An update on the medical treatment of Graves' hyperthyroidism

Mechanism of Prunella vulgaris L. and luteolin in restoring Tfh/Tfr balance and alleviating oxidative stress in Graves' disease

BACKGROUND

The pathophysiology of Graves' disease (GD) involves imbalances between follicular helper T (Tfh) and follicular regulatory T (Tfr) cells, as well as oxidative stress (OS). Prunella vulgaris L. (Xia Ku Cao, XKC) and its primary bioactive compound, luteolin, are recognized for their potential in treating GD. Yet, the mechanism accounting for the immune-modulatory and antioxidant effects of XKC remains elusive.

PURPOSE

This study aims to evaluate the pharmacological effects and elucidate the underlying mechanism of XKC and luteolin in a GD mouse model induced by recombinant adenovirus of TSH receptor A subunit (Ad-hTSHR-289).

METHODS

High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry (HPLC-QTOF MS) was used to detect the constituents of XKC. The GD model was established through inducing female BALB/c mice with three intramuscular injections of Ad-TSHR-289. Thyroid function, autoantibody and OS parameters were measured by ELISA. Changes of Tfh cells and Tfr cells were detected by flow cytometry. RT-qPCR, Western Blotting, immunohistochemistry were used to explore the related molecular mechanisms.

RESULTS

A total of 37 chemical components from XKC were identified by HPLC-QTOF MS, represented by flavonoids, steroids, terpenoids, and luteolin. XKC and luteolin reduced T4, TRAb levels and facilitated the recovery from thyroid damage in GD mice. Meanwhile, XKC and luteolin effectively alleviated OS by decreasing the levels of MDA, NOX2, 4-HNE, 8-OHdG, while increasing GSH level. Flow cytometry showed that XKC and luteolin restored the abnormal proportions of Tfh/Tfr and Tfh/Treg, and the mRNA levels of IL-21, Bcl-6 and Foxp3 in GD mice. In addition, XKC and luteolin inhibited PI3K, Akt, p-PI3K and p-Akt, but activated Nrf2 and HO-1.

CONCLUSION

XKC and luteolin could inhibit the development of GD in vivo by rebalancing Tfh/Tfr cells and alleviating OS. This therapeutic mechanism may involve the Nrf2/HO-1 and PI3K/Akt signaling pathways. Luteolin is the main efficacy material basis of XKC in countering GD. For the first time, we revealed the mechanism of XKC and luteolin in the treatment of GD from the perspective of autoimmune and OS.

Focus on Autoimmune Myocarditis in Graves' Disease: A Case-Based Review

The manifestations of hyperthyroidism-related myocardial damage are multitudinous, including arrhythmia, dilated cardiomyopathy, valvular diseases, and even cardiogenic shock. Acute myocarditis induced by thyrotoxicosis had been reported in a few studies. However, attention on its prevalence and underlying mechanisms is sorely lacking. Its long-term harm is often ignored, and it may eventually develop into dilated cardiomyopathy and heart failure. We report a case of Graves' disease with a progressive elevation of hypersensitive cardiac troponin-I at several days after discontinuation of the patient's anti-thyroid drugs. Cardiac magnetic resonance imaging (CMRI) showed inflammatory edema of some cardiomyocytes (stranded enhanced signals under T2 mapping), myocardial necrosis (scattered enhanced signals under T1 late gadolinium enhancement) in the medial and inferior epicardial wall, with a decreased left ventricular systolic function (48%), which implied a possibility of acute myocarditis induced by thyrotoxicosis. The patient was then given a transient glucocorticoid (GC) treatment and achieved a good curative effect. Inspired by this case, we aim to systematically elaborate the pathogenesis, diagnosis, and treatment of hyperthyroidism-induced autoimmune myocarditis. Additionally, we emphasize the importance of CMRI and GC therapy in the diagnosis and treatment of hyperthyroidism-related myocarditis.

