Treatment Of Autoimmune Thyroid Disease Research Articles

Autoimmune Thyroiditis and Vitamin D.

Hashimoto's thyroiditis (HT) is marked by self-tissue destruction as a consequence of an alteration in the adaptive immune response that entails the evasion of immune regulation. Vitamin D carries out an immunomodulatory role that appears to promote immune tolerance. The aim of this study is to elaborate a narrative review of the relationship between vitamin D status and HT and the role of vitamin D supplementation in reducing HT risk by modulating the immune system. There is extensive literature confirming that vitamin D levels are significantly lower in HT patients compared to healthy people. On the other hand, after the supplementation with cholecalciferol in patients with HT and vitamin D deficiency, thyroid autoantibody titers decreased significantly. Further knowledge of the beneficial effects of vitamin D in the prevention and treatment of autoimmune thyroid diseases requires the execution of additional randomized, double-blind, placebo-controlled trials and longer follow-up periods.

Yiqi Jiedu Xiaoying Decoction Improves Experimental Autoimmune Thyroiditis in Rats by Regulating Th17/Treg Cell Balance.

Experimental autoimmune thyroiditis (EAT) is a widely used animal model to study the pathogenesis and treatment of autoimmune thyroid diseases. Yiqi Jiedu Xiaoying Decoction (YJXD) is a traditional Chinese medicine formula with potential immunomodulatory effects. In this study, we investigated the therapeutic effects of YJXD on EAT in rats and explored its underlying mechanisms. Female Wistar rats were induced to develop EAT by immunization with thyroglobulin (Tg) and taken sodium iodide water (0.05%) and then treated with YJXD or sodium selenite. HE staining was used to observe the pathological changes of thyroid tissue in EAT rats. Th17 and Treg cell frequencies were analyzed by flow cytometry, and the expression levels of Th17- and Treg-related cytokines and thyroid autoantibody were determined by enzyme-linked immunosorbent assay (ELISA). The expression of Th17- and Treg-related transcriptional factors was detected by real-time polymerase chain reaction (RT-PCR) and Immunohistochemistry (IHC). Our results demonstrated that treatment with YJXD significantly attenuated the severity of EAT, as evidenced by reduced thyroid gland inflammatory infiltration and decreased serum thyroglobulin autoantibody levels. Importantly, YJXD treatment effectively modulated the Th17/Treg cell balance by suppressing Th17 cell differentiation and promoting Treg cell expansion. Moreover, YJXD was also found to regulate the expression levels of Th17- and Tregrelated cytokines and transcriptional factors, further supporting its immunomodulatory effects in EAT. YJXD exerted therapeutic effects on EAT by regulating the Th17/Treg cell balance, modulating the production of Th17- and Treg-related cytokines and the expression of transcriptional factors.

Targeting hnRNPC suppresses thyroid follicular epithelial cell apoptosis and necroptosis through m6A-modified ATF4 in autoimmune thyroid disease

Both environmental and genetic factors contribute to the etiology of autoimmune thyroid disease (AITD) including Graves’ disease (GD) and Hashimoto’s thyroiditis (HT). However, the exact pathogenesis and interactions that occur between environmental factors and genes remain unclear, and therapeutic targets require further investigation due to limited therapeutic options. To solve such problems, this study utilized single-cell transcriptome, whole transcriptome, full-length transcriptome (Oxford nanopore technology), and metabolome sequencing to examine thyroid lesion tissues from 2 HT patients and 2 GD patients as well as healthy thyroid tissue from 1 control subject. HT patients had increased ATF4-positive thyroid follicular epithelial (ThyFoEp) cells, which significantly increased endoplasmic reticulum stress. The enhanced sustained stress resulted in cell death mainly including apoptosis and necroptosis. The ATF4-based global gene regulatory network and experimental validation revealed that N6-methyladenosine (m6A) reader hnRNPC promoted the transcriptional activity, synthesis, and translation of ATF4 through mediating m6A modification of ATF4. Increased ATF4 expression initiated endoplasmic reticulum stress signaling, which when sustained, caused apoptosis and necroptosis in ThyFoEp cells, and mediated HT development. Targeting hnRNPC and ATF4 notably decreased ThyFoEp cell death, thus ameliorating disease progression. Collectively, this study reveals the mechanisms by which microenvironmental cells in HT and GD patients trigger and amplify the thyroid autoimmune cascade response. Furthermore, we identify new therapeutic targets for the treatment of autoimmune thyroid disease, hoping to provide a potential way for targeted therapy.

