Thyroid Autoimmunity: An Interplay of Factors. Thyroid Hormone. Elsevier; 2018. pp. 129-45. [DOI: 10.1016/bs.vh.2017.07.001]

Associations of per- and polyfluoroalkyl substances and alternatives with subclinical hypothyroidism in children: A cross-sectional study in China

There is growing experimental and epidemiological evidence linking perfluoroalkyl and polyfluoroalkyl substances (PFAS) exposure to thyroid dysfunction; however, the association between PFAS and their alternatives to subclinical hypothyroidism in children remains to be elucidated. This study investigated the association between 30 PFASs and thyroid function using serum samples from 194 children (aged 3-17 years) who participated in the Zhejiang Human Biomonitoring Program. Various thyroid function indicators, including free triiodothyronine, free thyroxine (FT4), and thyrotropin, were tested, and subclinical hypothyroidism was diagnosed. Linear regression was employed to examine the associations between individual PFASs and thyroid hormone levels, and logistic regression was applied to assess their associations with subclinical hypothyroidism. The quantile g-computation (qgcomp) method was used to examine the combined and individual effects of PFAS mixtures on thyroid function. Both PFASs and their alternatives were associated with altered thyroid hormone levels and subclinical hypothyroidism. A higher level of perfluorohexanoic acid (PFHpA) was associated with decreased FT4 with a reduction of -0.028 pmol/L (95 % confidence interval [95 % CI]: -0.047, -0.008) per unit increase as well as increased odds of subclinical hypothyroidism (odds ratio [OR] = 1.95; 95 % CI: 1.11, 3.53). Moreover, a higher PFAS mixture was associated with elevated odds of subclinical hypothyroidism (OR = 3.72; 95 % CI: 1.08, 12.85), in which PFHpA, in conjunction with 6:2 chlorinated perfluoroalkyl ether sulfonic acid, accounted for the greatest proportion of the variance. These findings augment our understanding of the adverse effects of PFASs and their alternatives on thyroid homeostasis, underscoring the need for further epidemiological research.

Autoimmune Thyroiditis Mitigates the Effect of Metformin on Plasma Prolactin Concentration in Men with Drug-Induced Hyperprolactinemia

Metformin inhibits the secretory function of overactive anterior pituitary cells, including lactotropes. In women of childbearing age, this effect was absent if they had coexisting autoimmune (Hashimoto) thyroiditis. The current study was aimed at investigating whether autoimmune thyroiditis modulates the impact of metformin on the plasma prolactin concentration in men. This prospective cohort study included two groups of middle-aged or elderly men with drug-induced hyperprolactinemia, namely subjects with concomitant Hashimoto thyroiditis (group A) and subjects with normal thyroid function (group B), who were matched for baseline prolactin concentration and insulin sensitivity. Titers of thyroid peroxidase and thyroglobulin antibodies, levels of C-reactive protein, markers of glucose homeostasis, concentrations of pituitary hormones (prolactin, thyrotropin, gonadotropins, and adrenocorticotropic hormone), free thyroxine, free triiodothyronine, testosterone, and insulin growth factor-1 were measured before and six months after treatment with metformin. Both study groups differed in titers of both antibodies and concentrations of C-reactive protein. The drug reduced the total and monomeric prolactin concentration only in group B, and the impact on prolactin correlated with the improvement in insulin sensitivity and systemic inflammation. There were no differences between the follow-up and baseline levels of the remaining hormones. The results allow us to conclude that autoimmune thyroiditis mitigates the impact of metformin on prolactin secretion in men.

Global scientific trends on thyroid disease in early 21st century: a bibliometric and visualized analysis

Background

Bibliometrics has been used to analyze the literature in the field of thyroid disease studies in the early 21st century, indicating the changes in current international study trends.

Methods

In this study, a bibliometric analysis of data retrieved from the Web of Science (WoS) database was conducted, and the publication trends and thematic evolution in the field of thyroid disease research from January 1, 2000, to November 16, 2022, were analyzed. A total of 69283 articles related to thyroid diseases were evaluated for their characteristics, including annual publication volume, countries, journals, institutions, authors, keywords, and references. VOSviewer was utilized to perform the analysis of co-authorship, co-citation, co-occurrence and descriptive.

