Relative levels of the inflammatory cytokine TNFα and the soluble CD40 ligand profile in serum correlate with the thyrotoxic activity of Graves' disease

Outcomes of Patients With Graves Disease 25 Years After Initiating Antithyroid Drug Therapy

CONTEXT

Graves disease (GD) is a leading cause of hyperthyroidism. Detailed investigations and predictors of long-term outcomes are missing.

OBJECTIVE

This work aimed to investigate the outcomes in GD 25 years after initiating antithyroid drug treatment, including disease course, clinical and biochemical predictors of relapse, and quality of life.

METHODS

A retrospective follow-up was conducted of GD patients that participated in a randomized trial from 1997 to 2001. Demographic and clinical data were obtained from medical records and questionnaires. Biobank samples were analyzed for inflammatory biomarkers and compared with age- and sex-matched healthy individuals.

RESULTS

We included 83% (182/218) of the patients from the original study. At the end of follow-up, normal thyroid function was achieved in 34%. The remaining had either active disease (1%), spontaneous hypothyroidism (13%), or had undergone ablative treatment with radioiodine (40%) or thyroidectomy (13%). Age younger than or equal to 40 years, thyroid eye disease (TED), smoking, and elevated levels of interleukin 6 and tumor necrosis factor receptor superfamily member 9 (TNFRS9) increased the risk of relapsing disease (odds ratio 3.22; 2.26; 2.21; 1.99; 2.36). At the end of treatment, CD40 was lower in patients who maintained normal thyroid function (P = .04). At the end of follow-up, 47% had one or more autoimmune diseases, including vitamin B12 deficiency (26%) and rheumatoid arthritis (5%). GD patients who developed hypothyroidism had reduced quality of life.

CONCLUSION

Careful lifelong monitoring is indicated to detect recurrence, hypothyroidism, and other autoimmune diseases. Long-term ATD treatment emerges as a beneficial first-line treatment option, especially in patients with young age at onset or presence of TED.

Serum Cytokine Profile, Beta-Hexosaminidase A Enzymatic Activity and GM2 Ganglioside Levels in the Plasma of a Tay-Sachs Disease Patient after Cord Blood Cell Transplantation and Curcumin Administration: A Case Report

Tay-Sachs disease (TSD) is a progressive neurodegenerative disorder that occurs due to a deficiency of a β hexosaminidase A (HexA) enzyme, resulting in the accumulation of GM₂ gangliosides. In this work, we analyzed the effect of umbilical cord blood cell transplantation (UCBCT) and curcumin administration on the course of the disease in a patient with adult TSD. The patient’s serum cytokine profile was determined using multiplex analysis. The level of GM₂ gangliosides in plasma was determined using mass spectrometry. The enzymatic activity of HexA in the plasma of the patient was assessed using a fluorescent substrate assay. The HexA α-subunit (HexA) concentration was determined using ELISA. It was shown that both UCBCT and curcumin administration led to a change in the patient’s cytokine profile. The UCBCT resulted in an increase in the concentration of HexA in the patient’s serum and in an improvement in the patient’s neurological status. However, neither UCBCT nor curcumin were able to alter HexA activity and the level of GM₂ in patient’s plasma. The data obtained indicate that UCBCT and curcumin administration can alter the immunity of a patient with TSD, reduce the level of inflammatory cytokines and thereby improve the patient’s condition.

Serum interferon levels associated with the disease activity in women with overt Graves' disease

BACKGROUND

Inflammatory cytokines participate in immune reactions and the pathogenesis of autoimmunity. Herein, we quantified four groups of inflammatory cytokines, including interferons (IFNs), the tumor necrosis factor (TNF) superfamily (TNFSF), interleukin (IL)-related cytokines, and bone and extracellular matrix remodeling-related cytokines to determine their contributions in women with overt Graves' disease (GD).

METHODS

Forty-three women with GD were enrolled in this cross-sectional study. Thirty-seven cytokines, thyroid-stimulating hormone (TSH), free thyroxine, and TSH receptor antibody (TSHRAb) were quantified. GD patients with a low TSH level at the time of sample collection were defined as having active GD.

