Regulatory T Cells in the Pathogenesis of Graves' Disease.

Maintaining a delicate balance between the prompt immune response to pathogens and tolerance towards self-antigens and commensals is crucial for health. T regulatory (Treg) cells are pivotal in preserving self-tolerance, serving as negative regulators of inflammation through the secretion of anti-inflammatory cytokines, interleukin-2 neutralization, and direct suppression of effector T cells. Graves' disease (GD) is a thyroid-specific autoimmune disorder primarily attributed to the breakdown of tolerance to the thyroid-stimulating hormone receptor. Given the limitations of currently available GD treatments, identifying potential pathogenetic factors for pharmacological targeting is of paramount importance. Both functional impairment and frequency reduction of Tregs seem likely in GD pathogenesis. Genome-wide association studies in GD have identified polymorphisms of genes involved in Tregs' functions, such as CD25 (interleukin 2 receptor), and Forkhead box protein P3 (FOXP3). Clinical studies have reported both functional impairment and a reduction in Treg frequency or suppressive actions in GD, although their precise involvement remains a subject of debate. This review begins with an overview of Treg phenotype and functions, subsequently delves into the pathophysiology of GD and into the existing literature concerning the role of Tregs and the balance between Tregs and T helper 17 cells in GD, and finally explores the ongoing studies on target therapies for GD.

Immunomodulatory role of vitamin D and selenium supplementation in newly diagnosed Graves' disease patients during methimazole treatment.

Introduction: Methimazole (MMI) represents the conventional therapeutic agent for Graves' disease (GD) hyperthyroidism, but MMI efficacy is limited since it marginally affects the underlying autoimmune process. In a previous study, we randomly assigned 42 newly diagnosed GD patients with insufficient vitamin D (VitD) and selenium (Se) levels to treatment with MMI alone (standard) or combined with selenomethionine and cholecalciferol (intervention) and observed a prompter resolution of hyperthyroidism in the intervention group. Methods: In the present study, we aimed to explore changes in peripheral T regulatory (Treg) and circulating natural killer (NK) cell frequency, circulating NK cell subset distribution and function, during treatment. Results: At baseline, circulating total CD3-CD56+NK cells and CD56bright NK cells were significantly higher in GD patients than in healthy controls (HC) (15.7 ± 9.6% vs 9.9 ± 5.6%, p=0.001; 12.2 ± 10.3% vs 7.3 ± 4.1%, p=0.02, respectively); no differences emerged in Treg cell frequency. Frequencies of total NK cells and CD56bright NK cells expressing the activation marker CD69 were significantly higher in GD patients than in HC, while total NK cells and CD56dim NK cells expressing CD161 (inhibitory receptor) were significantly lower. When co-cultured with the K562 target cell, NK cells from GD patients had a significantly lower degranulation ability compared to HC (p<0.001). Following 6 months of treatment, NK cells decreased in both the intervention and MMI-alone groups, but significantly more in the intervention group (total NK: -10.3%, CI 95% -15.8; -4.8% vs -3.6%, CI 95% -9; 1.8%, p=0.09 and CD56bright NK cells: -6.5%, CI 95% -10.1; -3 vs -0.9%, CI 95% -4.4; 2%, p=0.03). Compared to baseline, CD69+ NK cells significantly decreased, while degranulation ability slightly improved, although no differences emerged between the two treatment groups. Compared to baseline, Treg cell frequency increased exclusively in the intervention group (+1.1%, CI 95% 0.4; 1.7%). Discussion: This pilot study suggested that VitD and Se supplementation, in GD patients receiving MMI treatment, modulates Treg and NK cell frequency, favoring a more pronounced reduction of NK cells and the increase of Treg cells, compared to MMI alone. Even if further studies are needed, it is possible to speculate that this immunomodulatory action might have facilitated the prompter and better control of hyperthyroidism in the supplemented group observed in the previous study.

How Does Vitamin D Affect Immune Cells Crosstalk in Autoimmune Diseases?

