Different cytokine mRNA profiles in Graves' disease, Hashimoto's thyroiditis, and nonautoimmune thyroid disorders determined by quantitative reverse transcriptase polymerase chain reaction (RT-PCR)

Infrared Spectral Patterns of Thyroglobulin Bearing Thyroiditogenic Epitopes

Thyroglobulin is a major autoantigen to which autoimmune response, destroying the thyroid gland in Hashimoto's thyroiditis, is directed. To detect a pathological autoimmune response to thyroglobulin, as well as the successful induction of experimental autoimmune thyroiditis, thyroglobulin carrying thyroiditogenic epitopes is necessary. It is not known which features of thyroglobulin structure determine the presence of thyroiditogenic epitopes and can serve as markers of their presence. We compared structure of thyroglobulin bearing thyroiditogenic epitopes (freshly isolated thyroglobulin) and thyroglobulin which had lost thyroiditogenic epitopes (lyophilized thyroglobulin). Fourier-transform infrared (FTIR) spectroscopy was used to elucidate the structure of thyroglobulin. The markers indicating the presence of thyroiditogenic epitopes on thyroglobulin are the vibrations of diiodotyrosine, monoiodotyrosine/diiodotyrosine relation in the range of 0.24-0.43 (95% confidence interval) and relatively high (> 32%) α-helix content. The loss of thyroiditogenic epitopes on thyroglobulin is associated with a weakening or complete disappearance of diiodotyrosine oscillations and a decrease in the proportion of α-helices in secondary structure. Thyroglobulin extracted with phenylmethylsulfonyl fluoride (PMSF) added is characterized by the same relatively high monoiodotyrosine/diiodotyrosine relation and low proportion of alpha helices as thyroglobulin without thyroiditogenic epitopes. Therefore, serine protease inhibitor PMSF is not suitable for extraction of native thyroglobulin bearing thyroiditogenic epitopes. FTIR spectroscopy can be used to detect thyroiditogenic epitopes on thyroglobulin.

Treatment of Hypothyroidism and Stress Using Neuro-Emotional Technique (NET): A Case Study

Hypothyroidism is generally considered an autoimmune condition, and typical medical management involves taking levothyroxine (synthetic thyroid hormone) for life. This case report details the results of a mind-body intervention (MBI) called the Neuro-Emotional Technique (NET) used to treat a 28-year-old Caucasian female presenting with symptoms and bloodwork markers associated with two years of hypothyroidism and a long history of stress. The patient's medical doctor provided a diagnosis of hypothyroidism after blood tests showed that thyroid-stimulating hormone (TSH) levels were high at 6.87 mIU/L (where the acceptable range is 0.40-3.50 mIU/L) and free T4 (FT4) levels were low at 8.6 pmol/L (where the acceptable range is 9.0-19.0 pmol/L). Psychometric tests were completed at baseline and after 12 weeks of treatment to evaluate changes in mental health and emotional well-being. The Adverse Childhood Experiences Questionnaire (ACE-Q) revealed a high degree of childhood trauma that may have predisposed to the underlying autoimmune thyroid dysfunction. At the conclusion of the treatment period, serum thyroid-stimulating hormone (TSH) and free T4 were within normal ranges and psychometric indicators normalized. We hypothesize that these changes may be due to the stress-reducing mechanism of NET and outline possible mechanisms via the Psycho-Immune-Neuroendocrine (PINE) network. The PINE network model asserts that chronic stress acts as a potential driver of pathophysiology that can lead to one or more medical and mental health conditions. While further studies with larger sample sizes are required to establish whether these results could be extrapolated to a wider population, the results of this case suggest that it may be pertinent to consider co-management of subclinical hypothyroidism with a relatively quick and cost-effective MBI such as NET.

Evaluation of IL-10, MCP-1, IFN gamma, and protectin D1 levels in patients with Hashimoto's thyroiditis

PURPOSE

Hashimoto's thyroiditis (HT) is one of the most prevalent autoimmune endocrine diseases and caused by the loss of immune tolerance for the thyroid gland. Many pathophysiological mechanisms were speculated about the development of HT. In our study, we aimed to reveal the relationship between HT and IL-10, MCP-1, IFNɤ, and PD1 levels and compare them with control subjects.

METHODS

We collected 37 patients with HT and 25 controls referred to our outpatient clinic. The diagnosis of HT was based on the detection of circulating antibodies to thyroid antigens and decreasing echogenicity on thyroid USG in patients with appropriate clinical characteristics. Serum IL-10, MCP-1, IFNɤ, and PD1 levels were detected using an ELISA KIT (96 T) method according to the manufacturer's instructions.

RESULTS

All subjects were euthyroid (median TSH level was 1.68 mU/L in HT vs 1.83 mU/L in the controls, p = 0.672). Twenty-three of 37 patients with HT were taking L-thyroxin replacement. Levels of serum IL-10, IFNɤ, and PD1 in patients with HT were higher than the controls, but the differences were not statistically significant (p = 0.393, p = 0.495, and p = 0.052 respectively). The serum levels of MCP-1 in HT patients were statistically different and higher than the controls (p = 0.018). Correlation analysis displayed significant associations between IL-10, MCP-1, IFNɤ, and PD1 levels.

CONCLUSION

Our study demonstrated that serum MCP-1 levels in HT patients were significantly increased; on the other hand, significant difference was not found between HT patients and the controls in terms of serum IL-10, IFNɤ, and PD1 levels.

Decreased β-catenin expression contributes to IFNγ-induced chemokine secretion and lymphocyte infiltration in Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) is a very common organ-specific autoimmune disease characterized by lymphocyte infiltration and the destruction of thyroid follicular cells (TFCs), in which IFN-γ and chemokines play pivotal roles. Moreover, β-catenin has been implicated in the regulation of T cell infiltration. However, whether β-catenin is involved in Hashimoto's thyroiditis is unknown. Here, we examined β-catenin expression in thyroid tissues and investigated its role in the pathogenesis of HT. The results showed that β-catenin expression was markedly reduced in the thyroid tissues of HT patients; more importantly, IFN-γ treatment markedly reduced the expression of β-catenin and was accompanied by the secretion of chemokines such as CCL5, CXCL16, GRO-β, and GRO-γ in TFCs in vitro, which was attributed to GSK-3β/β-catenin signaling pathway activation. Collectively, the decreased expression of β-catenin might contribute to IFNγ-induced chemokine secretion and lymphocyte infiltration in the development of HT.

DNA methylation analysis within the IL2RA gene promoter in youth with autoimmune thyroid disease

BACKGROUND

Alpha-subunit of the interleukin-2 receptor (IL2RA) is involved in the regulation of T-cell function and has been related to autoimmune thyroid disease (AITD). Although the exact mechanisms are not fully understood, promoter methylation might account for differences in gene expression. The aim of this study was to investigate whether there are differences in the percentage of DNA methylation within the IL2RA gene promoter in young patients with AITD.

MATERIALS AND METHODS

In a cross-sectional design, the presence of DNA methylation in the IL2RA gene promoter was quantified, by real-time PCR and melting curve analysis, in modified genomic DNA isolated from blood samples of a total of 149 children and adolescents with AITD, including patients with Hashimoto thyroiditis (ΗΤ) (n = 60), Graves' disease (GD) (n = 9), concurrent diagnosis of HT and type 1 diabetes (T1DM + HT) (n = 25), and healthy controls (n = 55).

RESULTS

The percentage of DNA methylation in the IL2RA gene promoter was significantly decreased in patients with GD (26.0 ± 4.2%) but not in those with HT (36.3 ± 1.4%) in comparison with controls (41.3 ± 1.5%).

CONCLUSIONS

The observed DNA hypomethylation in the IL2RA gene promoter in patients with GD might be related to its increased expression, thus contributing to the etiopathogenesis of GD in childhood and adolescence.

Uterus globulin associated protein 1 (UGRP1) is a potential marker of progression of Graves' disease into hypothyroidism

Approximately 20% of Graves' disease (GD) patients may result eventually in hypothyroidism in their natural course. Uterus globulin-associated protein 1 (UGRP1) was associated with GD in our previous study. Here we investigated the role of UGRP1 in the development of autoimmune thyroid disease (AITD). The results showed that UGRP1 was expressed in the thyrocytes of most Hashimoto's thyroiditis (HT) patients and a proportion of GD patients (293 HT and 198 GD). The pathologic features of UGRP1-positive thyrocytes resembled "Hürthle cells", and were surrounded by infiltrated leukocytes. The positivity rate of TPOAb in UGRP1-positive GD patients was much higher than that in -negative GD patients. Moreover, UGRP1 was co-expressed with Fas and HLA-DR in the thyrocytes of AITD patients. We also found IL-1β but not Th1 or Th2 cytokines was able to upregulate the expression of UGRP1. Our findings indicated that UGRP1 may be a novel marker in thyrocytes to predict GD patients who develop hypothyroidism.