Results

The annual publication volume of thyroid disease research literature showed a fluctuating upward trend from 2000 to 2021, exceeding 5,000 articles for the first time in 2021. The United States (16120 counts, 678255 cities) ranks first in terms of publication volume and citation. Thyroid (n=3201) and Journal of Clinical Endocrinology&Metabolism (n=140399) are the most prolific and cited journals, respectively. The organization with the highest publication volume and citation frequency is Harvard University (1011 counts, 59429 cities), Miyauchi Akira (n=422), Schlumberger, and Martin (n=24839) possess the highest publication volume and citation frequency, respectively. Co-occurrence analysis of 307 keywords with frequencies of more than 20 resulted in 6 clusters (1): Thyroid dysfunction and diseases (2); mechanism of occurrence and development of thyroid cancer (3); autoimmune thyroiditis (4); scope and postoperative management of thyroid surgery (5); fine needle aspiration of thyroid nodules (6); radioactive iodine therapy for thyroid cancer. Active monitoring, thermal ablation, Lenvatinib, and long noncoding RNA refer to the latest keywords. Discussing the six clusters helps scholars to determine the scope and direction of studies.

Conclusion

Over the past two decades, the literature related to thyroid diseases has increased year by year, with closer collaboration between countries, institutions, and authors. In this study, the global trends, research hotspots, emerging subjects, and basic knowledge of literature related to thyroid diseases were respectively elucidated, which will facilitate researchers in this field to seek better development.

Sexual Function and Depressive Symptoms in Young Women with Euthyroid Hashimoto's Thyroiditis Receiving Vitamin D, Selenomethionine and Myo-Inositol: A Pilot Study

Thyroid autoimmunity is associated with an increased risk of sexual dysfunction. The aim of this study was to compare sexual functioning and depressive symptoms in women with Hashimoto's thyroiditis receiving different treatments. The study included euthyroid women with autoimmune thyroiditis, untreated or receiving vitamin D, selenomethionine, or myo-inositol. Apart from measuring antibody titers and hormone levels, all participants completed questionnaires evaluating female sexual function (FSFI) and depressive symptoms (BDI-II). In untreated women, the overall FSFI scores and domain scores for desire, arousal, lubrication, and sexual satisfaction were lower than in women receiving vitamin D, selenomethionine, and myo-inositol. In the vitamin D-treated women, the total FSFI scores and scores for desire and arousal were higher than in women receiving the remaining micronutrients. The BDI-II score was lowest in the vitamin D-treated women and highest in the untreated patients with thyroiditis. Vitamin D-treated women were also characterized by lower antibody titers and higher testosterone levels than the women receiving the remaining micronutrients. There were no differences in sexual functioning and depressive symptoms between the selenomethionine- and myo-inositol-treated women. The study results suggest that although all antibody-lowering treatments are associated with better sexual functioning and well-being in young women with euthyroid autoimmune thyroiditis, the greatest benefits are observed in patients receiving vitamin D.

The Effect of Metformin on Plasma Prolactin Levels in Young Women with Autoimmune Thyroiditis

Metformin decreases elevated prolactin levels, which are frequently found in patients with thyroid disorders. The aim of this study was to investigate whether thyroid autoimmunity modulates the impact of metformin on lactotrope secretory function. This study compared two matched groups of young women with prediabetes and mild-to-moderate prolactin excess: 28 subjects with coexisting euthyroid autoimmune thyroiditis (group 1) and 28 individuals without thyroid disorders (group 2), treated for six months with metformin (3 g daily). Thyroid antibody titers, glucose homeostasis markers, prolactin, thyrotropin, free thyroid hormones, FSH, LH, ACTH, IGF-1 and hsCRP were assessed at the beginning and at the end of the study. At entry, the study groups differed in antibody titers and hsCRP levels. Although the improvement in glucose homeostasis and the decrease in hsCRP levels were observed in both study groups, they were more pronounced in group 2. Only in group 2 did metformin reduce circulating prolactin levels (both total and monomeric). Prolactin-lowering properties of metformin positively correlated with baseline prolactin levels, baseline antibody titers (in group 1) and with the degree of reduction in hsCRP levels. The obtained results suggest that autoimmune thyroiditis may attenuate the impact of metformin on lactotrope secretory function.