Graves' orbitopathy: a multidisciplinary approach

Orbitopathy is the main extra thyroidal manifestation of Graves' disease. It is a very challenging condition, which requires a cooperation between many specialists (endocrinologists, ophthalmologists, radiologists, radiotherapeutic, orbital surgeons) for an optimal clinical management. An accurate diagnostic assessment is required, in order to plan an adequate treatment of Graves' orbitopathy. Medical therapy, radiotherapy or surgery may be necessary to control the disease. In this review, the authors analyze the various therapeutic strategies, as well the more recent therapies based on pharmacologic immunomodulation.

Selenium in the Treatment of Graves' Hyperthyroidism and Eye Disease

Based on the role of oxidative stress in the pathogenesis of Graves' hyperthyroidism (GH) and Graves' Orbitopathy (GO), a therapy with the antioxidant agent selenium has been proposed and a number of studies have been performed, both in vitro and in vivo. In GH, reactive oxygen species (ROS) contribute to the thyroid and peripheral tissues damage. In GO, tissue hypoxia, as well as ROS, are involved in the typical changes that occur in fibroadipose orbital tissue and the perimysium of extraocular muscles. Antioxidants have been proposed to improve the effects of antithyroid drugs in GH patients, as well as the remodeling of orbital tissues in patients with GO. Here, we reviewed the literature on the possible beneficial effects and clinical use of selenium in the management of patients with GH and GO. A randomized clinical trial on the use of selenium in patients with mild GO provided evidence for a beneficial effect; no data are available on more severe forms of GO. Although the real effectiveness of selenium in patients with GH remains questionable, its use in the management of mild GO is generally believed to be beneficial, and selenium administration has been included in the clinical practice for the patients with mild eye disease.

Oxidative Stress in Graves Disease and Graves Orbitopathy

Oxidative stress is involved in the pathogenesis of Graves hyperthyroidism (GH) and Graves orbitopathy (GO) and an antioxidant approach has been proposed for both. In GH, a disbalance of the cell redox state is associated with thyroid hyperfunction and antithyroid medications may reduce oxidative stress. Tissue hypoxia participates in the pathogenesis of GO, and oxygen free radicals are involved in the typical changes of orbital tissues as reported by in vitro and clinical studies. Antioxidant agents, especially selenium, have been proposed as a therapeutic option for GH and GO. A clinical study regarding the use of selenium in mild GO has provided evidence for a beneficial effect in the short term, even though its beneficial effects in the long term are still to be investigated. In addition to selenium, a protective role of other antioxidant agents, i.e., quercetin, enalapril, vitamin C, N-acetyl-L-cysteine and melatonin has been suggested by in vitro studies, although clinical studies are lacking. Here, we review the role of oxidative stress and antioxidant agents in GH and GO.

The rebel thyroid of a revolutionary First Lady

Nadezda Krupskaya, the revolutionary Russian and Lenin's wife, was affected by Graves' disease and many photos and portraits, including the painting of 1933 by Ivan Vladimirovich Kosmin, highlight evident goiter and exoftalmos. To treat Graves' disease, Krupskaya underwent to surgery performed by Theodor Kocher, considered the father of the modern thyroid surgery.

Safety of long-term antithyroid drug treatment? A systematic review

Continued low-dose MMI treatment for longer than 12-18 months may be considered in patients not in remission. However, ATDs are not free from adverse effects. We undertook a systematic review to clarify safety of long-term ATD treatment. Medline and the Cochrane Library for trials published between 1950 and Nov 2018 were systematically searched. We included original studies containing data for long-term (> 18 months) ATD treatment. Two reviewers independently extracted data from included trials and any disagreement was adjudicated by consensus. Of 615 related articles found, 12 fulfilled the criteria. Six articles had data for adults, five for non-adults and one article had data for both groups. The sample sizes ranged between 20 and 249 individuals, and the mean duration of ATD treatment ranged between 2.1 and 14.2 years. Considering all data from 1660 patients treated with ATD for a mean duration of 5.8 years (around 10,000 patient-years), major complications occurred only in 14 patients: 7 severe agranulocytosis, 5 severe liver damage, one ANCA-associated glomerulonephritis and one vasculitis with small cutaneous ulcerations. Minor complications rates were between 2 and 36%, while more complications were in higher doses and in the children. The most reported AE was cutaneous reaction; the other adverse events were elevated liver enzymes, leukocytopenia, arthritis, arthralgia, myalgia, thrombocytopenia, fever, nausea and oral aphthous. Long-term ATD treatment is safe, especially in low dose and in adults, indicating that it should be considered as an earnest alternative treatment for GD.