Increased Circulating Th17 but Decreased CD4+Foxp3+ Treg and CD19+CD1dhiCD5+ Breg Subsets in New-Onset Graves' Disease

Th17 and regulatory lymphocyte subsets such as Tregs and Bregs have been reported to play important roles in autoimmune diseases. The aim of this work was to perform quantitative studies of circulating Th17, Tregs, and Bregs in patients with new-onset Graves' disease (GD). Twenty GD patients and 20 healthy controls were involved in this study. Blood samples were taken for flow cytometry detection of CD4⁺IL-17⁺ Th17, CD4⁺Foxp3⁺ Tregs, and CD19⁺CD1d^hiCD5⁺ Bregs and meanwhile, for real-time PCR measurement of gene expressions of RORγt, IL-17 and IL-10. The proportions of Tregs and Bregs as well as the Foxp3 gene expression but not IL-10 were significantly decreased in GD group compared with the healthy controls. The frequency of Th17 together with the gene expressions of RORγt and IL-17 were significantly increased in the GD group. Furthermore, the Th17/Treg ratio was also significantly higher in GD group. A significant positive correlation between Th17 and TSAb (r = 0.656, p < 0.001) but significant negative correlations between Treg/Breg and TSAb (r = −0.339, p = 0.032; r = −0.759, p < 0.001) were identified among the participants. This study indicated that increased Th17 and impaired Treg responses, along with a decreased number of CD19⁺CD1d^hiCD5⁺ Breg cells, were involved in GD pathogenesis.

Childhood maltreatment is associated with increased risk of subclinical hypothyroidism in pregnancy

The critical importance of thyroid hormones for fetal development is well established. The developing fetus is dependent on the mother for adequate thyroid hormone supply, and maternal thyroid dysfunction in pregnancy may result in suboptimal fetal development. Because exposure to childhood maltreatment (CM) has been associated with thyroid dysfunction in the non-pregnant state, we sought to test the hypothesis that exposure to CM may represent a risk factor for the development of maternal hypothyroidism in pregnancy. The study was conducted in a healthy cohort of 102 pregnant mothers who were followed across the entire course of pregnancy. At each trimester thyroid-stimulating hormone (TSH) and free thyroxine (fT4) were measured in maternal serum. Experience of CM was assessed using the Childhood Trauma Questionnaire. After adjusting for potentially confounding variables, CM exposure was associated with increased TSH concentrations across pregnancy (F_1,94.6=11.52, p=0.001) and with a 4- to 7-fold increased risk of TSH levels above the trimester-specific clinical cut-off values. Women with clinically elevated TSH concentrations did not differ in fT4 concentrations from women with normal TSH concentrations (p>0.1), suggesting subclinical hypothyroidism. Our findings suggest that there is a substantial and clinically relevant increased risk for thyroid dysfunction during pregnancy among women exposed to abuse or neglect in their childhood. This could potentially have adverse consequences for fetal brain development. Thus, these findings highlight the critical importance of considering CM exposure as a potential risk factor for (subclinical) hypothyroidism in pregnancy.

Iodine-131 therapy alters the immune/inflammatory responses in the thyroids of patients with Graves' disease

The aim of the present study was to evaluate the serum levels of interleukin-6 (IL-6), CXC chemokine ligand-10 (CXCL-10) and intercellular adhesion molecule-l (ICAM-1) in patients with Graves' disease (GD) following iodine-131 (¹³¹I) therapy. A total of 30 patients with GD participated in the present study. Serum cytokine levels were measured with ELISA, and correlation analyses were performed. Serum levels of IL-6, CXCL-10 and ICAM-1 were significantly higher in patients with GD prior to treatment than those in the control subjects (P<0.01). Following ¹³¹I therapy, the serum levels of IL-6 and CXCL-10 in patients with GD were markedly increased within the first week, gradually decreased to the pretreatment level in the subsequent six months and decreased further at 18 months post-treatment. However, the serum levels of IL-6 and CXCL-10 in patients with GD at 18 months following ¹³¹I therapy remained significantly higher than in control subjects (P<0.01). Conversely, serum ICAM-1 levels in patients with GD were gradually increased in the 12 months following ¹³¹I therapy and reached a relatively stable level thereafter. Furthermore, the Pearson's correlation analysis indicated that the serum levels of IL-6, CXCL-10 and ICAM-1 were not associated with free triiodothyronine, the free thyroxine index, and thyroid-stimulating hormone in these patients. ¹³¹I therapy was able to alter the immune/inflammatory responses in the thyroids of patients with GD. However, these cytokines (IL-6, CXCL-10, and ICAM-1) are not associated with thyroid function; therefore, they cannot be used as prognostic markers for the ¹³¹I therapy of GD.

The teleost head kidney: Integrating thyroid and immune signalling

The head kidney, analogous to the mammalian adrenal gland, is an organ unique for teleost fish. It comprises cytokine-producing lymphoid cells from the immune system and endocrine cells secreting cortisol, catecholamines, and thyroid hormones. The intimate organization of the immune system and endocrine system in one single organ makes bidirectional signalling between these possible. In this review we explore putative interactions between the thyroid and immune system in the head kidney. We give a short overview of the thyroid system, and consider the evidence for the presence of thyroid follicles in the head kidney as a normal, healthy trait in fishes. From mammalian studies we gather data on the effects of three important pro-inflammatory cytokines (TNFα, IL-1β, IL-6) on the thyroid system. A general picture that emerges is that pro-inflammatory cytokines inhibit the activity of the thyroid system at different targets. Extrapolating from these studies, we suggest that the interaction of the thyroid system by paracrine actions of cytokines in the head kidney is involved in fine-tuning the availability and redistribution of energy substrates during acclimation processes such as an immune response or stress response.

Thyrotropin and CD40L Stimulate Interleukin-12 Expression in Fibrocytes: Implications for Pathogenesis of Thyroid-Associated Ophthalmopathy

BACKGROUND

Increased numbers of bone marrow-derived progenitor cells, known as fibrocytes, populate the peripheral circulation, orbit, and thyroid of patients with Graves' disease (GD). These cells have been implicated in the development of thyroid-associated ophthalmopathy. They can differentiate into myofibroblasts or adipocytes, produce inflammatory cytokines, and remodel tissue. This study sought to determine whether thyrotropin (TSH) and CD40 ligand (CD40L), implicated in the pathogenesis of GD, induce interleukin-12 (IL-12) in human fibrocytes.

MATERIALS AND METHODS

IL-12 protein concentrations and mRNA levels were measured by Luminex and real-time polymerase chain reaction, respectively. Flow cytometry assessed intracellular IL-12 concentrations. Vector containing IL-12p40 promoter was transfected into cultured fibrocytes, and promoter activity was monitored using luciferase assay.

RESULTS

TSH and CD40L stimulated intracellular IL-12 protein accumulation in peripheral blood fibrocytes. Inhibiting Akt and nuclear factor-κB (NF-κB) activity diminished IL-12 expression in fibrocytes, while TSH did not induce promoter activity. TSH-mediated IL-12 production required de novo synthesized proteins and augmented IL-12 mRNA stability. IL-12 production mediated by CD40L required tumor necrosis factor receptor-associated factor 6.

CONCLUSION

TSH and CD40L induce IL-12 expression in fibrocytes, and Akt and NF-κB mediate this activity. Given the importance of IL-12 in immune function, its production by fibrocytes may promote an inflammatory immune response and tissue remodeling in thyroid-associated ophthalmopathy.

Overexpression of Interleukin-4 in the Thyroid of Transgenic Mice Upregulates the Expression of Duox1 and the Anion Transporter Pendrin

BACKGROUND

The dual oxidases (Duox) are involved in hydrogen peroxide generation, which is essential for thyroid hormone synthesis, and therefore they are markers of thyroid function. During inflammation, cytokines upregulate DUOX gene expression in the airway and the intestine, suggesting a role for these proteins in innate immunity. It was previously demonstrated that interleukin-4 (IL-4) upregulates DUOX gene expression in thyrocytes. Although the role of IL-4 in autoimmune thyroid diseases has been studied extensively, the effects of IL-4 on thyroid physiology remain largely unknown. Therefore, a new animal model was generated to study the impact of IL-4 on thyroid function.

METHODS

Transgenic (Thyr-IL-4) mice with thyroid-targeted expression of murine IL-4 were generated. Transgene expression was verified at the mRNA and protein level in thyroid tissues and primary cultures. The phenotype of the Thyr-IL-4 animals was characterized by measuring serum thyroxine (T4) and thyrotropin levels and performing thyroid morphometric analysis, immunohistochemistry, whole transcriptome sequencing, quantitative reverse transcription polymerase chain reaction, and ex vivo thyroid function assays.

RESULTS

Thyrocytes from two Thyr-IL-4 mouse lines (#30 and #52) expressed IL-4, which was secreted into the extracellular space. Although 10-month-old transgenic animals had T4 and thyrotropin serum levels in the normal range, they had altered thyroid follicular structure with enlarged follicles composed of elongated thyrocytes containing numerous endocytic vesicles. These follicles were positive for T4 staining the colloid, indicating their capacity to produce thyroid hormones. RNA profiling of Thyr-IL-4 thyroid samples revealed modulation of multiple genes involved in inflammation, while no major leukocyte infiltration could be detected. Upregulated expression of Duox1, Duoxa1, and the pendrin anion exchanger gene (Slc26a4) was detected. In contrast, the iodide symporter gene Slc5a5 was markedly downregulated resulting in impaired iodide uptake and reduced thyroid hormone levels in transgenic thyroid tissue. Hydrogen peroxide production was increased in Thyr-IL-4 thyroid tissue compared with wild-type animals, but no significant oxidative stress could be detected.