TSHR-based chimeric antigen receptor T cell specifically deplete auto-reactive B lymphocytes for treatment of autoimmune thyroid disease

Graves' disease (GD) is a prominent antibody-mediated autoimmune disorder characterized by stimulating antibodies (TRAb) that target the thyroid-stimulating hormone receptor (TSHR). Targeting and eliminating TRAb-producing B lymphocytes hold substantial therapeutic potential for GD. In this study, we engineered a novel chimeric antigen receptor T cell (CAR-T) therapy termed TSHR-CAR-T. This CAR-T construct incorporates the extracellular domain of the TSH receptor fused with the CD8 transmembrane and intracellular signal domain (4-1BB). TSHR-CAR-T cells demonstrated the ability to recognize and effectively eliminate TRAb-producing B lymphocytes both in vitro and in vivo. Leveraging this autoantigen-based chimeric receptor, our findings suggest that TSHR-CAR-T cells offer a promising and innovative immunotherapeutic approach for the treatment of antibody-mediated autoimmune diseases, including GD.

Survey on selenium clinical supplementation in autoimmune thyroid disease.

Previous trials show that selenium could be a very useful tool in the control and treatment of autoimmune thyroid diseases. In this cross-sectional study, through a survey, we aim to evaluate Portuguese endocrinologists' perception and pattern of prescription of selenium supplements in these diseases and verify its agreement with current guidelines. The endocrinologists registered in the Portuguese Medical Association were sent an email with a web-based questionnaire, regarding their knowledge and use of selenium supplements in thyroid autoimmune pathology. A total of 105 physicians (33% of the total) submitted the survey. The selenium serum concentration in the general population was unknown to 80% of respondents. Over a third of respondents have never prescribed selenium for autoimmune thyroid disease. However, 89% are not afraid of recommending it, and 61% indicate Graves' orbitopathy as the pathology they would supplement. In Hashimoto's thyroiditis, 36% of respondents use selenium occasionally or frequently, and this percentage rises to 60% in Graves' disease. Although recommendations only encompass mild Graves' orbitopathy, selenium is prescribed across the spectrum of autoimmune thyroid diseases, probably due to recent studies that consistently show improvement of biochemical hallmarks in these patients. Further investigation is required on the impact of selenium supplements on primarily clinical outcomes and to identify disorders and/or patients who will benefit the most. Also, there is still insufficient knowledge of this field in the medical community, and evidence-based practice should continue to be promoted by endocrinology societies.

HLA-DRA Gene Polymorphisms Are Associated with Graves' Disease as an Autoimmune Thyroid Disease.

Background Autoimmune thyroid disease (AITD), one of the most prevalent organ-specific autoimmune diseases, mainly includes Graves' disease (GD) and Hashimoto's thyroiditis (HT). This study was aimed at researching the association between AITD and single nucleotide polymorphisms (SNPs) of the HLA-DRA gene. Methods Using Hi-SNP high-throughput sequencing technology, we detected the distribution of three SNPs (rs3177928, rs7197, and rs3129878) of HLA-DRA genotypes in 1033 AITD patients (634 GD and 399 HT ones) and 791 healthy volunteers in Chinese Han Population. Chi-square test, multivariate logistic regression, and haplotype analysis were performed by SPSS and Haploview software to analyze the relationship between HLA-DRA gene polymorphisms and AITD. Results The results show that allele frequency and genotype distribution of rs3177928 and rs7197 were correlated with AITD and GD compared with the healthy control group, but not with HT. Rs3177928 and rs7197 were correlated with AITD and HT in the allele model, dominant model, and overdominant model before and after gender and age adjustment, but not with HT. In addition, we found that two loci (rs3177928 and rs7197) constituted a linkage disequilibrium (LD) region, and haplotype AA was associated with AITD and GD. However, we found no association between rs3129878 and AITD. Conclusion Our study is the first to find that rs3177928 and rs7197 of HLA-DRA are significantly correlated with AITD and GD in the Chinese Han population. This will help further reveal the pathogenesis of AITD and provide new candidate genes for the prediction or treatment of AITD.