The MAGI2 gene polymorphism rs2160322 is associated with Graves' disease but not with Hashimoto's thyroiditis

PURPOSE

Autoimmune thyroid diseases (AITDs) are chronic organ-specific autoimmune disorders, predominantly including Graves' disease (GD), and Hashimoto's thyroiditis (HT). This study aimed to investigate whether single-nucleotide polymorphisms (SNPs) in MAGI2 and MAGI3 gene contributed to the etiology of AITDs.

METHODS

We conducted a case-control study including 1001 patients with AITDs (625 GD, 376 HT) and 846 healthy controls. Subgroup analyses in GD and HT were also performed.

RESULTS

The genotypes of rs2160322 in MAGI2 showed a borderline association with AITDs (P = 0.048), and they had a strong correlation with GD (P = 0.012). The frequency of the minor allele G of rs2160322 was significantly higher in the GD patients than in the controls (P = 0.027; OR 1.91; 95% CI 1.020-1.391), especially for GD females (P = 0.008; OR 1.304; 95% CI 1.072-1.587), and those who had positive family history (P = 0.011; OR 1.412; 95% CI 1.083-1.843). For genetic model analysis, the recessive model and homozygous model of rs2160322 showed significant associations with AITDs (P = 0.009; P = 0.019) and GD (P = 0.004; P = 0.005). Nevertheless, our study could not identify any relationship between these SNPs and HT. Due to the low mutation rate of rs1343126 in MAGI3, we were unable to obtain a credible conclusion on its association with AITDs.

CONCLUSIONS

Our study identified that MAGI2 rs2160322 was strongly associated with GD susceptibility. The potential dysfunction of tight junction proteins and aberrant epithelial barrier caused by abnormal MAGI2 expression may be a novel mechanism of GD.

Post-partum and non-post-partum relapsing Graves' hyperthyroidism display different response to anti-thyroid drugs

DESIGN

Graves' disease (GD) patients in remission after a full course of methimazole (MMI) therapy are at risk for a relapse of hyperthyroidism during the post-partum (PP) period, but whether this relapse may display any peculiarity is still unknown. Aim of this study was to compare GD patients undergoing a relapse of hyperthyroidism either in the PP period or not.

METHODS

We retrospectively evaluated forty-three GD female patients in their childbearing age who experienced a relapse of hyperthyroidism. Eighteen of them relapsed in the PP period (i.e. within 12 months after delivery, PP group); the remaining 25 relapsed elsewhere during life (NPP group).

RESULTS

Age at relapse, thyroid volume, thyroid function tests, TRAb titers, smoking habit, presence and degree of orbitopathy and duration of methimazole (MMI) treatment did not differ in the two groups. However, the remission rate was much greater (79%) in the PP as compared with the NPP (32%) group (P = 0.002). A significant reduction in TRAb levels occurred at 12-month MMI treatment in the PP (F = 9.016; P = 0.001), but not in the NPP group (F = 2.433; NS). At 12 months, the PP group had significantly lower mean TRAb levels (0.6 ± 1.1 U/L and 4.5 ± 4.7 U/L in the PP and the NPP group, respectively; P = 0.029).

CONCLUSIONS

Relapsing Graves' hyperthyroidism in the PP period is more prone to undergo a remission after a second course of MMI treatment. In these patients, a conservative therapeutic approach is more appropriate.

Does Graves' Orbitopathy Ever Disappear? Answers to an Old Question

OBJECTIVES

There is a general belief that Graves' orbitopathy (GO) is a "chronic" disease, namely that patients' eyes do not return to how they were before GO appeared. Here, we investigate this issue from both the patient's and the physician's point of view.

STUDY DESIGN

We studied the disappearance of GO, regardless of treatment, in all consecutive patients with a GO history of at least 10 years who came for a follow-up visit over a period of 5 years. Patients underwent an ophthalmological examination and were asked to answer a questionnaire on self-perception related to GO.