CONCLUSIONS

This is the first study to show that ectopic expression of IL-4 in thyroid tissue upregulates Duox1/Duoxa1 and Slc26a4 expression in the thyroid. The present data demonstrate that IL-4 could affect thyroid morphology and function, mainly by downregulating Slc5a5 expression, while maintaining a normal euthyroid phenotype.

Modulation of T-Bet and GATA-3 expression in experimental autoimmune thyroiditis rats through ginsenoside treatment

Hashimoto's thyroiditis (HT) is one of the most common organ-specific autoimmune diseases. Increasing evidence indicates that HT may be characterized by an imbalance in the helper T cell subsets Th1 and Th2. Traditional Chinese Medicine (TCM) considers HT as a chronic exhaustion disease, leading to deficiency of qi. In TCM, qi indicates the functional power of the organs of the human body; hence TCM recommends focusing the treatment of HT so as to increase qi production. Ginseng is a well-known herbal medicine exhibiting a variety of efficacies, its main function-being to generate qi. Ginseng's principal active component is ginsenoside, and modern pharmacology has shown that ginsenoside demonstrates biphasic immunomodulatory effects that can be utilized for the treatment of immune disorders. Previous work demonstrated that ginsenoside has a therapeutic effect on HT, but its mechanism is unknown. Experimental autoimmune thyroiditis rats were produced in order to investigate whether ginsenoside can modulate Th1/Th2 imbalance, the direct objective being to examine modulation of IFN-γ and IL-4 by ELISA, and the gene and protein expression of T-bet and GATA-3 by real-time PCR and Western blot. IFN-γ levels were increased while IL-4 levels decreased in EAT rats; treatment with ginsenoside led to decreased peripheral blood IFN-γ levels, with low doses statistically significant. Ginsenoside produced a biphasic effect on IL-4, with low and moderate doses promoting and high doses inhibiting secretion. Both protein and mRNA levels of T-bet were markedly reduced, while GATA-3 was significantly increased by ginsenoside.

Increased IL-21/IL-21R expression and its proinflammatory effects in autoimmune thyroid disease

To determine the potential role of interleukin-21 (IL-21) / IL-21 receptor (IL-21R) in the pathogenesis of autoimmune thyroid disease (AITD) mainly known as Graves' disease (GD) and Hashimoto's thyroiditis (HT). IL-21 and IL-21R of peripheral blood samples and/or thyroid tissues from AITD patients and healthy controls were analyzed by ELISA, quantitative real-time polymerase chain reaction (qRT-PCR), flow cytometry and immunohistochemistry. In vitro, the mRNA and protein of inflammatory cytokines of cultured peripheral blood mononuclear cells (PBMCs) upon recombinant human IL-21 (rhIL-21) stimulation were detected. There was an increased serum concentration of IL-21 in untreated GD and HT patients, and IL-21(+)CD3(+)CD8(-)T cells were significantly increased in PBMCs of HT patients compared with healthy volunteers. The IL-21 mRNA expression in PBMCs increased dramatically in GD and HT patients, and marked augmentations of IL-21 and IL-21R mRNA in thyroid tissues of HT patients were observed. Immunohistochemical staining confirmed the expression of IL-21R protein in HT thyroid cells and lymphocytes. In vitro, PBMCs from GD cultured with rhIL-21 induced increased IL-17A but decreased IL-4 production, while from HT stimulated by rhIL-21 induced augmented production of IFN-γ. In conclusion, the expression of IL-21 and IL-21R were up-regulated in AITD and may be involved in the pathogenesis of the disease through augmenting aberrant immune cascade.

Thyroid hydrogen peroxide production is enhanced by the Th2 cytokines, IL-4 and IL-13, through increased expression of the dual oxidase 2 and its maturation factor DUOXA2

The dual oxidases (DUOX) 1 and 2 constitute the major components of the thyroid H(2)O(2)-generating system required for thyroid hormone synthesis. With their maturation factor, DUOXA1 or DUOXA2, they share the same bidirectional promoter allowing coexpression of DUOX/DUOXA in the same tissue. However, the molecular mechanisms regulating their transcription in the human thyroid gland are not well characterized yet. Inflammatory molecules associated with autoimmune thyroid diseases have been shown to repress the thyroid function by down-regulating the expression of the major thyroid differentiation markers. These findings led us to investigate the effects of the main cytokines involved in Hashimoto thyroiditis (IFN-γ) and Graves' diseases (IL-4/IL-13) on the transcriptional regulation of DUOX and their corresponding DUOXA genes in thyroid cells. Human thyrocytes exposed to the Th2 cytokines IL-4 and IL-13 showed up-regulation of DUOX2 and DUOXA2 genes but not DUOX1/DUOXA1. The DUOX2/DUOXA2 induction was rapid and associated with a significant increase of calcium-stimulated extracellular H(2)O(2) generation. IFN-γ treatment inhibited DUOX gene expression and repressed the Th2 cytokine-dependent DUOX2/DUOXA2 expression. In another DUOX-expressing model, the human intestinal Caco-2 cell line, expression of DUOX2 and DUOXA2 mRNA was also positively modulated by IL-4 and IL-13. Analysis of the IL-4 signaling pathway revealed that the JAK1-STAT6 cascade activated by the IL-4 type 2 receptor is required for DUOX2/DUOXA2 induction. The present data open new perspectives for a better understanding of the pathophysiology of thyroid autoimmune diseases considering DUOX2-mediated oxidative damages.

Increased frequency of follicular helper T cells in patients with autoimmune thyroid disease

CONTEXT

Follicular helper T (Tfh) cells exert an important role in the autoimmune diseases.

AIM

Our study aimed to explore the role of Tfh cells in patients with autoimmune thyroid disease (AITD).

DESIGN

Tfh cell is a new subset regulating the antibody production of B cell. Previous studies implicated CD4+CXCR5+ICOShigh or CD4+CXCR5+PD-1high as the markers of circulating Tfh cells. Sixty-five patients with AITD and 30 healthy controls were enrolled in the current study. The percentages of circulating Tfh cells were assessed by flow cytometry. The correlation between the percentages of CD4+CXCR5+ICOShigh T cells and the levels of autoantibodies or hormones was also analyzed. Additionally, polyphasic methods were applied to investigate the status of Tfh cells in thyroid glands of Hashimoto's thyroiditis patients.

RESULTS

Increased percentages of circulating Tfh cells in AITD patients were detected, and a positive correlation between the percentages of circulating Tfh cells and the serum concentrations of anti-TSH receptor-Ab/thyroperoxidase-Ab/thyroglobulin-Ab was confirmed. A positive or modest relationship between the percentages of circulating Tfh cells and serum free T3 or free T4 was revealed in Graves' disease patients. Additionally, follow-up analysis indicated that in some Graves' disease patients the percentage of circulating Tfh cells decreased after treatment. Furthermore, a certain number of CD4+CXCR5+ICOShigh T cells together with enhanced expression of IL-21 and Bcl-6 mRNA were detected in thyroid tissues from Hashimoto's thyroiditis patients.

CONCLUSION

The current study discovered an increased frequency of Tfh cells in AITD patients, which implies that this cell subset might play an important role in the pathogenesis of AITD.

Identification of functionally distinct TRAF proinflammatory and phosphatidylinositol 3-kinase/mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (PI3K/MEK) transforming activities emanating from RET/PTC fusion oncoprotein

Thyroid carcinomas that harbor RET/PTC oncogenes are well differentiated, relatively benign neoplasms compared with those expressing oncogenic RAS or BRAF mutations despite signaling through shared transforming pathways. A distinction, however, is that RET/PTCs induce immunostimulatory programs, suggesting that, in the case of this tumor type, the additional pro-inflammatory pathway reduces aggressiveness. Here, we demonstrate that pro-inflammatory programs are selectively activated by TRAF2 and TRAF6 association with RET/PTC oncoproteins. Eliminating this mechanism reduces pro-inflammatory cytokine production without decreasing transformation efficiency. Conversely, ablating MEK/ERK or PI3K/AKT signaling eliminates transformation but not pro-inflammatory cytokine secretion. Functional uncoupling of the two pathways demonstrates that intrinsic pro-inflammatory pathways are not required for cellular transformation and suggests a need for further investigation into the role inflammation plays in thyroid tumor progression.