The importance and effectiveness of nutritional counselling in patients with autoimmune thyroid diseases in Poland

BACKGROUND

Autoimmune thyroid diseases are the most common diseases in humans. Their pathogenesis is complex, pushing patients to search different ways of alleviating their effects, one of which is diet change. The aim of this study was to assess the role of medical personnel in shaping eating habits in patients with autoimmune thyroid disease based on experiences declared by patients.

METHODS

We examined 208 individuals, of which 205 were qualified for final investigation. We selected study participants using accidental sampling, based on their appearance in health care facilities, including the ones providing endocrinological advices. The relationships between the qualitative features were tested using the Chi-square test of independence, assuming the significance level of p < 0.05. In the case of the expected cardinality  < 10, the Chi-square test with correction for Yates continuity was used, while for the cardinality  < 5-the Fisher exact test.

RESULTS

People with thyroid disease are statistically more likely to use dietitian advice than people without thyroid disease. The highest percentage of respondents decided to modify their nutrition due to their own initiative. In addition, patients with autoimmune thyroid disease are statistically more likely to consider changing their diet to improve their well-being. The connection between the source of advice and modification of eating behaviour was also noted.

CONCLUSION

Thanks to the joint effort of medical staff, patients can receive reliable knowledge about their disease, treatment and nutrition adapted to their needs. Trial registration approved by the Bioethics Committee of Medical University of Silesia in Katowice (opinion no.: PCN/0022/KB1/80/2).

Hypothyroidism

Hypothyroidism is the common clinical condition of thyroid hormone deficiency and, if left untreated, can lead to serious adverse health effects on multiple organ systems, with the cardiovascular system as the most robustly studied target. Overt primary hypothyroidism is defined as elevated thyroid-stimulating hormone (TSH) concentration in combination with free thyroxine (fT₄) concentration below the reference range. Subclinical hypothyroidism, commonly considered an early sign of thyroid failure, is defined by elevated TSH concentrations but fT₄ concentrations within the reference range. Hypothyroidism is classified as primary, central or peripheral based on pathology in the thyroid, the pituitary or hypothalamus, or peripheral tissue, respectively. Acquired primary hypothyroidism is the most prevalent form and can be caused by severe iodine deficiency but is more frequently caused by chronic autoimmune thyroiditis in iodine-replete areas. The onset of hypothyroidism is insidious in most cases and symptoms may present relatively late in the disease process. There is a large variation in clinical presentation and the presence of hypothyroid symptoms, especially in pregnancy and in children. Levothyroxine (LT4) is the mainstay of treatment and is one of the most commonly prescribed drugs worldwide. After normalization of TSH and fT₄ concentrations, a considerable proportion of patients treated with LT4 continue to have persistent complaints, compromising quality of life. Further research is needed regarding the appropriateness of currently applied reference ranges and treatment thresholds, particularly in pregnancy, and the potential benefit of LT4/liothyronine combination therapy for thyroid-related symptom relief, patient satisfaction and long-term adverse effects.

Stem cells therapy for thyroid diseases: progress and challenges

Background

Thyroid hormones are indispensable for organ development and maintaining homeostasis. Thyroid diseases, including thyroiditis and thyroid cancer, affect the normal secretion of hormones and result in thyroid dysfunction.

Objective

This review focuses on therapeutic applications of stem cells for thyroid diseases.

Methods

A literature search of Medline and PubMed was conducted (January 2000–July 2021) to identify recent reports on stem cell therapy for thyroid diseases.

Results

Stem cells are partially developed cell types. They have the capacity to form specialized cells. Besides embryonic stem cells and mesenchymal stem cells, organ resident stem cells and cancer stem cells are recently reported to have important roles in forming organ specific cells and cancers. Stem cells, especially mesenchymal stem cells, have anti-inflammatory and anticancer functions as well.