RESULTS

Patients with active GD had higher IFN-α2, IFN-γ, IFN-λ1, and IFN-λ2 levels than those with inactive GD. In addition, certain TNFSF cytokines, including soluble cluster of differentiation 30 (sCD30), TNFSF member 14 (TNFSF14), pentraxin (PTX)-3, soluble TNF receptor 2 (sTNF-R2), and thymic stromal lymphopoietin (TSLP) were higher in active GD than in inactive GD. Moreover, active GD patients had higher IL-2, IL-12(p40), osteocalcin (OCN), and matrix metalloproteinase (MMP)-3 than inactive GD patients. All IFNs except IFN-λ1 were correlated with TSHRAb titers. Moreover, TNFSF cytokines, consisting of B-cell-activating factor, sCD30, TNFSF14, PTX-3, sTNF-R2, and TSLP, were associated with TSHRAb levels.

CONCLUSIONS

Serum IFNs could be the most remarkable cytokines in modulating the disease severity and TSHRAb titers in women with full-blown GD. Further molecular-based research to clarify the actual role of IFNs in the disease progression of GD is needed.

Decreased Treg Cell and TCR Expansion Are Involved in Long-Lasting Graves' Disease

Graves' disease (GD) is a T cell-mediated organ-specific autoimmune disorder. GD patients who have taken anti-thyroid drugs (ATDs) for more than 5 years with positive anti-thyroid stimulating hormone receptor autoantibodies value were defined as persistent GD (pGD). To develop novel immunotherapies for pGD, we investigated the role of T cells in the long-lasting phase of GD. Clinical characteristics were compared between the pGD and newly diagnosed GD (nGD) (N = 20 respectively). Flow cytometric analysis was utilized to determine the proportions of Treg and Th17 cells (pGD, N = 12; nGD, N = 14). T cell receptor sequencing (TCR-seq) and RNA sequencing (RNA-seq) were also performed (pGD, N = 13; nGD, N = 20). Flow cytometric analysis identified lower proportions of Th17 and Treg cells in pGD than in nGD (P = 0.0306 and P = 0.0223). TCR-seq analysis revealed a lower diversity (P = 0.0025) in pGD. Specifically, marked clonal expansion, represented by an increased percentage of top V-J recombination, was observed in pGD patients. Interestingly, pGD patients showed more public T cell clonotypes than nGD patients (2,741 versus 966). Meanwhile, RNA-seq analysis revealed upregulation of the inflammation and chemotaxis pathways in pGD. Specifically, the expression of pro-inflammatory and chemotactic genes (IL1B, IL13, IL8, and CCL4) was increased in pGD, whereas Th17 and Treg cells associated genes (RORC, CARD9, STAT5A, and SATB1) decreased in pGD. Additionally, TCR diversity was negatively correlated with the expression of pro-inflammatory or chemotactic genes (FASLG, IL18R1, CCL24, and CCL14). These results indicated that Treg dysregulation and the expansion of pathogenic T cell clones might be involved in the long-lasting phase of GD via upregulating chemotaxis or inflammation response. To improve the treatment of pGD patients, ATDs combined therapies, especially those aimed at improving Treg cell frequencies or targeting specific expanded pathogenic TCR clones, are worth exploring in the future.

Soluble CD40 Ligand Levels in Children with Newly Diagnosed Graves’ Disease

OBJECTIVE

Soluble CD40 ligand (sCD40L) is elevated in various autoimmune disorders, which may have diagnostic and therapeutic implications. The aims of the current study were to evaluate serum sCD40L concentrations in children with newly diagnosed Graves’ disease (GD) and to correlate its levels with patients’ clinical and laboratory parameters.

METHODS

This study included 48 children with newly diagnosed GD and 48 healthy children. Serum thyroid-stimulating hormone (TSH) (TSH, fT4 and fT3), TSH receptor antibodies (TRAbs), high sensitivity C-reactive protein (hsCRP) and sCD40L levels and thyroid volume were measured.

RESULTS

Compared to control subjects, children with GD had higher thyroid volume standard deviation scores (SDS) (p=0.001), and higher levels of hsCRP (p=0.001), TRAbs (p=0.001) and sCD40L (p=0.001). Significant correlations were found between sCD40L and age (p=0.01), thyroid volume SDS (p=0.001), hsCRP (p=0.01) and TRAbs (p=0.001). In multivariate analysis, sCD40L concentrations were correlated with TRAbs [odds ratio (OR)=3.1, 95% confidence intervals (CI): 2.2-2.7, p=0.001] and thyroid volume SDS (OR=2.1, 95% CI: 1.2-2.7, p=0.001).