Vitamin D and autoimmune thyroid diseases (part 2)

The paper is devoted to the disclosure of mechanisms underlying the ability of vitamin D to modulate inflammatory processes in autoimmune thyroid diseases. Vitamin D receptor (VDR) was found to be expressed in many activated immune cells. Calcitriol affects monocytes and dendritic cells by inhibiting the production of inflammatory cytokines, it has effects on differentiation and maturation of antigen-presenting cells, resulting in the suppression of activation and proliferation of T-lymphocytes. Vitamin D was established to be able to shift the differentiation of CD4+ cells towards type 2 T­helpers (Th2) and T­-regulatory phenotypes and inhibit the development and activity of T-helpers of type 17 (Th17) and type 1 (Th1). In recent years, researchers have drawn attention to the regulatory effect of vitamin D on the balance of Treg /Th17 cells. It has been assumed that mutual Th17 and Treg conversion is feasible due to the tight relationship of the processes of differentiation of these cells and presence of the general key development factor — transforming growth factor­β (TGF­β). Proteins of the Smad family play a crucial role in the transmission of TGFβ signals, and Smad3 is important for Treg cells, while Smad7 is associated with the proinflammatory phenotype of T cells. Experiments have established the ability of vitamin D to suppress Smad7 expression, thus promoting increased Smad3 synthesis. Vitamin D has an inhibitory effect on the expression of Th17 cytokines and the differentiation of Th17 cells into pathogenic types. Results of several investigations demonstrated that cholecalciferol preparations had a beneficial effect on thyroid pathology, but these data are ambiguous. Further research is needed to determine the effectiveness of vitamin D intake in the prevention and treatment of autoimmune thyroid disease.

THYROID FUNCTION OF RATS WITH EXPERIMENTAL AIT AT AN EARLY PERIOD AFTER THE INJECTION OF BIOPREPARATIONS OF CORD BLOOD

The development of new methods for the treatment of autoimmune thyroid disease is an actual problem of endocrinology. The aim of research was studying of the cell-free effect biological product of cord blood with immunomodulatory properties "Cryocell-Cryocord " on rats’ thyroid function with AIT simulated at an early period of the study. Simulation of autoimmune thyroiditis was carried out by immunization with a suboperatively isolated human thyroid antigen in combination completing Freund's adjuvant on 30 adult male rats weighing 130 - 150 g. Correction was carried out by parenteral ingection of the "Cryocell-Cryocord". Hormonal research (determination of the content of thyroid hormones and antibodies to thyroglobulin (TG-AT) were effected by using standard test kits for enzyme-linked immunosorbent assay at early stages after exposure (7 days, 1 month). Statistical maintained of the results was carried out using the methods of variation statistics. It was used normal distribution to unpaired Student's test to compare indicators. The difference was considered significant at p<0.05. It has been shown the biological preparation of cord blood "Cryocell - Cryocord" has a positive effect with induced autoimmune thyroiditis. It has been noted the normalizing result of the effected correction on the thyroid function of animals in the early period of the studying. It has been proved after the introduction of the biological preparation "Cryocell - Cryocord" in animals with experimental autoimmune thyroiditis observed the inhibition of the manifestations of autoimmune aggression and the normalization of the functional activity of the thyroid gland. These investigations can be the foundation for the development of a new approach to the treatment of patients.

