Graves' disease

The Pathology of Hyperthyroidism

This article reviews those pathologic lesions which are associated with clinical and/or biochemical hyperthyroidism. Beginning with the descriptive pathology of classical Graves' disease and the less common toxic nodular goiter and hyper-functioning thyroid nodules, this paper describes the effects of non-thyroidal hormones, glandular function (including pituitary and hypothalamic lesions), ectopic production of thyroid stimulating proteins by non-thyroidal neoplasms, exogenous drug reactions causing hyper-function and finally conditions associated with a mechanic- destructive cause of hyperthyroidism.

An improved method for the establishment of a model of Graves' disease in BALB/c mice

The present study aimed to develop a stable Graves' disease (GD) model in BALB/c mice by immunization and electroporation (EP). A total of 90 mice were divided into experimental (n=50), control (n=20) and blank (n=20) groups. The recombinant plasmid pcDNA3.1/thyroid-stimulating hormone (TSH) receptor 268 was constructed and injected into the bilateral gastrocnemius of experimental group mice at weeks 1, 4, 7 and 10. Equal volumes of saline were injected into the control and blank groups at the same time. The experimental and control groups were subjected to EP at the same time and location to enhance immunization. The levels of total serum thyroxine (T₄) and serum TSH were examined by radioimmunoassay and immunoradiometric assay, respectively. The levels of serum thyrotropin receptor N-terminal (TRAb N) and C-terminal (TRAb C) antibodies were assessed by ELISA. Whole body pertechnetate (99mTcO₄-) imaging was performed. Mouse weight and thyroid morphology and pathology were analyzed. The GD BALB/c mouse model was successfully established, with a positive rate of 79.17% (38/48). T₄ levels increased from baseline levels of 12.05±4.23 to 52.51±23.58 ng/ml by week 12 (P<0.0001). TSH levels decreased from baseline levels of 5.53±2.78 to 1.43±0.89 µIU/ml by week 12 (P<0.0001). TRAb N antibody levels increased from baseline levels of 0.006±0.002 to 0.278±0.106 mIU/ml by week 12 (P<0.0001). TRAb C antibody levels increased from baseline levels of 11.111±2.808 to 46.701±26.436 arbitrary units/ml by week 12 (P<0.0001). At week 21, TSH levels remained reduced compared with pre-immunization levels (P<0.0001). Although T₄, and TRAb N and C levels decreased, they remained increased compared with preimmunization levels (P<0.0001, P<0.0001, P=0.001). There were no significant alterations in antibody levels between the control and blank groups. Following four immunizations, the uptake of 99mTcO₄- by the thyroid was significantly increased in the experimental group. The mean weight of the experimental mice was significantly reduced compared with the control and blank groups (all P<0.0001). Furthermore, the thyroid glands of the immunized mice were enlarged and exhibited lymphocyte infiltration, fewer colloid nodules and an increased height of epithelial cells. In conclusion, by injecting recombinant plasmid pcDNA3.1/TSHR268 and EP, a GD mouse model was successfully established.

Analysis of ¹³¹I therapy and correlation factors of Graves' disease patients: a 4-year retrospective study

OBJECTIVE

To analyze the correlation therapeutic effects of first sufficiency ¹³¹I therapy in Graves' disease patients and improve its one-time curative ratio.

METHODS

Seven hundred and sixty-six patients (age range 12-77 years, mean 40.46 ± 13.12 years), including 237 men (range 12-77 years, 40.98 ± 12.64 years) and 529 women (range 14-75 years, 40.22 ± 13.34 years), who received the first I treatment were studied. The relevant examinations were performed before ¹³¹I therapy: the maximal radioactive iodine uptake of thyroid (RAIUmax), the effective half-life (EHL), the ultrasound of thyroid to calculate its weight, thyroid imaging with single-photon emission computed tomography and serum-free triiodothyronine (FT₃), free thyroxine (FT₄), sensitive thyroid-stimulating hormone (sTSH), anti-thyrotrophin receptor antibody (TRAb), thyroid-stimulating immunoglobulin, thyroglobulin antibody (TgAb), and anti-thyroid microsome antibody (TMAb). After the ¹³¹I dosage was determined, all the patients took ¹³¹I once orally. The ¹³¹I dosage range was 74-592 MBq (221.63 ± 100.64 MBq). A clinical and laboratory assessment was performed at 1, 3, 6, and 12 months after ¹³¹I therapy. Patients were divided into the clinically recovered group (symptoms and signs disappeared, free thyroid hormone levels were within or below the normal range, and sTSH was within or above the normal range) and the clinically unhealed group (symptoms and signs disappeared partially, free thyroid hormone levels were still above the normal range or within the normal range for a time and then increased again, and sTSH was constantly below the normal range). Data were analyzed by the unpaired t-test, the independent samples t-test, the χ² test, logistic regression, and Pearson bivariate correlation.