CONCLUSION

This preliminary study has evidence of high concentrations of sCD40L in children with newly diagnosed GD and a correlation between sCD40L and both TRAbs and thyroid volume, which may indicate a biologically active role for sCD40L in the pathogenesis of GD.

Simultaneous measurement of twenty-nine circulating cytokines and growth factors in female patients with overt autoimmune thyroid diseases

Cytokines and growth factors participate in immune responses, and the pathogenesis of autoimmune diseases. Herein, we simultaneously examined differential levels of 29 circulating factors to determine their associations in female patients with overt autoimmune thyroid disease (AITD). We enrolled 40 patients with Graves' disease (GD), 20 patients with Hashimoto's thyroiditis (HT), and 14 healthy controls. Twenty-nine circulating factors were simultaneously measured. GD patients with low thyroid-stimulating hormone at the time of sample collection were defined as having active GD. B-cell activating factor (BAFF) levels were associated with GD and HT (p = .001 and .001, respectively) and interferon (IFN)-α levels were higher in the HT group than in the control group (p = .021). Significant associations of serum BAFF and tumour necrosis factor (TNF)-α levels with free thyroxin (FT4) were present in HT (r = -0.498, p = .026, and r = 0.544, p = .013, respectively). Meanwhile, there were significant associations of FT4 with interleukin (IL)-4 and eotaxin levels in GD (r = 0.354, p = .025 and r = 0.384, p = .014, respectively). In active GD, serum BAFF and eotaxin level were correlated with FT4 levels (r = 0.465, p = .034, and r = 0.463, p = .035, respectively). In conclusion, BAFF is the best circulating indicator to identify GD and HT among all chosen 29 biomarkers, and it could be used to predict the disease severity in HT and active GD. Meanwhile, IFN-α could be another reliable parameter for recognising HT.

Decreased mRNA Expressions of CD40L in Patients with Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease that preferentially affects central nerve system. Herein, we evaluated changes of CD40L and CD40 mRNA expressions in NMOSD and controls to explore their potential roles in development of NMOSD. The expressions of CD40L and CD40 mRNA in peripheral blood mononuclear cells (PBMCs) from patients with NMOSD and healthy controls were detected by quantitative real-time PCR (qPCR). Kruskal-Wallis tests were used to compare expression levels of CD40L and CD40 mRNA between groups, and Spearman correlation analysis was performed to evaluate correlation between mRNA expression levels and annual relapse rate (ARR) of NMOSD. A total of 71 patients with NMOSD and 42 gender- and age-matched healthy volunteers were recruited in our study. Compared with healthy controls, expression of CD40L mRNA was significantly decreased in untreated patients with NMOSD, and similar trends were observed also in CD40 mRNA expression although the difference was not significant. Other than that, immunosuppressants not only successfully increased CD40L and CD40 mRNA levels during remission of NMOSD, but also corrected the negative correlation between CD40L mRNA expression and annual relapse rate (ARR) of patients NMOSD. These results favored the long-term prognosis of NMOSD patients. Our results suggest that decreased expressions of CD40L mRNA may be involved in developing of NMOSD and the proper CD40L mRNA levels benefit to prevent attacks of NMOSD. Nevertheless, the relationship between protein and mRNA expressions of CD40L and their underlying roles in the pathogenesis of NMOSD remains to be further studied.

Differential profiling of lacrimal cytokines in patients suffering from thyroid-associated orbitopathy

The aim was to investigate the levels of cytokines and soluble IL-6R in the tears of patients with thyroid-associated orbitopathy (TAO) disease. Schirmer’s test was adopted to collect tears from TAO patients (N = 20, 17 women, mean age (±SD): 46.0 years (±13.4)) and healthy subjects (N = 18, 10 women, 45.4 years (±18.7)). Lacrimal cytokines and soluble IL-6R (sIL-6R) were measured using a 10-plex panel (Meso Scale Discovery Company) and Invitrogen Human sIL-6R Elisa kit, respectively. Tear levels of IL-10, IL-12p70, IL-13, IL-6 and TNF-α appeared significantly higher in TAO patients than in healthy subjects. Interestingly, IL-10, IL-12p70 and IL-8 levels increased in tears whatever the form of TAO whereas IL-13, IL-6 and TNF-α levels were significantly elevated in inflammatory TAO patients, meaning with a clinical score activity (CAS) ≥ 3, compared to controls. Furthermore, only 3 cytokines were strongly positively correlated with CAS (IL-13 Spearman coeff. r: 0.703, p = 0.0005; IL-6 r: 0.553, p = 0.011; IL-8 r: 0.618, p = 0.004, respectively). Finally, tobacco use disturbed the levels of several cytokines, especially in patient suffering of TAO. The differential profile of lacrimal cytokines could be useful for the diagnosis of TAO patients. Nevertheless, the tobacco use of these patients should be taken into account in the interpretation of the cytokine levels.