Effects of vitamin D in thyroid autoimmune pathologies: literature review and own data

Background. Vitamin D (VD) is a versatile steroid hormone that regulates the activity of several thousand genes. Over the past decades, numerous diseases associated with VD deficiency have been reported, including cancer and autoimmune thyroid disorders. Researches revealed that VD can influence the development and course of these diseases. The VD participation in modulation of the hypothalamus-pituitary-thyroid gland axis, both at the level of the pituitary gland and at that of the thyroid, has been shown. The effect of VD on autoimmune diseases, including thyroid autoimmune diseases, is widely studied. Most of the existing data support the relationship between VD deficiency and a greater tendency to develop and higher antibody titers associated with Hashimoto’s thyroiditis, Graves’ disease (GD) and postpartum thyroiditis. An important fact is that epidemiological studies have demonstrated a high prevalence of VD deficiency or insufficiency throughout the world. VD insufficiency is a potent dietary trigger that results in severe, chronic diseases. The question arises how reliable is the relationship between VD and autoimmune thyroid diseases (AITD). Although the results of the studies performed are somewhat contradictory, the vast majority of data indicates a link between VD deficiency and an increased risk of developing the disease, high antibody titers, and difficulties in treatment. Genetic polymorphisms associated with VD function and metabolism also have some influence on the risk of ATD. With regard to the precise nature of the relationship between VD and AITD, it is believed that VD plays a small but significant role in the AITD pathogenesis. After the AITD development, its consequence may be an increase in VD deficiency. It is the need to determine the effect of VD supplementation in the prevention and treatment of AITD and its optimal level directly for clinical practice. It is necessary for clinical practice to determine the effect of VD supplements in the prevention and treatment of AITD and its optimal level. A study, the purpose of which was to study the content of VD, namely 25(OH)D in 176 patients with GD complicated by autoimmune ophthalmopathy (AO) and to identify a correlation relationship with antithyroid antibodies (TPO, TSHR-Ab) was carried out at the State Institution “V.P. Komissarenko Institute of Endocrinology and Metabolism of the National Academy of Medical Sciences of Ukraine”. Materials and methods. The levels of 25(OH)D, TSH, TSHR-Ab, TPO were determined by enzyme immunoassay using standard kits from Siemens firm. During the study, 176 patients were divided into two groups, depending on the presence of AO: the first group consisted of patients with GD without AO (62 people), the second group included patients with GD and AO (114 people). Results. In GD, 91.78 % of patients (161 people) have an insufficient level of 25(OH)D content: a suboptimal level was recorded in 42 patients (23.86 %), and a deficit — in 119 patients (67.61 %). A significant negative correlation relationship was revealed between TSHR-Ab and 25(OH)D in the group of patients with GD and AO — with a lower level of 25(OH)D, the higher values of TSHR-Ab correlate. Compensation of the 25(OH)D deficiency leads to a significant (P< 0.05) decrease in the levels of TSHR-Ab and TPO in patients with GD. Besides, there is a large body of literature available lin-king vitamin D to thyroid autoimmunity as a result of cross-sectional studies and observations. Conclusions. Thus, there is still an urgent need for large multicenter studies to evaluate the effect of vitamin D supplementation on meaningful long-term clinical endpoints in AITD.

3,5-T2-A Janus-Faced Thyroid Hormone Metabolite Exerts Both Canonical T3-Mimetic Endocrine and Intracrine Hepatic Action.