RESULTS

We studied 99 consecutive patients with a GO duration ≥10 years. Between the first and the last observation, patients received several types of treatment for their thyroid disease and/or for GO. At the end of follow-up, GO was considered disappeared based on objective criteria in 8 patients (∼8%) and based on subjective criteria in 24 patients (∼24%). When we considered both subjective and objective criteria, only 2 patients (∼2%) had all criteria fulfilled and could be considered as GO-free.

CONCLUSIONS

GO is a chronic disease in the vast majority of patients. Even after a very long time since its onset, complete disappearance is rare, although a minority of patients believe they do not have GO anymore and an even lower proportion do not have relevant GO signs. Our findings have obvious implications in patient management and counseling.

[Autoimmune diseases of the thyroid gland]

Autoimmune diseases of the thyroid gland are considered to be the most frequent cause of thyroid gland disorders. Autoimmune thyroid diseases consist of two subgroups: autoimmune thyroiditis (AIT) and Graves' disease. The AIT is the most common human autoimmune disease. Infiltration of the thyroid gland with cytotoxic T‑cells can lead to an initial thyrotoxicosis und during the course to hypothyroidism due to destruction of the thyroid gland. Substitution with Levothyroxine is indicated for manifest hypothyroidism and subclinical hypothyroidism with increased thyroid antibodies with the intention of normalizing the serum thyroid stimulating hormone (TSH). Graves' disease is characterized by the appearance of stimulating TSH receptor antibodies leading to hyperthyroidism. Endocrine ophthalmopathy may also occur. Ablative therapy with radioiodine therapy or thyroidectomy is administered to patients with Graves' disease without remission after at least 1 year of antithyroid drug therapy.

Emphasis on the early diagnosis of antithyroid drug-induced agranulocytosis: retrospective analysis over 16 years at one Chinese center

PURPOSE

Antithyroid drug (ATD)-induced agranulocytosis is a rare but life-threatening adverse drug reaction that occurs in patients during the treatment of Graves' disease. We aimed to comprehensively examine data for patients with this rare complication and to improve the clinical safety of ATDs.

METHODS

We retrospectively reviewed the medical records of 64 hospitalized patients diagnosed with ATD-induced agranulocytosis between 2000 and 2015.

RESULTS

Agranulocytosis occurred in 52 (81.3%) patients within the first 3 months after initiation of ATD therapy. Fever (84.4%) and sore throat (82.8%) were the most common symptoms. Although they experienced symptoms, 30 (46.9%) patients did not seek treatment immediately and delayed their diagnosis of agranulocytosis. The minimum granulocyte count was lower in the patients diagnosed after the appearance of symptoms than in those diagnosed before the appearance of symptoms (0.01 × 10⁹/L (0 × 10⁹/L - 0.06 × 10⁹/L) versus 0.26 × 10⁹/L (0.05 × 10⁹/L - 0.40 × 10⁹/L), P < 0.001). The interval days from the appearance of symptoms to the diagnosis of agranulocytosis were negatively correlated with the minimum granulocyte count (r = -0.348, P = 0.005). In addition, a lower minimum granulocyte count was associated with a longer recovery time (β = -11.899, 95% CI -15.304 to -8.496).

CONCLUSIONS

Our findings have demonstrated that delayed diagnosis of ATD-induced agranulocytosis is common in our population. Delayed diagnosis is associated with severe agranulocytosis and may prolong the recovery time from agranulocytosis. Monitoring of the white blood cell and granulocyte counts may be an effective way to establish an early diagnosis and prevent progression to severe agranulocytosis.

Graves' orbitopathy, idiopathic orbital inflammatory pseudotumor and Epstein-Barr virus infection: a serological and molecular study

OBJECTIVE

One of the hypotheses on the pathogenesis of autoimmune diseases, including Graves' disease (GD) and Graves' orbitopathy (GO), involves bacterial or viral infections. Recently, Epstein-Barr virus (EBV) has been proposed to play a role in the pathogenesis of idiopathic orbital inflammatory pseudotumor (IOIP) in Asians. The aim of the present study was to investigate the possible association of GO with EBV infection/exposure, as compared with IOIP, using serum and tissue samples, as well as primary cultures of orbital fibroblasts.