Circulating MicroRNAs in Graves' Disease in Relation to Clinical Activity

BACKGROUND

Understanding the roles of circulating microRNAs (miRNAs) can provide important and novel information regarding disease pathogenesis and a patient's clinical condition. Circulating miRNAs, such as exosomal miRNA, may regulate various bioactivities related to intercellular communication. However, the circulation of miRNAs in Graves' disease (GD) in relation to disease activity has never been elucidated. This study aimed to identify circulating miRNAs in GD in relation to disease activity and whether their exosomes play a role in the pathogenesis of GD.

METHODS

Circulating miRNAs were measured in serum obtained from seven intractable GD patients, seven GD patients in remission, and seven healthy controls using the miScript miRNA PCR Array. Altered miRNAs selected from array data were validated in 65 subjects. To investigate exosome biology, peripheral blood mononuclear cells (PBMCs) were incubated with exosomes isolated from the subjects' sera. mRNAs were quantified for cytokines using quantitative real-time polymerase chain reaction.

RESULTS

Circulating miR-23b-5p and miR-92a-39 were increased in GD patients in remission compared with intractable GD patients (p < 0.05). On the other hand, let-7g-3p and miR-339-5p were decreased in GD patients in remission compared with intractable GD patients (p < 0.05). Exosomes from intractable GD patients stimulated mRNA expression for IL-1β and TNF-α compared with GD patients in remission or healthy controls.

CONCLUSIONS

This study demonstrates that different levels of circulating miRNAs are associated with intractable GD. Moreover, serum exosomes of patients with intractable GD may activate immune cells, which may play an important role in GD pathogenesis.

CD40 Expression in Fibrocytes Is Induced by TSH: Potential Synergistic Immune Activation

Context

Fibrocytes appear to participate in inflammation and tissue remodeling in patients with thyroid-associated ophthalmopathy (TAO). These patients have increased frequencies of circulating TSH receptor (TSHR)- and CD40-positive fibrocytes, suggesting TSHR and CD40 may play roles in proinflammatory cytokine production, which ultimately leads to orbital inflammation and tissue remodeling.

Objective

To investigate the potential interactions between the TSHR and CD40 signaling pathways and their roles in IL-6 and TNF-α production.

Design and Outcome Measures

CD40 expression on fibrocytes was assessed using flow cytometry; IL-6 and TNF-α protein release using Luminex technology; increased IL-6 and TNF-α mRNA abundance, using real-time PCR; TSH- and CD40 ligand (CD40L)-stimulated Akt phosphorylation in fibrocytes, by western blot analysis; TSHR-CD40 protein-protein interaction, using co-immunoprecipitation, and CD40-TSHR co-localization, using immunocytochemistry.

Results

TSH enhances CD40 expression at a pre-translational level in fibrocytes. Production of IL-6 and TNF-α after costimulation with TSH and CD40L was greater than that after TSH or CD40L stimulation alone. TSH and CD40L costimulation also resulted in greater Akt phosphorylation. Akt and nuclear factor (NF)-κB inhibitors significantly reduced cytokine production after TSH and CD40L costimulation. TSHR and CD40L are colocalized on the cell surface and form a complex.

Conclusions

TSHR and CD40 in fibrocytes appear to be physically and functionally related. TSH stimulates CD40 production on the fibrocyte surface. Cytokine expression upon simultaneous stimulation of TSHR and CD40 is greater than levels achieved with TSH or CD40L alone. Increased expression of CD40 by TSH is a potential mechanism for this process.