Over the last decades, thyroid hormone metabolites (THMs) received marked attention as it has been demonstrated that they are bioactive compounds. Their concentrations were determined by immunoassay or mass-spectrometry methods. Among those metabolites, 3,5-diiodothyronine (3,5-T2), occurs at low nanomolar concentrations in human serum, but might reach tissue concentrations similar to those of T4 and T3, at least based on data from rodent models. However, the immunoassay-based measurements in human sera revealed remarkable variations depending on antibodies used in the assays and thus need to be interpreted with caution. In clinical experimental approaches in euthyroid volunteers and hypothyroid patients using the immunoassay as the analytical tool no evidence of formation of 3,5-T2 from its putative precursors T4 or T3 was found, nor was any support found for the assumption that 3,5-T2 might represent a direct precursor for serum 3-T1-AM generated by combined deiodination and decarboxylation from 3,5-T2, as previously documented for mouse intestinal mucosa. We hypothesized that lowered endogenous production of 3,5-T2 in patients requiring T4 replacement therapy after thyroidectomy or for treatment of autoimmune thyroid disease, compared to production of 3,5-T2 in individuals with intact thyroid glands might contribute to the discontent seen in a subset of patients with this therapeutic regimen. So far, our observations do not support this assumption. However, the unexpected association between high serum 3,5-T2 and elevated urinary concentrations of metabolites related to coffee consumption requires further studies for an explanation. Elevated 3,5-T2 serum concentrations were found in several situations including impaired renal function, chronic dialysis, sepsis, non-survival in the ICU as well as post-operative atrial fibrillation (POAF) in studies using a monoclonal antibody-based chemoluminescence immunoassay. Pilot analysis of human sera using LC-linear-ion-trap-mass-spectrometry yielded 3,5-T2 concentrations below the limit of quantification in the majority of cases, thus the divergent results of both methods need to be reconciliated by further studies. Although positive anti-steatotic effects have been observed in rodent models, use of 3,5-T2 as a muscle anabolic, slimming or fitness drug, easily obtained without medical prescription, must be advised against, considering its potency in suppressing the HPT axis and causing adverse cardiac side effects. 3,5-T2 escapes regular detection by commercially available clinical routine assays used for thyroid function tests, which may be seriously disrupted in individuals self-administering 3,5-T2 obtained over-the counter or from other sources.

Effect of Halofuginone on the Pathogenesis of Autoimmune Thyroid Disease in Different Mice Models

Our objectives were to investigate the therapeutic effect of halofuginone (HF) in the treatment of autoimmune thyroid diseases (AITDs) and explore its underlying mechanism of action. The Graves' disease (GD) model was generated by immunizing female BALB/c mice with adenovirus expressing the TSH receptor A subunit (Ad-TSHR289). The Ad-TSHRA+HF and Ad- TSHRA+DMSO groups were injected intraperitoneally with HF or the vehicle control (DMSO), respectively. The autoimmune thyroiditis (AIT) group consisted of female NOD.H-2h4 mice that were administered NaI in the drinking water and intraperitoneally injected daily with the vehicle control (DMSO) during the study period. The AIT/HF group consisted of female NOD.H-2h4 mice that were administered NaI in the drinking water and intraperitoneally injected daily with HF. The frequencies of splenic Th17 cells, Tregs and Bregs were determined by flow cytometry. The mRNA levels of IL-17, forkhead box P3 (Foxp3), RORγt and IL-10 were determined by real-time PCR. In both Ad-TSHRA+DMSO and Ad-TSHRA+HF groups, 10 out of 15 mice displayed serum T4 and TSAb levels above 3 SD beyond the mean control levels. The number of CD4+CD25+Foxp3+ T lymphocytes in the GD model was significantly increased in the HF group compared with the DMSO group (P < 0.05). The mRNA level of Foxp3 was significantly increased in the Ad-TSHRA+HF group compared with the Ad-TSHRA+DMSO group (P < 0.05). However, neither the abundance of CD4+IL-17+ T cell subpopulation nor the mRNA expression level of RORγt differed significantly between the Ad-TSHRA+HF and Ad-TSHRA+DMSO groups (P > 0.05). The serum TgAb titer was significantly reduced in the AIT/HF group compared with the AIT group (P < 0.01). The differences in the number of CD4+CD25+Foxp3+ T lymphocytes and the mRNA levels of Foxp3 between the AIT/HF and AITgroups were not significant (P > 0.05). However, the number of CD4+IL-17+ T cells and the mRNA levels of IL-17 and RORγt were significantly increased in HF-treated mice compared with the non-treated AIT-induced mice (P < 0.05). Treatment with HF significantly decreased the incidence of AIT by decreasing the number of CD4+IL-17+ T cells.