Thyrocyte interleukin-18 expression is up-regulated by interferon-γ and may contribute to thyroid destruction in Hashimoto's thyroiditis

Interferon-γ (IFN-γ) has a direct role in thyroid destruction in autoimmune thyroiditis. Interleukin-18 (IL-18), a pro-inflammatory cytokine with potent IFN-γ inducing activities, may play an important role in Th1-mediated autoimmune diseases. The purpose of this study was to characterize the expression and localization of IL-18 in the thyroid tissues of Hashimoto's thyroiditis (HT) and to investigate the effect of IFN-γ on IL-18 expression in isolated human thyroid follicular cells (TFCs). Thyroid tissues obtained from six euthyroid patients with HT and six control subjects were used to detect IL-18 expression by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical staining. Human TFCs were isolated and incubated for 48 h with or without IFN-γ, tumour necrosis factor-α (TNF-α) or IL-1β. IL-18 expression was analysed by RT-PCR, immunofluorescent double staining and western blot. We found that IL-18 expression was increased in the thyroid tissues of HT compared with control thyroid tissues. TFCs were major cell types expressing IL-18 in the thyroid tissues of HT. IL-18 was constitutively expressed in isolated human TFCs, and the expression was significantly up-regulated by IFN-γ rather than TNF-α or IL-1β. Western bolt revealed that a 24-kDa band corresponding to pro-IL-18 was broadened in the lysates of IFN-γ-treated TFCs. Our results demonstrated that IL-18 expression is up-regulated in the TFCs of HT patients and in primary human TFCs exposed to IFN-γ. Therefore, intrathyroidal interaction between IL-18 and IFN-γ may have a role in promoting the local immune response, which contributes to the thyroid destruction seen in HT.

Thyroid autoimmunity and its association with cellular and humoral immunity in women with reproductive failures

PROBLEM

thyroid autoimmunity (TAI), which is T helper (Th)1-cell-mediated autoimmunity to thyrocytes, is associated with increased risk of miscarriages and highly prevalent in women with infertility. We aim at investigating the prevalence of TAI in women with recurrent spontaneous abortions (RSA) or unexplained infertility (UI) and its relationship with cellular and humoral immune abnormalities.

METHOD OF STUDY

prevalence of antiphospholipid antibodies, anti-nuclear antibody, other non-organ-specific antibodies (NOSAs; anti-dsDNA, anti-ssDNA, anti-histone, anti-Scl70), peripheral blood natural killer (NK) cell levels (%) and cytotoxicity, and CD3(+) /CD4(+) Th1/Th2 cell ratios were compared in women with and without TAI. Thyroid functional tests (TFT) were analyzed in both groups before and after pregnancy.

RESULTS

tumor necrosis factor-α/IL-10 expressing CD3(+) /CD4(+) cell ratios (P < 0.05), CD56(+) NK cell levels (P < 0.05), the prevalence of anticardiolipin antibodies (P < 0.05) and other NOSAs (P < 0.005) were significantly higher in women with TAI when compared to women without TAI. Changes in thyroid-stimulating hormone levels between before and after pregnancy in women with TAI were significantly higher when compared to those of women without TAI (P < 0.05).

CONCLUSION

TAI is associated with impaired cellular and humoral immune responses in women with RSA or UI. In women with TAI, serial TFT is recommended when pregnancy is established.

Possible association of CEA expression with oxyphilic change but not with C-cell hyperplasia in Hashimoto's thyroiditis

Reactive C-cell hyperplasia (CCH) has been observed in cases of autoimmune Hashimoto's thyroiditis; however, its occurrence in Graves' disease, the other major autoimmune disorder, has not yet been investigated. On the other hand, although Carcinoembryonic Antigen (CEA) serum levels have been reported elevated in patients with autoimmune thyroid disease (ATD), the source of CEA production at the cellular level is not elucidated. The aim of this study was to evaluate CCH and CEA immunohistochemical expression and comparatively analyze them in 136 ATD cases (107 Hashimoto's and 29 Graves' disease cases) and 20 cases of nodular hyperplasia (NH). Immunohistochemistry using monoclonal antibodies to chromogranin and CEA was performed. A scoring system for CCH and semiquantitative evaluation for CEA expression were applied. C-cell hyperplasia was absent in NH cases. In contrast, it was detected in 11% of ATD cases being more frequently observed in Hashimoto's (12.1%) than Graves' disease (6.8%) CCH associated to male sex and older age of Hashimoto's patients. CEA was detected only in ATD cases (33.8%), in C-cells and in follicular cells as well, being more frequently detected in Graves' (44.8%) than Hashimoto's (30.8%) disease. An interesting finding was an emerging possible association of CEA expression with oxyphilic change but not with C-cell hyperplasia in Hashimoto's thyroiditis. No significant correlation was established between CCH and CEA follicular cell expression in neither disease. In conclusion, C-cell hyperplasia and CEA expression may be encountered in the setting of Hashimoto's thyroiditis and Graves' disease.

Chronic inflammatory disease, lymphoid tissue neogenesis and extranodal marginal zone B-cell lymphomas

Chronic autoimmune or pathogen-induced immune reactions resulting in lymphoid neogenesis are associated with development of malignant lymphomas, mostly extranodal marginal zone B-cell lymphomas (MZBCLs). In this review we address (i) chemokines and adhesion molecules involved in lymphoid neogenesis; (ii) the autoimmune diseases and pathogens which are associated with development of B-cell lymphomas; (iii) the molecular mechanisms involved in the initiation and progression of MZBCL; and (iv) 'potential' mouse models for MZBCL.

Cytokines in Thyroid Autoimmunity

The role of cytokines in the pathogenesis of autoimmune thyroid disease (ATD) has been extensively investigated over the past years. In patients with ATD, these molecules can be found in both the thyroid and sites of extrathyroidal complications of the disease. Cytokines can affect the autoimmune process through a number of mechanisms including recruitment of inflammatory cells and upregulation of molecules essential for perpetuation of the inflammatory response in the affected site. In addition, cytokines can interfere with thyroid hormone synthesis, implicating them directly in thyroid dysfunction found in ATD patients. Also, these molecules can modulate the function of cells in orbital tissue, which results in localised oedema, indicating a central role for cytokines in the development of proptosis, the cardinal feature of thyroid associated ophthalmopathy.

The balance shift in Th1/Th2 related IL-12/IL-5 cytokines in Graves' disease during methimazole therapy

Th1 and Th2-like cytokines are involved in the pathogenesis of Graves' disease. The shift in balance in IL-12/IL-5 cytokines was applied in judging the immunological events in 74 patients with Graves' disease (50 had ophthalmopathy) during methimazole therapy and in 15 controls. The serum levels of IL-12 and IL-5 were measured with enzyme-linked immunosorbent assay in all Graves' patients. Twelve cases for IL-5 and 20 cases for IL-12 were positive. In Graves' patients only those without ophthalmopathy had higher levels of IL-12 when compared to controls (192.66 +/- 29.19 vs. 85.09 +/- 8.95 pg/ml, P < 0.04). After 2 months of methimazole therapy in Graves' patients without ophthalmopathy an increase in the ratio of IL-12 to IL-5 was also observed as compared to those with eye symptoms (91.78 +/- 34.14 vs. 20.72 +/- 6.36, P < 0.015). Age-related difference in the serum level of IL-5 could be demonstrated between Graves' patients without and those with ophthalmopathy aged < or = 35 years (4.89 +/- 0.57 vs. 50.14 +/- 20.2 pg/ml, P < 0.002). No association was found among the serum levels of IL-5 or IL-12, thyroid hormones and TSH receptor antibodies. The results demonstrated a difference in the balance shift of IL-12/IL-5 between Graves' patients with and without ophthalmopathy. The increased ratio of IL-12 to IL-5 after methimazole therapy could be explained by the elevation of serum IL-12 due to methimazole therapy and the age-related decrease of serum IL-5.

No immunological benefit of selenium in consecutive patients with autoimmune thyroiditis

BACKGROUND

Recently it has been demonstrated that after selenium (Se) supplementation in autoimmune thyroiditis (AIT) patients, there was a significant decrease of thyroid peroxidase (TPO) autoantibody (TPOAb) levels. The aim of our study was to evaluate the immunological benefit of Se administration in unselected AIT patients and thus address the question whether Se administration should generally be recommended for AIT patients.

METHODS

Thirty-six consecutive AIT patients (aged 19-85 years) were included in the present study. In addition to their levothyroxine (LT(4)) treatment, 18 patients received 200 microg (2.53 micromol) sodium selenite per day orally for the time span of 3 months, whereas 18 patients received placebo. All patients had measurement of thyroid hormones, thyrotropin (TSH), autoantibodies (thyroglobulin antibodies [TgAb] and TPOAb), Se levels, and intracellular cytokine detection in CD4(+) and CD8(+) T cells of peripheral blood mononuclear cells (PBMC) by flow cytometry before and after Se or placebo administration.

RESULTS

No significant difference in the TPOAb levels was found after Se administration (524 +/- 452 vs. 505 +/- 464 IU/mL; p > 0.05). Furthermore, we found no significant differences in the CD4(+) or CD8(+) cytokine pattern (IFN-gamma, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, TNF-alpha, TNF-beta) in patients before and after Se administration, in patients before and after placebo administration and between Se group and placebo group before and after Se vs. placebo administration.

CONCLUSION

We demonstrate that Se administration in our AIT patient's cohort does not induce significant immunological changes, either in terms of cytokine production patterns of peripheral T lymphocytes or of TPOAb levels. Our data suggest that AIT patients with moderate disease activity (in terms of TPOAb and cytokine production patterns) may not (equally) benefit as patients with high disease activity.

