONTEXT: IgG4-positive (+) plasma cells have been reported in both Riedel's thyroiditis (RT) and Hashimoto's thyroiditis (HT). These cells are the hallmark of IgG4-related disease (IgG4-RD). OBJECTIVE: We sought to determine whether RT is part of IgG4-RD spectrum. DESIGN, SETTING AND PATIENTS: This was a case-control study performed at a tertiary medical centre. We included RT cases from the period 1958 to 2008 that had sufficient paraffin-embedded tissue for IgG4 immunostaining. Controls were patients with HT, age and gender matched, with similar pathology criteria. MAIN OUTCOME MEASURE: The main outcome measures were the intensity of the IgG4 staining and the clinical and histological correlates with IgG4-RD. RESULTS: Six pairs of RT and HT were analysed. The mean age was 44·7 years. In both groups, 5/6 cases had positive IgG4 staining. The mean number of IgG4 + cells/ HPF, normalized to the degree of inflammation, was 3·2 ± 3·0 SD (RT) vs 0·9 ± 0·7 (HT), P = 0·15, for fibrotic areas and 2·1 ± 2·3 SD vs 1·0 ± 0·8 (P = 0·39) for areas with lymphoid aggregates. We found the number of IgG4 +  cells in RT to be inversely correlated with the duration of disease (P = 0·046). Three RT cases had associated comorbidities from the IgG4-RD spectrum while none of the HT cases had such conditions. CONCLUSIONS: Riedel's thyroiditis is a component of IgG4-RD with the density of the IgG4 +  lymphocytic infiltrate being time dependent. In this small study, we did not identify differences in IgG4 infiltration between RT and HT, minimizing the utility of this marker in RT diagnosis.

Development and Pilot Testing of an Encounter Tool for Shared Decision Making About the Treatment of Graves' Disease.

BACKGROUND: The best treatment option for patients with Graves' disease (GD) depends on each person's situation and how the differences between the treatment options matter to them in bringing resolution to their illness. The objective of this study was to develop and test an encounter decision tool (GD Choice) for patients and clinicians to engage in shared decision making about the treatment of GD. METHODS: GD Choice was developed using an iterative process based on the principles of interaction design and participatory action research. To evaluate the impact of the tool, a controlled before-after study was conducted, assessing the use of GD Choice versus usual care (UC). RESULTS: Sixty-eight patients were enrolled, 37 to UC and 31 to GD Choice. At baseline, the groups were similar. Treatment discussion length was similar in both arms. After their visit, patients in both groups had similar knowledge about the options, except for GD Choice patients knowing significantly more about the complications of treatment (correctly answered by 83% vs. 55%; p = 0.04). Compared with UC, patients in the GD Choice arm had greater involvement in decision making observed on video recordings of clinical encounters (mean OPTION scale score, 35% vs. 30%; p = 0.02), but reported similar levels of decisional comfort and participation in shared decision making. CONCLUSIONS: GD Choice increases engagement in the decision-making process and knowledge regarding intervention complications without increasing the length of consultation. These promising results support the conduct of a randomized trial of GD Choice versus UC in a large multicenter trial.

Forkhead Transcription Factor FOXO1 Is Regulated by Both a Stimulatory Thyrotropin Receptor Antibody and Insulin-Like Growth Factor-1 in Orbital Fibroblasts from Patients with Graves' Ophthalmopathy.