The expression of microvesicles in the blood of patients with Graves' disease and its relationship to treatment

OBJECTIVE

Graves' disease (GD) is an autoimmune disease characterized by the presence of circulating autoantibodies against thyroid-stimulating hormone (TSH) receptor. Despite extensive research, the pathogenic mechanisms remain unclear. Immune responses associated with the disease may lead to cell activation/apoptosis and the release of microvesicles (MVs) into the circulation. MVs can display biological activities which may aggravate GD further. We studied immune mechanisms in GD by investigating the numbers and phenotype of circulating MVs in patients before and after antithyroid therapy with thiamazole.

PATIENTS AND MEASUREMENTS

Samples were obtained from 15 patients with GD in the acute phase of hyperthyroidism and following 17-26 months treatment and 14 healthy controls. MVs from platelets, endothelial cells and monocytes exposing inflammation/activation markers (P-selectin, CD40 ligand, E-selectin and HMGB1) and MVs containing nuclear molecules were measured with flow cytometry.

RESULTS

Patients had elevated baseline values of MVs (P < 0·001 for all types of MVs), while the levels decreased during thiamazole treatment (P < 0·05 for all types of MVs). The majority of MV populations remained, however, significantly higher in patients after treatment compared to levels in controls.

CONCLUSIONS

GD patients have elevated levels of MVs that carry molecules with potential biological activities. MVs are significantly reduced after antithyroid treatment with thiamazole but still higher compared to levels in healthy controls. Assessment of MV levels and pattern may therefore provide additional information on underlying immune disturbances not obtained by measurements of hormone levels alone.

Th1, Th2, and Th17 Cytokine Involvement in Thyroid Associated Ophthalmopathy

To determine serum cytokine profiles in Graves' disease (GD) patients with or without active and inactive thyroid associated ophthalmopathy (TAO), we recruited 65 subjects: 10 GD only (without TAO), 25 GD + active TAO, 20 GD + TAO, and 10 healthy controls. Liquid chip assay was used to measure serum Th1/Th2/Th17 cytokines including IFN-γ (interferon-gamma), TNF-α (tumor necrosis factor-alpha), IL-1α (interleukin-1 alpha), IL-1Ra (IL-1 receptor antagonist), IL-2, IL-4, IL-6, and IL-17 and two chemokines: RANTES (regulated upon activation, normal T cell expressed and secreted) and IP-10 (IFN-γ-induced protein 10). Serum levels of TSH (thyroid stimulating hormone) receptor autoantibodies (TRAb) were measured using an enzyme linked immunosorbent assay. Compared with healthy controls, TAO patients showed significantly elevated serum levels of IFN-γ, TNF-α, IL-1α, IL-4, IL-6, IL-17, and IP-10. Comparing active and inactive TAO, serum Th1 cytokines IFN-γ and TNF-α were elevated in active TAO, while serum Th2 cytokine IL-4 was elevated in inactive TAO. Serum Th17 cytokine IL-17 was elevated in GD but reduced in both active and inactive TAO. A positive correlation was found between TRAb and IFN-γ, TNF-α, IL-1α, IL-2, IL-4, and IL-6. Taken together, serum Th1/Th2/Th17 cytokines and chemokines reflect TAO disease activity and may be implicated in TAO pathogenesis.

Definition of the transcription factor TdIF1 consensus-binding sequence through genomewide mapping of its binding sites

TdIF1 was originally identified as a protein that directly binds to terminal deoxynucleotidyltransferase, TdT. Through in vitro selection assays (SELEX), we recently showed that TdIF1 recognizes both AT-tract and a specific DNA sequence motif, 5'-TGCATG-3', and can up-regulate the expression of RAB20 through the latter motif. However, whether TdIF1 binds to these sequences in the cells has not been clear and its other target genes remain to be identified. Here, we determined in vivo TdIF1-binding sequences (TdIF1-invivoBMs) on the human chromosomes through ChIP-seq analyses. The result showed a 160-base pair cassette containing 'AT-tract~palindrome (inverted repeat)~AT-tract' as a likely target sequence of TdIF1. Interestingly, the core sequence of the palindrome in the TdIF1-invivoBMs shares significant similarity to the above 5'-TGCATG-3' motif determined by SELEX in vitro. Furthermore, spacer sequences between AT-tract and the palindrome contain many potential transcription factor binding sites. In luciferase assays, TdIF1 can up-regulate transcription activity of the promoters containing the TdIF1-invivoBM, and this effect is mainly through the palindrome. Clusters of this motif were found in the potential target genes. Gene ontology analysis and RT-qPCR showed the enrichment of some candidate targets of TdIF1 among the genes involved in the regulation of ossification. Potential modes of transcription activation by TdIF1 are discussed.