Conclusions

This review outlines the therapeutic potency of embryonic stem cells, mesenchymal stem cells, thyroid resident stem cells, and thyroid cancer stem cells in thyroid cells’ regeneration, thyroid function modulation, thyroiditis suppression, and antithyroid cancers. Stem cells represent a promising form of treatment for thyroid disorders.

Epitopes specificity of antibodies to thyroid peroxidase in patients with Graves’ disease, Hashimoto’s thyroiditis and overlap-syndrome

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Further research that may shed light on specificity of MAbs in various TAIDs is strongly needed.

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Heterogeneity of epitopes recognized by anti-TPO in patients with HT, GD and overlap-syndrome may help to clarify specificity of MAbs in various TAIDs.

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Various MAbs in HT, GD and overlap-syndrome is different and this might be influenced by concentration of TPO in blood serum.

Background

Antibodies against thyroid peroxidase (anti-TPO) serve as clinical markers of thyroid autoimmune diseases (TAIDs). By trying to elucidate the causes of heterogeneity in autoantibody levels among patients with different TAIDs it becomes possible to clarify the pathophysiology of GD and HT.

Objective

To investigate the heterogeneity of epitopes recognized by anti-TPO in patients with Hashimoto’s thyroiditis (HT), Graves’ disease (GD) and overlap-syndrome.

Methods

We carried out a cross-sectional study on 398 patients with GD, HT and overlap syndrome and analyzed the specificity of epitopes and binding constants of TPO with monoclonal antibodies (MAbs). Ten MAbs to TPO were used, of which five were reactive with native TPO and the rest were reactive with denaturated TPO.

Results

The autoantibodies in blood serum of HT patients inhibited the binding of MAb63 more significantly than those in serum of GD patients: 59.62 % versus 54.02 %, respectively (p = 0.001). The anti-TPOs in serum of GD patients inhibited the binding of MAb77 more significantly than those in serum of HT patients: 54.36 % versus 51.13 %, respectively (p = 0.047). The binding of MAb45 was more inhibited in serum of patients with anti-TPO concentration over 1000 IU/ml (58.36 %). The blood serum of patients with overlap-syndrome showed less significant inhibition of MAb63 binding than that of patients with no overlap-syndrome: 52.47 % versus 58.81 %, respectively (p = 0.043).

Conclusion

Mapping the epitopes to TPO with the help of MAbs may improve the differential diagnosis between different thyroid autoimmunities.

Effects of vitamin D treatment on thyroid function and autoimmunity markers in patients with Hashimoto's thyroiditis-A meta-analysis of randomized controlled trials

Introduction

Recent evidence suggested that vitamin D deficiency was associated with Hashimoto's thyroiditis (HT) pathogenesis and thyroid hypofunction. This study aimed to investigate whether vitamin D supplementation would be effective in the prevention and progression of hypothyroidism in patients with HT.

Methods

PubMed, Embase and the Cochrane library were searched for randomized controlled trials (RCTs) and prospective cohort studies published from inception to August 2021.

Results

A total of 7 cohorts of patients from six clinical trials with 258 patients with HT were included. Significant difference was found (WMD = 19.00, 95% CI: 12.43, 25.58, p < 0.001; I² = 90.0%, p_{heterogeneity} < 0.001) between the vitamin D group and control group in serum 25‐hydroxyvitamin D level. And the combined results indicated vitamin D supplementation significantly reduced the level of thyroid peroxidase antibodies (TPO‐Ab) compared to the control group (WMD = −158.18, 95% CI: −301.92, −14.45, p = 0.031; I² = 68.8%, p_{heterogeneity} = 0.007). Whereas no significant differences were found on the levels of thyroid‐stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4) compared to the control group (p > 0.05).

What is New and Conclusion

Our study demonstrated that vitamin D treatment might significantly increase the serum 25(OH)D levels and produce changes in TPO‐Ab titres.

No significant association was found between serum vitamin D treatment and the levels of TG‐Ab, TSH, FT3 and FT4, suggesting that vitamin D is not associated with the function of the thyroid in patients with HT.