BACKGROUND: Activation of thyrotropin receptor (TSHR) and/or insulin-like growth factor (IGF-1) receptor (IGF-1R) enhances HA production and adipogenesis in orbital fibroblasts from patients with Graves' ophthalmopathy (GO) and recapitulates the tissue remodeling characteristic of the orbit in GO. A functional relationship between TSHR and IGF-1R has long been postulated, and recently bidirectional crosstalk between the receptors in GO fibroblasts was demonstrated. Because the transcription factor Forkhead box O-1 (FOXO1) was recently shown to be a critical downstream mediator of TSH and IGF-1 effects on thyrocyte proliferation, studies were designed to determine whether FOXO1 might similarly act as a common mediator of M22, a stimulatory TSHR antibody (TSAb), and IGF-1 in GO orbital fibroblasts. METHODS: FOXO1 mRNA and protein were measured in orbital tissue specimens derived from normal individuals and patients with GO. In addition, the control of FOXO1 cellular localization was investigated using quantitative Western blotting of fractionated cell lysates from orbital fibroblasts treated with M22 and/or IGF-1 with or without specific TSHR, IGF-1R, or PI3K/AKT1/2 inhibitors. RESULTS: Significantly lower levels of both FOXO1 mRNA and protein were found in GO orbital tissue specimens compared with normal orbital tissues (M = 39%, p = 0.043; M = 46.4%; p = 0.028, respectively). In addition, treatment of GO orbital cultures with M22, IGF-1, or M22 plus IGF-1 increased cytoplasmic FOXO1 compared with control (1.63-fold, p = 0.008; 1.68-fold, p = 0.001; 1.61-fold, p ≤ 0.001, respectively) and decreased nuclear FOXO1 (M = 28%, p = 0.002; M = 38%, p ≤ 0.001; M = 35%, p = 0.007, respectively). These effects were inhibited by co-treatment with the respective, but not the opposite, receptor antagonist. AKT inhibition of M22 or IGF-1-treated cultures was found to increase nuclear (1.4-fold, p = 0.026; 1.3-fold, p = 0.001, respectively) and decrease cytoplasmic (24.2%, p = 0.001; 36%, p = 0.004, respectively) FOXO1 localization. CONCLUSIONS: These data point to FOXO1 as an important mediator of TSAb and IGF-1 action via their cognate receptors in GO orbital fibroblasts. These findings provide a link between the low FOXO1 protein levels demonstrated in GO orbital tissue and the tissue remodeling characteristic of GO, and suggest novel therapy for GO aimed at increasing nuclear expression of FOXO1 in GO target cells.

Randomized controlled trial of rituximab in patients with Graves' orbitopathy.

CONTEXT: Graves' orbitopathy (GO) is a potentially sight-threatening disease for which available medical therapy is not uniformly successful. Multiple case series suggest that rituximab (RTX) may be effective therapy for GO patients. OBJECTIVE: To determine the efficacy of RTX in GO. DESIGN: It is a prospective, randomized, double-masked, placebo-controlled trial. SETTING: The study was conducted at a large academic private practice. PATIENTS: Twenty five patients with active moderate to severe GO were enrolled, and 21 completed the study to the primary endpoint. INTERVENTIONS: Two RTX infusions (1000 mg each) or two saline infusions were given 2 weeks apart. MAIN OUTCOME MEASURES: The primary endpoint was a reduction in clinical activity score (CAS) assessed as a continuum and separately as improvement by ≥ 2 points at 24 weeks. Secondary endpoints included success and failure rates, proportions showing clinically significant improvement in proptosis, lid fissure width, diplopia score, lagophthalmos and disease severity, and changes in those parameters, orbital fat/ muscle volume and quality-of-life. RESULTS: The treatment groups were similar in all parameters at baseline. The last observation was carried forward if the patient discontinued prematurely. No differences were found in the proportions of patients showing CAS improvement at 24 weeks (25% placebo; 31% RTX, P = .75) or in CAS decrease from baseline to 24 or 52 weeks [mean 1.5 points (1.8 SD) placebo; 1.2 (2 SD) RTX at 24 weeks, P = .73]. Similarly, there were no differences between groups in any of the secondary endpoints at either 24 or 52 weeks. There were four adverse events (AE) in 3/12 placebo patients and 11 AE in 8/13 RTX-treated patients; 5/6 moderate or severe AE occurred in the RTX group. CONCLUSION: RTX offered no additional benefit over placebo to our patients with active and moderate to severe GO and carried with it non-negligible adverse effects.

Amiodarone-induced thyrotoxicosis in adults with congenital heart disease--clinical presentation and response to therapy.