METHODS

Thirty-one patients were studied, including four with IOIP, ten with GO, nine with GD without GO and eight control patients without IOIP, GD and GO. All patients with IOIP and GO underwent orbital decompression. Control patients underwent palpebral surgery. Fibroadipose orbital tissue samples were collected. Serum anti-EBV antibodies were measured in all patients. EBV-DNA was measured in blood samples, orbital tissue samples and primary cultures of orbital fibroblasts.

RESULTS

Serum assays showed that the vast majority of patients have had a previous exposure to EBV, but no one had an acute infection. EBV-DNA was detected in ~40% of blood samples from GO, GD and control patients, but in none of the IOIP samples. EBV-DNA was not detected in any of the orbital tissue samples tested or in primary cultures of orbital fibroblasts.

CONCLUSIONS

EBV infection does not seem to be associated with GD, GO and IOIP in Caucasians. Whether EBV is involved in IOIP in Asians or other populations remains to be confirmed.

Low regulatory T cell and high IL-17 mRNA expression in a mouse Graves' disease model

PURPOSE

Graves' disease (GD) is an autoimmune thyroid disease, and the most important characteristic of it is the presence of the thyroid-stimulating antibody (TSAb). The mechanisms of the TSAb elevation are still uncertain. Recent studies have suggested that the dysregulation of regulatory T cell (Treg) and T helper 17 (Th17) might stimulate the production of TSAb and be a pathogenesis of GD. However, the role of Treg and Th17 cells in the pathogenesis of GD is still debated. Our aim is to assess changes of Treg and Th17 cells in the spleen of a mouse in an in vivo GD model and try to explain the pathogenesis of GD.

METHODS

We used an adenovirus expressing the autoantigen thyroid-stimulating hormone receptor (Ad-TSHR289) to immunise mice in order to induce GD in the model. Flow cytometry was used to measure the frequencies of splenic Treg and Th17 cells and real-time PCR to analyse the mRNA expression of forkhead box P3(Foxp3) and interleukin-17(IL-17).

RESULTS

Compared with the Ad-Control group, the frequencies of CD4⁺CD25⁺Foxp3⁺ Treg cells were significantly decreased (p = 0.007) and gene expression of Foxp3 was down-regulated (p = 0.001) in the Ad-TSHR289 group. Though there was no significant difference in CD4⁺IL-17⁺ T cell subpopulation between the two groups (p = 0.336), the IL-17 mRNA expression was significantly up-regulated in the Ad-TSHR289 group (p = 0.001).

CONCLUSIONS

The pathogenesis of GD may be associated with reduced Treg cells and increased IL-17 gene expression. The increased IL-17 mRNA needs to be explained by other mechanisms but not Th17 cells.

The Efficacy of Rituximab Combined with 131I for Ophthalmic Outcomes of Graves' Ophthalmopathy Patients

PURPOSE

The purpose of this study is to examine the effectiveness of introducing both rituximab (RTX) and 131I for active Graves' ophthalmopathy (GO) with hyperthyroidism.

METHODS

In total, 217 patients suffering from active GO with hyperthyroidism were included in this research. All subjects were randomly assigned to 3 groups. Patients in group A solely received 131I treatment; group B1 underwent a methylprednisolone treatment in combination with 131I treatment; and group B2 received an RTX in combination with 131I treatment. Hyperthyroidism treatment outcomes, orbital volumetry, ophthalmic assessments, serum cytokine levels, and adverse effects were measured after treatment.

RESULTS

The orbital volumetry principle was significantly different from 24 weeks after the start of treatment among all 3 groups, and improvements in most ophthalmic parameters were regarded significantly different among 3 groups (all p < 0.05). The expression levels of miR-146a and most serum cytokines were regarded significantly different from 24 weeks after the start of treatment among 3 groups (all p < 0.05).

CONCLUSIONS

In comparison with other therapies, RTX treatment in combination with 131I treatment is considered to be more effective for hyperthyroidism with active GO.