The role of stress in the clinical expression of thyroid autoimmunity

During stress, activation of the hypothalamic-pituitary-adrenal axis and the sympathoadrenal system leads to increased secretion of glucocorticoids and catecholamines, respectively, in order to maintain homeostasis. Recent evidence suggests that stress hormones, acting on antigen-presenting immune cells, may influence the differentiation of bipotential T helper (Th) cells away from Th1 and toward a Th2 phenotype. This results in suppression of cellular immunity and potentiation of humoral immunity. Thyroid autoimmunity is clinically expressed as Hashimoto's thyroiditis (HT) and its variants (sporadic or postpartum thyroiditis) or as Grave's disease (GD). The different phenotypic expression of thyroid autoimmunity is largely dependent on the balance of Th1 versus Th2 immune response. A predominantly Th1-mediated immune activity may promote apoptotic pathways on thyroid follicular cells leading to thyroid cell destruction and HT. Conversely, predominance of Th2-mediated immune response may induce antigen-specific B lymphocytes to produce anti-TSH receptor (TSHr) antibodies causing GD. The weight of evidence from epidemiological and case-control studies supports an association between stress and GD. On the other hand, there is little information available on the effect of stress on HT, but there is evidence for an increase in postpartum thyroiditis, following the cellular immune suppressive effect of pregnancy. Whether stress has a causative effect on GD remains elusive. Circumstantial evidence supports the hypothesis that stress may influence the clinical expression of thyroid autoimmunity in susceptible individuals favoring the development of GD by shifting the Th1-Th2 balance away for Th1 and toward Th2. Conversely, recovery from stress or the immune suppressive effect of pregnancy may induce a Th2 to Th1 "return shift" leading to autoimmune (sporadic) or postpartum thyroiditis, respectively.

Kidney function and markers of inflammation in elderly persons without chronic kidney disease: the health, aging, and body composition study

Inflammatory markers are elevated in persons with estimated glomerular filtration rates less than 60 ml/min/1.73 m2. As cystatin C may detect small changes in kidney function not detected by estimated glomerular filtration rate, we evaluated the association between cystatin C and serum markers of inflammation in older adults with estimated glomerular filtration rate >or=60. This is an analysis using measures from the Health, Aging, and Body Composition Study, a cohort of well-functioning adults aged 70-79 years. Cystatin C correlated with all five inflammatory biomarkers: C-reactive protein (r=0.08), interleukin-6 (r=0.19), tumor necrosis factor alpha (TNF-alpha) (r=0.41), soluble TNF receptor 1 (STNF-R1) (r=0.61), and soluble TNF receptor 2 (STNF-R2) (r=0.54); P<0.0005 for all. In adjusted analyses, cystatin C concentrations appeared to have stronger associations with each biomarker compared with estimated glomerular filtration rate or serum creatinine. Participants with a cystatin C>or=1.0 mg/l had significantly higher levels of all five biomarkers compared to those with a cystatin C<1.0 (mean differences ranging 16-29%, all P<0.05). Cystatin C has a linear association with inflammatory biomarkers in an ambulatory elderly cohort with estimated glomerular filtration rates >or=60; associations are particularly strong with TNF-alpha and the STNF-R.

A differential association of interferon-gamma high-producing allele T and low-producing allele A (+874 A/T) with Hashimoto's thyroiditis and Graves' disease

Cytokines play a crucial role in the pathogenesis of autoimmune thyroid disease. The aim of this study was to investigate the relationship of the single base change polymorphic variants identified in the first intron of interferon-gamma (IFN-gamma) (+874 T/A) with susceptibility to thyroid dysfunctions. A total of 340 subjects were included in the study comprising of 190 patients (104 patients with Hashimoto's thyroiditis, 26 with non-Hashimoto's hypothyroidism and 60 Graves' disease) and 150 controls. Genotyping was done by amplification refractory mutation system-polymerase chain reaction using a set of sequence-specific primers. Statistical analysis revealed a significant association between high IFN-gamma-producing genotype TT and Hashimoto's thyroiditis compared to controls (P value < 0.001). On the other hand, the frequency of genotype TT was decreased in patients with Graves' hyperthyroidism with a significant increase in low IFN-gamma-producing genotype AA among this group (P = 0.03). To conclude the results of the study suggest a differential association of high- and low-producing alleles of IFN-gamma gene with Hashimoto's thyroiditis and Graves' disease. The high IFN-gamma-producing allele T was observed to be associated with Hashimoto's thyroiditis in the present study where as in Graves' hyperthyroidism the association was observed to be stronger with the low producing allele A.

Regulatory T cells in human autoimmune thyroid disease

CONTEXT

T regulatory cells have a key role in the pathogenesis of autoimmune diseases in different animal models. However, less information is available regarding these cells in human autoimmune thyroid diseases (AITD).

OBJECTIVE

The objective of the study was to analyze different regulatory T cell subsets in patients with AITD.

DESIGN

We studied by flow cytometry and immunohistochemistry different T regulatory cell subsets in peripheral blood mononuclear cells (PBMCs) and thyroid cell infiltrates from 20 patients with AITD. In addition, the function of T(REG) lymphocytes was assessed by cell proliferation assays. Finally, TGF-beta mRNA in thyroid tissue and its in vitro synthesis by thyroid mononuclear cells (TMCs) was determined by RNase protection assay and quantitative PCR.

RESULTS

PBMCs from AITD patients showed an increased percent of CD4+ lymphocytes expressing glucocorticoid-induced TNF receptor (GITR), Foxp3, IL-10, TGF-beta, and CD69 as well as CD69+CD25(bright), CD69+TGF-beta, and CD69+IL-10+ cells, compared with controls. TMCs from these patients showed an increased proportion of CD4+GITR+, CD4+CD69+, and CD69+ cells expressing CD25(bright), GITR, and Foxp3, compared with autologous PBMCs. Furthermore, a prominent infiltration of thyroid tissue by CD69+, CD25+, and GITR+ cells, with moderate levels of Foxp3+ lymphocytes, was observed. The suppressive function of peripheral blood T(REG) cells was defective in AITD patients. Finally, increased levels of TGF-beta mRNA were found in thyroid tissue, and thyroid cell infiltrates synthesized in vitro significant levels of TGF-beta upon stimulation through CD69.

CONCLUSIONS

Although T regulatory cells are abundant in inflamed thyroid tissue, they are apparently unable, in most cases, to downmodulate the autoimmune response and the tissue damage seen in AITD.

Clinical utility of 2',5'-oligoadenylate synthetase activity measurement: using whole blood as a highly sensitive method to detect the effects of IFN

Research progress on the pleiotropic effects of interferons (IFN) has thus far required detecting responses by weak IFN signals. The activity of 2',5'-oligoadenylate synthetase (2-5OAS) is a valuable indicator in the prognosis and IFN treatment of patients with viral diseases such as hepatitis B and C. Although serum samples generally are used to measure enzyme activity, their values depend on the exact conditions under which blood is stored and the degree of haemolysis that occurs during blood drawing or serum separation. This study presents an improved method of evaluating 2-5OAS activity by using whole blood samples containing heparin, which are frozen and then thawed, instead of serum samples. This method is more reliable, convenient, and 50-100 times more sensitive than the conventional methods of measuring serum 2-5OAS activity. The reliability and sensitivity of this improved method enables detection of the effects of low doses of oral IFN administration or changes in the IFN and cytokine system by infection or autoimmune diseases.

Thyroid cancer and the immune system: a model for effective immune surveillance

Differentiated thyroid cancers, including papillary and follicular variants, are a useful model with which to examine interactions between cancer and the immune system. Differentiated thyroid cancers are detected in only 20,000 individuals annually in the USA, but thyroid microcarcinomas (< 1 cm in diameter) are far more common. This suggests that the immune system might restrain the growth of these microcarcinomas. On the clinical level, patients with lymphocytes that infiltrate into papillary thyroid cancer have improved survival, supporting the notion that immune system activation might improve this. Together, these observations suggest that the growth and distant spread of thyroid carcinoma are suppressed by mechanisms of immune surveillance, possibly involving lymphocytes, macrophages and their secreted products. In this review, we examine the general hypothesis of immune surveillance and the data pertaining to the roles of lymphocytes, dendritic cells and cytokines in the immune response against thyroid cancers.