OBJECTIVE: The development of amiodarone-induced thyrotoxicosis (AIT) can threaten the hemodynamic stability of adult patients with congenital heart disease (CHD). Here, we describe the natural history and treatment response of AIT in this at-risk population. METHODS: We studied retrospectively all cases of AIT that occurred in CHD patients at our institution after a minimum of 3 months on amiodarone. Subjects were identified from the cohort of adults with CHD who were treated at the Mayo Clinic Adult CHD clinic between 1987 and 2009. RESULTS: We identified 23 cases of AIT: 7 were type 1, 13 were type 2, and 3 were undefined due to insufficient data. Most patients were symptomatic (17 of 23, 74%), with arrhythmia and weight loss as the most common symptoms. The majority (12 of 23, 52%) were initially observed; 10 patients (43%) were treated medically and 1 patient (5%) underwent thyroidectomy. Four patients from the observation group eventually required active treatment and 3 patients from the medical group required surgery. Asymptomatic patients tended to resolve under observation (5 of 7, 71.4%) rather than progress to active treatment (0 of 4) (P = .06). Discontinuation of amiodarone, AIT type, or use of perchlorate did not impact AIT duration. CONCLUSION: AIT in CHD patients exhibits a wide range of severity and sensitivity to medical therapy. Asymptomatic patients display a trend toward AIT resolution with observation alone. Amiodarone continuation does not appear to impact management outcome or disease duration. Additional studies in this high-risk population could identify elements of pathophysiology that would point toward better disease prevention and treatment.

Mentoring interdisciplinary research teams for the study of sex and gender differences in health and disease.

Initiatives to hasten the translation of basic science discoveries to clinical care have necessitated the development of new approaches to interdisciplinary collaboration and training of future investigators. This has been nowhere more important than in the study of sex differences with implications for extension into areas of gender medicine. Clearly, gaining better understanding of the role that sex and gender play in health and disease is essential to the implementation of truly individualized medicine. This case report will describe our experiences in developing the Mayo Clinic Building Interdisciplinary Research Programs in Women's Health (BIRCWH) program, an interdisciplinary research and training program in women's health and sex and gender differences. We identify both our successes and the barriers we have encountered in order that others who are developing similar programs might benefit from our experiences.

Comparative effectiveness of therapies for Graves' hyperthyroidism: a systematic review and network meta-analysis.

CONTEXT: Several treatment options are available for Graves' disease (GD), including antithyroid drugs (ATDs), radioactive iodine (RAI), and thyroidectomy. OBJECTIVE: The primary outcome was to determine the relapse rates of various treatment options. The secondary outcome was to present data regarding adverse effects of ATDs. DATA SOURCES: We searched multiple databases through March 2012. STUDY SELECTION: Eligible studies were randomized clinical trials and comparative cohort studies in adults that included 2 or more treatment options for GD. DATA EXTRACTION: Two reviewers independently selected studies, appraised study quality, extracted outcome data, and determined adverse effect profiles. DATA SYNTHESIS: We found 8 studies with 1402 patients from 5 continents. Mean follow-up duration in months was: ATDs, 57; RAI, 64; and surgery, 59. Studies were at moderate to high risk of bias. Network meta-analysis suggested higher relapse rates with ATDs (52.7%; 352 of 667) than RAI (15%, 46 of 304) (odds ratio = 6.25; 95% confidence interval, 2.40-16.67) and with ATDs than surgery (10%; 39 of 387) (odds ratio = 9.09; 95% confidence interval, 4.65-19.23). There was no significant difference in relapse between RAI and surgery. Examination of 31 cohort studies identified adverse effects of ATDs in 692 of 5136 (13%) patients. These were more common with methimazole, mainly owing to dermatological complications, whereas hepatic effects were more common with propylthiouracil use. CONCLUSION: We confirm the relatively high relapse rate of ATD therapy in comparison with RAI or surgery, along with a significant side effect profile for these drugs. These data can inform discussion between physicians and patients regarding the choice of therapy for GD. The limited quality of the evidence in the literature underlines the need for future randomized clinical trials in this area.

A small molecule antagonist inhibits thyrotropin receptor antibody-induced orbital fibroblast functions involved in the pathogenesis of Graves ophthalmopathy.