Vitiligo and chronic autoimmune thyroiditis

Vitiligo, the discoloration of the skin, has different autoimmune mechanisms reflected by many biomarkers as shown by skin histology, staining for CD4 and CD8 T lymphocytes, chemokine ligand 9 or circulating cytokines such as interleukin (IL)-1 beta, interferon (IFN)-gamma, transforming growth factor (TGF)-beta, antibodies, markers of oxidative stress, chemokines, and others. In this narrative review, we aim to overview vitiligo in relationship with chronic autoimmune thyroiditis. Regarding vitiligo, more than 50 different genetic loci have been associated with this disease, and the heritability is high. There is a 20% risk of an environmental connection which may also act as a trigger; moreover, the association with human leukocyte antigen (HLA) expression is well recognized. The specific lesions display CD8+ tissue-resident memory T cells as continuous key activators of melanocytes. The association with chronic thyroiditis is based on common autoimmune background and excessive reactive oxygen species that destroy melanocytes and thyrocytes (oxidative stress hypothesis) with thyroxine and melanin as target molecules, thus sharing a common origin: tyrosine. Moreover, common epigenetic anomalies or mutations of the Forkhead transcription factor D3 (FOXD3) have been described. Since vitiligo affects up to 1–2% of the population worldwide and 34% of patients have positive thyroid antibodies, apart from common autoimmunity background and oxidative stress toxicity, the association is clinically relevant for different practitioners.

A Chinese Patent Medicine JiaYanKangTai Alleviates Inflammatory Lesions of Experimental Autoimmune Thyroiditis by Regulating Interleukin-17 Signaling

OBJECTIVE

This study was aimed to investigate the effects of JiaYanKangTai (JYKT) on regulating interleukin-17 (IL-17) signaling in rats with autoimmune thyroiditis.

METHODS

Lewis rats were administrated with JYKT for eight weeks after a seven-week subcutaneous injection of thyroglobulin with adjuvant and feeding iodine water. Ultrasonography was performed and total volume of thyroid was calculated. The expressions of autoantibodies and hormones were detected. Morphological changes of thyroid were observed. Metabolomics profile and metabolic network analysis were conducted. IL-17 signaling was detected by polymerase chain reaction and immunohistochemistry separately.

RESULTS

JYKT reduced the mean volumes of thyroid, decreased both levels of TPOAb and TGAb, and alleviated lymphocytic infiltration of the thyroid. Metabolic network analysis of metabolomics proved IL-17 signaling pathway as a critical pathway in JYKT administration for autoimmune thyroiditis. JYKT downregulated expressions of IL-17A, TRAF6, p-ERK1/2 and TNF-α.

CONCLUSION

JYKT alleviated inflammatory lesions of experimental autoimmune thyroiditis by regulating IL-17 signaling.

Impact of dehydroepiandrosterone on thyroid autoimmunity and function in men with autoimmune hypothyroidism

Background Testosterone administration was found to have a protective effect on thyroid autoimmunity in men with autoimmune (Hashimoto's) thyroiditis. Objective The present study was aimed at assessing whether oral dehydroepiandrosterone affects thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity in men with subclinical hypothyroidism induced by Hashimoto's thyroiditis. Setting The study was conducted at Medical University of Silesia, Katowice, Poland. Method The study enrolled 32 elderly men with autoimmune hypothyroidism and low dehydroepiandrosterone-sulfate levels. Based on patient preference, the participants either received oral dehydroepiandrosterone (50 mg daily; n = 16) or remained untreated (n = 16). Apart from measuring antibody titers and hormone levels, we calculated baseline and post-treatment values of three structure parameters of thyroid homeostasis. Main outcome measure Serum titers of thyroid peroxidase and thyroglobulin antibodies. Results At baseline, there were no significant differences in the investigated parameters between both groups of men. All participants completed the study. Oral dehydroepiandrosterone increased dehydroepiandrosterone-sulfate and testosterone levels, as well as had a neutral effect on estradiol levels. The increase in dehydroepiandrosterone-sulfate correlated with treatment-induced changes in serum testosterone. Moreover, dehydroepiandrosterone reduced titers of thyroid peroxidase and thyroglobulin antibodies, decreased serum thyrotropin levels, reduced Jostel's thyrotropin index as well as increased thyroid's secretory capacity. Treatment-induced changes in thyroid antibody titers, thyrotropin levels, Jostel's thyrotropin index and thyroid's secretory capacity correlated with the increase in dehydroepiandrosterone-sulfate and testosterone levels. Conclusion The obtained results show that exogenous dehydroepiandrosterone may exert a beneficial effect on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity in men with autoimmune thyroiditis and subclinical hypothyroidism.