Differential requirement of signal transducer and activator of transcription-4 (Stat4) and Stat6 in a thyrotropin receptor-289-adenovirus-induced model of Graves' hyperthyroidism

T helper type 1 (Th1) and Th2 cells have critical roles in the development of cell-mediated and humoral immune responses, respectively. This division of function predicts that Th1 cells mediate inflammatory diseases and Th2 cells promote antibody (Ab)-mediated autoimmunity. Our previous studies using HEK-293 cells expressing the extracellular domain of the TSH receptor (TSHR) showed that Stat4-/- mice, which lack Th1 cells, are susceptible, whereas Stat6-/- mice, which lack Th2 cells, are resistant to the induction of Graves' hyperthyroidism. To investigate the role of Stat4 and Stat6 genes in other murine models of hyperthyroidism, we injected wild-type BALB/c, Stat4-/-, and Stat6-/- mice with an adenovirus expressing amino acid residues 1-289 of TSHR (TSHR-289-ad or 289-ad). The viral system induces a much stronger immune response with much more rapid onset of disease. Our results showed that 56% of wild-type, 75% of Stat4-/-, and 39% of Stat6-/- mice developed hyperthyroidism. Hyperthyroid mice exhibited thyroid stimulatory Abs. The Stat4-/- mice developed a higher incidence and greater severity of hyperthyroidism compared with wild-type and Stat6-/- mice. BALB/c and Stat4-/- mice showed significantly higher TSHR Abs of the IgG1 subclass and IL-4 compared with Stat6-/- mice. In contrast, Stat6-/- mice had predominantly the IgG2a subclass of TSHR Ab and produced significantly higher amounts of IFN-gamma than BALB/c and Stat4-/- mice. All hyperthyroid mice showed enlarged thyroid glands with hyperactivity. These results suggest that in the TSHR-289-ad model, the Th2 cells are more efficient in mediating disease, but in the absence of Th2 cells, Th1 cells may still initiate a reduced incidence of Graves' hyperthyroidism.

Graves' disease and Hashimoto's thyroiditis in monozygotic twins: case study as well as transcriptomic and immunohistological analysis of thyroid tissues

OBJECTIVE

To report on the rare simultaneous occurrence of Graves' disease (GD) and Hashimoto's thyroiditis (HT) in monozygotic twins.

DESIGN

We compared the pattern of thyroid tissue-derived cDNAs to gain insight into previous and ongoing immune destruction and reconstruction processes using microarrays. The results were confirmed by immunohistology and real-time PCR.

RESULTS

Destruction of thyroid tissue in HT reduced levels of thyrocyte-related cDNAs and cDNAs encoding extracellular matrix components, but increased levels of proteases involved in extracellular matrix degradation compared with GD. Lymphocytic infiltrates forming ectopic follicles replaced the thyroid tissue almost completely in HT. Thus, lymphocyte-related cDNA levels were higher in HT than in GD. The same was true for many chemokines and their receptors, which not only enable migration towards the thyroid but also maintain the lymphocytic infiltrate. HT also showed increased levels of cDNAs encoding molecules related to apoptosis than did GD. Surprisingly, the Th1- and Th2-specific cytokine profiles suggested for HT and GD respectively could not be confirmed. cDNAs encoding factors and receptors involved in angiogenesis were increased in GD compared with HT.

CONCLUSIONS

Comparison of gene expression reflects the cellular differences between the two types of autoimmune thyroid disease in twins with identical genetic and similar environmental background.

Insight into Graves' hyperthyroidism from animal models

Graves' hyperthyroidism can be induced in mice or hamsters by novel approaches, namely injecting cells expressing the TSH receptor (TSHR) or vaccination with TSHR-DNA in plasmid or adenoviral vectors. These models provide unique insight into several aspects of Graves' disease: 1) manipulating immunity toward Th1 or Th2 cytokines enhances or suppresses hyperthyroidism in different models, perhaps reflecting human disease heterogeneity; 2) the role of TSHR cleavage and A subunit shedding in immunity leading to thyroid-stimulating antibodies (TSAbs); and 3) epitope spreading away from TSAbs and toward TSH-blocking antibodies in association with increased TSHR antibody titers (as in rare hypothyroid patients). Major developments from the models include the isolation of high-affinity monoclonal TSAbs and analysis of antigen presentation, T cells, and immune tolerance to the TSHR. Studies of inbred mouse strains emphasize the contribution of non-MHC vs. MHC genes, as in humans, supporting the relevance of the models to human disease. Moreover, other findings suggest that the development of Graves' disease is affected by environmental factors, including infectious pathogens, regardless of modifications in the Th1/Th2 balance. Finally, developing immunospecific forms of therapy for Graves' disease will require painstaking dissection of immune recognition and responses to the TSHR.

Relation of anti-TPO autoantibody titre and T-lymphocyte cytokine production patterns in Hashimoto's thyroiditis

OBJECTIVE

Cytokines produced by cytotoxic T cells or autoantibodies lead to thyroid cell damage and/or cell death in Hashimoto's thyroiditis (HT). Anti-TPO autoantibodies (TPOAb) are the most frequently represented autoantibodies in the sera of patients with HT. Data describing the quantitative correlation between TPOAb titre and cytokine pattern are missing so far. To our knowledge this is the first study systematically evaluating the correlation of possible parameters of disease activity such as changes in CD4 and CD8 T-cell cytokine production and of TPOAb titre.

METHODS

Twenty-four consecutive patients (aged 29-58) with verified HT under levothyroxine therapy were included in the present study. The patients were divided into two groups. Group I: 12 HT patients with a high TPOAb titre (> 1000 U/ml), group II: 12 HT patients with a low TPOAb titre (< 100 U/ml). All patients underwent intracellular cytokine detection in CD4 and CD8 T cells of peripheral blood mononuclear cells (PBMC) by flow cytometry. Twelve healthy volunteers matched in sex and age consisted the control group (group III).

RESULTS

T cells from patients with a high TPOAb titre (group I) had significantly higher percentages of cells producing IFN-gamma compared to healthy donors (group III). A detailed analysis of cytokine production patterns revealed that this was accompanied by an increased frequency of single IFN-gamma positive cells, i.e. cells not expressing other cytokines tested, such as IL-2, IL-4, IL-5, IL-6, IL-10, IL-13 or TNF-beta. Similarly, patients in group I also showed higher percentages of TNF-alpha positive cells than healthy donors (group III). In this case, cells expressing TNF-alpha alone as well as cells coexpressing TNF-alpha and IFN-gamma were found at significantly higher frequencies. On the other hand, cytokine production patterns of patients with a low TPOAb titre (group II) showed significant difference neither to patients of group I nor to healthy donors (group III).

CONCLUSION

Taken together, we were able for the first time to demonstrate that high TPOAb titre correlates with increased frequencies of T cells producing Th/Tc1 cytokines, probably responsible for thyroid cell damage and/or death in Hashimoto's thyroiditis.

In vivo and in vitro effects of statins on lymphocytes in patients with Hashimoto's thyroiditis

BACKGROUND

Statins have apoptotic effects on many cell types. Hashimoto's thyroiditis (HT) is an autoimmune disease in which cell-mediated autoimmune mechanisms are pathogenetically involved.

OBJECTIVE

The aim of this study was to evaluate the in vivo effects of Simvastatin on thyroid function, lymphocyte subtypes and also to investigate the apoptotic effects of Simvastatin, Mevastatin, Pravastatin and Cerivastatin on lymphocytes from patients with HT.

METHODS

In the first part of the study, 11 patients with HT and subclinical hypothyroidism (SH) were given Simvastatin (20 mg/day) for 8 weeks. Ten patients with SH and HT served as the control group. No treatment was given to controls. Thyroid function, C-reactive protein (CRP) levels and lymphocyte subtypes of both groups were determined before the study and after 8 weeks. In the second part of the study, the apoptotic effects of statins on lymphocytes were evaluated in patients with HT (n = 10) and normal subjects (n = 10) in vitro. Apoptosis was investigated by using Annexin-V and propidium iodide. Lymphocytes from patients and controls were incubated with different concentrations of Simvastatin, Cerivastatin, Mevastatin and Pravastatin.

RESULTS

An increase in serum free tri-iodothyronine and free thyroxine levels and a decrease in TSH levels were observed (P < 0.05) with Simvastatin treatment. CD4+ cells and B lymphocytes increased whilst CD8+ cells, natural killer cells and activated T lymphocytes decreased significantly in the treatment group (P < 0.05). The CRP level of the group also decreased with Simvastatin but it did not reach significance (P = 0.057). None of parameters was found to be different from the baseline in the control group. In in vitro experiments, apoptosis was observed in CD3 + (both in CD8+ and CD4+ cells) with all statins in both patient and control samples. Mevalonate, which was used in experiments, reversed apoptosis in some but not all samples.

CONCLUSIONS

The results of this study suggested that Simvastatin is an immune modulatory agent and improves thyroid function in patients with HT. This effect is probably mediated via lymphocyte apoptosis as demonstrated with in vitro experiments and is not confined to Simvastatin since Mevastatin, Pravastatin and Cerivastatin also induced apoptosis in lymphocytes.

Coexpression of preprotachykinin A and B transcripts in the bovine corpus luteum and evidence for functional neurokinin receptor activity in luteal endothelial cells and ovarian macrophages

Nonneuronal cell sources of tachykinins, such as substance P (SP) and neurokinin B (NKB), have been demonstrated in leukocytes, endothelial cells and endocrine cells, and may play a role in corpus luteum (CL) development. For this reason, we analyzed mRNA presence for the two tachykinin precursors together with the neurokinin-1 receptor and the neurokinin-3 receptor (NK-1R and NK-3R, preferred by SP and NKB, respectively) in bovine CL at various stages in the luteal phase. Using the RT-PCR technique, we detected coexpression for the preprotachykinin A gene (PPT-A), which encodes SP and neurokinin A (NKA), and the preprotachykinin B gene (PPT-B) for NKB in the CL at the development, secretion and regression stages. Coexpression was also noted for NK-1R and NK-3R gene transcripts. Cultures of endothelial cells (ECs) derived from bovine CL expressed NK-1R and NK-3R mRNA, as did ovarian macrophages. Agonist treatment induced a stronger intracellular calcium ([Ca2+]i) increase after activation of NK-1R compared to NK-3R, a result that we verified by calcium imaging. This is the first evidence for functional tachykinin receptor activity in luteal ECs and ovarian macrophages from bovine CL.