Relapse prediction in Graves´ disease: Towards mathematical modeling of clinical, immune and genetic markers

PROBLEM

Graves' disease (GD) is an important and prevalent thyroid autoimmune disorder. Standard therapy for GD consists of antithyroid drugs (ATD) with treatment periods of around 12 months but relapse is frequent. Since predictors for relapse are difficult to identify the individual decision making for optimal treatment is often arbitrary.

METHODS

After reviewing the literature on this topic we summarize important factors involved in GD and with respect to their potential for relapse prediction from markers before and after treatment. This information was used to design a mathematical model integrating thyroid hormone parameters, thyroid size, antibody titers and a complex algorithm encompassing genetic predisposition, environmental exposures and current immune activity in order to arrive at a prognostic index for relapse risk after treatment.

CONCLUSION

In the search for a tool to analyze and predict relapse in GD mathematical modeling is a promising approach. In analogy to mathematical modeling approaches in other diseases such as viral infections, we developed a differential equation model on the basis of published clinical trials in patients with GD. Although our model needs further evaluation to be applicable in a clinical context, it provides a perspective for an important contribution to a final statistical prediction model.

Management of hyperthyroidism due to Graves' disease: frequently asked questions and answers (if any)

Graves' disease is the most common cause of hyperthyroidism in iodine-replete areas. Although progress has been made in our understanding of the pathogenesis of the disease, no treatment targeting pathogenic mechanisms of the disease is presently available. Therapies for Graves' hyperthyroidism are largely imperfect because they are bound to either a high rate of relapsing hyperthyroidism (antithyroid drugs) or lifelong hypothyroidism (radioiodine treatment or thyroidectomy). Aim of the present article is to offer a practical guidance to the reader by providing evidence-based answers to frequently asked questions in clinical practice.

Beneficial role of ascorbic and folic acids antioxidants against thyroxin-induced testicular dysfunction in hyperthyroid rats

Thyroid hormones play a fundamental role in the regulation of metabolism of almost all mammalian tissue including the reproductive system. Hyperthyroidism in early life may cause delayed sexual maturation, although physical development is normal and skeletal growth may be accelerated. Hyperthyroidism after puberty influences reproductive functions and increases testosterone level. The aim of this work is to study the effect of induced hyperthyroidism by L-thyroxine sodium administration on the testis of rats and to evaluate the ameliorating role of different antioxidants as ascorbic acid and folic acid on the hyperthyroid state via the assessment of different biochemical markers, histopathological and immunochemical sections. DNA analysis of the D1 deiodinase was performed to determine genetic mutation due to hyperthyroidism. The results showed partially disrupted in the measured biochemical parameters and spermatogenesis in hyperthyroid rats. Post-administration of both folic and ascorbic acids together in hyperthyroid rats showed the best ameliorating effects on the thyroid hormones, testosterone, testicular GGT and ALP, and all oxidative stress markers. There is no genetic mutations that occurred in D1 deiodinase due to hyperthyroidism. These findings were indicated by the proliferating cell nuclear antigen (PCNA) studies of testes.

Outcome Prediction of Treatment of Graves' Hyperthyroidism with Antithyroid Drugs

Graves' disease is the most common cause of hyperthyroidism in iodine-replete areas and is ultimately due to antibodies interacting with the TSH receptor on thyroid follicular cells [TSH-receptor antibody (TRAb)]. Antithyroid drugs (ATDs) belonging to the family of thionamides are the first-line treatment in Europe. ATD treatment is commonly continued for 18-24 months. Its major limitation is the high rate of relapses after drug withdrawal. Factors particularly bound to subsequent relapses are the large thyroid volume, smoking habit, persistence of TRAb in the circulation at the end of treatment, and the post-partum period. Under these conditions, consideration should be given to a definitive therapy for hyperthyroidism (radioiodine treatment, thyroidectomy), particularly if the patient is at risk of cardiovascular complications that might be exacerbated by persistence or recurrence of hyperthyroidism.