Vitamin D is a secosteroid hormone that is highly involved in bone health. Mounting evidence revealed that, in addition to the regulation of mineral metabolism, vitamin D is implicated in cell proliferation and differentiation, vascular and muscular functions, and metabolic health. Since the discovery of vitamin D receptors in T cells, local production of active vitamin D was demonstrated in most immune cells, addressing the interest in the clinical implications of vitamin D status in immune surveillance against infections and autoimmune/inflammatory diseases. T cells, together with B cells, are seen as the main immune cells involved in autoimmune diseases; however, growing interest is currently focused on immune cells of the innate compartment, such as monocytes, macrophages, dendritic cells, and natural killer cells in the initiation phases of autoimmunity. Here we reviewed recent advances in the onset and regulation of Graves' and Hashimoto's thyroiditis, vitiligo, and multiple sclerosis in relation to the role of innate immune cells and their crosstalk with vitamin D and acquired immune cells.

A potential role of human RNASET2 overexpression in the pathogenesis of Graves' disease.

Genetic variation of the gene encoding for the only human enzyme of the T2 ribonucleases family (RNASET2) emerged in genome-wide association studies as a putative risk hotspot for Graves' disease (GD). T2 ribonucleases activities include immune regulation, induction of cell apoptosis and differentiation. Several reports supported the hypothesis that RNASET2 represents a "danger" message addressed to the innate immune system in peculiar conditions. This was a longitudinal, case-control study. RNASET2 protein levels were assessed in blood samples from 34 consecutive newly diagnosed GD patients and in healthy controls. At enrollment, RNASET2 levels were significantly higher in GD patients (98.5 ± 29.1 ng/ml) compared to healthy controls (72.5 ± 27.9 ng/ml, p = 0.001). After 6 months of methimazole treatment, RNASET2 levels significantly decrease and return to levels similar to healthy controls (62.4 ± 22 ng/ml, p = 0.69). These preliminary results suggest that RNASET2 is overexpressed in patients with GD and might represent an "alarm signal" generated by thyroid cells in response to endogenous or environmental stress to alert the immune system.

Add-On Effect of Selenium and Vitamin D Combined Supplementation in Early Control of Graves' Disease Hyperthyroidism During Methimazole Treatment.

Prompt and stable control of hyperthyroidism is fundamental to avoid the detrimental effects of thyroid hormone excess, and antithyroid drugs, mainly methimazole (MMI), represent the first-line treatment for Graves' disease (GD) hyperthyroidism. Decreased serum concentrations of selenium (Se) and calcifediol (25(OH)D, VitD) have been reported in newly diagnosed GD patients in observational studies. Low Se levels might exacerbate oxidative stress by compromising the antioxidant machinery's response to reactive oxygen species, and low VitD levels might hamper the anti-inflammatory immune response. We performed a randomized controlled clinical trial (EudraCT 2017-00505011) to investigate whether Se and cholecalciferol (VitD) addition to MMI is associated with a prompter control of hyperthyroidism. Forty-two consecutive patients with newly-onset GD and marginal/insufficient Se and VitD levels were randomly assigned to treatment with either MMI monotherapy or MMI combined with Se and VitD. Se treatment was withdrawn after 180 days, while the other treatments were continued. Combination therapy resulted in a significantly greater reduction in serum FT4 concentration at 45 days (-37.9 pg/ml, CI 95%, -43.7 to -32.2 pg/ml) and 180 days (-36.5 pg/ml, CI 95%, -42 to -30.9 pg/ml) compared to MMI monotherapy (respectively: -25.7 pg/ml, CI 95%, -31.6 to -19.7 pg/ml and -22.9 pg/ml, CI 95%, -28 to -17.3 pg/ml, p 0.002). Data at 270 days confirmed this trend (-37.8 pg/ml, CI 95%, -43.6 to -32.1 pg/ml vs -24.4 pg/ml, CI 95%, -30.3 to -18.4 pg/ml). The quality of life (QoL) score was investigated by the validated "Thyroid-related Patient-Reported Outcome" questionnaire (ThyPRO). ThyPRO composite score showed a greater improvement in the intervention group at 45 days (-14.6, CI 95%, -18.8 to -10.4), 180 (-9, CI 95%, -13.9 to -4.2) and 270 days (-14.3, CI 95%, -19.5 to -9.1) compared to MMI group (respectively, -5.2, CI 95%, -9.5 to -1; -5.4, CI 95%, -10.6 to -0.2 and -3.5, CI 95%, -9 to -2.1, p 0-6 months and 6-9 months <0.05). Our results suggest that reaching optimal Se and VitD levels increases the early efficacy of MMI treatment when Se and VitD levels are suboptimal.