CONTEXT: Graves ophthalmopathy (GO) is an autoimmune disorder characterized by increased adipogenesis and hyaluronan (HA) production by orbital fibroblasts. Circulating autoantibodies (thyroid-stimulating antibodies [TSAbs]) directed at the thyrotropin receptor (TSHR) on these cells stimulate or augment these cellular processes. A recently developed drug-like small molecule inverse agonist of TSHR, NCGC00229600, termed 1, binds to TSHR and blocks basal and stimulated signal transduction. OBJECTIVE: The purpose of this article was to determine whether 1 might inhibit HA production and relevant signaling pathways in orbital fibroblasts cultured in the presence of monoclonal TSAbs or bovine TSH (bTSH). DESIGN: Primary cultures of undifferentiated GO orbital fibroblasts (n = 13) were untreated or treated with a TSAb (M22 or MS-1) or bTSH in serum-free medium, with or without 1 or a TSHR neutral antagonist, NCGC00242595, termed 2, which does not inhibit basal signaling but does inhibit stimulated signaling. MAIN OUTCOME MEASURES: cAMP production, Akt phosphorylation (Ser473pAkt in media and immunoblotting for pAkt/total Akt), and HA production were analyzed. RESULTS: Compound 1 inhibited basal cAMP, pAkt, and HA production and that stimulated by M22 in undifferentiated orbital fibroblasts. Inhibition of HA production was dose-dependent, with a half-maximal inhibitory dose of 830 nM. This compound also inhibited MS-1- and bTSH-stimulated cAMP, pAkt, and HA production. Compound 2 did not inhibit basal HA production but did inhibit M22-stimulated HA production. CONCLUSIONS: Because cAMP, pAkt, and HA production are fibroblast functions that are activated via TSHR signaling and are important in the pathogenesis of GO, small molecule TSHR antagonists may prove to be effective in the treatment or prevention of the disease in the future.

Bioidentical compounded hormones: a pharmacokinetic evaluation in a randomized clinical trial.

OBJECTIVE: Bioidentical compounded hormone therapy is popular among patients, but providers do not have pharmacokinetic information or dosing guidelines for these preparations. Our objective was to compare the pharmacokinetics of the commonly used compounded preparations with conventional hormonal preparations that are considered bioequivalent in practice. METHODS: We conducted a randomized, blinded, four-arm 16-day clinical trial of forty postmenopausal women assigned to one of three doses of a compounded estrogen cream (Bi-est (80:20); 2.0, 2.5, or 3.0 mg)+compounded oral progesterone 100 mg, or to a conventional estradiol patch (Vivelle-Dot™ 0.05 mg)+Prometrium™ 100mg. Serum levels of estrone, estradiol, estriol, and progesterone were obtained at multiple time intervals during the first 24-h, and at steady-state. RESULTS: Results were analyzable for 37/40 women. Study medications were well tolerated. The AUC at 24h and at steady-state for estrogens remained consistently lower for all doses of Bi-est tested relative to the patch. The difference was statistically significant for Bi-est 2.0mg (AUC-estradiol=181 vs. 956; p<0.001) and 2.5mg (AUC-estradiol=286 vs. 917; p<0.001). Estriol levels remained low in all study arms. Serum progesterone levels were comparable in conventional vs. compounded groups. CONCLUSIONS: This pharmacokinetic trial showed that the currently used doses of compounded hormones yield lower levels of estrogen compared to the standard-dose estradiol patch. To find comparable doses, further studies are needed. This successfully conducted randomized controlled study attests to the feasibility of using a similar design in the setting of a larger clinical trial.

Cohort study on radioactive iodine-induced hypothyroidism: implications for Graves' ophthalmopathy and optimal timing for thyroid hormone assessment.