RESULTS

The one-time curative ratio of ¹³¹I therapy was 78.7% (including euthyroidism and hypothyroidism). Multiplicity in healing patients fit the logistic regression equation. The accuracy of discrimination of the equation was 79.5%. The influential factors of ¹³¹I therapy were age, RAIUmax, EHL, TRAb, and TgAb. RAIUmax and EHL were the protecting factors. Age, TRAb, and TgAb were the risk factors. TRAb influenced the one-time curative ratio between patients with negative and positive TRAb, which was higher in men (2.836 times) than in women (1.438 times).

CONCLUSION

¹³¹I therapy is an effective intervention for Graves' disease. The higher the RAIUmax and (or) the longer the EHL, the higher the possibility of a one-time cure. Elder patients or patients with a positive TRAb and (or) TgAb have a lower possibility of a one-time cure. Women with a positive TRAb should be administered an increased ¹³¹I dose to improve the curative effect.

Is the measurement of inferior thyroid artery blood flow velocity by color-flow Doppler ultrasonography useful for differential diagnosis between gestational transient thyrotoxicosis and Graves' disease? A prospective study

OBJECTIVE

To determine the role of peak systolic velocity, end-diastolic velocity and resistance indices of both the right and left inferior thyroid arteries measured by color-flow Doppler ultrasonography for a differential diagnosis between gestational transient thyrotoxicosis and Graves' disease during pregnancy.

METHODS

The right and left inferior thyroid artery-peak systolic velocity, end-diastolic velocity and resistance indices of 96 patients with thyrotoxicosis (41 with gestational transient thyrotoxicosis, 31 age-matched pregnant patients with Graves' disease and 24 age- and sex-matched non-pregnant patients with Graves' disease) and 25 age and sex-matched healthy euthyroid subjects were assessed with color-flow Doppler ultrasonography.

RESULTS

The right and left inferior thyroid artery-peak systolic and end-diastolic velocities in patients with gestational transient thyrotoxicosis were found to be significantly lower than those of pregnant patients with Graves' disease and higher than those of healthy euthyroid subjects. However, the right and left inferior thyroid artery peak systolic and end-diastolic velocities in pregnant patients with Graves' disease were significantly lower than those of non-pregnant patients with Graves' disease. The right and left inferior thyroid artery peak systolic and end-diastolic velocities were positively correlated with TSH-receptor antibody levels. We found an overlap between the inferior thyroid artery-blood flow velocities in a considerable number of patients with gestational transient thyrotoxicosis and pregnant patients with Graves' disease.

CONCLUSIONS

This study suggests that the measurement of inferior thyroid artery-blood flow velocities with color-flow Doppler ultrasonography does not have sufficient sensitivity and specificity to be recommended as an initial diagnostic test for a differential diagnosis between gestational transient thyrotoxicosis and Graves' disease during pregnancy.

The role of TSH receptor antibodies in the management of Graves' disease

The central role of thyrotropin receptor antibodies (TRAbs) in the pathogenesis of Graves' disease has been recognised for several decades. However, the practical application of testing for TRAbs in clinical decision making remains the subject of controversy. The diagnosis of Graves' disease can be made in most cases simply based on a patient's clinical presentation. The TRAb test is therefore of most value in ambiguous clinical scenarios such as in the differential diagnosis of unilateral exophthalmos, euthyroid Graves' ophthalmopathy, subclinical hyperthyroidism, thyrotoxicosis associated with hyperemesis gravidarum, amiodarone-induced thyrotoxicosis and painless thyroiditis. It may also have a role in predicting the risk of a recurrence of Graves' disease following a course of antithyroid drug treatment. One further clinical utility of the TRAb test is in pregnancy where antibody titre measured during the third trimester is used to predict the risk of neonatal thyroid dysfunction. The TRAb titre not only aids in clinching a difficult diagnosis but can also help guide treatment in some patients. Although the TRAb assay has become more affordable in recent years, cost remains an important factor when considering its use routinely. Nonetheless, this is an underutilised blood test that could augment standard endocrine investigations in the differential diagnosis of hyperthyroidism.