Management of Graves' hyperthyroidism: present and future.

INTRODUCTION: Graves' disease (GD) is an autoimmune disorder due to loss of tolerance to the thyrotropin receptor (TSHR) and ultimately caused by stimulatory TSHR antibodies (TSHR-Ab). GD may be associated with extrathyroidal manifestations, mainly Graves' orbitopathy. Treatment of GD relies on antithyroid drugs (ATDs), radioactive iodine (RAI), thyroidectomy. The major ATD limitation is the high recurrence rate after treatment. The major drawback of RAI and thyroidectomy is the inevitable development of permanent hypothyroidism. AREAS COVERED: Original articles, clinical trials, systematic reviews, meta-analyses from 1980 to 2021 were searched using the following terms: Graves' disease, management of Graves' disease, antithyroid drugs, radioactive iodine, thyroidectomy, Graves' orbitopathy, thyroid-eye disease. EXPERT OPINION: ATDs are the first-line treatment worldwide, are overall safe and usually given for 18-24 months, long-term treatment may decrease relapses. RAI is safe, although associated with a low risk of GO progression, particularly in smokers. Thyroidectomy requires skilled and high-volume surgeons. Patients play a central role in the choice of treatment within a shared decision-making process. Results from targeted therapies acting on different steps of the autoimmune process, including iscalimab, ATX-GD-59, rituximab, blocking TSHR-Ab, small molecules acting as antagonists of the TSHR, are preliminary or preclinical, but promising in medium-to-long perspective.

Vitamin D, Chronic Migraine, and Extracranial Pain: Is There a Link? Data From an Observational Study.

Several studies focused on the role of vitamin D (vitD) in pain chronification. This study focused on vitD level and pain chronification and extension in headache disorders. Eighty patients with primary headache underwent neurological examination, laboratory exams, including serum calcifediol 25(OH)D, and headache features assessment along with three questionnaires investigating depression, anxiety, and allodynia. The 86.8% of the population had migraine (48% episodic and 52% chronic). The 44.1% of patients had extracranial pain, and 47.6% suffered from allodynia. A vitD deficit, namely a serum 25(OH)D level <20 ng/ml, was detectable in 46.1% of the patients, and it occurred more frequently (p = 0.009) in patients suffering from chronic migraine (CM)-medication overuse migraine (MOH) (62.9%) than in episodic migraine (EM, 25.7%) or tension-type headache (TTH, 11.4%). The occurrence of extracranial pain and allodynia was higher in the CM-MOH than in the EM and in the TTH groups but was not related to the co-occurrence of vitD deficiency (Fisher's exact test p = 0.11 and p = 0.32, respectively). Our findings show that 25(OH)D deficit is also related to chronic headache, probably because of vitD anti-inflammatory and tolerogenic properties, reinforcing the idea of a neuroinflammatory mechanism underpinning migraine chronification.

Negative impact of high body mass index on cetuximab-mediated cellular cytotoxicity against human colon carcinoma cells.

This study assessed the relationship between the ability of Natural Killer (NK) cells to activate antibody-dependent cellular cytotoxicity against human HT29 colorectal cancer cells exposed to cetuximab and the body mass index of the human subjects from whom the NK cells had been obtained. NK cells obtained from 73 human donors were co-incubated with HT-29 human colon cancer cells in the presence or absence of cetuximab. Antibody-dependent cellular cytotoxicity was assessed by measuring LDH release. A significant negative correlation was observed between body mass index and cetuximab-induced antibody-dependent cellular cytotoxicity. NK cells obtained from subjects who were overweight or with obesity were less efficient in killing cetuximab-treated HT29 cells than those derived from normal weight donors. Our results suggest that the success of cetuximab-containing regimens might be impaired in overweight and obese patients with colorectal cancer.

Epidemiology, Natural History, Risk Factors, and Prevention of Graves' Orbitopathy.