Vitamin D and Autoimmune Thyroid Disease-Cause, Consequence, or a Vicious Cycle?

Vitamin D is a steroid hormone traditionally connected to phosphocalcium metabolism. The discovery of pleiotropic expression of its receptor and of the enzymes involved in its metabolism has led to the exploration of the other roles of this vitamin. The influence of vitamin D on autoimmune disease-namely, on autoimmune thyroid disease-has been widely studied. Most of the existing data support a relationship between vitamin D deficiency and a greater tendency for development and/or higher titers of antibodies linked to Hashimoto's thyroiditis, Graves' disease, and/or postpartum thyroiditis. However, there have also been some reports contradicting such relationships, thus making it difficult to establish a unanimous conclusion. Even if the existence of an association between vitamin D and autoimmune thyroid disease is assumed, it is still unclear whether it reflects a pathological mechanism, a causal relationship, or a consequence of the autoimmune process. The relationship between vitamin D's polymorphisms and this group of diseases has also been the subject of study, often with divergent results. This text presents a review of the recent literature on the relationship between vitamin D and autoimmune thyroid disease, providing an analysis of the likely involved mechanisms. Our thesis is that, due to its immunoregulatory role, vitamin D plays a minor role in conjunction with myriad other factors. In some cases, a vicious cycle is generated, thus contributing to the deficiency and aggravating the autoimmune process.

The Association of Obesity with Autoimmune Thyroiditis and Thyroid Function-Possible Mechanisms of Bilateral Interaction

A growing number of patients suffer from autoimmune diseases, including autoimmune thyroid disease. There has simultaneously been a significant increase in the prevalence of obesity worldwide. It is still an open question whether adiposity can directly influence activation of inflammatory processes affecting the thyroid in genetically predisposed individuals. Adipokines, biologically active substances derived from the adipocytes, belong to a heterogenic group of compounds involved in numerous physiological functions, including the maintenance of metabolism, hormonal balance, and immune response. Notably, the presence of obesity worsens the course of selected autoimmune diseases and impairs response to treatment. Moreover, the excess of body fat may result in the progression of autoimmune diseases. Nutritional status, body weight, and energy expenditure may influence thyroid hormone secretion. Interestingly, thyroid hormones might influence the activity of adipose tissue as metabolic alterations related to fat tissue are observed under pathological conditions in which there are deficits or overproduction of thyroid hormones. Functioning TSH receptors are expressed on adipocytes. Thermogenesis may presumably be stimulated by TSH binding to its receptor on brown adipocytes. There could be a bilateral interaction between the thyroid and adipose. Obesity may influence the onset and course of autoimmune disease.

The effect of vitamin D on thyroid autoimmunity in euthyroid men with autoimmune thyroiditis and testosterone deficiency

BACKGROUND

Autoimmune (Hashimoto's thyroiditis) is characterized by a strong female preponderance, which may suggest that sex hormones have an impact on thyroid autoimmunity. The aim of this study was to investigate whether testosterone determines vitamin D action on thyroid antibody titers and thyroid function tests in men with autoimmune thyroiditis and low testosterone levels.