Functional expression of the thyrotropin receptor in C cells: new insights into their involvement in the hypothalamic-pituitary-thyroid axis

Thyroid C cells, or parafollicular cells, are mainly known for producing calcitonin, a hormone involved in calcium homeostasis with hypocalcemic and hypophosphatemic effects. Classically, the main endocrine activity of this cell population has been believed to be restricted to its roles in serum calcium and bone metabolism. Nonetheless, in the last few years evidence has been accumulating in the literature with regard to local regulatory peptides secreted by C cells, such as somatostatin, ghrelin, thyrotropin releasing hormone or the recently described cocaine- and amphetamine-related transcript, which could modify thyroid function. As thyrotropin is the main hormone controlling the hypothalamic-pituitary-thyroid axis and, accordingly, thyroid function, we have examined the functional expression of the thyrotropin receptor in C-cell lines and in thyroid tissues. We have found that rat and human C-cell lines express the thyrotropin receptor at both mRNA and protein levels. Furthermore, incubation of C cells with thyrotropin resulted in a 10-fold inhibition of thyrotropin-receptor expression, and a concomitant decrease of the steady-state mRNA levels for calcitonin and calcitonin gene-related peptide determined by quantitative real-time PCR was found. Finally, thyrotropin receptor expression by C cells was confirmed at protein level in both normal and pathological thyroid tissues by immunohistochemistry and immunofluorescence. These results confirm that C cells, under regulation by thyrotropin, are involved in the hypothalamic-pituitary-thyroid axis and suggest a putative role in local fine-tuning of follicular cell activity.

Diagnostic terminology and morphologic criteria for cytologic diagnosis of thyroid lesions: a synopsis of the National Cancer Institute Thyroid Fine-Needle Aspiration State of the Science Conference

The National Cancer Institute (NCI) sponsored the NCI Thyroid Fine-needle Aspiration (FNA) State of the Science Conference on October 22-23, 2007 in Bethesda, MD. The two-day meeting was accompanied by a permanent informational website and several on-line discussion periods between May 1 and December 15, 2007 (http://thyroidfna.cancer.gov). This document summarizes matters regarding diagnostic terminology/classification scheme for thyroid FNA interpretation and cytomorphologic criteria for the diagnosis of various benign and malignant thyroid lesions. (http://thyroidfna.cancer.gov/pages/info/agenda/).

Prognostic value of thyrotropin receptor antibodies (TRAb) in Graves' disease: a 120 months prospective study

In most trials, at least 30-60% of patients with Graves' disease treated with antithyroid drugs relapse within 2 years after therapy withdrawal. At present, there are no prognostic parameters available early in treatment to indicate patients likely to achieve long-term remission. Because thyrotropin receptor autoantibodies (TRAb) are specific for Graves' disease, we evaluated the ability of their levels and of their rate of change to predict long-term prognosis. In our study 216 consecutive patients with newly diagnosed Graves' disease started a therapy with methimazole. Patients were treated until they achieved euthyroidism and TRAb were measured at 6-month intervals throughout a follow up of 120 months. Our study demonstrated that at the onset of hyperthyroidism patients' age, sex, fT4 levels and goiter size had no prognostic value in predicting long-term prognosis (respectively p = 0.79; p = 0.98; p = 0.83; p = 0.89). On the contrary, at the time of diagnosis TRAb titer was a good predictor of the final outcome (p<0.001); a titer equal to (or) more than 46.5 UI/L could identify patients who had never achieved long-term remission with a sensitivity of 52% and a specificity of 78%. Also fall rate of TRAb at 6 months of follow up and after therapy withdrawal were useful to predict the final outcome (p<0.001). At 6 months of follow up the time of therapy withdrawal, a decrease of TRAb lower than 52.3% or even its increase could identify patients who had never achieved permanent remission with a sensitivity of 55% and a specificity of 79.1%. No single parameter among TRAb, satisfactory identified a sub-set of patients who achieved long remission. Accordingly to our data, the best result in predicting long term remission is probably given by the presence of at least one of the two features evaluated at 6 months (TRAb titer and/or percentage of TRAb fall rate), with a sensitivity of 63% and specificity of 88%. TRAb titers evaluated both at the onset of hyperthyroidism that at 6 months of therapy or their rate of fall at 6 months and at ATD withdrawal are predictors of outcome. However, the presence of at least one, between titers of TRAb or their rate of fall at six months, resulted to be the best predictor of remission with the higher sensitivity and specificity.