Defect of a subpopulation of natural killer immune cells in Graves' disease and Hashimoto's thyroiditis: normalizing effect of dehydroepiandrosterone sulfate

BACKGROUND

The study of the natural killer (NK) immune compartment could provide important findings to help in the understanding of some of the pathogenetic mechanisms related to autoimmune thyroid diseases (Graves' disease (GD) and Hashimoto's thyroiditis (HT)). Within this context, it was suggested that alterations in NK cell cytotoxicity (NKCC) and NK production of cytokines might occur in subjects with GD and HT, whereas the normalization of NK functions could potentially contribute to the prevention of the onset or the progression of both diseases.

OBJECTIVE

Due to the hypothesis of alterations in NK in autoimmune thyroid diseases, we were interested to evaluate NKCC in GD and HT patients and to modulate NK function and secretory activity with cytokines and dehydroepiandrosterone sulfate (DHEAS) in an attempt to normalize NK cell defect.

DESIGN

We studied 13 patients with recent onset Graves' disease, 11 patients with Hashimoto's thyroiditis at first diagnosis and 15 age-matched healthy subjects.

METHODS

NK cells were concentrated at a density of 7.75x10(6) cells/ml by negative immunomagnetic cell separation and validated by FACScan as CD16+/CD56+cells. NK cells were incubated with interleukin-2 (IL-2) and interferon-beta (IFN-beta) and co-incubated with DHEAS at different molar concentrations for measuring NKCC and the secretory pattern of tumor necrosis factor-alpha (TNF-alpha) from NK cells.

RESULTS

Lower spontaneous, IL-2- and IFN-beta-modulated NKCC was demonstrated in GD and HT patients compared with healthy subjects (P<0.001). A decrease in spontaneous and IL-2-modulated TNF-alpha release from NK cells was also found in both groups of patients (P<0.001). The co-incubation of NK cells with IL-2/IFN-beta+DHEAS at different molar concentrations (from 10(-8) to 10(-5) M/ml/NK cells) promptly normalized NKCC and TNF-alpha secretion in GD and HT patients.

CONCLUSIONS

A functional defect of a subpopulation of NK immune cells, involving both NKCC and the secretory activity, was demonstrated in newly-diagnosed GD and HT patients. This defect can be reversed by a dose-dependent treatment with DHEAS. The impairment of NK cell activity in autoimmune thyroid diseases could potentially determine a critical expansion of T/B-cell immune compartments leading to the generation of autoantibodies and to the pathogenesis of thyroid autoimmunity.

Graves' disease after interleukin-2 therapy in a patient with human immunodeficiency virus infection

Interleukin-2 (IL-2) is a cytokine that regulates the proliferation and differentiation of lymphocytes, and is currently used clinically in the treatment of assorted malignancies. Additionally, IL-2 is being actively investigated in clinical trials for treatment of human immunodeficiency virus (HIV) infection. Patients treated with IL-2 are susceptible to autoimmune thyroid disease (AITD), presenting as thyroiditis, which leads to either thyrotoxicosis or hypothyroidism, if not correctly and promptly identified and treated. IL-2-induced hypothyroidism can also sometimes follow a thyrotoxic phase. However, the development of Graves' disease (GD) in this clinical setting has not been reported to date. Here, we report the case of a 39-year-old HIV-infected man in whom GD developed after IL-2 therapy. We correlated the immunologic parameters pertinent to the patient's HIV infection status with clinical, hormonal, and serologic evidence of GD during its emergence. This revealed an association between peripheral blood cell numbers of specific lymphocyte subpopulations (CD4(+), CD3(+)CD25(+), and naïve T-cells) and serum levels of markers for AITD (free thyroxine [T(4)] and thyroid-stimulating immunoglobulin). Interestingly, no association was found between natural killer (NK) cell numbers and AITD markers. The immunopathogenesis of GD in this patient may be similar to that hypothesized for the GD that occurs in immune-reconstituted patients after combination antiretroviral therapy. From a practical standpoint, we propose that patients who have received or are receiving treatment with IL-2 who show signs of hyperthyroidism need to be carefully evaluated for GD.

Cellular immune responses in autoimmune thyroid disease

Recent research in autoimmune thyroid disease (AITD) has largely focused on delineation of the autoantigens and their epitopes, but there is now renewed interest in the immunoregulatory properties of T cells, an understanding of which may explain the emergence of AITD in experimental settings. T cell recognition of autoantigens has shown considerable intra- and interindividual heterogeneity, and a mixed pattern of cytokine production indicates that both the Th1 and Th2 limbs of the helper T cell response are involved in all types of AITD. It is now clear that secretion of chemokines and cytokines within the thyroid accounts for the accumulation and expansion of the intrathyroidal lymphocyte pool, and that the thyroid cells themselves contribute to this secretion. The thyroid cells also produce a number of proinflammatory molecules which will tend to exacerbate the autoimmune process. Thyroid cell destruction in autoimmune hypothyroidism is dependent on T cell-mediated cytotoxicity with the likely additional effect of death receptor-mediated apoptosis.

T-lymphocyte cytokine production patterns in nonimmune severe hypothyroid state and after thyroid hormone replacement therapy

The influence of thyroid hormones on the immune system is controversial. We analyzed the cytokine expression pattern of T lymphocytes in patients with severe nonimmune hypothyroidism in order to establish the role of thyroid hormones on the immune system. The study comprised 7 patients (1 male and 6 females) 20 to 76 years of age (mean age, 53 years), without signs of chronic thyroiditis, verified by histology and laboratory data. The patients were studied 5 weeks after total thyroidectomy. Peripheral blood mononuclear cell (PBMC) cultures and intracellular cytokine detection by flow cytometry before and after thyroid hormone replacement therapy were performed (free thyroxine [FT4] 0.030 +/- 0.034 ng/dL, versus FT4: 2.16 +/- 0.68 ng/dL). The control group consisted of 7 healthy subjects (FT4: 1.20 +/- 0.21 ng/dL). We found no significant differences in the cytokine pattern (interferon [IFN]-gamma, IL-2, interleukin [IL]-4, IL-5, IL-6, IL-10, IL-13, tumor necrosis factor [TNF]-alpha, TNF-beta) of CD4+ and CD8+ between the matched groups (hypothyroid subjects versus controls, levothyroxine treated subjects versus controls). Our data show no change in the type 1/type 2 balance of peripheral CD4+ and CD8+ T lymphocytes from patients with nonimmune hypothyroidism. According to our results, the hypothyreotic state does not contribute to the reported changes in cytokine production patterns in Hashimoto's thyroiditis.

Methimazole upregulates T-cell-derived cytokines without improving the existing Th1/Th2 imbalance in Graves' disease

There is probably a systemic shift of cytokine production in patients with Graves' disease (GD) toward the Th2 cytokine response. Methimazole (MMI) is the first choice for patients with GD and presumably has some direct immunomodulatory action. The aim of this study was to evaluate the balance shift in Th1/Th2 cytokines in patients with GD after 1 yr of MMI treatment, when compared to the same balance in patients with newly diagnosed GD before treatment and in healthy controls. Peripheral blood mononuclear cells (PBMC) were isolated from 17 healthy volunteers, from 18 patients with newly diagnosed GD before treatment and from 15 euthyroid patients with GD after 1 yr of MMI treatment. The PBMC were activated with ionomycin and phorbol 12-myristate 13-acetate (PMA). The concentrations of Th1/Th2 related cytokines [interferon (IFN)-gamma, interleukin (IL)-12 vs IL-4, IL-10] in the culture supernatants were measured by ELISA. PBMC from patients with GD after treatment produced significantly more IFN-gamma and IL-4 than PBMC from patients with GD before treatment, but there were no significant differences in calculated ratios of Th1 against Th2 cytokines between these two groups. When compared to PBMC from healthy controls, PBMC from patients with GD after treatment produced significantly more IL-4 and significantly less IL-12. The calculated IL-12/IL-4 ratio after treatment was significantly lower than the same ratio from healthy controls. In conclusion, our results show no significant change in the ratio between Th1 and Th2 cytokines produced by PBMC from patients with GD after 1 yr of MMI treatment, when compared to the ratio before treatment. The ongoing prevalence of the Th2 immune response after treatment speaks against the immunomodulatory action of the drug on the systemic level.