Simultaneous measurement of serum chemokines in autoimmune thyroid diseases: possible role of IP-10 in the inflammatory response

Autoimmune thyroid diseases (AITDs), including Graves' diseases (GD) and Hashimoto's thyroiditis (HT), are the most common autoimmune diseases, and are mainly mediated by T cells that produce cytokines and chemokines in abnormal amounts. Few reports have described the circulating chemokines active in AITDs. Recently, we used a new multiplex immunobead assay to simultaneously measure cytokines and chemokines in small volume serum samples from patients with AITDs. We measured 23 selected serum chemokines in patients with GD (n=45) or HT (n=26), and healthy controls (n=9). GD patients were further classified as either untreated, intractable, or in remission, while HT patients were classified as either hypothyroid or euthyroid. Of the 23 serum chemokines assayed, only the serum level of IP-10 (CXCL10/interferon-γ-inducible protein 10) was elevated, depending on disease activity, in GD or HT compared with healthy controls. However, the serum level of IP-10 was also increased in both untreated GD patients and hypothyroid HT patients, suggesting that levels of this cytokine may not be affected by disease specificity. In conclusion, autoimmune inflammation in patients with AITD is closely related to the level of the serum chemokine, IP-10. Therefore, IP-10 might be a good biomarker for tissue inflammation in the thyroid, but not a useful biomarker for predicting disease specific activity, the progression of AITDs, or responsiveness to treatment because of its independence from thyroid function or disease specificity.

Prothrombotic alterations in plasma fibrin clot properties in thyroid disorders and their post-treatment modifications

INTRODUCTION

Available data on fibrin clot properties and fibrinolysis in hyperthyroidism and hypothyroidism are inconsistent. Our objective was to assess the impact of effective treatment of hyper- and hypothyroidism on fibrin clot characteristics.

MATERIAL AND METHODS

In a case-control study, ex vivo plasma fibrin clot permeability (Ks) and efficiency of fibrinolysis were assessed in 35 consecutive hyperthyroid and 35 hypothyroid subjects versus 30 controls. All measurements were performed before and after 3months of thyroid function normalizing therapy.

RESULTS

At baseline, hyperthyroid, but not hypothyroid, patients had lower Ks than controls (p<0.0001). Hyperthyroid and hypothyroid groups compared with controls had prolonged clot lysis time (CLT), and lower rate of D-dimer release from clots (D-Drate) (all p<0.05). The regression analysis adjusted for fibrinogen showed that in hyperthyroid patients, pre-treatment thyroid stimulating hormone (TSH) independently predicted Ks, while thrombin activatable fibrinolysis inhibitor (TAFI) antigen predicted CLT. In hypothyroid individuals a similar regression model showed that TSH independently predicts CLT. After 3months of thyroid function normalizing therapy, 32 (91.4%) hyperthyroid and 30 (85.7%) hypothyroid subjects achieved euthyroidism and had improved fibrin clot properties (all p<0.05), with normalization of Ks in hyperthyroid and lysability in hypothyroid patients.

CONCLUSIONS

Both hyper- and mild-to-moderate hypothyroidism are associated with prothrombotic plasma fibrin clot phenotype and restoration of euthyroidism improves clot phenotype. Abnormal fibrin clot phenotype might contribute to thromboembolic risk in thyroid disease.

The role of osteopontin in the induction of the CD40 ligand in Graves' disease

OBJECTIVE

Graves' disease (GD) is a common autoimmune disease involved autoantibody production. Although we previously reported that osteopontin (OPN), a proinflammatory protein, affected development of GD through NF-κB activation, little is known about the role of OPN in regulating immunoglobulin production in GD. CD40 Ligand (CD40L) is expressed on the surface of activated CD4+T cells and costimulates CD40 on B cells, stimulating production of immunoglobulins, a process which has been reported to play a vital role in immunological signalling transduction in several autoimmune diseases. This study sought to characterize the relationship between CD40L and GD development, as well as investigating the role of OPN in modulating immunoglobulin production in GD via CD40L.