GO is the most frequent extrathyroidal manifestation of Graves' disease, although it may rarely occur in euthyroid/hypothyroid patients with chronic autoimmune thyroiditis. It is a relatively infrequent disorder, and men tend to have more severe ocular involvement at an older age. The prevalence of GO is lower than in the past among patients with recent onset Graves' hyperthyroidism, and moderate-to-severe forms requiring aggressive treatments are no more than 5-6% of all cases of GO. After an initial inflammatory (active) phase and a phase of stabilization (plateau phase), GO tends to improve and eventually inactivates (inactive or burnt-out phase). Minimal-to-mild GO often remits spontaneously, but complete restitutio ad integrum almost never occurs when GO is more than mild. Several risk factors contribute to its development on a yet undefined genetic background. Cigarette smoking is the most important of them. Early diagnosis, control and removal of modifiable risk factors, early treatment of mild forms of GO may effectively limit the risk of progression to more severe forms, which have a profound and dramatic impact on the quality of life of affected individuals, and remain a therapeutic challenge, often requiring long-lasting and multiple medical and surgical therapies.

Immunological Drivers in Graves' Disease: NK Cells as a Master Switcher.

Graves' disease (GD) is a common autoimmune cause of hyperthyroidism, which is eventually related to the generation of IgG antibodies stimulating the thyrotropin receptor. Clinical manifestations of the disease reflect hyperstimulation of the gland, causing thyrocyte hyperplasia (goiter) and excessive thyroid hormone synthesis (hyperthyroidism). The above clinical manifestations are preceded by still partially unraveled pathogenic actions governed by the induction of aberrant phenotype/functions of immune cells. In this review article we investigated the potential contribution of natural killer (NK) cells, based on literature analysis, to discuss the bidirectional interplay with thyroid hormones (TH) in GD progression. We analyzed cellular and molecular NK-cell associated mechanisms potentially impacting on GD, in a view of identification of the main NK-cell subset with highest immunoregulatory role.

When primary hyperparathyroidism comes as good news.

SUMMARY: Brown tumors are osteoclastic, benign lesions characterized by fibrotic stroma, intense vascularization and multinucleated giant cells. They are the terminal expression of the bone remodelling process occurring in advanced hyperparathyroidism. Nowadays, due to earlier diagnosis, primary hyperparathyroidism keeps few of the classical manifestations and brown tumors are definitely unexpected. Thus, it may happen that they are misdiagnosed as primary or metastatic bone cancer. Besides bone imaging, endocrine evaluation including measurement of serum parathyroid hormone and calcium (Ca) levels supports the pathologist to address the diagnosis. Herein, a case of multiple large brown tumors misdiagnosed as a non-treatable osteosarcoma is described, with special regards to diagnostic work-up. After selective parathyroidectomy, treatment with denosumab was initiated and a regular follow-up was established. The central role of multidisciplinary approach involving pathologist, endocrinologist and oncologist in the diagnostic and therapeutic work-up is reported. In our opinion, the discussion of this case would be functional especially for clinicians and pathologists not used to the differential diagnosis in uncommon bone disorders. LEARNING POINTS: Brown tumors develop during the remodelling process of bone in advanced and long-lasting primary or secondary hyperparathyroidism. Although rare, they should be considered during the challenging diagnostic work-up of giant cell lesions. Coexistence of high parathyroid hormone levels and hypercalcemia in primary hyperparathyroidism is crucial for the diagnosis. A detailed imaging study includes bone X-ray, bone scintiscan and total body CT; to rule out bone malignancy, evaluation of bone lesion biopsy should include immunostaining for neoplastic markers as H3G34W and Ki67 index. If primary hyperparathyroidism is confirmed, selective parathyroidectomy is the first-line treatment. In advanced bone disease, treatment with denosumab should be considered, ensuring a strict control of Ca levels.

Preoperative management in patients with Graves' disease.