Pregnancy outcome in women treated with methimazole or propylthiouracil during pregnancy

PURPOSE

Control of thyroid function in hyperthyroid women during pregnancy is based on antithyroid drugs (ATD) [propylthiouracil (PTU) and methimazole (MMI)]. While a teratogenic effect has been suggested for MMI and, more recently, for PTU, a clear demonstration is still lacking. Aim of this study was to assess the safety of ATD during pregnancy.

METHODS

A total of 379 pregnancies were retrospectively recruited in eight Italian Departments of Endocrinology and divided in five groups: (1) MMI-treated and euthyroid throughout pregnancy (n = 89); (2) MMI-treated and hyperthyroid on at least two occasions (n = 35); (3) PTU-treated women and euthyroid throughout pregnancy (n = 32); (4) PTU-treated women and hyperthyroid on at least two occasions (n = 20); and (5) non-ATD-treated (n = 203). Data on maternal thyroid function, miscarriages, type of delivery, neonatal weight, length and TSH, perinatal complications and congenital malformation were analyzed.

RESULTS

The gestational age at delivery, the rate of vaginal delivery, neonatal weight, length and neonatal TSH did not significantly differ among groups. In all groups, the rates of spontaneous miscarriage and of major congenital malformations were not higher than in the general population. No newborns were born with a phenotype similar to those described in the "MMI embryopathy".

CONCLUSIONS

While a clear demonstration of a teratogenic effect of MMI is currently lacking, it seems reasonable to follow the current guidelines and advice for PTU treatment in hyperthyroid women during the first trimester of pregnancy. Further, large and prospective worldwide studies will be needed to fully clarify the issue of ATD safety during pregnancy.

Etiopathogenesis of Basedow's disease. Trends and current aspects

Basedow's disease (BD) owes its name to the German physician Karl Adolph von Basedow, who described in 1840 the clinical picture of exophthalmic toxic goitre. More than one century after the seminal paper of Karl von Basedow, the ultimate cause of BD remains to be fully elucidated. In the last years, evidence was accumulated indicating that BD is a polygenic and multifactorial disease that develops as a result of a complex interplay between genetic susceptibility and environmental and endogenous factors, which leads to the loss of immune tolerance to thyroid antigens and in particular to the TSH receptor. Our aim is to review the current knowledge on the pathogenesis of BD. To this purpose, we will firstly focus our attention on the role of genetic factors (the HLA complex, the genes encoding for thyroglobulin, the TSH receptor, CD40, CTLA-4 and PTPN22), and of environmental factors (iodine, infections, psychological stress, gender, smoking, thyroid damage, vitamin D, selenium, immune modulating agents) as possible causes of BD. Taking advantage of the experimental animal models of BD, we will then focus on the immunological mechanisms leading to the loss of tolerance in BD. The pathogenic role played by the chemokine system will be also reviewed.

Total thyroid ablation in Graves' orbitopathy

Graves' orbitopathy (GO) is an autoimmune condition almost always associated with autoimmune thyroid disease, especially Graves' disease (GD). According to the most widely accepted model, the autoantigens responsible for GO would include molecules expressed by thyroid epithelial cells that are present also in orbital tissues. The high likelihood that the etiologies of GO and of the underlying autoimmune thyroid diseases are somehow linked is confirmed by the very close relationship between GO, the onset and the course of Graves' diseases, the size of the thyroid gland, and most importantly, thyroid function and thyroid treatment. Based on these considerations, it has been proposed that complete removal of thyroid antigens and of thyroid infiltrating lymphocytes, the so-called total thyroid ablation (TTA), may be followed by an attenuation of the immune reaction against orbital antigens, and ultimately by an amelioration of GO. The possibility that TTA, achieved by near total thyroidectomy followed by radioiodine, may be beneficial for GO was initially suggested by two retrospective studies and more recently by two prospective, randomized clinical trials conducted in patients with moderate GO treated with intravenous glucocorticoids. Although there seemed to be no difference in the long term, compared with near total thyroidectomy alone TTA was associated with a shorter time required for GO to improve, or anyway to reach its best possible outcome, and with a lesser requirement for additional treatments for GO to improve. Whether this is sufficient to offer ablation to patients remains a matter of discussion. At present, this procedure could be offered only to patients scheduled to thyroidectomy and glucocorticoid treatment.