Treatment of pretibial myxedema with intralesional immunomodulating therapy.

ObjectiveLocal immune regulation therapy has been one of the therapeutic methods used for the treatment of autoimmune thyroid disease in patients with pretibial myxedema (PTM). However, the poor response rate and high recurrence rate are still major problems. Whether a premixed corticosteroid, compound betamethasone, could enhance remission rate and decrease recurrence rate in patients with PTM was investigated in the present study.Subjects and methodsWe have performed a clinical utility observation of compound betamethasone with intralesional injections based on basic thyroid disease treatment in 32 PTM patients between January 2008 and August 2016. The patients were followed up for 2 years, and the clinical outcomes and side effects were calculated and analyzed.ResultsAll patients had a complete remission after different times of injection. A total of 21.7% patients had complete remission with one time of injection, 34.8% with two times of injection, 17.4% with three times of injection, 4.3% with four times of injection, and 4.3% with five times of injection. In all, 56.3% patients with a disease duration of <6 months had complete remission after a 1-month treatment, 37.5% patients with a disease duration between 6 months and 12 months had complete remission after a 2-month treatment, 3.1% patients with a disease duration of 2 years had complete remission after a 5-month treatment, and 3.1% with a disease duration of 5 years had complete remission after a 7-month treatment.ConclusionCompound betamethasone with multipoint intralesional injection is a feasible, effective, and secure novel strategy in the treatment of PTM.

Autoimmune Thyroid Disease with Hypothyroidism in Adult Celiac Disease

Evidence largely from earlier prevalence studies and recent population-based studies indicate that there is a strong clinical association between autoimmune thyroid disease and adult celiac disease. In part, at least, this appears to be related to common genetically-based determinants as well as a common embryonic origin since the fetal thyroid is derived from the pharyngeal gut. Specific phenotypic features have been described if both disorders are defined, including dermatitis herpetiformis, and a greater risk for a malignant complication, including lymphoma, especially if celiac disease is initially diagnosed at a late age. Some phenotypic characteristics of autoimmune thyroid disease, such as orbitopathy, may be an important clue to occult celiac disease. Similarly, a high thyroxine dose requirement for treatment of autoimmune thyroid disease may be another phenotypic characteristic of undetected celiac disease. Serological screening for celiac disease should be considered if autoimmune thyroid disease is detected.

The value and controversy of thyroid peroxidase antibody in the diagnosis and treatment of autoimmune thyroid disease

Thyroid peroxidase antibody (TPOAb) play an important role in the diagnosis of autoimmune thyroid disease. Chemiluminescence immunoassay (CLIA) is a new method been strongly recommended in recent years. The definition of positive value of TPOAb is inconsistent. The definition of TPOAb positive value is important for exploring the development of autoimmune thyroid disease. TPOAb is significantly increased in Hashimoto′s disease and the titer is associated with the degree of infiltration and destruction of thyroid follicular. It is essential to monitor TPOAb in postpartum thyroiditis and early pregnancy. The positive of TPOAb is closely related to the adverse pregnancy outcomes caused by various risk factors. Graves disease combined with Hashimoto′s must to be considered. (Chin J Lab Med, 2015, 38: 884-887) Key words: Thyroid Diseases; Thyroiditis, autoimmune; Iodide peroxidase; Autoantibody

Does selenium supplementation affect thyroid function? Results from a randomized, controlled, double-blinded trial in a Danish population