Graves' disease is the most frequent cause of hyperthyroidism in iodine-sufficient geographical areas and is characterized by the presence in patients' serum of autoantibodies directed against the thyrotropin receptor (TRAb) that cause overproduction and release of thyroid hormones. Clinical presentation results from both hyperthyroidism and underlying autoimmunity. The diagnosis is based on characteristic clinical features and biochemical abnormalities. If serum thyrotropin (TSH) is low, serum free thyroxine (FT4) and free triiodothyronine (FT3) concentrations should be measured to distinguish between subclinical (with normal circulating thyroid hormones) and overt hyperthyroidism (with increased circulating thyroid hormones). Graves' disease is treated with any of three effective and relatively safe initial treatment options: antithyroid drugs (ATDs), radioactive iodine ablation (RAIU), and surgery. Total thyroidectomy is favored in several clinical situations, such as intolerance, ineffectiveness or recurrence after ATD treatment, radioiodine therapy contraindicated, documented or suspected thyroid malignancy, one or more large thyroid nodules, coexisting moderate-to-severe active Graves' orbitopathy, women planning a pregnancy within 6 months. Whenever surgery is selected as treatment, selection of an expert high-volume thyroid surgeons is fundamental and careful preoperative management is essential to optimize surgical outcomes. Pretreatment with ATDs in order to promptly achieve the euthyroid state is recommended to avoid the risk of precipitating thyroid storm during surgery. For the majority of patients, euthyroidism is achieved after few weeks of ATD treatment. Beta-blockers, such as propranolol, are often added effectively to control hyperthyroid symptoms. Saturated solution of potassium iodide (SSKI) or potassium iodine (Lugol's solution), given for a short period prior to surgery, in order to reduce both thyroid hormone release and thyroid gland vascularity, is beneficial to decrease intra-operative blood loss.

Cardiometabolic healthy and unhealthy obesity: does vitamin D play a role?

OBJECTIVE: The aim of this observational study was to clarify the link between vitamin D status and metabolic syndrome (MetS) in people with visceral obesity. DESIGN AND METHODS: One hundred ninety-six consecutive patients (152 women; mean age 51 ± 13 years) with visceral obesity (mean body weight 103 ± 20 kg, mean waist circumference (WC) 119 ± 13 cm) were enrolled at the Obesity Outpatient Clinic of the University of Insubria in Varese. Anthropometric measurements were recorded. Laboratory tests, including vitamin D (25(OH)D)), fasting blood glucose (FBG), lipid profile, liver and kidney function tests were assessed. Vitamin D status was defined according to the European Society of Endocrinology guidelines, MetS to the 2009 harmonized definition. RESULTS: An inverse association emerged among 25(OH)D, body mass index (BMI) (P = 0.001) and WC (all P = 0.003). Serum 25(OH)D levels were inversely related to FBG and systolic blood pressure (SBP) (respectively, P = 0.01 and 0.02). Median serum 25(OH)D levels were 13.3 ng/mL (CI 95% 12; 15) in MetS and 16 ng/mL (CI 95% 14; 18) (P = 0.01) in non-MetS patients. Among patients with MetS, lower 25(OH)D concentrations were related to higher risk of hypertension (HT) (odds ratio (OR) 1.7, CI 95%, 0.7;4) and hyperglycemia (IFG)/type 2 diabetes (OR 5.5, CI 95% 2; 14). CONCLUSION: Vitamin D status and MetS are inversely correlated in visceral obesity, particularly with regard to glucose homeostasis and BP. More extensive studies are required to investigate the potential for causality.

Multilayer Microstructure of Idiopathic Epiretinal Macular Membranes.

PURPOSE: To identify the ultramicroscopic structure of idiopathic epiretinal macular membranes (iEMMs) by scanning electron microscopy (SEM). METHODS: We examined 28 iEMMs surgically removed from 28 eyes of 28 patients. All specimens, previously observed at stereomicroscope, were treated with an osmium maceration technique. Fine resolution of iEMMs' 3D architecture and their interaction with the retina were studied using a Philips SEM-FEG XL-30 microscope. RESULTS: The specimens appeared as laminar connective structures partially or completely adherent to the inner limiting membrane (ILM). We identified 4 types of structures: ( 1 ) distinct layers of thin sheets of woven fibers; ( 2 ) folded layers of inhomogeneous thickness of fibrous material more consistent; ( 3 ) thicker and more rigid layers recognizable as collagen fibrils with typical 64-nm period, collagen fibrils isolated or intermingled between them; ( 4 ) lacunar structures with inflammatory and/or necrotic material. The first 3 types of structures appear to thicken towards a centripetal direction from the ILM to the vitreous in order from 1 to 3. The interface of ILM-iEMM tissue shows particular small bridges of connection. Cells are rarely found, especially in the tissue near the ILM. CONCLUSIONS: Layers of various materials follow one another in iEMMs. Cells are rarely found. The interface ILM-iEMM tissue shows particular small bridges of connection. The dynamic modeling of bended layers begins in soft tissue.