BACKGROUND: Graves' ophthalmopathy (GO) develops or worsens in up to one-third of patients treated with radioactive iodine (RAI) for Graves' hyperthyroidism. We sought to identify the prevalence of development or worsening of GO in patients treated with RAI for Graves' hyperthyroidism and to identify the risk factors associated with that outcome. METHODS: We identified a retrospective cohort of consecutive patients treated with RAI at Mayo Clinic (Rochester, MN) between 2005 and 2006. We assessed their medical records for evidence of hypothyroidism and development or worsening of GO in the year after therapy. Hypothyroidism was defined as thyrotropin >3.0 mIU/L or free thyroxine <0.8 ng/dL. RESULTS: We identified 291 consecutive patients who received RAI therapy during the study period, with 195 out of 291 having complete follow-up data for a one-year period. GO was present in 46 out of 195 patients (23.6%) at baseline. After RAI treatment, GO developed or worsened in 25 out of 195 patients (12.8%) and it was associated with hypothyroidism at first follow-up (p=0.011) with an odds ratio (OR) of 3.3 [95% confidence interval (CI) 1.3-8.7]. More smokers than nonsmokers developed new or worse GO (17.7% vs. 11.8%), but that difference did not reach statistical significance (p=0.35). Preexisting GO (24% of patients) was associated with a higher risk for negative GO outcome compared with patients who had no GO at baseline (11%; p=0.021). Both development of hypothyroidism by the first visit after RAI therapy (OR 3.6) and preexistent GO (OR 2.8) remained significant in a multivariate analysis. Development of hypothyroidism was more likely in patients with longer duration to first follow-up (p<0.001). By 6-8 weeks after RAI treatment, the prevalence of hypothyroidism was ∼40%, while that of hyperthyroidism was only 20%. CONCLUSIONS: The presence of hypothyroidism at the first assessment of thyroid function after RAI administration is a strong predictor for adverse GO outcome. This risk is highest in patients with preexisting GO. We suggest that in order to prevent clinical hypothyroidism and the associated risk for GO, the optimal time for first measurement of fT4 is before 6 weeks after RAI therapy.

Body mass index and the development of amiodarone-induced thyrotoxicosis in adults with congenital heart disease--a cohort study.

INTRODUCTION: Amiodarone-induced thyrotoxicosis (AIT) is a recognized complication of amiodarone treatment with limited management options. Its predisposing factors are incompletely defined yet a higher prevalence was reported in adults with congenital heart disease (CHD). Therefore we sought to determine the incidence and risk factors for AIT in adults with CHD. METHODS: At a tertiary care center we followed a historical cohort of amiodarone-treated CHD patients for the period 1987-2009. Follow-up concluded at AIT diagnosis or with last thyroid assessment on amiodarone. Cumulative incidence of AIT was calculated. AIT association with nutritional status was hypothesized a priori. RESULTS: AIT developed in 23/169 patients or 13.6%. The AIT incidence peaked in the 3rd year at 7.7%. AIT patients had a lower body mass index (BMI) at AMIO initiation compared with the rest of the cohort (mean ± standard deviation: 21.9 ± 2.9 vs. 25.1 ± 5.0; p<0.001). Patients with BMI<21 were more likely to develop thyrotoxicosis (RR=6.1) compared to those with BMI>25 (p<0.001). Presence of goiter was strongly associated with AIT (RR 3.6, p=0.002). Affected patients had a trend for higher cyanotic heart disease prevalence (34.8% vs. 17.8%, p=0.059). On multivariate analysis body mass index and goiter remained independent predictors of outcome. CONCLUSIONS: BMI<21 at initiation of amiodarone therapy and presence of goiter are strong predictors of AIT in this population. Its incidence is time dependent. These predictors can be used clinically in assessing overall impact of amiodarone therapy in congenital heart disease patients.

A drug-like antagonist inhibits thyrotropin receptor-mediated stimulation of cAMP production in Graves' orbital fibroblasts.

BACKGROUND: Fibroblasts (FIBs) within the retro-orbital space of patients with Graves' disease (GOFs) express thyrotropin receptors (TSHRs) and are thought to be an orbital target of TSHR-stimulating autoantibodies in Graves' ophthalmopathy (GO). Recently, we developed a low molecular weight, drug-like TSHR antagonist (NCGC00229600) that inhibited TSHR activation in a model cell system overexpressing TSHRs and in normal human thyrocytes expressing endogenous TSHRs. Herein, we test the hypothesis that NCGC00229600 will inhibit activation of TSHRs endogenously expressed in GOFs. METHODS: Three strains of GOFs, previously obtained from patients with GO, were studied as undifferentiated FIBs and after differentiation into adipocytes (ADIPs), and another seven strains were studied only as FIBs. ADIP differentiation was monitored by morphology and measurement of adiponectin mRNA. FIBs and ADIPs were treated with the TSH- or TSHR-stimulating antibody M22 in the absence or presence of NCGC00229600 and TSHR activation was monitored by cAMP production. RESULTS: FIBs contained few if any lipid vesicles and undetectable levels of adiponectin mRNA, whereas ADIPs exhibited abundant lipid vesicles and levels of adiponectin mRNA more than 250,000 times greater than FIBs; TSHR mRNA levels were 10-fold higher in ADIPs than FIBs. FIBs exhibited higher absolute levels of basal and forskolin-stimulated cAMP production than ADIPs. Consistent with previous findings, TSH stimulated cAMP production in the majority of ADIP strains and less consistently in FIBs. Most importantly, NCGC00229600 reduced both TSH- and M22-stimulated cAMP production in GOFs. CONCLUSIONS: These data confirm previous findings that TSHR activation may cause increased cAMP production in GOFs and show that NCGC00229600 can inhibit TSHR activation in GOFs. These findings suggest that drug-like TSHR antagonists may have a role in treatment of GO.