Long-term outcome of Graves' orbitopathy following high-dose intravenous glucocorticoids and orbital radiotherapy

OBJECTIVE

Intravenous (iv) glucocorticoids (GC) (ivGC) and orbital radiotherapy (ORT) are commonly used in active Graves' orbitopathy (GO), with favorable outcomes in up to 80% of patients. However, little is known on the factors that may affect GO outcome in the long term, an issue that we investigated here.

METHODS

We studied retrospectively 96 untreated patients with GO, identified out of 787 consecutive patients who came to our GO Clinic for a follow-up visit between September 2010 and June 2013. After the first observation, patients were treated with ivGC and ORT and were then re-examined after a median period of 55.5 months. The primary end-point was the possible relation between GO outcome and several individual variables.

RESULTS

Exophthalmometry, eyelid aperture, CAS, diplopia and visual acuity (the latter only in patients with an initial reduction) improved significantly after treatment. Overall, 67.7% of patients had improved and were considered as responders, whereas the remaining (29.1% stable and 4.5% worsened) were considered as non-responders. Age, smoking, thyroid volume, thyroid treatment, serum anti-TSH receptor autoantibodies and individual GO features at first observation did not affect the outcome of GO, which, in contrast, was affected by gender and by the time elapsed between first and last observation. Thus, the prevalence of responders was higher in females (76.4 vs 48% in males, P = 0.02) and the time elapsed between first and last observation was greater in responders (58 vs 39 months in non-responders, P = 0.02). Whereas the prevalence of responders and non-responders was similar up to 36 months, there was an increase in responders beginning between 37 and 48 months and reaching a peak of ~80% between 61 and 72 months, to plateau thereafter.

CONCLUSIONS

Given the limitations of retrospective investigations, our study confirms that the combination of GC and ORT is effective in GO and shows that females have greater chances to respond to treatment. The notorious tendency of GO to improve spontaneously with time most likely contributes the long-term outcome of the eye syndrome.

Elevation of serum creatine kinase during methimazole treatment of Graves disease in a 13-year-old girl and a literature review of similar cases

We report a 13-year-old girl with Graves disease, who showed an increased level of serum creatine kinase (CK) accompanied by myalgia after methimazole (MMI) treatment. This patient developed muscular pain two weeks after MMI administration, along with increased CK levels. The level of thyroid hormone was within the normal range when she showed increased CK levels. After the MMI dose was decreased and levo-thyroxine was added, serum CK levels decreased to normal and the myalgia improved. The pathophysiologic mechanism of this effect has not yet been elucidated. An acute relatively hypothyroid state occurs secondary to antithyroid drug (ATD) administration in chronic hyperthyroidism, which may cause changes in the CK levels. In this report, we present a rare pediatric case, along with a literature review of similar cases. In the initial state of MMI treatment, myalgia should be detected and when it occurs, CK levels should be measured. The clinical strategy of monitoring CK levels with the aim of normalizing thyroid hormones is helpful in case of the development of adverse reactions, such as myalgia, during ATD treatment for Graves disease in children.

Role of genetic and non-genetic factors in the etiology of Graves' disease

In spite of the advancements in understanding the pathogenic mechanisms of Graves' disease (GD), its ultimate cause remains elusive. The majority of investigators agree that GD is likely a multifactorial disease, due to a complex interplay of genetic and non-genetic factors that lead to the loss of immune tolerance to thyroid antigens and to the initiation of a sustained autoimmune reaction. Twin and family studies support a role of genetic factors, among which the HLA complex, CD40, CTLA-4, PTPN22, FCRL3, thyroglobulin, and the TSH receptor may be involved. Among non-genetic factors, iodine, infections, psychological stress, gender, smoking, thyroid damage, vitamin D, selenium, immune modulating agents, and periods of immune reconstitution may contribute the development of the diseases. Here we review in detail the respective role of genetic and non-genetic factors in the etiology of GD, taking advantage of the great bulk of data generated especially over the past 30 years.