Selenium is present in the active site of proteins important for thyroid hormone synthesis and metabolism. The objective of this study is to investigate the effect of selenium supplementation in different doses on thyroid function, under conditions of suboptimal dietary selenium intake. The Danish PREvention of Cancer by Intervention with SElenium pilot study (DK-PRECISE) is a randomized, double-blinded, placebo-controlled trial. A total of 491 males and females aged 60-74 years were randomized to 100 μg (n=124), 200 μg (n=122), or 300 μg (n=119) selenium-enriched yeast or matching yeast-based placebo tablets (n=126). A total of 361 participants, equally distributed across treatment groups, completed the 5-year intervention period. Plasma samples were analyzed for selenium and serum samples for TSH, free triiodothyronine (FT3), and free thyroxine (FT4) at baseline, and after 6 months, and 5 years of supplementation. Plasma selenium concentrations increased significantly and dose-dependently in treatment groups receiving selenium (P<0.001). Serum TSH and FT4 concentrations decreased significantly and dose-dependently by 0.066 mIU/l (P=0.010) and 0.11 pmol/l (P=0.015), respectively, per 100 μg/day increase, with insignificant differences between 6 months and 5 years. No significant effects were found for FT3 and FT3:FT4 ratio. In euthyroid subjects, selenium supplementation minutely and dose-dependently affects thyroid function, when compared with placebo, by decreasing serum TSH and FT4 concentrations. Based on these findings, selenium supplementation is not warranted under conditions of marginal selenium deficiency. However, a role for selenium supplementation in the treatment of autoimmune thyroid diseases is still unresolved.

Interleukin-10 influences susceptibility to experimental autoimmune thyroiditis independently of the H-2 gene.

Both BALB/c and C57BL/6 mice are relatively resistant to experimental autoimmune thyroiditis (EAT) due to their histocompatibility (H-2) genetic background; however, susceptibility to EAT is also influenced by other genetic factors. Given the curative effect of interleukin-10 (IL-10) on thyroiditis, in the present study, we investigated whether IL-10 functions as a non-H-2 genetic factor that influences the development of EAT in mice with an EAT-resistant genetic background. In this study, we observed that the development of EAT could be induced in both C57BL/6 IL-10‑deficient (IL-10-/-) and BALB/c IL-10-/- female mice following immunization with mTg, which indicated that IL-10 may be a non-H-2 factor that affects susceptibility to EAT. However, the role of the H-2 factor remained dominant, as the incidence of EAT was low and its severity was mild. We further investigated the underlying pathogenic mechanisms of EAT in IL-10-/- female mice. We found that Th1 cells, Th17 cells, CD4+CD25+Foxp3+ regulatory T cells, and their associated cytokines were all involved in the development of EAT. The absence of IL-10 promoted the polarization of pathogenic cells and the production of associated cytokines, and suppressed the proliferation of protective T cell clones. Together, these factors may contribute to the development of EAT in IL-10-/- mice. In conclusion, our data demonstrate that IL-10 plays a critical role in the susceptibility to EAT, and a better understanding of the role of IL-10 in autoimmune thyroiditis may facilitate the development of novel strategies for the treatment of autoimmune thyroid diseases.

Prophylactic and therapeutic efficacies of a selective inhibitor of the immunoproteasome for Hashimoto's thyroiditis, but not for Graves' hyperthyroidism, in mice

Major histocompatibility complex (MHC) class I-restricted T cell epitopes are generated mainly by the immunoproteasome in antigen-presenting cells. Therefore, inhibition of activity of this proteolytic complex molecule is thought to be a potential treatment for cell-mediated autoimmune diseases. We therefore studied the efficacy of an immunoproteasome inhibitor, ONX 0914 (formerly PR-957), for the treatment of autoimmune thyroid diseases, including cell-mediated Hashimoto's thyroiditis and autoantibody-mediated Graves' hyperthyroidism using mouse models. Our data show that ONX 0914 was effective prophylactically and therapeutically at suppressing the degree of intrathyroidal lymphocyte infiltration and, to a lesser degree, the titres of anti-thyroglobulin autoantibodies in non-obese diabetic (NOD)-H2(h4) mice, an iodine-induced autoimmune thyroiditis model. It also inhibited differentiation of T cells to T helper type 1 (Th1) and Th17 cells, effector T cell subsets critical for development of thyroiditis in this mouse strain. In contrast, its effect on the Graves' model was negligible. Although ONX 0914 exerts its immune-suppressive effect through not only suppression of immune proteasome but also other mechanism(s), such as inhibition of T cell differentiation, the present results suggest that the immunoproteasome is a novel drug target in treatment of Hashimoto's thyroiditis in particular and cell-mediated autoimmune diseases in general.