A risk prediction index for amiodarone-induced thyrotoxicosis in adults with congenital heart disease.

Amiodarone therapy in adults with congenital heart disease (CHD) is associated with a significant risk of amiodarone-induced thyrotoxicosis (AIT). We developed a risk index to identify those patients being considered for amiodarone treatment who are at high risk for AIT. We reviewed the health records of adults with CHD and assessed the association between potential clinical predictors and AIT. Significant predictors were included in multivariate analyses. The parameter estimates from multivariate analysis were subsequently used to develop a risk index. 169 adults met eligibility criteria and 23 developed AIT. The final model included age, cyanotic heart disease and BMI. The risk index developed identified 3 categories of risk. Their AIT likelihood ratios were: 0.37 for low risk (95% CI 0.15-0.92); 1.12 for medium risk (95% CI 0.65-1.91); and 3.47 for high risk (95% CI 1.7-7.11). The AIT predicted risk in our population was 5% for the low risk group, 15% for the medium risk group and 47% for the high risk group. Conclusions. We derived the first model to quantify the risk for developing AIT among adults with CHD. Before using it clinically to help selecting among alternative antiarrhythmic options, it needs validation in an independent population.

A stimulatory thyrotropin receptor antibody enhances hyaluronic acid synthesis in graves' orbital fibroblasts: inhibition by an IGF-I receptor blocking antibody.

CONTEXT: Graves' ophthalmopathy (GO) is characterized by expanded volume of the orbital fat and extraocular muscle tissues and elevated levels of TSH receptor autoantibodies (TRAb). The expansion of orbital tissues involves accumulation of hyaluronic acid (HA) within the orbit. OBJECTIVE: The objective of the study was to determine whether a monoclonal stimulatory TRAb (M22) impacts HA synthesis in GO orbital cells and, if so, whether this might be blocked by an IGF-I receptor (IGF-IR)-blocking antibody (1H7) or inhibitors of various downstream signaling cascades. DESIGN: GO orbital fibroblast cultures (n = 6) were treated with M22, bovine TSH (bTSH), or IGF-I in serum-free medium. Some cultures also received 1H7, LY294002, rapamycin, or protein kinase A inhibitor. MAIN OUTCOME MEASURES: HA production and phosphorylated Akt levels in media or immunoblotting for phosphorylated Akt were measured. RESULTS: M22 or bTSH stimulated HA synthesis (2.1-fold with 100 ng/ml M22 and 1.9-fold with 10 U/liter bTSH; P < 0.05 each). M22-induced HA synthesis was inhibited by LY294002 or rapamycin but not by protein kinase inhibitor. HA synthesis stimulated by M22 or IGF-I was inhibited by 1H7 (mean 36.6 ± 5.6% and mean 45.8 ± 7.6%, respectively; P < 0.05 each). Similarly, M22- or IGF-I-stimulated Akt phosphorylation was inhibited by 1H7 (mean 54 ± 9.6 and 36.1 ± 8.8%, respectively; P = 0.01 each). CONCLUSIONS: The stimulatory TRAb M22 increases HA production in undifferentiated GO orbital fibroblasts via phosphoinositide 3-kinase/phosphorylated AKT/mammalian target of rapamycin activation. Blockade of IGF-IR inhibits both HA synthesis and Akt phosphorylation induced by M22 or IGF-I in these cells, suggesting that TSH receptor and IGF-IR signaling may be closely linked in the GO orbit.