METHODS

The study included 36 men with testosterone deficiency, 17 of whom had been treated for at least 26 weeks with oral testosterone undecanoate (120 mg daily). Because of coexistent euthyroid Hashimoto's thyroiditis, all participants were then treated with vitamin D (100 μg daily). Serum titers of thyroid peroxidase and thyroglobulin antibodies, serum levels of thyrotropin, free thyroid hormones, testosterone and 25-hydroxyvitamin D, as well as Jostel's thyrotropin index, SPINA-GT and SPINA-GD were assessed before vitamin D treatment and 26 weeks later.

RESULTS

With the exception of testosterone levels, there were no significant differences between both study groups in serum hormone levels, antibody titers and thyroid function tests. All participants completed the study. In addition to increasing 25-hydroxyvitamin D levels, vitamin D increased SPINA-GT and reduced thyroid peroxidase and thyroglobulin antibody titers. In testosterone-treated men, vitamin D increased testosterone levels. Vitamin D did not affect serum levels of thyrotropin, free thyroid hormones, Jostel's thyrotropin index and SPINA-GD. Treatment-induced changes in thyroid antibody titers and SPINA-GT were more pronounced in testosterone-treated than testosterone-naïve men.

CONCLUSIONS

The obtained results suggest that the beneficial effect on thyroid autoimmunity and thyroid secretory function is stronger in men receiving testosterone therapy.

The effect of spironolactone on thyroid autoimmunity in euthyroid men with Hashimoto's thyroiditis

WHAT IS KNOWN AND OBJECTIVE

Hashimoto's thyroiditis, also referred to as autoimmune thyroiditis, is characterized by sexual dimorphism, suggesting an important role of sex hormones in its development. No interventional study has investigated whether drugs exerting antiandrogen properties affect thyroid antibody titres and thyroid function tests in subjects with autoimmune thyroiditis.

METHODS

This study included 35 levothyroxine-naïve men with euthyroid Hashimoto's thyroiditis. At the physician's discretion, 18 men were then treated with spironolactone (50-200 mg daily), while the remaining patients (n = 17) received other diuretics. Serum levels of thyrotropin, free thyroid hormones, testosterone and 25-hydroxyvitamin D, as well as titres of thyroid peroxidase and thyroglobulin, were measured at the beginning of the study and 6 months later. Based on hormone levels, constant structure parameters of thyroid homeostasis were calculated.

RESULTS AND DISCUSSION

At baseline, there was no difference between the treatment arms in terms of thyroid antibody titres, hormone levels and the calculated parameters of thyroid homeostasis. Thirty-two patients completed the study. Spironolactone increased thyroid antibody titres, decreased testosterone and 25-hydroxyvitamin D levels and reduced SPINA-GT. The drug produced a neutral effect on serum levels of thyrotropin, free thyroid hormones, Jostel's thyrotropin index and SPINA-GD. The effect of spironolactone on antibody titres correlated with treatment-induced changes in SPINA-GT, testosterone and 25-hydroxyvitamin D. No significant changes in antibody titres, hormone levels and the calculated parameters of thyroid homeostasis were observed in spironolactone-naïve men.

WHAT IS NEW AND CONCLUSION

The obtained results indicate that spironolactone may exert an unfavourable effect on progression of autoimmune thyroiditis in men.

Bystander activation and autoimmunity

The interaction over time of genetic, epigenetic and environmental factors (i.e., autoimmune ecology) increases or decreases the liability an individual would have to develop an autoimmune disease (AD) depending on the misbalance between risk and protective effects. Pathogens have been the most common antecedent events studied, but multiple other environmental factors including xenobiotic chemicals, drugs, vaccines, and nutritional factors have been implicated into the development of ADs. Three main mechanisms have been offered to explain the development of autoimmunity: molecular mimicry, epitope spreading, and bystander activation. The latter is characterized by auto-reactive B and T cells that undergo activation in an antigen-independent manner, influencing the development and course of autoimmunity. Activation occurs due to a combination of an inflammatory milieu, co-signaling ligands, and interactions with neighboring cells. In this review, we will discuss the studies performed seeking to define the role of bystander activation in systemic and organ-specific ADs. In all cases, we are cognizant of individual differences between hosts and the variable latency time for clinical expression of disease, all of which have made our understanding of the etiology of loss of immune tolerance difficult and enigmatic.