METHODS

Forty incident patients with GD, twenty-one patients with GD in remission and twenty-seven healthy controls were recruited. Both membrane-bound and soluble forms of CD40L were measured, and their correlations with clinical parameters were studied. In addition, correlation between OPN and CD40L level was also examined. Furthermore, we studied the regulatory effect of OPN on CD40L in CD4+T cells.

RESULTS

We demonstrated that the CD40L levels were enhanced in patients with GD and recovered in patients with GD in remission. CD40L levels correlated with clinical GD diagnostic parameters and OPN concentration. Moreover, human recombinant OPN and plasma samples from patients with GD increased CD40L expression, which could be significantly suppressed by OPN monoclonal antibody. In addition, CD40L antibody blocked the immunoglobulin production augmented by OPN in cultured peripheral blood mononuclear cells (PBMCs), isolated from patients with GD and healthy subjects.

CONCLUSION

These results indicate that CD40L is induced by OPN and serves as the downstream effector of OPN for immunoglobulin production in GD development.

Type I and type II interferons inhibit both basal and tumor necrosis factor-α-induced CXCL8 secretion in primary cultures of human thyrocytes

Interferons (IFNs) and tumor necrosis factor-α (TNF-α) cooperate in activating several inflammation-related genes, which sustain chronic inflammation in autoimmune thyroid disease (AITD). Much is known about the positive signaling of IFNs to activate gene expression in AITD, while the mechanisms by which IFNs negatively regulate genes remain less studied. While IFNs inhibit CXCL8 secretion in several human cell types, their effects on thyroid cells were not evaluated. Our aim was to study the interplay between TNF-α and type I or type II IFNs on CXCL8 secretion by human thyroid cells. CXCL8 was measured in supernatants of primary cultures of thyroid cells basally and after a 24-h incubation with TNF-α. CXCL8 was detected in thyroid cell supernatants in basal conditions (96.2±23.5 pg/mL) being significantly increased (784.7±217.3 pg/mL; P<0.0001 vs. basal) by TNF-α. Twenty-four hour incubation with IFN-γ or IFN-β or IFN-α dose dependently and significantly inhibited both basal and TNF-α-induced CXCL8 secretion. The degree of the inhibitory effect was IFN-γ>IFN-β>IFN-α. This study demonstrates that type I and type II IFNs downregulate both basal and TNF-α-induced CXCL8 secretion by human thyrocytes, IFN-γ being the most powerful inhibitor. Future studies aimed at a better comprehension of the interplay between CXCL8 and thyroid diseases appear worthwhile.

The association between severity of obstructive sleep apnea and prevalence of Hashimoto's thyroiditis

Obstructive sleep apnea (OSA) has long been suggested to increase the risk of development of autoimmune diseases. We investigated the prevalence of Hashimoto's thyroiditis (HT) in 245 euthyroid individuals, who were suspected of having OSA. After polysomnography, subjects were grouped according to apnea-hypopnea index (AHI) consecutively as controls (n=27F/32M, AHI<5), mild-OSA (n=22F/37M, 5≤AHI<15), moderate-OSA (n=23F/38M, 15≤AHI<30) and severe-OSA (n=30F/36M, AHI≥30). Diagnosis of HT based on thyroid ultrasound and positivity of serum anti-thyroglobulin (anti-TG) and anti-thyroid peroxidase (anti-TPO) antibodies. Hashimoto's thyroiditis was diagnosed in 32.2% of controls and in 46.8% of all OSA patients (p=0.03). Severe-OSA patients had the highest HT frequency (51.5%) compared to controls (p=0.02), mild-OSA (42.3%, p=0.03) and moderate-OSA (45.9%, p=0.05) groups. Forty-two of control subjects (71.2%) were negative for both of the anti-TPO and anti-TG, whereas 99 (53.2%) of OSA subjects were positive at least for one of them (p=0.01). HT was detected in 62% of females, 29% of males (p<0.001). Severe female OSA patients had the highest HT prevalence (73.3%), while male control subjects had the lowest (18.7%) among all groups (p<0.001). There was no significant correlation between thyroid volume and severity of OSA but isthmus thickness was significantly correlated to AHI (p<0.01, r=0.22). In conclusion, OSA patients presented higher HT prevalence parallel to severity of OSA, especially among women. These results may lead to further investigations about relation between OSA and auto-immune thyroiditis and to development of screening schemas for severe-OSA patients for early diagnosis of HT before development of hypothyroidism.