IRIS: methodological assessment of psychopathological disease in a cohort of hirsute women.

BACKGROUND: Hirsutism in females can be a source of considerable psychological distress and a threat to female identity. The aim of our study was to evaluate a possible relationship between facial, total body hair involvement and physical, mental and social well-being during 12 months of follow-up and treatment. Both objective and subjective methods of evaluating hirsutism were used: the Ferriman-Gallwey (FG) scoring method and the questionnaires General Health Questionnaire (GHQ)-12, Polycystic Ovary Syndrome Questionnaire (PCOSQ) and SF-12. METHODS: The total of 469 female patients (mean age 27.61±7.63 years) was enrolled in 27 Italian centers participating in this study. Higher total body score was correlated to significant emotional discomfort. The correlation between the FG total body score, the facial score and physical/mental health was found to be significant in all the patients assessed by SF-12 questionnaire. The ongoing reduction of GHQ-12 score was found for the facial FG score at the first follow-up (T0-T1 period) and at the second one (T0-T2). No relationship was found between T1 and T2. At both 6 (T1) and 12 months (T2) follow-up an increase of PCOSQ Score (psychological improvement) was accompanied by a concomitant reduction of the FG Score (reduction of hirsutism). Physical health assessed by SF-12 questionnaire does not change at both 6- and 12-month follow-up, but mental health decreased at both T1 and T2. RESULTS: The clinical improvement was achieved at 6 months regardless on treatment used and it was maintained for the next six-month follow-up. The clinical outcome could be assessed both by FG Score both through questionnaires administrated to each patient with hirsutism. CONCLUSIONS: For the evaluation of psychopathological discomfort the most appropriate questionnaire was GHQ-12, because of it major sensitivity to identify the psychological discomfort in the hirsutism.

Hürthle Cells Adenoma of the Thyroid with Post-surgical Implants in the Neck: Clinical, Morphological, and Molecular Analysis of Three Cases.

Thyroid implants in the soft tissue of the neck are very rare findings of traumatic, iatrogenic, or neoplastic origins. We describe the clinico-pathological and molecular analysis of three cases with an initial diagnosis of follicular adenoma, Hürthle cell variant (FA-HCT), which developed cervical thyroid implants at 60, 59, and 36 months after thyroid surgery, followed by further neck recurrences, and, eventually, by distant metastases. A systematic review of all histopathological samples of both the primary lesions and the neck implants was performed. Molecular study included the analysis of pan-RAS and BRAF mutations and RET/PTC1, RET/PTC3, and PAX8/PPARγ rearrangements. The review of the original slides and of additional re-cuts of each block of the thyroid lesions did not show any sign of capsular and/or vascular invasion; thus, the original diagnoses of FA-HCT were confirmed. When sampling adequacy was considered, it turned out that the capsule was completely evaluable in case #3, whereas 85 % was evaluable for case #1 and less than 50 % for case #2. We cannot exclude that cases #1 and #2 were carcinomas that had not been completely sampled. The first occurring neck implants showed neither histological signs of malignancy nor the presence of lymphoid tissue. However, further neck recurrences had different histological aspects, with a clear infiltrative growth. Moreover, a mesenchymal reaction forming a sort of capsule was observed around oncocytic cells along with signs of vascular invasion. Molecular analysis revealed no alterations in the genes and rearrangements studied. Oncocytic thyroid implants in the neck soft tissue should be regarded as metastasis, even in the absence of clear-cut signs of malignancy and in the case of a bona fide diagnosis of Hürthle cells adenoma of the thyroid.