Chinese herbal medicines for hyperthyroidism

BACKGROUND

Hyperthyroidism is a disease in which excessive amounts of thyroid hormones circulate in the blood. Patients, among other things suffer from tachycardia, warm moist skin and raised body temperature. The treatment of hyperthyroidism includes symptom relief and therapy with antithyroid medications, radioiodine and thyroidectomy. Medicinal herbs are used alone or in combination with antithyroid agents to treat hyperthyroidism in China and some other countries.

OBJECTIVES

To assess the effects of Chinese herbal medicines for treating hyperthyroidism.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE, The Cochrane Library, the Chinese Biomedical Database.

SELECTION CRITERIA

Randomised controlled trials comparing the effects of Chinese herbal medicines alone with Chinese herbal medicines combined with antithyroid drugs, radioiodine or both.

DATA COLLECTION AND ANALYSIS

Three authors interviewed authors of all potentially relevant studies by telephone to verify randomisation procedures. One author entered data into a data extraction form and another author verified the results of this procedure.

MAIN RESULTS

Thirteen relevant trials with 1770 participants were included. All of them were of low quality. Fifty-two studies still need to be assessed because the original authors could not be interviewed. None of these trials analysed mortality, health related quality of life, economic outcomes or compliance. Compared to antithyroid drugs alone the results showed that Chinese herbal medicines combined with antithyroid drugs may offer benefits in lowering relapse rates, reducing the incidence of adverse effects, relieving symptoms, improving thyroid antibody status and thyroid function. Two trials investigated Chinese herbal medicine versus radioiodine and reported improvements in anxiety, tachycardia and heat intolerance. However, thyroid function - with the exception of restored thyroid stimulating hormone (TSH) - was not significantly altered.

AUTHORS' CONCLUSIONS

The results suggest that traditional Chinese herbal medicines added to other routine treatment have a therapeutic potential for people with hyperthyroidism. However, due to methodological limitations, we could not identify a well-designed trial to provide strong evidence for Chinese traditional herbal medicine in the treatment of hyperthyroidism. Thus, we currently cannot recommend any single preparation or formulation for clinical use.

Co-occurrence of autoimmune thyroid disease in a multiple sclerosis cohort

Background

Multiple sclerosis (MS), Hashimoto's disease and Graves' disease are autoimmune diseases that may share similar pathogenic mechanisms. The co-occurrence rates and demographic characteristics of Graves' disease and Hashimoto's disease (HT) in our MS population are compared with the general population.

Methods

The prevalence of thyroid disease in our MS patients was determined by chart review and survey. Previous diagnosis of thyroid disease, age at diagnosis, treatment used, and about the use of disease modifying medications used to treat their MS were asked. Chart reviews were used to estimate the population prevalence of Graves' disease and Hashimoto's disease and to estimate the demographics of patients with thyroid disease.

Results

A significant co-occurrence of Graves' disease with MS (p = 0.002), and a non-significant co-occurrence of Hashimoto's disease were noted (p = 0.097). No difference in the age of onset or gender of thyroid disease in MS patients compared to the general population was found.

Conclusion

There is a significant co-occurrence in patients with MS and Graves' disease, and a trend to co-occurrence in patients with MS and Hashimoto's disease. There are no differences in the demographics of patients with thyroid disease in our MS patients compared to the general population.