Association study of autoimmune thyroid disease at 5q23-q33 in Japanese patients

As part of a genome scan to locate familial Graves' disease (GD) and Hashimoto's thyroiditis (HT) genes, an autoimmune thyroid disease (AITD) susceptibility locus has recently been identified at 5q31-q33 in a Japanese population. We performed an association study using six microsatellite markers located at this locus in a set of 440 unrelated Japanese AITD patients and 218 Japanese controls. We found significant allelic association between AITD and three markers located in 5q23-q33. GD demonstrated significant associations with two of these markers, while HT did not show significant associations with any markers. Further, when patients with GD were stratified according to clinical manifestations, the association was significantly different from the other subgroup of each category. These findings suggest the presence of susceptible genes of AITD, especially distinct subgroups of GD, in or near 5q23-q33.

Increase in immunoglobulin G3-secreting cells in intractable Graves' disease

Isotype switching of immunoglobulin (Ig)-secreting cells is regulated by a set of cytokines. In the present study, we studied the relation between the number of peripheral blood mononuclear cells spontaneously secreting IgG, IgM, IgA, and their subclasses and the disease severities in autoimmune thyroid diseases. Ig-secreting cells were measured by enzyme-linked immunospot (ELISPOT) assay in 99 euthyroid patients with Graves' disease (GD) or Hashimoto's disease (HD) and 13 normal subjects. The number of IgG3-secreting cells was significantly higher in patients with intractable GD who had been undergoing treatment with antithyroid drugs for more than 5 years but who did not go into remission than in patients with GD in remission. This number correlated significantly with the serum level of thyrotropin receptor antibody (TRAb) in all patients with GD. These data suggest that the number of IgG3-secreting cells whose isotype switching is stimulated by interleukin (IL)-10 and IL-4 may be related to the disease severity of GD and to the level of TRAb after long-term treatment with antithyroid drugs.

Distinctive response of thyroid-infiltrating mononuclear cells to B cell activation through CD40 and interleukin-4 in Graves' patients

The possible role of abnormal T cell-dependent B-cell activation in Graves' disease was investigated by comparing lymphocyte subset distribution and the production of soluble CD8 (sCD8), sCD23, IL-10 and IL-12 by peripheral blood cells (PBMC) and thyroid-infiltrating lymphocytes (TL) in vitro. In TL, the percentage of CD8(+) cells was slightly higher and the sCD8 concentration was significantly higher than in PBMC. The ratio CD23(+) cells to CD20(+) cells (activated B/pan B cells) was increased in TL compared to PBMC from Graves' or normal controls, although the percentage of CD20(+) cells was decreased. Compared to PBMC in Graves' disease, the relative ratio of IL-10 to IL-12 release (IL-10/IL-12) by unstimulated TL was increased, despite a lack of significant difference between PBMC and TL in mean values for either IL-10 or IL-12 secretion. Incubating PBMC with a combination of anti-CD40 monoclonal antibodies and interleukin-4 (IL-4) resulted in B cell activation, reflected in an increase in the sCD23 level in both controls and Graves' patients, but especially prominent in the latter. Stimulation with anti-CD40 antibody and IL-4 also decreased the percentage of CD8(+) cells in PBMC but not TL from both Graves' disease and normal controls, and the percentage of CD8(+) cells in TL was higher than PBMC after the stimulation. The sCD23 concentration in TL was decreased compared to PBMC both in patients with Graves' disease and normal controls. However, in contrast to the increased responses observed in Graves' PBMC or normal controls after stimulation, sCD23 levels remained the same in stimulated TL from Graves' patients. This combination of B cell stimulants increased production of IL-10 in PBMC but not in TL obtained from patients with Graves' disease, and the increased IL-10/IL-12 ratio declined to a value no different from that in PBMC group after stimulation. Thus, T cell-dependent B-cell activation via a CD40 pathway may cause a shift in the Th(1)/Th(2) balance to Th(2) dominance in Graves' disease, while increased CD8(+) cells in TL may suppress sCD23 production and IL-10-producing Th(2) cells.

Relation of CD30 molecules on T-cell subsets to the severity of autoimmune thyroid disease

The prognosis of patients with autoimmune thyroid disease (AITD) varies. To clarify the immunologic differences among patients with various severities of AITD, we examined two types of molecules on peripheral T lymphocytes: CD195 (CCR5), which express dominantly on CD4(+) type 1 helper T (T(H)1) cells, and CD30, which is known as a marker of CD4(+) type 2 helper T (T(H)2) cells and a regulatory molecule of CD8(+) autoreactive cytotoxic T cells. We found presence of patients with high proportion (> 9%) of CD30 expression in CD4(+) cells in a group of patients with Graves' disease (GD) in remission compared to the patients with intractable GD and a decrease in the intensity of CD30 expression on CD8(+) cells from patients with severe Hashimoto's disease (HD) treated for hypothyroidism compared to patients with untreated and euthyroid HD. There was no difference in CD195 expression between these patients with GD or HD with different severities, but there was a decreased intensity of CD195(+) cells in thyrotoxic patients with GD. These results indicate that CD30 molecules on CD4(+) and CD8(+) cells may be related to the severities of GD and HD, respectively.

Dendritic cells infected with adenovirus expressing the thyrotrophin receptor induce Graves' hyperthyroidism in BALB/c mice

Dendritic cells (DCs) are the most potent antigen-presenting cells and a prerequisite for the initiation of primary immune response. This study was performed to investigate the contribution of DCs to the initiation of Graves' hyperthyroidism, an organ-specific autoimmune disease in which the thyrotrophin receptor (TSHR) is the major autoantigen. DCs were prepared from bone marrow precursor cells of BALB/c mice by culturing with granulocyte macrophage-colony stimulating factor and interleukin-4. Subcutaneous injections of DCs infected with recombinant adenovirus expressing the TSHR (but not beta-galactosidase) in syngeneic female mice induced Graves'-like hyperthyroidism (8 and 35% of mice after two and three injections, respectively) characterized by stimulating TSHR antibodies, elevated serum thyroxine levels and diffuse hyperplasitc goiter. TSHR antibodies determined by ELISA were of both IgG1 (Th2-type) and IgG2a (Th1-type) subclasses, and splenocytes from immunized mice secreted interferon-gamma (a Th1 cytokine), not interleukin-4 (a Th2 cytokine), in response to TSHR antigen. Surprisingly, IFN-gamma secretion, and induction of antibodies and disease were almost completely suppressed by co-administration of alum/pertussis toxin, a Th2-dominant adjuvant, whereas polyriboinosinic polyribocytidylic acid, a Th1-inducer, enhanced splenocyte secretion of IFN-gamma without changing disease incidence. These observations demonstrate that DCs efficiently present the TSHR to naive T cells to induce TSHR antibodies and Graves'-like hyperthyroidism in mice. In addition, our results challenge the previous concept of Th2 dominance in Graves' hyperthyroidism and provide support for the role of Th1 immune response in disease pathogenesis.

Histamine inhibits the production of interferon-induced protein of 10 kDa in human squamous cell carcinoma and melanoma

Interferon-induced protein of (IP-10) inhibits tumor progression. Tumor cells can produce interferon-induced protein of IP-10 in response to interferon-g. Histamine in the vicinity of tumor cells may sustain the tumor progression. We examined the in vitro effects of histamine on interferon-induced protein of IP-10 production in human squamous cell carcinoma and melanoma. Histamine suppressed interferon-g-mediated interferon-induced protein of IP-10 secretion and mRNA expression in SV40-transformed keratinocytes, SCC15, SCC4, and melanoma WM115, WM266-4, and C32. Histamine suppressed interferon-g-induced interferon-mediated protein of IP-10 promoter activation in these cells, and the interferon-stimulated response element on the promoter was responsible for the suppression. Histamine suppressed interferon-g-mediated transcription through the interferon-stimulated response element and signal transducer and activator of transcription 1alpha binding to the interferon-stimulated response element. Histamine suppressed interferon-g-induced tyrosine phosphorylation of the signal transducer and activator of transcription 1alpha, Janus tyrosine kinase 1, and Janus tyrosine kinase 2. Histamine-mediated suppression on the interferon-g-induced interferon-mediated protein of IP-10 synthesis was counteracted by the H2 receptor antagonist cimetidine, adenylate cyclase inhibitor SQ22536, and protein kinase A inhibitor H-89, but were not affected by H1 receptor antagonist mepyramine. Cimetidine, SQ22536, and H-89 also counteracted histamine-mediated suppression on the interferon-g-induced transcription through the interferon-stimulated response element, signal transducer and activator of transcription 1alpha binding to the interferon-stimulated response element, and tyrosine phosphorylation of the signal transducer and activator of transcription 1alpha, Janus tyrosine kinase 1, and Janus tyrosine kinase 2. Histamine increased intracellular 3',5'-adenosine cyclic monophosphate level and protein kinase A activity in squamous cell carcinoma and melanoma, and the effects of histamine were blocked by cimetidine. These results suggest that histamine may interact with H2 receptor on squamous cell carcinoma and melanoma and generate 3',5'-adenosine cyclic monophosphate, which may activate protein kinase A. The cyclic 3',5'-adenosine monophosphate/protein kinase A signaling pathway induced by histamine may inhibit interferon-g-induced signal transducer and activator of transcription 1alpha activation and suppress interferon-induced protein of IP-10 synthesis.