Thyroid Autoantibodies and Pregnancy Outcomes

Autoimmune thyroid disease has been associated with several adverse pregnancy outcomes. Increased risk of spontaneous miscarriage and placental abruption in women with thyroid antibodies has been confirmed in multiple studies. However, benefit of intervention and treatment of autoimmune thyroid disease in otherwise euthyroid pregnant women has not been sufficiently studied. The data on the association of thyroid antibodies and recurrent pregnancy loss or preterm birth are conflicting and a statistically significant association has not been shown in large studies. At present time, routine screening and treatment of autoimmune thyroid disease in euthyroid pregnant women is not warranted.

Elocalcitol Inhibits Inflammatory Responses in Human Thyroid Cells and T Cells

T-helper 1 (Th1) cell-mediated inflammatory responses predominate in the early pathogenesis of Graves' disease (GD), whereas Th2 cell-mediated immunity may play a role in later stages. The chemokine CXCL10 and its receptor CXCR3 are expressed in most thyroid glands of early GD patients. Circulating CXCL10 levels inversely correlate with disease duration; CXCL10 maximal expression also correlates with interferon (IFN)gamma levels in recent GD onset. Methimazole (MMI) reduces CXCL10 secretion by isolated thyrocytes, decreases serum CXCL10 levels, and promotes a transition from Th1 to Th2 dominance in patients in GD active phase. Vitamin D receptor agonists exhibit antiinflammatory properties and promote tolerance induction. We investigated the effects and the mechanism of action of a nonhypercalcemic vitamin D receptor agonist, elocalcitol (BXL-628), compared with MMI on CXCL10 secretion induced by proinflammatory cytokines. Furthermore, we studied the effects of both drugs on Th1, Th17, and Th2 cytokine secretion in CD4+ T cells. ELISA, cytometry, immunocytochemistry, Western blot, and quantitative real-time PCR were used for protein and gene analysis. In human thyrocytes, elocalcitol inhibited IFNgamma and TNFalpha-induced CXCL10 protein secretion more potently than MMI. Elocalcitol impaired both cytokine intracellular pathways, whereas MMI was effective only on the IFNgamma pathway. In CD4+ T cells, elocalcitol decreased Th1- and Th17-type cytokines, and promoted Th2-type cytokine secretion. Elocalcitol and MMI inhibited Th1 cytokine-mediated responses in thyrocytes and CD4+ T cells. In addition, elocalcitol promoted a shift toward a Th2 response. In conclusion, elocalcitol could represent a novel pharmacological tool in the treatment of autoimmune thyroid diseases.

Effect of Herbal Medicines on Cytokine-Induced Cytotoxicity and Major Histocompatibility Complex (MHC) Class II Antigen Expression in Rat Thyroid Cells

The effects of herbal medicines that constitute Gam-du-tang and Gung-gui-tang on cytokine-induced cytotoxicity and thyroid major histocompatibility complex (MHC) class II antigen expression in FRTL rat thyrocytes were investigated. No effect on cell growth was found with interferon (IFN)-gamma. However, tumor necrosis factor (TNF)-alpha was cytotoxic, and this was increased by preincubation with IFN-gamma. Ethanol extract of Glycyrrhizae Radix, black beans, Angelicae Radix, and Cnidii Rhizoma (0.3-15 mg/ml) in both regimens significantly inhibited IFN-gamma and TNF-alpha-mediated cytotoxicity of rat thyroid cells (p<0.05, p<0.01). In addition, IFN-gamma (1-100 U/ml) treatment induced class II antigen expression in up to 60% of FRTL cells, as detected by a murine monoclonal antibody to rat MHC class II antigen (FITC-OX6). Aberrant thyroid cell MHC class II antigen expression induced by IFN-gamma is suppressed by the extract of herbal medicines. These results indicate that herbal medicines inhibit cytokine-induced thyroid cell destruction, therefore, may have therapeutic potential in the treatment of autoimmune thyroid disease.